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gerrit-public.fairphone.software / toolchain / llvm-project / b1ed91f3978377294d4620c53ca81beed08b73c7 / . / llvm / docs / LangRef.html
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5 <title>LLVM Assembly Language Reference Manual</title>
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7 <meta name="author" content="Chris Lattner">
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Reid Spencercb84e432004-08-26 20:44:00 +0000[diff] [blame]9 content="LLVM Assembly Language Reference Manual.">
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11</head>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]12
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]13<body>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]14
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]15<h1>LLVM Language Reference Manual</h1>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]16<ol>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]17 <li><a href="#abstract">Abstract</a></li>
18 <li><a href="#introduction">Introduction</a></li>
19 <li><a href="#identifiers">Identifiers</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]20 <li><a href="#highlevel">High Level Structure</a>
21 <ol>
22 <li><a href="#modulestructure">Module Structure</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]23 <li><a href="#linkage">Linkage Types</a>
24 <ol>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]25 <li><a href="#linkage_private">'<tt>private</tt>' Linkage</a></li>
26 <li><a href="#linkage_linker_private">'<tt>linker_private</tt>' Linkage</a></li>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]27 <li><a href="#linkage_linker_private_weak">'<tt>linker_private_weak</tt>' Linkage</a></li>
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]28 <li><a href="#linkage_linker_private_weak_def_auto">'<tt>linker_private_weak_def_auto</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]29 <li><a href="#linkage_internal">'<tt>internal</tt>' Linkage</a></li>
30 <li><a href="#linkage_available_externally">'<tt>available_externally</tt>' Linkage</a></li>
31 <li><a href="#linkage_linkonce">'<tt>linkonce</tt>' Linkage</a></li>
32 <li><a href="#linkage_common">'<tt>common</tt>' Linkage</a></li>
33 <li><a href="#linkage_weak">'<tt>weak</tt>' Linkage</a></li>
34 <li><a href="#linkage_appending">'<tt>appending</tt>' Linkage</a></li>
35 <li><a href="#linkage_externweak">'<tt>extern_weak</tt>' Linkage</a></li>
Chris Lattner80d73c72009-10-10 18:26:06 +0000[diff] [blame]36 <li><a href="#linkage_linkonce_odr">'<tt>linkonce_odr</tt>' Linkage</a></li>
Bill Wendling8693ef82009-07-20 02:41:50 +0000[diff] [blame]37 <li><a href="#linkage_weak">'<tt>weak_odr</tt>' Linkage</a></li>
38 <li><a href="#linkage_external">'<tt>externally visible</tt>' Linkage</a></li>
39 <li><a href="#linkage_dllimport">'<tt>dllimport</tt>' Linkage</a></li>
40 <li><a href="#linkage_dllexport">'<tt>dllexport</tt>' Linkage</a></li>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]41 </ol>
42 </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]43 <li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]44 <li><a href="#namedtypes">Named Types</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]45 <li><a href="#globalvars">Global Variables</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]46 <li><a href="#functionstructure">Functions</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]47 <li><a href="#aliasstructure">Aliases</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]48 <li><a href="#namedmetadatastructure">Named Metadata</a></li>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]49 <li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]50 <li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]51 <li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]52 <li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]53 <li><a href="#datalayout">Data Layout</a></li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]54 <li><a href="#pointeraliasing">Pointer Aliasing Rules</a></li>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]55 <li><a href="#volatile">Volatile Memory Accesses</a></li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]56 </ol>
57 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]58 <li><a href="#typesystem">Type System</a>
59 <ol>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]60 <li><a href="#t_classifications">Type Classifications</a></li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]61 <li><a href="#t_primitive">Primitive Types</a>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]62 <ol>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]63 <li><a href="#t_integer">Integer Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]64 <li><a href="#t_floating">Floating Point Types</a></li>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]65 <li><a href="#t_x86mmx">X86mmx Type</a></li>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]66 <li><a href="#t_void">Void Type</a></li>
67 <li><a href="#t_label">Label Type</a></li>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]68 <li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]69 </ol>
70 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]71 <li><a href="#t_derived">Derived Types</a>
72 <ol>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]73 <li><a href="#t_aggregate">Aggregate Types</a>
74 <ol>
75 <li><a href="#t_array">Array Type</a></li>
76 <li><a href="#t_struct">Structure Type</a></li>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]77 <li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]78 <li><a href="#t_vector">Vector Type</a></li>
79 </ol>
80 </li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]81 <li><a href="#t_function">Function Type</a></li>
82 <li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]83 </ol>
84 </li>
85 </ol>
86 </li>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]87 <li><a href="#constants">Constants</a>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]88 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]89 <li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]90 <li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]91 <li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
92 <li><a href="#undefvalues">Undefined Values</a></li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]93 <li><a href="#trapvalues">Trap Values</a></li>
Chris Lattner2bfd3202009-10-27 21:19:13 +0000[diff] [blame]94 <li><a href="#blockaddress">Addresses of Basic Blocks</a></li>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]95 <li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]96 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]97 </li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]98 <li><a href="#othervalues">Other Values</a>
99 <ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]100 <li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]101 <li><a href="#metadata">Metadata Nodes and Metadata Strings</a></li>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]102 </ol>
103 </li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]104 <li><a href="#intrinsic_globals">Intrinsic Global Variables</a>
105 <ol>
106 <li><a href="#intg_used">The '<tt>llvm.used</tt>' Global Variable</a></li>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]107 <li><a href="#intg_compiler_used">The '<tt>llvm.compiler.used</tt>'
108 Global Variable</a></li>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]109 <li><a href="#intg_global_ctors">The '<tt>llvm.global_ctors</tt>'
110 Global Variable</a></li>
111 <li><a href="#intg_global_dtors">The '<tt>llvm.global_dtors</tt>'
112 Global Variable</a></li>
113 </ol>
114 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]115 <li><a href="#instref">Instruction Reference</a>
116 <ol>
117 <li><a href="#terminators">Terminator Instructions</a>
118 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]119 <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
120 <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]121 <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]122 <li><a href="#i_indirectbr">'<tt>indirectbr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]123 <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]124 <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]125 <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]126 </ol>
127 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]128 <li><a href="#binaryops">Binary Operations</a>
129 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]130 <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]131 <li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]132 <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]133 <li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]134 <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]135 <li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]136 <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
137 <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
138 <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]139 <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
140 <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
141 <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]142 </ol>
143 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]144 <li><a href="#bitwiseops">Bitwise Binary Operations</a>
145 <ol>
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]146 <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
147 <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
148 <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]149 <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]150 <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]151 <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]152 </ol>
153 </li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]154 <li><a href="#vectorops">Vector Operations</a>
155 <ol>
156 <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
157 <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
158 <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]159 </ol>
160 </li>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]161 <li><a href="#aggregateops">Aggregate Operations</a>
162 <ol>
163 <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
164 <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
165 </ol>
166 </li>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]167 <li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]168 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]169 <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]170 <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
171 <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
172 <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]173 </ol>
174 </li>
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]175 <li><a href="#convertops">Conversion Operations</a>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]176 <ol>
177 <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
178 <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
179 <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
180 <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
181 <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]182 <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
183 <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
184 <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
185 <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]186 <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
187 <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]188 <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]189 </ol>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]190 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]191 <li><a href="#otherops">Other Operations</a>
192 <ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]193 <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
194 <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]195 <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]196 <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]197 <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]198 <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]199 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]200 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]201 </ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]202 </li>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]203 <li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]204 <ol>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]205 <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
206 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]207 <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
208 <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
209 <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]210 </ol>
211 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]212 <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
213 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]214 <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
215 <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
216 <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]217 </ol>
218 </li>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]219 <li><a href="#int_codegen">Code Generator Intrinsics</a>
220 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]221 <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
222 <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
223 <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
224 <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
225 <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
226 <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
Dan Gohmane58f7b32010-05-26 21:56:15 +0000[diff] [blame]227 <li><a href="#int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswellaa1c3c12004-04-09 16:43:20 +0000[diff] [blame]228 </ol>
229 </li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]230 <li><a href="#int_libc">Standard C Library Intrinsics</a>
231 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]232 <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
233 <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
234 <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
235 <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
236 <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]237 <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
238 <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
239 <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Dan Gohmane635c522011-05-27 00:36:31 +0000[diff] [blame]240 <li><a href="#int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a></li>
241 <li><a href="#int_log">'<tt>llvm.log.*</tt>' Intrinsic</a></li>
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]242 <li><a href="#int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a></li>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]243 </ol>
244 </li>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]245 <li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]246 <ol>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]247 <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]248 <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
249 <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
250 <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]251 </ol>
252 </li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]253 <li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
254 <ol>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]255 <li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
256 <li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
257 <li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
258 <li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
259 <li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]260 <li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]261 </ol>
262 </li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]263 <li><a href="#int_fp16">Half Precision Floating Point Intrinsics</a>
264 <ol>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]265 <li><a href="#int_convert_to_fp16">'<tt>llvm.convert.to.fp16</tt>' Intrinsic</a></li>
266 <li><a href="#int_convert_from_fp16">'<tt>llvm.convert.from.fp16</tt>' Intrinsic</a></li>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]267 </ol>
268 </li>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]269 <li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]270 <li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]271 <li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]272 <ol>
273 <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]274 </ol>
275 </li>
Bill Wendlingf85850f2008-11-18 22:10:53 +0000[diff] [blame]276 <li><a href="#int_atomics">Atomic intrinsics</a>
277 <ol>
278 <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
279 <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
280 <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
281 <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
282 <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
283 <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
284 <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
285 <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
286 <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
287 <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
288 <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
289 <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
290 <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
291 </ol>
292 </li>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]293 <li><a href="#int_memorymarkers">Memory Use Markers</a>
294 <ol>
295 <li><a href="#int_lifetime_start"><tt>llvm.lifetime.start</tt></a></li>
296 <li><a href="#int_lifetime_end"><tt>llvm.lifetime.end</tt></a></li>
297 <li><a href="#int_invariant_start"><tt>llvm.invariant.start</tt></a></li>
298 <li><a href="#int_invariant_end"><tt>llvm.invariant.end</tt></a></li>
299 </ol>
300 </li>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]301 <li><a href="#int_general">General intrinsics</a>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]302 <ol>
Reid Spencer5b2cb0f2007-07-20 19:59:11 +0000[diff] [blame]303 <li><a href="#int_var_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]304 '<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]305 <li><a href="#int_annotation">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]306 '<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]307 <li><a href="#int_trap">
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]308 '<tt>llvm.trap</tt>' Intrinsic</a></li>
309 <li><a href="#int_stackprotector">
310 '<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]311 <li><a href="#int_objectsize">
312 '<tt>llvm.objectsize</tt>' Intrinsic</a></li>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]313 </ol>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]314 </li>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]315 </ol>
316 </li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]317</ol>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]318
319<div class="doc_author">
320 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
321 and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]322</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]323
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]324<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]325<h2><a name="abstract">Abstract</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]326<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]327
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]328<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]329
330<p>This document is a reference manual for the LLVM assembly language. LLVM is
331 a Static Single Assignment (SSA) based representation that provides type
332 safety, low-level operations, flexibility, and the capability of representing
333 'all' high-level languages cleanly. It is the common code representation
334 used throughout all phases of the LLVM compilation strategy.</p>
335
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]336</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]337
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]338<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]339<h2><a name="introduction">Introduction</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]340<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]341
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]342<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]343
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]344<p>The LLVM code representation is designed to be used in three different forms:
345 as an in-memory compiler IR, as an on-disk bitcode representation (suitable
346 for fast loading by a Just-In-Time compiler), and as a human readable
347 assembly language representation. This allows LLVM to provide a powerful
348 intermediate representation for efficient compiler transformations and
349 analysis, while providing a natural means to debug and visualize the
350 transformations. The three different forms of LLVM are all equivalent. This
351 document describes the human readable representation and notation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]352
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]353<p>The LLVM representation aims to be light-weight and low-level while being
354 expressive, typed, and extensible at the same time. It aims to be a
355 "universal IR" of sorts, by being at a low enough level that high-level ideas
356 may be cleanly mapped to it (similar to how microprocessors are "universal
357 IR's", allowing many source languages to be mapped to them). By providing
358 type information, LLVM can be used as the target of optimizations: for
359 example, through pointer analysis, it can be proven that a C automatic
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]360 variable is never accessed outside of the current function, allowing it to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]361 be promoted to a simple SSA value instead of a memory location.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]362
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]363<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]364<h4>
365 <a name="wellformed">Well-Formedness</a>
366</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]367
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]368<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]369
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]370<p>It is important to note that this document describes 'well formed' LLVM
371 assembly language. There is a difference between what the parser accepts and
372 what is considered 'well formed'. For example, the following instruction is
373 syntactically okay, but not well formed:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]374
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]375<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]376%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]377</pre>
378
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]379<p>because the definition of <tt>%x</tt> does not dominate all of its uses. The
380 LLVM infrastructure provides a verification pass that may be used to verify
381 that an LLVM module is well formed. This pass is automatically run by the
382 parser after parsing input assembly and by the optimizer before it outputs
383 bitcode. The violations pointed out by the verifier pass indicate bugs in
384 transformation passes or input to the parser.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]385
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]386</div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]387
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]388</div>
389
Chris Lattner87a3dbe2007-10-03 17:34:29 +0000[diff] [blame]390<!-- Describe the typesetting conventions here. -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]391
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]392<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]393<h2><a name="identifiers">Identifiers</a></h2>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]394<!-- *********************************************************************** -->
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]395
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]396<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]397
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]398<p>LLVM identifiers come in two basic types: global and local. Global
399 identifiers (functions, global variables) begin with the <tt>'@'</tt>
400 character. Local identifiers (register names, types) begin with
401 the <tt>'%'</tt> character. Additionally, there are three different formats
402 for identifiers, for different purposes:</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]403
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]404<ol>
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]405 <li>Named values are represented as a string of characters with their prefix.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]406 For example, <tt>%foo</tt>, <tt>@DivisionByZero</tt>,
407 <tt>%a.really.long.identifier</tt>. The actual regular expression used is
408 '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. Identifiers which require
409 other characters in their names can be surrounded with quotes. Special
410 characters may be escaped using <tt>"\xx"</tt> where <tt>xx</tt> is the
411 ASCII code for the character in hexadecimal. In this way, any character
412 can be used in a name value, even quotes themselves.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]413
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]414 <li>Unnamed values are represented as an unsigned numeric value with their
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]415 prefix. For example, <tt>%12</tt>, <tt>@2</tt>, <tt>%44</tt>.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]416
Reid Spencer8f08d802004-12-09 18:02:53 +0000[diff] [blame]417 <li>Constants, which are described in a <a href="#constants">section about
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]418 constants</a>, below.</li>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]419</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]420
Reid Spencerb23b65f2007-08-07 14:34:28 +0000[diff] [blame]421<p>LLVM requires that values start with a prefix for two reasons: Compilers
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]422 don't need to worry about name clashes with reserved words, and the set of
423 reserved words may be expanded in the future without penalty. Additionally,
424 unnamed identifiers allow a compiler to quickly come up with a temporary
425 variable without having to avoid symbol table conflicts.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]426
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]427<p>Reserved words in LLVM are very similar to reserved words in other
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]428 languages. There are keywords for different opcodes
429 ('<tt><a href="#i_add">add</a></tt>',
430 '<tt><a href="#i_bitcast">bitcast</a></tt>',
431 '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names
432 ('<tt><a href="#t_void">void</a></tt>',
433 '<tt><a href="#t_primitive">i32</a></tt>', etc...), and others. These
434 reserved words cannot conflict with variable names, because none of them
435 start with a prefix character (<tt>'%'</tt> or <tt>'@'</tt>).</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]436
437<p>Here is an example of LLVM code to multiply the integer variable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]438 '<tt>%X</tt>' by 8:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]439
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]440<p>The easy way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]441
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]442<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]443%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]444</pre>
445
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]446<p>After strength reduction:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]447
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]448<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]449%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]450</pre>
451
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]452<p>And the hard way:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]453
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]454<pre class="doc_code">
Gabor Greifbd0328f2009-10-28 13:05:07 +0000[diff] [blame]455%0 = <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
456%1 = <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]457%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]458</pre>
459
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]460<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several important
461 lexical features of LLVM:</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]462
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]463<ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]464 <li>Comments are delimited with a '<tt>;</tt>' and go until the end of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]465 line.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]466
467 <li>Unnamed temporaries are created when the result of a computation is not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]468 assigned to a named value.</li>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]469
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]470 <li>Unnamed temporaries are numbered sequentially</li>
471</ol>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]472
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]473<p>It also shows a convention that we follow in this document. When
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]474 demonstrating instructions, we will follow an instruction with a comment that
475 defines the type and name of value produced. Comments are shown in italic
476 text.</p>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]477
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]478</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]479
480<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]481<h2><a name="highlevel">High Level Structure</a></h2>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]482<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]483<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]484<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]485<h3>
486 <a name="modulestructure">Module Structure</a>
487</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]488
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]489<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]490
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]491<p>LLVM programs are composed of "Module"s, each of which is a translation unit
492 of the input programs. Each module consists of functions, global variables,
493 and symbol table entries. Modules may be combined together with the LLVM
494 linker, which merges function (and global variable) definitions, resolves
495 forward declarations, and merges symbol table entries. Here is an example of
496 the "hello world" module:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]497
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]498<pre class="doc_code">
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]499<i>; Declare the string constant as a global constant.</i>&nbsp;
Nick Lewyckyfea7ddc2011-01-29 01:09:53 +0000[diff] [blame]500<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a>&nbsp;<a href="#globalvars">constant</a>&nbsp;<a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]501
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]502<i>; External declaration of the puts function</i>&nbsp;
503<a href="#functionstructure">declare</a> i32 @puts(i8*) <i>; i32 (i8*)* </i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]504
505<i>; Definition of main function</i>
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]506define i32 @main() { <i>; i32()* </i>&nbsp;
507 <i>; Convert [13 x i8]* to i8 *...</i>&nbsp;
508 %cast210 = <a href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8*</i>&nbsp;
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]509
Chris Lattner54a7be72010-08-17 17:13:42 +0000[diff] [blame]510 <i>; Call puts function to write out the string to stdout.</i>&nbsp;
511 <a href="#i_call">call</a> i32 @puts(i8* %cast210) <i>; i32</i>&nbsp;
512 <a href="#i_ret">ret</a> i32 0&nbsp;
513}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]514
515<i>; Named metadata</i>
516!1 = metadata !{i32 41}
517!foo = !{!1, null}
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]518</pre>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]519
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]520<p>This example is made up of a <a href="#globalvars">global variable</a> named
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]521 "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" function,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]522 a <a href="#functionstructure">function definition</a> for
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]523 "<tt>main</tt>" and <a href="#namedmetadatastructure">named metadata</a>
524 "<tt>foo"</tt>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]525
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]526<p>In general, a module is made up of a list of global values, where both
527 functions and global variables are global values. Global values are
528 represented by a pointer to a memory location (in this case, a pointer to an
529 array of char, and a pointer to a function), and have one of the
530 following <a href="#linkage">linkage types</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]531
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]532</div>
533
534<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]535<h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]536 <a name="linkage">Linkage Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]537</h3>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]538
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]539<div>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]540
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]541<p>All Global Variables and Functions have one of the following types of
542 linkage:</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]543
544<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]545 <dt><tt><b><a name="linkage_private">private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]546 <dd>Global values with "<tt>private</tt>" linkage are only directly accessible
547 by objects in the current module. In particular, linking code into a
548 module with an private global value may cause the private to be renamed as
549 necessary to avoid collisions. Because the symbol is private to the
550 module, all references can be updated. This doesn't show up in any symbol
551 table in the object file.</dd>
Rafael Espindola6de96a12009-01-15 20:18:42 +0000[diff] [blame]552
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]553 <dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt></dt>
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]554 <dd>Similar to <tt>private</tt>, but the symbol is passed through the
555 assembler and evaluated by the linker. Unlike normal strong symbols, they
556 are removed by the linker from the final linked image (executable or
557 dynamic library).</dd>
558
559 <dt><tt><b><a name="linkage_linker_private_weak">linker_private_weak</a></b></tt></dt>
560 <dd>Similar to "<tt>linker_private</tt>", but the symbol is weak. Note that
561 <tt>linker_private_weak</tt> symbols are subject to coalescing by the
562 linker. The symbols are removed by the linker from the final linked image
563 (executable or dynamic library).</dd>
Bill Wendlinga3c6f6b2009-07-20 01:03:30 +0000[diff] [blame]564
Bill Wendling578ee402010-08-20 22:05:50 +0000[diff] [blame]565 <dt><tt><b><a name="linkage_linker_private_weak_def_auto">linker_private_weak_def_auto</a></b></tt></dt>
566 <dd>Similar to "<tt>linker_private_weak</tt>", but it's known that the address
567 of the object is not taken. For instance, functions that had an inline
568 definition, but the compiler decided not to inline it. Note,
569 unlike <tt>linker_private</tt> and <tt>linker_private_weak</tt>,
570 <tt>linker_private_weak_def_auto</tt> may have only <tt>default</tt>
571 visibility. The symbols are removed by the linker from the final linked
572 image (executable or dynamic library).</dd>
573
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]574 <dt><tt><b><a name="linkage_internal">internal</a></b></tt></dt>
Bill Wendling36321712010-06-29 22:34:52 +0000[diff] [blame]575 <dd>Similar to private, but the value shows as a local symbol
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]576 (<tt>STB_LOCAL</tt> in the case of ELF) in the object file. This
577 corresponds to the notion of the '<tt>static</tt>' keyword in C.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]578
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]579 <dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt></dt>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]580 <dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]581 into the object file corresponding to the LLVM module. They exist to
582 allow inlining and other optimizations to take place given knowledge of
583 the definition of the global, which is known to be somewhere outside the
584 module. Globals with <tt>available_externally</tt> linkage are allowed to
585 be discarded at will, and are otherwise the same as <tt>linkonce_odr</tt>.
586 This linkage type is only allowed on definitions, not declarations.</dd>
Chris Lattner184f1be2009-04-13 05:44:34 +0000[diff] [blame]587
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]588 <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt></dt>
Chris Lattnere20b4702007-01-14 06:51:48 +0000[diff] [blame]589 <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
Chris Lattner0de4caa2010-01-09 19:15:14 +0000[diff] [blame]590 the same name when linkage occurs. This can be used to implement
591 some forms of inline functions, templates, or other code which must be
592 generated in each translation unit that uses it, but where the body may
593 be overridden with a more definitive definition later. Unreferenced
594 <tt>linkonce</tt> globals are allowed to be discarded. Note that
595 <tt>linkonce</tt> linkage does not actually allow the optimizer to
596 inline the body of this function into callers because it doesn't know if
597 this definition of the function is the definitive definition within the
598 program or whether it will be overridden by a stronger definition.
599 To enable inlining and other optimizations, use "<tt>linkonce_odr</tt>"
600 linkage.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]601
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]602 <dt><tt><b><a name="linkage_weak">weak</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]603 <dd>"<tt>weak</tt>" linkage has the same merging semantics as
604 <tt>linkonce</tt> linkage, except that unreferenced globals with
605 <tt>weak</tt> linkage may not be discarded. This is used for globals that
606 are declared "weak" in C source code.</dd>
607
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]608 <dt><tt><b><a name="linkage_common">common</a></b></tt></dt>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]609 <dd>"<tt>common</tt>" linkage is most similar to "<tt>weak</tt>" linkage, but
610 they are used for tentative definitions in C, such as "<tt>int X;</tt>" at
611 global scope.
612 Symbols with "<tt>common</tt>" linkage are merged in the same way as
613 <tt>weak symbols</tt>, and they may not be deleted if unreferenced.
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]614 <tt>common</tt> symbols may not have an explicit section,
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]615 must have a zero initializer, and may not be marked '<a
Chris Lattner0aff0b22009-08-05 05:41:44 +0000[diff] [blame]616 href="#globalvars"><tt>constant</tt></a>'. Functions and aliases may not
617 have common linkage.</dd>
Chris Lattnerd0554882009-08-05 05:21:07 +0000[diff] [blame]618
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]619
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]620 <dt><tt><b><a name="linkage_appending">appending</a></b></tt></dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]621 <dd>"<tt>appending</tt>" linkage may only be applied to global variables of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]622 pointer to array type. When two global variables with appending linkage
623 are linked together, the two global arrays are appended together. This is
624 the LLVM, typesafe, equivalent of having the system linker append together
625 "sections" with identical names when .o files are linked.</dd>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]626
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]627 <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]628 <dd>The semantics of this linkage follow the ELF object file model: the symbol
629 is weak until linked, if not linked, the symbol becomes null instead of
630 being an undefined reference.</dd>
Anton Korobeynikova0554d92007-01-12 19:20:47 +0000[diff] [blame]631
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]632 <dt><tt><b><a name="linkage_linkonce_odr">linkonce_odr</a></b></tt></dt>
633 <dt><tt><b><a name="linkage_weak_odr">weak_odr</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]634 <dd>Some languages allow differing globals to be merged, such as two functions
635 with different semantics. Other languages, such as <tt>C++</tt>, ensure
Bill Wendling03bcd6e2010-07-01 21:55:59 +0000[diff] [blame]636 that only equivalent globals are ever merged (the "one definition rule"
637 &mdash; "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]638 and <tt>weak_odr</tt> linkage types to indicate that the global will only
639 be merged with equivalent globals. These linkage types are otherwise the
640 same as their non-<tt>odr</tt> versions.</dd>
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]641
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]642 <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattnerd79749a2004-12-09 16:36:40 +0000[diff] [blame]643 <dd>If none of the above identifiers are used, the global is externally
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]644 visible, meaning that it participates in linkage and can be used to
645 resolve external symbol references.</dd>
Reid Spencer7972c472007-04-11 23:49:50 +0000[diff] [blame]646</dl>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]647
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]648<p>The next two types of linkage are targeted for Microsoft Windows platform
649 only. They are designed to support importing (exporting) symbols from (to)
650 DLLs (Dynamic Link Libraries).</p>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]651
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]652<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]653 <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]654 <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]655 or variable via a global pointer to a pointer that is set up by the DLL
656 exporting the symbol. On Microsoft Windows targets, the pointer name is
657 formed by combining <code>__imp_</code> and the function or variable
658 name.</dd>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]659
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]660 <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt></dt>
Anton Korobeynikovd61d39e2006-09-14 18:23:27 +0000[diff] [blame]661 <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]662 pointer to a pointer in a DLL, so that it can be referenced with the
663 <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
664 name is formed by combining <code>__imp_</code> and the function or
665 variable name.</dd>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]666</dl>
667
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]668<p>For example, since the "<tt>.LC0</tt>" variable is defined to be internal, if
669 another module defined a "<tt>.LC0</tt>" variable and was linked with this
670 one, one of the two would be renamed, preventing a collision. Since
671 "<tt>main</tt>" and "<tt>puts</tt>" are external (i.e., lacking any linkage
672 declarations), they are accessible outside of the current module.</p>
673
674<p>It is illegal for a function <i>declaration</i> to have any linkage type
675 other than "externally visible", <tt>dllimport</tt>
676 or <tt>extern_weak</tt>.</p>
677
Duncan Sands12da8ce2009-03-07 15:45:40 +0000[diff] [blame]678<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]679 or <tt>weak_odr</tt> linkages.</p>
680
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]681</div>
682
683<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]684<h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]685 <a name="callingconv">Calling Conventions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]686</h3>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]687
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]688<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]689
690<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]691 and <a href="#i_invoke">invokes</a> can all have an optional calling
692 convention specified for the call. The calling convention of any pair of
693 dynamic caller/callee must match, or the behavior of the program is
694 undefined. The following calling conventions are supported by LLVM, and more
695 may be added in the future:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]696
697<dl>
698 <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]699 <dd>This calling convention (the default if no other calling convention is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]700 specified) matches the target C calling conventions. This calling
701 convention supports varargs function calls and tolerates some mismatch in
702 the declared prototype and implemented declaration of the function (as
703 does normal C).</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]704
705 <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]706 <dd>This calling convention attempts to make calls as fast as possible
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]707 (e.g. by passing things in registers). This calling convention allows the
708 target to use whatever tricks it wants to produce fast code for the
709 target, without having to conform to an externally specified ABI
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]710 (Application Binary Interface).
711 <a href="CodeGenerator.html#tailcallopt">Tail calls can only be optimized
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]712 when this or the GHC convention is used.</a> This calling convention
713 does not support varargs and requires the prototype of all callees to
714 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]715
716 <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]717 <dd>This calling convention attempts to make code in the caller as efficient
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]718 as possible under the assumption that the call is not commonly executed.
719 As such, these calls often preserve all registers so that the call does
720 not break any live ranges in the caller side. This calling convention
721 does not support varargs and requires the prototype of all callees to
722 exactly match the prototype of the function definition.</dd>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]723
Chris Lattnera179e4d2010-03-11 00:22:57 +0000[diff] [blame]724 <dt><b>"<tt>cc <em>10</em></tt>" - GHC convention</b>:</dt>
725 <dd>This calling convention has been implemented specifically for use by the
726 <a href="http://www.haskell.org/ghc">Glasgow Haskell Compiler (GHC)</a>.
727 It passes everything in registers, going to extremes to achieve this by
728 disabling callee save registers. This calling convention should not be
729 used lightly but only for specific situations such as an alternative to
730 the <em>register pinning</em> performance technique often used when
731 implementing functional programming languages.At the moment only X86
732 supports this convention and it has the following limitations:
733 <ul>
734 <li>On <em>X86-32</em> only supports up to 4 bit type parameters. No
735 floating point types are supported.</li>
736 <li>On <em>X86-64</em> only supports up to 10 bit type parameters and
737 6 floating point parameters.</li>
738 </ul>
739 This calling convention supports
740 <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> but
741 requires both the caller and callee are using it.
742 </dd>
743
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]744 <dt><b>"<tt>cc &lt;<em>n</em>&gt;</tt>" - Numbered convention</b>:</dt>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]745 <dd>Any calling convention may be specified by number, allowing
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]746 target-specific calling conventions to be used. Target specific calling
747 conventions start at 64.</dd>
Chris Lattner573f64e2005-05-07 01:46:40 +0000[diff] [blame]748</dl>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]749
750<p>More calling conventions can be added/defined on an as-needed basis, to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]751 support Pascal conventions or any other well-known target-independent
752 convention.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]753
754</div>
755
756<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]757<h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]758 <a name="visibility">Visibility Styles</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]759</h3>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]760
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]761<div>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]762
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]763<p>All Global Variables and Functions have one of the following visibility
764 styles:</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]765
766<dl>
767 <dt><b>"<tt>default</tt>" - Default style</b>:</dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]768 <dd>On targets that use the ELF object file format, default visibility means
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]769 that the declaration is visible to other modules and, in shared libraries,
770 means that the declared entity may be overridden. On Darwin, default
771 visibility means that the declaration is visible to other modules. Default
772 visibility corresponds to "external linkage" in the language.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]773
774 <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]775 <dd>Two declarations of an object with hidden visibility refer to the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]776 object if they are in the same shared object. Usually, hidden visibility
777 indicates that the symbol will not be placed into the dynamic symbol
778 table, so no other module (executable or shared library) can reference it
779 directly.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]780
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]781 <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
Anton Korobeynikov39f3cff2007-04-29 18:35:00 +0000[diff] [blame]782 <dd>On ELF, protected visibility indicates that the symbol will be placed in
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]783 the dynamic symbol table, but that references within the defining module
784 will bind to the local symbol. That is, the symbol cannot be overridden by
785 another module.</dd>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]786</dl>
787
788</div>
789
790<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]791<h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]792 <a name="namedtypes">Named Types</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]793</h3>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]794
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]795<div>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]796
797<p>LLVM IR allows you to specify name aliases for certain types. This can make
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]798 it easier to read the IR and make the IR more condensed (particularly when
799 recursive types are involved). An example of a name specification is:</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]800
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]801<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]802%mytype = type { %mytype*, i32 }
803</pre>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]804
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]805<p>You may give a name to any <a href="#typesystem">type</a> except
Chris Lattner249b9762010-08-17 23:26:04 +0000[diff] [blame]806 "<a href="#t_void">void</a>". Type name aliases may be used anywhere a type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]807 is expected with the syntax "%mytype".</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]808
809<p>Note that type names are aliases for the structural type that they indicate,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]810 and that you can therefore specify multiple names for the same type. This
811 often leads to confusing behavior when dumping out a .ll file. Since LLVM IR
812 uses structural typing, the name is not part of the type. When printing out
813 LLVM IR, the printer will pick <em>one name</em> to render all types of a
814 particular shape. This means that if you have code where two different
815 source types end up having the same LLVM type, that the dumper will sometimes
816 print the "wrong" or unexpected type. This is an important design point and
817 isn't going to change.</p>
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]818
819</div>
820
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]821<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]822<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]823 <a name="globalvars">Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]824</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]825
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]826<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]827
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]828<p>Global variables define regions of memory allocated at compilation time
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]829 instead of run-time. Global variables may optionally be initialized, may
830 have an explicit section to be placed in, and may have an optional explicit
831 alignment specified. A variable may be defined as "thread_local", which
832 means that it will not be shared by threads (each thread will have a
833 separated copy of the variable). A variable may be defined as a global
834 "constant," which indicates that the contents of the variable
835 will <b>never</b> be modified (enabling better optimization, allowing the
836 global data to be placed in the read-only section of an executable, etc).
837 Note that variables that need runtime initialization cannot be marked
838 "constant" as there is a store to the variable.</p>
Chris Lattner5d5aede2005-02-12 19:30:21 +0000[diff] [blame]839
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]840<p>LLVM explicitly allows <em>declarations</em> of global variables to be marked
841 constant, even if the final definition of the global is not. This capability
842 can be used to enable slightly better optimization of the program, but
843 requires the language definition to guarantee that optimizations based on the
844 'constantness' are valid for the translation units that do not include the
845 definition.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]846
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]847<p>As SSA values, global variables define pointer values that are in scope
848 (i.e. they dominate) all basic blocks in the program. Global variables
849 always define a pointer to their "content" type because they describe a
850 region of memory, and all memory objects in LLVM are accessed through
851 pointers.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]852
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]853<p>Global variables can be marked with <tt>unnamed_addr</tt> which indicates
854 that the address is not significant, only the content. Constants marked
Rafael Espindolaf1ed7812011-01-15 08:20:57 +0000[diff] [blame]855 like this can be merged with other constants if they have the same
856 initializer. Note that a constant with significant address <em>can</em>
857 be merged with a <tt>unnamed_addr</tt> constant, the result being a
858 constant whose address is significant.</p>
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]859
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]860<p>A global variable may be declared to reside in a target-specific numbered
861 address space. For targets that support them, address spaces may affect how
862 optimizations are performed and/or what target instructions are used to
863 access the variable. The default address space is zero. The address space
864 qualifier must precede any other attributes.</p>
Christopher Lamb308121c2007-12-11 09:31:00 +0000[diff] [blame]865
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]866<p>LLVM allows an explicit section to be specified for globals. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]867 supports it, it will emit globals to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]868
Chris Lattner78e00bc2010-04-28 00:13:42 +0000[diff] [blame]869<p>An explicit alignment may be specified for a global, which must be a power
870 of 2. If not present, or if the alignment is set to zero, the alignment of
871 the global is set by the target to whatever it feels convenient. If an
872 explicit alignment is specified, the global is forced to have exactly that
Chris Lattner4bd85e42010-04-28 00:31:12 +0000[diff] [blame]873 alignment. Targets and optimizers are not allowed to over-align the global
874 if the global has an assigned section. In this case, the extra alignment
875 could be observable: for example, code could assume that the globals are
876 densely packed in their section and try to iterate over them as an array,
877 alignment padding would break this iteration.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]878
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]879<p>For example, the following defines a global in a numbered address space with
880 an initializer, section, and alignment:</p>
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]881
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]882<pre class="doc_code">
Dan Gohmanaaa679b2009-01-11 00:40:00 +0000[diff] [blame]883@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner5760c502007-01-14 00:27:09 +0000[diff] [blame]884</pre>
885
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]886</div>
887
888
889<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]890<h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]891 <a name="functionstructure">Functions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]892</h3>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]893
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]894<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]895
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]896<p>LLVM function definitions consist of the "<tt>define</tt>" keyword, an
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]897 optional <a href="#linkage">linkage type</a>, an optional
898 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]899 <a href="#callingconv">calling convention</a>,
900 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]901 <a href="#paramattrs">parameter attribute</a> for the return type, a function
902 name, a (possibly empty) argument list (each with optional
903 <a href="#paramattrs">parameter attributes</a>), optional
904 <a href="#fnattrs">function attributes</a>, an optional section, an optional
905 alignment, an optional <a href="#gc">garbage collector name</a>, an opening
906 curly brace, a list of basic blocks, and a closing curly brace.</p>
Anton Korobeynikovc7f9f3d2007-01-23 12:35:46 +0000[diff] [blame]907
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]908<p>LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
909 optional <a href="#linkage">linkage type</a>, an optional
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]910 <a href="#visibility">visibility style</a>, an optional
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]911 <a href="#callingconv">calling convention</a>,
912 an optional <tt>unnamed_addr</tt> attribute, a return type, an optional
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]913 <a href="#paramattrs">parameter attribute</a> for the return type, a function
914 name, a possibly empty list of arguments, an optional alignment, and an
915 optional <a href="#gc">garbage collector name</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]916
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]917<p>A function definition contains a list of basic blocks, forming the CFG
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]918 (Control Flow Graph) for the function. Each basic block may optionally start
919 with a label (giving the basic block a symbol table entry), contains a list
920 of instructions, and ends with a <a href="#terminators">terminator</a>
921 instruction (such as a branch or function return).</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]922
Chris Lattnera59fb102007-06-08 16:52:14 +0000[diff] [blame]923<p>The first basic block in a function is special in two ways: it is immediately
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]924 executed on entrance to the function, and it is not allowed to have
925 predecessor basic blocks (i.e. there can not be any branches to the entry
926 block of a function). Because the block can have no predecessors, it also
927 cannot have any <a href="#i_phi">PHI nodes</a>.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]928
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]929<p>LLVM allows an explicit section to be specified for functions. If the target
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]930 supports it, it will emit functions to the section specified.</p>
Chris Lattner662c8722005-11-12 00:45:07 +0000[diff] [blame]931
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]932<p>An explicit alignment may be specified for a function. If not present, or if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]933 the alignment is set to zero, the alignment of the function is set by the
934 target to whatever it feels convenient. If an explicit alignment is
935 specified, the function is forced to have at least that much alignment. All
936 alignments must be a power of 2.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]937
Rafael Espindola45e6c192011-01-08 16:42:36 +0000[diff] [blame]938<p>If the <tt>unnamed_addr</tt> attribute is given, the address is know to not
939 be significant and two identical functions can be merged</p>.
940
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]941<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]942<pre class="doc_code">
Chris Lattner0ae02092008-10-13 16:55:18 +0000[diff] [blame]943define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]944 [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
945 &lt;ResultType&gt; @&lt;FunctionName&gt; ([argument list])
946 [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
947 [<a href="#gc">gc</a>] { ... }
948</pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]949
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]950</div>
951
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]952<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]953<h3>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]954 <a name="aliasstructure">Aliases</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]955</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]956
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]957<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]958
959<p>Aliases act as "second name" for the aliasee value (which can be either
960 function, global variable, another alias or bitcast of global value). Aliases
961 may have an optional <a href="#linkage">linkage type</a>, and an
962 optional <a href="#visibility">visibility style</a>.</p>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]963
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]964<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]965<pre class="doc_code">
Duncan Sands7e99a942008-09-12 20:48:21 +0000[diff] [blame]966@&lt;Name&gt; = alias [Linkage] [Visibility] &lt;AliaseeTy&gt; @&lt;Aliasee&gt;
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]967</pre>
Anton Korobeynikova97b6942007-04-25 14:27:10 +0000[diff] [blame]968
969</div>
970
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]971<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]972<h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]973 <a name="namedmetadatastructure">Named Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]974</h3>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]975
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]976<div>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]977
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]978<p>Named metadata is a collection of metadata. <a href="#metadata">Metadata
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]979 nodes</a> (but not metadata strings) are the only valid operands for
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]980 a named metadata.</p>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]981
982<h5>Syntax:</h5>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]983<pre class="doc_code">
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]984; Some unnamed metadata nodes, which are referenced by the named metadata.
985!0 = metadata !{metadata !"zero"}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]986!1 = metadata !{metadata !"one"}
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]987!2 = metadata !{metadata !"two"}
Dan Gohman58cd65f2010-07-13 19:48:13 +0000[diff] [blame]988; A named metadata.
Dan Gohman093cb792010-07-21 18:54:18 +0000[diff] [blame]989!name = !{!0, !1, !2}
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]990</pre>
Devang Pateld1a89692010-01-11 19:35:55 +0000[diff] [blame]991
992</div>
993
994<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]995<h3>
996 <a name="paramattrs">Parameter Attributes</a>
997</h3>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]998
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]999<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1000
1001<p>The return type and each parameter of a function type may have a set of
1002 <i>parameter attributes</i> associated with them. Parameter attributes are
1003 used to communicate additional information about the result or parameters of
1004 a function. Parameter attributes are considered to be part of the function,
1005 not of the function type, so functions with different parameter attributes
1006 can have the same function type.</p>
1007
1008<p>Parameter attributes are simple keywords that follow the type specified. If
1009 multiple parameter attributes are needed, they are space separated. For
1010 example:</p>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1011
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1012<pre class="doc_code">
Nick Lewyckydac78d82009-02-15 23:06:14 +0000[diff] [blame]1013declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattnerd2597d72008-10-04 18:33:34 +0000[diff] [blame]1014declare i32 @atoi(i8 zeroext)
1015declare signext i8 @returns_signed_char()
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1016</pre>
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1017
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1018<p>Note that any attributes for the function result (<tt>nounwind</tt>,
1019 <tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1020
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1021<p>Currently, only the following parameter attributes are defined:</p>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1022
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1023<dl>
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1024 <dt><tt><b>zeroext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1025 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarichac106272011-03-16 22:20:18 +0000[diff] [blame]1026 should be zero-extended to the extent required by the target's ABI (which
1027 is usually 32-bits, but is 8-bits for a i1 on x86-64) by the caller (for a
1028 parameter) or the callee (for a return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1029
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1030 <dt><tt><b>signext</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1031 <dd>This indicates to the code generator that the parameter or return value
Cameron Zwarich341c36d2011-03-17 14:21:58 +0000[diff] [blame]1032 should be sign-extended to the extent required by the target's ABI (which
1033 is usually 32-bits) by the caller (for a parameter) or the callee (for a
1034 return value).</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1035
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1036 <dt><tt><b>inreg</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1037 <dd>This indicates that this parameter or return value should be treated in a
1038 special target-dependent fashion during while emitting code for a function
1039 call or return (usually, by putting it in a register as opposed to memory,
1040 though some targets use it to distinguish between two different kinds of
1041 registers). Use of this attribute is target-specific.</dd>
Chris Lattner5cee13f2008-01-11 06:20:47 +0000[diff] [blame]1042
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1043 <dt><tt><b><a name="byval">byval</a></b></tt></dt>
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1044 <dd><p>This indicates that the pointer parameter should really be passed by
1045 value to the function. The attribute implies that a hidden copy of the
1046 pointee
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1047 is made between the caller and the callee, so the callee is unable to
1048 modify the value in the callee. This attribute is only valid on LLVM
1049 pointer arguments. It is generally used to pass structs and arrays by
1050 value, but is also valid on pointers to scalars. The copy is considered
1051 to belong to the caller not the callee (for example,
1052 <tt><a href="#readonly">readonly</a></tt> functions should not write to
1053 <tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattnerd78dbee2010-11-20 23:49:06 +0000[diff] [blame]1054 values.</p>
1055
1056 <p>The byval attribute also supports specifying an alignment with
1057 the align attribute. It indicates the alignment of the stack slot to
1058 form and the known alignment of the pointer specified to the call site. If
1059 the alignment is not specified, then the code generator makes a
1060 target-specific assumption.</p></dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1061
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1062 <dt><tt><b><a name="sret">sret</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1063 <dd>This indicates that the pointer parameter specifies the address of a
1064 structure that is the return value of the function in the source program.
1065 This pointer must be guaranteed by the caller to be valid: loads and
1066 stores to the structure may be assumed by the callee to not to trap. This
1067 may only be applied to the first parameter. This is not a valid attribute
1068 for return values. </dd>
1069
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1070 <dt><tt><b><a name="noalias">noalias</a></b></tt></dt>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1071 <dd>This indicates that pointer values
1072 <a href="#pointeraliasing"><i>based</i></a> on the argument or return
Dan Gohmande256292010-07-02 23:46:54 +0000[diff] [blame]1073 value do not alias pointer values which are not <i>based</i> on it,
1074 ignoring certain "irrelevant" dependencies.
1075 For a call to the parent function, dependencies between memory
1076 references from before or after the call and from those during the call
1077 are "irrelevant" to the <tt>noalias</tt> keyword for the arguments and
1078 return value used in that call.
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1079 The caller shares the responsibility with the callee for ensuring that
1080 these requirements are met.
1081 For further details, please see the discussion of the NoAlias response in
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1082 <a href="AliasAnalysis.html#MustMayNo">alias analysis</a>.<br>
1083<br>
John McCall72ed8902010-07-06 21:07:14 +0000[diff] [blame]1084 Note that this definition of <tt>noalias</tt> is intentionally
1085 similar to the definition of <tt>restrict</tt> in C99 for function
Chris Lattner5eff9ca2010-07-06 20:51:35 +0000[diff] [blame]1086 arguments, though it is slightly weaker.
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]1087<br>
1088 For function return values, C99's <tt>restrict</tt> is not meaningful,
1089 while LLVM's <tt>noalias</tt> is.
1090 </dd>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1091
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1092 <dt><tt><b><a name="nocapture">nocapture</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1093 <dd>This indicates that the callee does not make any copies of the pointer
1094 that outlive the callee itself. This is not a valid attribute for return
1095 values.</dd>
1096
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]1097 <dt><tt><b><a name="nest">nest</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1098 <dd>This indicates that the pointer parameter can be excised using the
1099 <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
1100 attribute for return values.</dd>
1101</dl>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1102
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1103</div>
1104
1105<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1106<h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1107 <a name="gc">Garbage Collector Names</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1108</h3>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1109
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1110<div>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1111
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1112<p>Each function may specify a garbage collector name, which is simply a
1113 string:</p>
1114
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1115<pre class="doc_code">
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1116define void @f() gc "name" { ... }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1117</pre>
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1118
1119<p>The compiler declares the supported values of <i>name</i>. Specifying a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1120 collector which will cause the compiler to alter its output in order to
1121 support the named garbage collection algorithm.</p>
1122
Gordon Henriksen71183b62007-12-10 03:18:06 +0000[diff] [blame]1123</div>
1124
1125<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1126<h3>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1127 <a name="fnattrs">Function Attributes</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1128</h3>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1129
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1130<div>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1131
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1132<p>Function attributes are set to communicate additional information about a
1133 function. Function attributes are considered to be part of the function, not
1134 of the function type, so functions with different parameter attributes can
1135 have the same function type.</p>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1137<p>Function attributes are simple keywords that follow the type specified. If
1138 multiple attributes are needed, they are space separated. For example:</p>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1139
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1140<pre class="doc_code">
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1141define void @f() noinline { ... }
1142define void @f() alwaysinline { ... }
1143define void @f() alwaysinline optsize { ... }
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1144define void @f() optsize { ... }
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1145</pre>
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1146
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1147<dl>
Charles Davisbe5557e2010-02-12 00:31:15 +0000[diff] [blame]1148 <dt><tt><b>alignstack(&lt;<em>n</em>&gt;)</b></tt></dt>
1149 <dd>This attribute indicates that, when emitting the prologue and epilogue,
1150 the backend should forcibly align the stack pointer. Specify the
1151 desired alignment, which must be a power of two, in parentheses.
1152
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1153 <dt><tt><b>alwaysinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1154 <dd>This attribute indicates that the inliner should attempt to inline this
1155 function into callers whenever possible, ignoring any active inlining size
1156 threshold for this caller.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1157
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1158 <dt><tt><b>hotpatch</b></tt></dt>
Charles Davis1b2d3722010-10-25 16:29:03 +0000[diff] [blame]1159 <dd>This attribute indicates that the function should be 'hotpatchable',
Charles Davis74205252010-10-25 19:07:39 +0000[diff] [blame]1160 meaning the function can be patched and/or hooked even while it is
1161 loaded into memory. On x86, the function prologue will be preceded
1162 by six bytes of padding and will begin with a two-byte instruction.
1163 Most of the functions in the Windows system DLLs in Windows XP SP2 or
1164 higher were compiled in this fashion.</dd>
Charles Davis22fe1862010-10-25 15:37:09 +0000[diff] [blame]1165
Dan Gohman8bd11f12011-06-16 16:03:13 +0000[diff] [blame]1166 <dt><tt><b>nonlazybind</b></tt></dt>
1167 <dd>This attribute suppresses lazy symbol binding for the function. This
1168 may make calls to the function faster, at the cost of extra program
1169 startup time if the function is not called during program startup.</dd>
1170
Jakob Stoklund Olesen74bb06c2010-02-06 01:16:28 +0000[diff] [blame]1171 <dt><tt><b>inlinehint</b></tt></dt>
1172 <dd>This attribute indicates that the source code contained a hint that inlining
1173 this function is desirable (such as the "inline" keyword in C/C++). It
1174 is just a hint; it imposes no requirements on the inliner.</dd>
1175
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1176 <dt><tt><b>naked</b></tt></dt>
1177 <dd>This attribute disables prologue / epilogue emission for the function.
1178 This can have very system-specific consequences.</dd>
1179
1180 <dt><tt><b>noimplicitfloat</b></tt></dt>
1181 <dd>This attributes disables implicit floating point instructions.</dd>
1182
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1183 <dt><tt><b>noinline</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1184 <dd>This attribute indicates that the inliner should never inline this
1185 function in any situation. This attribute may not be used together with
1186 the <tt>alwaysinline</tt> attribute.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1187
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1188 <dt><tt><b>noredzone</b></tt></dt>
1189 <dd>This attribute indicates that the code generator should not use a red
1190 zone, even if the target-specific ABI normally permits it.</dd>
Devang Patel9eb525d2008-09-26 23:51:19 +0000[diff] [blame]1191
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1192 <dt><tt><b>noreturn</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1193 <dd>This function attribute indicates that the function never returns
1194 normally. This produces undefined behavior at runtime if the function
1195 ever does dynamically return.</dd>
Bill Wendlinga8130172008-11-13 01:02:51 +0000[diff] [blame]1196
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1197 <dt><tt><b>nounwind</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1198 <dd>This function attribute indicates that the function never returns with an
1199 unwind or exceptional control flow. If the function does unwind, its
1200 runtime behavior is undefined.</dd>
Bill Wendling0f5541e2008-11-26 19:07:40 +0000[diff] [blame]1201
Nick Lewycky14b58da2010-07-06 18:24:09 +0000[diff] [blame]1202 <dt><tt><b>optsize</b></tt></dt>
1203 <dd>This attribute suggests that optimization passes and code generator passes
1204 make choices that keep the code size of this function low, and otherwise
1205 do optimizations specifically to reduce code size.</dd>
1206
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1207 <dt><tt><b>readnone</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1208 <dd>This attribute indicates that the function computes its result (or decides
1209 to unwind an exception) based strictly on its arguments, without
1210 dereferencing any pointer arguments or otherwise accessing any mutable
1211 state (e.g. memory, control registers, etc) visible to caller functions.
1212 It does not write through any pointer arguments
1213 (including <tt><a href="#byval">byval</a></tt> arguments) and never
1214 changes any state visible to callers. This means that it cannot unwind
1215 exceptions by calling the <tt>C++</tt> exception throwing methods, but
1216 could use the <tt>unwind</tt> instruction.</dd>
Devang Patel310fd4a2009-06-12 19:45:19 +0000[diff] [blame]1217
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1218 <dt><tt><b><a name="readonly">readonly</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1219 <dd>This attribute indicates that the function does not write through any
1220 pointer arguments (including <tt><a href="#byval">byval</a></tt>
1221 arguments) or otherwise modify any state (e.g. memory, control registers,
1222 etc) visible to caller functions. It may dereference pointer arguments
1223 and read state that may be set in the caller. A readonly function always
1224 returns the same value (or unwinds an exception identically) when called
1225 with the same set of arguments and global state. It cannot unwind an
1226 exception by calling the <tt>C++</tt> exception throwing methods, but may
1227 use the <tt>unwind</tt> instruction.</dd>
Anton Korobeynikovc8ce7b082009-07-17 18:07:26 +0000[diff] [blame]1228
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1229 <dt><tt><b><a name="ssp">ssp</a></b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1230 <dd>This attribute indicates that the function should emit a stack smashing
1231 protector. It is in the form of a "canary"&mdash;a random value placed on
1232 the stack before the local variables that's checked upon return from the
1233 function to see if it has been overwritten. A heuristic is used to
1234 determine if a function needs stack protectors or not.<br>
1235<br>
1236 If a function that has an <tt>ssp</tt> attribute is inlined into a
1237 function that doesn't have an <tt>ssp</tt> attribute, then the resulting
1238 function will have an <tt>ssp</tt> attribute.</dd>
1239
Bill Wendling7f4a3362009-11-02 00:24:16 +0000[diff] [blame]1240 <dt><tt><b>sspreq</b></tt></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1241 <dd>This attribute indicates that the function should <em>always</em> emit a
1242 stack smashing protector. This overrides
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1243 the <tt><a href="#ssp">ssp</a></tt> function attribute.<br>
1244<br>
1245 If a function that has an <tt>sspreq</tt> attribute is inlined into a
1246 function that doesn't have an <tt>sspreq</tt> attribute or which has
1247 an <tt>ssp</tt> attribute, then the resulting function will have
1248 an <tt>sspreq</tt> attribute.</dd>
Bill Wendlingb175fa42008-09-07 10:26:33 +0000[diff] [blame]1249</dl>
1250
Devang Patelcaacdba2008-09-04 23:05:13 +0000[diff] [blame]1251</div>
1252
1253<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1254<h3>
Chris Lattner93564892006-04-08 04:40:53 +0000[diff] [blame]1255 <a name="moduleasm">Module-Level Inline Assembly</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1256</h3>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1257
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1258<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1259
1260<p>Modules may contain "module-level inline asm" blocks, which corresponds to
1261 the GCC "file scope inline asm" blocks. These blocks are internally
1262 concatenated by LLVM and treated as a single unit, but may be separated in
1263 the <tt>.ll</tt> file if desired. The syntax is very simple:</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1264
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1265<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]1266module asm "inline asm code goes here"
1267module asm "more can go here"
1268</pre>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1269
1270<p>The strings can contain any character by escaping non-printable characters.
1271 The escape sequence used is simply "\xx" where "xx" is the two digit hex code
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1272 for the number.</p>
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1273
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1274<p>The inline asm code is simply printed to the machine code .s file when
1275 assembly code is generated.</p>
1276
Chris Lattner91c15c42006-01-23 23:23:47 +0000[diff] [blame]1277</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1278
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1279<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1280<h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1281 <a name="datalayout">Data Layout</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1282</h3>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1283
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1284<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1285
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1286<p>A module may specify a target specific data layout string that specifies how
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1287 data is to be laid out in memory. The syntax for the data layout is
1288 simply:</p>
1289
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]1290<pre class="doc_code">
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1291target datalayout = "<i>layout specification</i>"
1292</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1293
1294<p>The <i>layout specification</i> consists of a list of specifications
1295 separated by the minus sign character ('-'). Each specification starts with
1296 a letter and may include other information after the letter to define some
1297 aspect of the data layout. The specifications accepted are as follows:</p>
1298
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1299<dl>
1300 <dt><tt>E</tt></dt>
1301 <dd>Specifies that the target lays out data in big-endian form. That is, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1302 bits with the most significance have the lowest address location.</dd>
1303
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1304 <dt><tt>e</tt></dt>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1305 <dd>Specifies that the target lays out data in little-endian form. That is,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1306 the bits with the least significance have the lowest address
1307 location.</dd>
1308
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1309 <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1310 <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1311 <i>preferred</i> alignments. All sizes are in bits. Specifying
1312 the <i>pref</i> alignment is optional. If omitted, the
1313 preceding <tt>:</tt> should be omitted too.</dd>
1314
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1315 <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1316 <dd>This specifies the alignment for an integer type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1317 <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
1318
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1319 <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1320 <dd>This specifies the alignment for a vector type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1321 <i>size</i>.</dd>
1322
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1323 <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1324 <dd>This specifies the alignment for a floating point type of a given bit
Dale Johannesence522852010-05-28 18:54:47 +0000[diff] [blame]1325 <i>size</i>. Only values of <i>size</i> that are supported by the target
1326 will work. 32 (float) and 64 (double) are supported on all targets;
1327 80 or 128 (different flavors of long double) are also supported on some
1328 targets.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1329
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1330 <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1331 <dd>This specifies the alignment for an aggregate type of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1332 <i>size</i>.</dd>
1333
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1334 <dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
1335 <dd>This specifies the alignment for a stack object of a given bit
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1336 <i>size</i>.</dd>
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1337
1338 <dt><tt>n<i>size1</i>:<i>size2</i>:<i>size3</i>...</tt></dt>
1339 <dd>This specifies a set of native integer widths for the target CPU
1340 in bits. For example, it might contain "n32" for 32-bit PowerPC,
1341 "n32:64" for PowerPC 64, or "n8:16:32:64" for X86-64. Elements of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1342 this set are considered to support most general arithmetic
Chris Lattnera381eff2009-11-07 09:35:34 +0000[diff] [blame]1343 operations efficiently.</dd>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1344</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1345
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1346<p>When constructing the data layout for a given target, LLVM starts with a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]1347 default set of specifications which are then (possibly) overridden by the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1348 specifications in the <tt>datalayout</tt> keyword. The default specifications
1349 are given in this list:</p>
1350
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1351<ul>
1352 <li><tt>E</tt> - big endian</li>
Dan Gohman8ad777d2010-02-23 02:44:03 +0000[diff] [blame]1353 <li><tt>p:64:64:64</tt> - 64-bit pointers with 64-bit alignment</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1354 <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
1355 <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
1356 <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
1357 <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]1358 <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1359 alignment of 64-bits</li>
1360 <li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
1361 <li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
1362 <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
1363 <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
1364 <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar7921a592009-06-08 22:17:53 +0000[diff] [blame]1365 <li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1366</ul>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1367
1368<p>When LLVM is determining the alignment for a given type, it uses the
1369 following rules:</p>
1370
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1371<ol>
1372 <li>If the type sought is an exact match for one of the specifications, that
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1373 specification is used.</li>
1374
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1375 <li>If no match is found, and the type sought is an integer type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1376 smallest integer type that is larger than the bitwidth of the sought type
1377 is used. If none of the specifications are larger than the bitwidth then
1378 the the largest integer type is used. For example, given the default
1379 specifications above, the i7 type will use the alignment of i8 (next
1380 largest) while both i65 and i256 will use the alignment of i64 (largest
1381 specified).</li>
1382
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1383 <li>If no match is found, and the type sought is a vector type, then the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1384 largest vector type that is smaller than the sought vector type will be
1385 used as a fall back. This happens because &lt;128 x double&gt; can be
1386 implemented in terms of 64 &lt;2 x double&gt;, for example.</li>
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1387</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1388
Reid Spencer50c723a2007-02-19 23:54:10 +0000[diff] [blame]1389</div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1390
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1391<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1392<h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1393 <a name="pointeraliasing">Pointer Aliasing Rules</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1394</h3>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1395
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1396<div>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1397
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1398<p>Any memory access must be done through a pointer value associated
Andreas Bolkae39f0332009-07-27 20:37:10 +0000[diff] [blame]1399with an address range of the memory access, otherwise the behavior
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1400is undefined. Pointer values are associated with address ranges
1401according to the following rules:</p>
1402
1403<ul>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1404 <li>A pointer value is associated with the addresses associated with
1405 any value it is <i>based</i> on.
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1406 <li>An address of a global variable is associated with the address
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1407 range of the variable's storage.</li>
1408 <li>The result value of an allocation instruction is associated with
1409 the address range of the allocated storage.</li>
1410 <li>A null pointer in the default address-space is associated with
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1411 no address.</li>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1412 <li>An integer constant other than zero or a pointer value returned
1413 from a function not defined within LLVM may be associated with address
1414 ranges allocated through mechanisms other than those provided by
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1415 LLVM. Such ranges shall not overlap with any ranges of addresses
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1416 allocated by mechanisms provided by LLVM.</li>
Dan Gohmandf12d082010-07-02 18:41:32 +0000[diff] [blame]1417</ul>
1418
1419<p>A pointer value is <i>based</i> on another pointer value according
1420 to the following rules:</p>
1421
1422<ul>
1423 <li>A pointer value formed from a
1424 <tt><a href="#i_getelementptr">getelementptr</a></tt> operation
1425 is <i>based</i> on the first operand of the <tt>getelementptr</tt>.</li>
1426 <li>The result value of a
1427 <tt><a href="#i_bitcast">bitcast</a></tt> is <i>based</i> on the operand
1428 of the <tt>bitcast</tt>.</li>
1429 <li>A pointer value formed by an
1430 <tt><a href="#i_inttoptr">inttoptr</a></tt> is <i>based</i> on all
1431 pointer values that contribute (directly or indirectly) to the
1432 computation of the pointer's value.</li>
1433 <li>The "<i>based</i> on" relationship is transitive.</li>
1434</ul>
1435
1436<p>Note that this definition of <i>"based"</i> is intentionally
1437 similar to the definition of <i>"based"</i> in C99, though it is
1438 slightly weaker.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1439
1440<p>LLVM IR does not associate types with memory. The result type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1441<tt><a href="#i_load">load</a></tt> merely indicates the size and
1442alignment of the memory from which to load, as well as the
Dan Gohman4eb47192010-06-17 19:23:50 +0000[diff] [blame]1443interpretation of the value. The first operand type of a
Andreas Bolka8ae4e242009-07-29 00:02:05 +0000[diff] [blame]1444<tt><a href="#i_store">store</a></tt> similarly only indicates the size
1445and alignment of the store.</p>
Dan Gohman6154a012009-07-27 18:07:55 +0000[diff] [blame]1446
1447<p>Consequently, type-based alias analysis, aka TBAA, aka
1448<tt>-fstrict-aliasing</tt>, is not applicable to general unadorned
1449LLVM IR. <a href="#metadata">Metadata</a> may be used to encode
1450additional information which specialized optimization passes may use
1451to implement type-based alias analysis.</p>
1452
1453</div>
1454
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1455<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1456<h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1457 <a name="volatile">Volatile Memory Accesses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1458</h3>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1459
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1460<div>
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]1461
1462<p>Certain memory accesses, such as <a href="#i_load"><tt>load</tt></a>s, <a
1463href="#i_store"><tt>store</tt></a>s, and <a
1464href="#int_memcpy"><tt>llvm.memcpy</tt></a>s may be marked <tt>volatile</tt>.
1465The optimizers must not change the number of volatile operations or change their
1466order of execution relative to other volatile operations. The optimizers
1467<i>may</i> change the order of volatile operations relative to non-volatile
1468operations. This is not Java's "volatile" and has no cross-thread
1469synchronization behavior.</p>
1470
1471</div>
1472
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1473</div>
1474
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1475<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1476<h2><a name="typesystem">Type System</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1477<!-- *********************************************************************** -->
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1478
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1479<div>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1480
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1481<p>The LLVM type system is one of the most important features of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1482 intermediate representation. Being typed enables a number of optimizations
1483 to be performed on the intermediate representation directly, without having
1484 to do extra analyses on the side before the transformation. A strong type
1485 system makes it easier to read the generated code and enables novel analyses
1486 and transformations that are not feasible to perform on normal three address
1487 code representations.</p>
Chris Lattner6af02f32004-12-09 16:11:40 +0000[diff] [blame]1488
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1489<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1490<h3>
1491 <a name="t_classifications">Type Classifications</a>
1492</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1493
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1494<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1495
1496<p>The types fall into a few useful classifications:</p>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1497
1498<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1499 <tbody>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1500 <tr><th>Classification</th><th>Types</th></tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1501 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1502 <td><a href="#t_integer">integer</a></td>
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1503 <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1504 </tr>
1505 <tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1506 <td><a href="#t_floating">floating point</a></td>
1507 <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1508 </tr>
1509 <tr>
1510 <td><a name="t_firstclass">first class</a></td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1511 <td><a href="#t_integer">integer</a>,
1512 <a href="#t_floating">floating point</a>,
1513 <a href="#t_pointer">pointer</a>,
Dan Gohman08783a882008-06-18 18:42:13 +0000[diff] [blame]1514 <a href="#t_vector">vector</a>,
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]1515 <a href="#t_struct">structure</a>,
1516 <a href="#t_array">array</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1517 <a href="#t_label">label</a>,
1518 <a href="#t_metadata">metadata</a>.
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1519 </td>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1520 </tr>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1521 <tr>
1522 <td><a href="#t_primitive">primitive</a></td>
1523 <td><a href="#t_label">label</a>,
1524 <a href="#t_void">void</a>,
Tobias Grosser4c8c95b2010-12-28 20:29:31 +0000[diff] [blame]1525 <a href="#t_integer">integer</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1526 <a href="#t_floating">floating point</a>,
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1527 <a href="#t_x86mmx">x86mmx</a>,
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1528 <a href="#t_metadata">metadata</a>.</td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1529 </tr>
1530 <tr>
1531 <td><a href="#t_derived">derived</a></td>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1532 <td><a href="#t_array">array</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1533 <a href="#t_function">function</a>,
1534 <a href="#t_pointer">pointer</a>,
1535 <a href="#t_struct">structure</a>,
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1536 <a href="#t_vector">vector</a>,
1537 <a href="#t_opaque">opaque</a>.
Dan Gohman93bf60d2008-10-14 16:32:04 +0000[diff] [blame]1538 </td>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1539 </tr>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]1540 </tbody>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1541</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1542
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1543<p>The <a href="#t_firstclass">first class</a> types are perhaps the most
1544 important. Values of these types are the only ones which can be produced by
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1545 instructions.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1546
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1547</div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1548
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1549<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1550<h3>
1551 <a name="t_primitive">Primitive Types</a>
1552</h3>
Chris Lattner43542b32008-01-04 04:34:14 +0000[diff] [blame]1553
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1554<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1555
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1556<p>The primitive types are the fundamental building blocks of the LLVM
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1557 system.</p>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1558
1559<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1560<h4>
1561 <a name="t_integer">Integer Type</a>
1562</h4>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1563
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1564<div>
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1565
1566<h5>Overview:</h5>
1567<p>The integer type is a very simple type that simply specifies an arbitrary
1568 bit width for the integer type desired. Any bit width from 1 bit to
1569 2<sup>23</sup>-1 (about 8 million) can be specified.</p>
1570
1571<h5>Syntax:</h5>
1572<pre>
1573 iN
1574</pre>
1575
1576<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
1577 value.</p>
1578
1579<h5>Examples:</h5>
1580<table class="layout">
1581 <tr class="layout">
1582 <td class="left"><tt>i1</tt></td>
1583 <td class="left">a single-bit integer.</td>
1584 </tr>
1585 <tr class="layout">
1586 <td class="left"><tt>i32</tt></td>
1587 <td class="left">a 32-bit integer.</td>
1588 </tr>
1589 <tr class="layout">
1590 <td class="left"><tt>i1942652</tt></td>
1591 <td class="left">a really big integer of over 1 million bits.</td>
1592 </tr>
1593</table>
1594
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1595</div>
1596
1597<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1598<h4>
1599 <a name="t_floating">Floating Point Types</a>
1600</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1601
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1602<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1603
1604<table>
1605 <tbody>
1606 <tr><th>Type</th><th>Description</th></tr>
1607 <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
1608 <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
1609 <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
1610 <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
1611 <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
1612 </tbody>
1613</table>
1614
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1615</div>
1616
1617<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1618<h4>
1619 <a name="t_x86mmx">X86mmx Type</a>
1620</h4>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1621
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1622<div>
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1623
1624<h5>Overview:</h5>
1625<p>The x86mmx type represents a value held in an MMX register on an x86 machine. The operations allowed on it are quite limited: parameters and return values, load and store, and bitcast. User-specified MMX instructions are represented as intrinsic or asm calls with arguments and/or results of this type. There are no arrays, vectors or constants of this type.</p>
1626
1627<h5>Syntax:</h5>
1628<pre>
Dale Johannesenb1f0ff12010-10-01 01:07:02 +0000[diff] [blame]1629 x86mmx
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]1630</pre>
1631
1632</div>
1633
1634<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1635<h4>
1636 <a name="t_void">Void Type</a>
1637</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1638
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1639<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1640
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1641<h5>Overview:</h5>
1642<p>The void type does not represent any value and has no size.</p>
1643
1644<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1645<pre>
1646 void
1647</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1648
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1649</div>
1650
1651<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1652<h4>
1653 <a name="t_label">Label Type</a>
1654</h4>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1655
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1656<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1657
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1658<h5>Overview:</h5>
1659<p>The label type represents code labels.</p>
1660
1661<h5>Syntax:</h5>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1662<pre>
1663 label
1664</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1665
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1666</div>
1667
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1668<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1669<h4>
1670 <a name="t_metadata">Metadata Type</a>
1671</h4>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1672
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1673<div>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1674
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1675<h5>Overview:</h5>
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1676<p>The metadata type represents embedded metadata. No derived types may be
1677 created from metadata except for <a href="#t_function">function</a>
1678 arguments.
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1679
1680<h5>Syntax:</h5>
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1681<pre>
1682 metadata
1683</pre>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1684
Nick Lewyckyadbc2842009-05-30 05:06:04 +0000[diff] [blame]1685</div>
1686
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1687</div>
Chris Lattner7824d182008-01-04 04:32:38 +0000[diff] [blame]1688
1689<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1690<h3>
1691 <a name="t_derived">Derived Types</a>
1692</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1693
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1694<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1695
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1696<p>The real power in LLVM comes from the derived types in the system. This is
1697 what allows a programmer to represent arrays, functions, pointers, and other
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]1698 useful types. Each of these types contain one or more element types which
1699 may be a primitive type, or another derived type. For example, it is
1700 possible to have a two dimensional array, using an array as the element type
1701 of another array.</p>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1702
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1703</div>
1704
1705
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1706<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1707<h4>
1708 <a name="t_aggregate">Aggregate Types</a>
1709</h4>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1710
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1711<div>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1712
1713<p>Aggregate Types are a subset of derived types that can contain multiple
1714 member types. <a href="#t_array">Arrays</a>,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1715 <a href="#t_struct">structs</a>, and <a href="#t_vector">vectors</a> are
1716 aggregate types.</p>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]1717
1718</div>
1719
Reid Spencer138249b2007-05-16 18:44:01 +0000[diff] [blame]1720<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1721<h4>
1722 <a name="t_array">Array Type</a>
1723</h4>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1724
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1725<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1726
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1727<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1728<p>The array type is a very simple derived type that arranges elements
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1729 sequentially in memory. The array type requires a size (number of elements)
1730 and an underlying data type.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1731
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1732<h5>Syntax:</h5>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1733<pre>
1734 [&lt;# elements&gt; x &lt;elementtype&gt;]
1735</pre>
1736
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1737<p>The number of elements is a constant integer value; <tt>elementtype</tt> may
1738 be any type with a size.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]1739
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1740<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1741<table class="layout">
1742 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1743 <td class="left"><tt>[40 x i32]</tt></td>
1744 <td class="left">Array of 40 32-bit integer values.</td>
1745 </tr>
1746 <tr class="layout">
1747 <td class="left"><tt>[41 x i32]</tt></td>
1748 <td class="left">Array of 41 32-bit integer values.</td>
1749 </tr>
1750 <tr class="layout">
1751 <td class="left"><tt>[4 x i8]</tt></td>
1752 <td class="left">Array of 4 8-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1753 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1754</table>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1755<p>Here are some examples of multidimensional arrays:</p>
1756<table class="layout">
1757 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1758 <td class="left"><tt>[3 x [4 x i32]]</tt></td>
1759 <td class="left">3x4 array of 32-bit integer values.</td>
1760 </tr>
1761 <tr class="layout">
1762 <td class="left"><tt>[12 x [10 x float]]</tt></td>
1763 <td class="left">12x10 array of single precision floating point values.</td>
1764 </tr>
1765 <tr class="layout">
1766 <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
1767 <td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1768 </tr>
1769</table>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1770
Dan Gohmanc74bc282009-11-09 19:01:53 +0000[diff] [blame]1771<p>There is no restriction on indexing beyond the end of the array implied by
1772 a static type (though there are restrictions on indexing beyond the bounds
1773 of an allocated object in some cases). This means that single-dimension
1774 'variable sized array' addressing can be implemented in LLVM with a zero
1775 length array type. An implementation of 'pascal style arrays' in LLVM could
1776 use the type "<tt>{ i32, [0 x float]}</tt>", for example.</p>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]1777
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1778</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1779
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1780<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1781<h4>
1782 <a name="t_function">Function Type</a>
1783</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1784
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1785<div>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1786
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1787<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1788<p>The function type can be thought of as a function signature. It consists of
1789 a return type and a list of formal parameter types. The return type of a
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]1790 function type is a first class type or a void type.</p>
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]1791
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1792<h5>Syntax:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1793<pre>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1794 &lt;returntype&gt; (&lt;parameter list&gt;)
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1795</pre>
1796
John Criswell4c0cf7f2005-10-24 16:17:18 +0000[diff] [blame]1797<p>...where '<tt>&lt;parameter list&gt;</tt>' is a comma-separated list of type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1798 specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
1799 which indicates that the function takes a variable number of arguments.
1800 Variable argument functions can access their arguments with
1801 the <a href="#int_varargs">variable argument handling intrinsic</a>
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1802 functions. '<tt>&lt;returntype&gt;</tt>' is any type except
Nick Lewycky93e06a52009-09-27 23:27:42 +0000[diff] [blame]1803 <a href="#t_label">label</a>.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]1804
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1805<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1806<table class="layout">
1807 <tr class="layout">
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1808 <td class="left"><tt>i32 (i32)</tt></td>
1809 <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1810 </td>
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1811 </tr><tr class="layout">
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1812 <td class="left"><tt>float&nbsp;(i16,&nbsp;i32&nbsp;*)&nbsp;*
Reid Spencer655dcc62006-12-31 07:20:23 +0000[diff] [blame]1813 </tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1814 <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]1815 an <tt>i16</tt> and a <a href="#t_pointer">pointer</a> to <tt>i32</tt>,
1816 returning <tt>float</tt>.
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1817 </td>
1818 </tr><tr class="layout">
1819 <td class="left"><tt>i32 (i8*, ...)</tt></td>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]1820 <td class="left">A vararg function that takes at least one
1821 <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
1822 which returns an integer. This is the signature for <tt>printf</tt> in
Reid Spencer58c08712006-12-31 07:18:34 +0000[diff] [blame]1823 LLVM.
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1824 </td>
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1825 </tr><tr class="layout">
1826 <td class="left"><tt>{i32, i32} (i32)</tt></td>
Nick Lewycky14d1ccc2009-09-27 07:55:32 +0000[diff] [blame]1827 <td class="left">A function taking an <tt>i32</tt>, returning a
1828 <a href="#t_struct">structure</a> containing two <tt>i32</tt> values
Devang Patele3dfc1c2008-03-24 05:35:41 +0000[diff] [blame]1829 </td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1830 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1831</table>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]1832
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1833</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1834
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1835<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1836<h4>
1837 <a name="t_struct">Structure Type</a>
1838</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1839
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1840<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1841
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1842<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1843<p>The structure type is used to represent a collection of data members together
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1844 in memory. The elements of a structure may be any type that has a size.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1845
Jeffrey Yasskinf991bbb2010-01-11 19:19:26 +0000[diff] [blame]1846<p>Structures in memory are accessed using '<tt><a href="#i_load">load</a></tt>'
1847 and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a field
1848 with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
1849 Structures in registers are accessed using the
1850 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' and
1851 '<tt><a href="#i_insertvalue">insertvalue</a></tt>' instructions.</p>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1852
1853<p>Structures may optionally be "packed" structures, which indicate that the
1854 alignment of the struct is one byte, and that there is no padding between
1855 the elements. In non-packed structs, padding between field types is defined
1856 by the target data string to match the underlying processor.</p>
1857
1858<p>Structures can either be "anonymous" or "named". An anonymous structure is
1859 defined inline with other types (e.g. <tt>{i32, i32}*</tt>) and a named types
1860 are always defined at the top level with a name. Anonmyous types are uniqued
1861 by their contents and can never be recursive since there is no way to write
1862 one. Named types can be recursive.
1863</p>
1864
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1865<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1866<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1867 %T1 = type { &lt;type list&gt; } <i>; Named normal struct type</i>
1868 %T2 = type &lt;{ &lt;type list&gt; }&gt; <i>; Named packed struct type</i>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1869</pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1870
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1871<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1872<table class="layout">
1873 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1874 <td class="left"><tt>{ i32, i32, i32 }</tt></td>
1875 <td class="left">A triple of three <tt>i32</tt> values</td>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1876 </tr>
1877 <tr class="layout">
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]1878 <td class="left"><tt>{&nbsp;float,&nbsp;i32&nbsp;(i32)&nbsp;*&nbsp;}</tt></td>
1879 <td class="left">A pair, where the first element is a <tt>float</tt> and the
1880 second element is a <a href="#t_pointer">pointer</a> to a
1881 <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
1882 an <tt>i32</tt>.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1883 </tr>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1884 <tr class="layout">
1885 <td class="left"><tt>&lt;{ i8, i32 }&gt;</tt></td>
1886 <td class="left">A packed struct known to be 5 bytes in size.</td>
1887 </tr>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1888</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]1889
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1890</div>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1891
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]1892<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1893<h4>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1894 <a name="t_opaque">Opaque Type</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1895</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1896
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1897<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1898
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1899<h5>Overview:</h5>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1900<p>Opaque types are used to represent named structure types that do not have a
1901 body specified. This corresponds (for example) to the C notion of a forward
1902 declared structure.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1903
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1904<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1905<pre>
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1906 %X = type opaque
1907 %52 = type opaque
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1908</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1909
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1910<h5>Examples:</h5>
1911<table class="layout">
1912 <tr class="layout">
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1913 <td class="left"><tt>opaque</tt></td>
1914 <td class="left">An opaque type.</td>
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1915 </tr>
1916</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1917
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1918</div>
1919
Chris Lattnerb1ed91f2011-07-09 17:41:24 +0000[diff] [blame^]1920
1921
Andrew Lenharth8df88e22006-12-08 17:13:00 +0000[diff] [blame]1922<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1923<h4>
1924 <a name="t_pointer">Pointer Type</a>
1925</h4>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1926
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1927<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1928
1929<h5>Overview:</h5>
Dan Gohman88481112010-02-25 16:50:07 +0000[diff] [blame]1930<p>The pointer type is used to specify memory locations.
1931 Pointers are commonly used to reference objects in memory.</p>
1932
1933<p>Pointer types may have an optional address space attribute defining the
1934 numbered address space where the pointed-to object resides. The default
1935 address space is number zero. The semantics of non-zero address
1936 spaces are target-specific.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1937
1938<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does it
1939 permit pointers to labels (<tt>label*</tt>). Use <tt>i8*</tt> instead.</p>
Chris Lattner4a67c912009-02-08 19:53:29 +0000[diff] [blame]1940
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1941<h5>Syntax:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]1942<pre>
1943 &lt;type&gt; *
1944</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1945
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]1946<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1947<table class="layout">
1948 <tr class="layout">
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]1949 <td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1950 <td class="left">A <a href="#t_pointer">pointer</a> to <a
1951 href="#t_array">array</a> of four <tt>i32</tt> values.</td>
1952 </tr>
1953 <tr class="layout">
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]1954 <td class="left"><tt>i32 (i32*) *</tt></td>
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1955 <td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]1956 href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1957 <tt>i32</tt>.</td>
1958 </tr>
1959 <tr class="layout">
1960 <td class="left"><tt>i32 addrspace(5)*</tt></td>
1961 <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
1962 that resides in address space #5.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1963 </tr>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1964</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1965
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]1966</div>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1967
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1968<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]1969<h4>
1970 <a name="t_vector">Vector Type</a>
1971</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1972
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]1973<div>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1974
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1975<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1976<p>A vector type is a simple derived type that represents a vector of elements.
1977 Vector types are used when multiple primitive data are operated in parallel
1978 using a single instruction (SIMD). A vector type requires a size (number of
Duncan Sands31c0e0e2009-11-27 13:38:03 +0000[diff] [blame]1979 elements) and an underlying primitive data type. Vector types are considered
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]1980 <a href="#t_firstclass">first class</a>.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1981
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1982<h5>Syntax:</h5>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1983<pre>
1984 &lt; &lt;# elements&gt; x &lt;elementtype&gt; &gt;
1985</pre>
1986
Chris Lattnerf11031a2010-10-10 18:20:35 +0000[diff] [blame]1987<p>The number of elements is a constant integer value larger than 0; elementtype
1988 may be any integer or floating point type. Vectors of size zero are not
1989 allowed, and pointers are not allowed as the element type.</p>
Chris Lattner37b6b092005-04-25 17:34:15 +0000[diff] [blame]1990
Chris Lattnerc8cb6952004-08-12 19:12:28 +0000[diff] [blame]1991<h5>Examples:</h5>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]1992<table class="layout">
1993 <tr class="layout">
Chris Lattner747359f2007-12-19 05:04:11 +0000[diff] [blame]1994 <td class="left"><tt>&lt;4 x i32&gt;</tt></td>
1995 <td class="left">Vector of 4 32-bit integer values.</td>
1996 </tr>
1997 <tr class="layout">
1998 <td class="left"><tt>&lt;8 x float&gt;</tt></td>
1999 <td class="left">Vector of 8 32-bit floating-point values.</td>
2000 </tr>
2001 <tr class="layout">
2002 <td class="left"><tt>&lt;2 x i64&gt;</tt></td>
2003 <td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencerc3c4c4f2004-11-01 08:19:36 +0000[diff] [blame]2004 </tr>
2005</table>
Dan Gohman142ccc02009-01-24 15:58:40 +0000[diff] [blame]2006
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2007</div>
2008
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2009<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2010<h2><a name="constants">Constants</a></h2>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2011<!-- *********************************************************************** -->
2012
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2013<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2014
2015<p>LLVM has several different basic types of constants. This section describes
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2016 them all and their syntax.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2017
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2018<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2019<h3>
2020 <a name="simpleconstants">Simple Constants</a>
2021</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2022
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2023<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2024
2025<dl>
2026 <dt><b>Boolean constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2027 <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]2028 constants of the <tt><a href="#t_integer">i1</a></tt> type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2029
2030 <dt><b>Integer constants</b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2031 <dd>Standard integers (such as '4') are constants of
2032 the <a href="#t_integer">integer</a> type. Negative numbers may be used
2033 with integer types.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2034
2035 <dt><b>Floating point constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2036 <dd>Floating point constants use standard decimal notation (e.g. 123.421),
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2037 exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
2038 notation (see below). The assembler requires the exact decimal value of a
2039 floating-point constant. For example, the assembler accepts 1.25 but
2040 rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
2041 constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2042
2043 <dt><b>Null pointer constants</b></dt>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]2044 <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2045 and must be of <a href="#t_pointer">pointer type</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2046</dl>
2047
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2048<p>The one non-intuitive notation for constants is the hexadecimal form of
2049 floating point constants. For example, the form '<tt>double
2050 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than)
2051 '<tt>double 4.5e+15</tt>'. The only time hexadecimal floating point
2052 constants are required (and the only time that they are generated by the
2053 disassembler) is when a floating point constant must be emitted but it cannot
2054 be represented as a decimal floating point number in a reasonable number of
2055 digits. For example, NaN's, infinities, and other special values are
2056 represented in their IEEE hexadecimal format so that assembly and disassembly
2057 do not cause any bits to change in the constants.</p>
2058
Dale Johannesencd4a3012009-02-11 22:14:51 +0000[diff] [blame]2059<p>When using the hexadecimal form, constants of types float and double are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2060 represented using the 16-digit form shown above (which matches the IEEE754
2061 representation for double); float values must, however, be exactly
2062 representable as IEE754 single precision. Hexadecimal format is always used
2063 for long double, and there are three forms of long double. The 80-bit format
2064 used by x86 is represented as <tt>0xK</tt> followed by 20 hexadecimal digits.
2065 The 128-bit format used by PowerPC (two adjacent doubles) is represented
2066 by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit format
2067 is represented by <tt>0xL</tt> followed by 32 hexadecimal digits; no
2068 currently supported target uses this format. Long doubles will only work if
2069 they match the long double format on your target. All hexadecimal formats
2070 are big-endian (sign bit at the left).</p>
2071
Dale Johannesen33e5c352010-10-01 00:48:59 +0000[diff] [blame]2072<p>There are no constants of type x86mmx.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2073</div>
2074
2075<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2076<h3>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]2077<a name="aggregateconstants"></a> <!-- old anchor -->
2078<a name="complexconstants">Complex Constants</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2079</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2080
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2081<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2082
Chris Lattner361bfcd2009-02-28 18:32:25 +0000[diff] [blame]2083<p>Complex constants are a (potentially recursive) combination of simple
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2084 constants and smaller complex constants.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2085
2086<dl>
2087 <dt><b>Structure constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2088 <dd>Structure constants are represented with notation similar to structure
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2089 type definitions (a comma separated list of elements, surrounded by braces
2090 (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
2091 where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>".
2092 Structure constants must have <a href="#t_struct">structure type</a>, and
2093 the number and types of elements must match those specified by the
2094 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2095
2096 <dt><b>Array constants</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2097 <dd>Array constants are represented with notation similar to array type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2098 definitions (a comma separated list of elements, surrounded by square
2099 brackets (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74
2100 ]</tt>". Array constants must have <a href="#t_array">array type</a>, and
2101 the number and types of elements must match those specified by the
2102 type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2103
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2104 <dt><b>Vector constants</b></dt>
Reid Spencer404a3252007-02-15 03:07:05 +0000[diff] [blame]2105 <dd>Vector constants are represented with notation similar to vector type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2106 definitions (a comma separated list of elements, surrounded by
2107 less-than/greater-than's (<tt>&lt;&gt;</tt>)). For example: "<tt>&lt; i32
2108 42, i32 11, i32 74, i32 100 &gt;</tt>". Vector constants must
2109 have <a href="#t_vector">vector type</a>, and the number and types of
2110 elements must match those specified by the type.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2111
2112 <dt><b>Zero initialization</b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2113 <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]2114 value to zero of <em>any</em> type, including scalar and
2115 <a href="#t_aggregate">aggregate</a> types.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2116 This is often used to avoid having to print large zero initializers
2117 (e.g. for large arrays) and is always exactly equivalent to using explicit
2118 zero initializers.</dd>
Nick Lewycky49f89192009-04-04 07:22:01 +0000[diff] [blame]2119
2120 <dt><b>Metadata node</b></dt>
Nick Lewycky8e2c4f42009-05-30 16:08:30 +0000[diff] [blame]2121 <dd>A metadata node is a structure-like constant with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2122 <a href="#t_metadata">metadata type</a>. For example: "<tt>metadata !{
2123 i32 0, metadata !"test" }</tt>". Unlike other constants that are meant to
2124 be interpreted as part of the instruction stream, metadata is a place to
2125 attach additional information such as debug info.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2126</dl>
2127
2128</div>
2129
2130<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2131<h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2132 <a name="globalconstants">Global Variable and Function Addresses</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2133</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2134
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2135<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2136
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2137<p>The addresses of <a href="#globalvars">global variables</a>
2138 and <a href="#functionstructure">functions</a> are always implicitly valid
2139 (link-time) constants. These constants are explicitly referenced when
2140 the <a href="#identifiers">identifier for the global</a> is used and always
2141 have <a href="#t_pointer">pointer</a> type. For example, the following is a
2142 legal LLVM file:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2143
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2144<pre class="doc_code">
Chris Lattner00538a12007-06-06 18:28:13 +0000[diff] [blame]2145@X = global i32 17
2146@Y = global i32 42
2147@Z = global [2 x i32*] [ i32* @X, i32* @Y ]
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2148</pre>
2149
2150</div>
2151
2152<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2153<h3>
2154 <a name="undefvalues">Undefined Values</a>
2155</h3>
2156
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2157<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2158
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2159<p>The string '<tt>undef</tt>' can be used anywhere a constant is expected, and
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2160 indicates that the user of the value may receive an unspecified bit-pattern.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2161 Undefined values may be of any type (other than '<tt>label</tt>'
2162 or '<tt>void</tt>') and be used anywhere a constant is permitted.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2163
Chris Lattner92ada5d2009-09-11 01:49:31 +0000[diff] [blame]2164<p>Undefined values are useful because they indicate to the compiler that the
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2165 program is well defined no matter what value is used. This gives the
2166 compiler more freedom to optimize. Here are some examples of (potentially
2167 surprising) transformations that are valid (in pseudo IR):</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2168
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2169
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2170<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2171 %A = add %X, undef
2172 %B = sub %X, undef
2173 %C = xor %X, undef
2174Safe:
2175 %A = undef
2176 %B = undef
2177 %C = undef
2178</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2179
2180<p>This is safe because all of the output bits are affected by the undef bits.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2181 Any output bit can have a zero or one depending on the input bits.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2182
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2183<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2184 %A = or %X, undef
2185 %B = and %X, undef
2186Safe:
2187 %A = -1
2188 %B = 0
2189Unsafe:
2190 %A = undef
2191 %B = undef
2192</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2193
2194<p>These logical operations have bits that are not always affected by the input.
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2195 For example, if <tt>%X</tt> has a zero bit, then the output of the
2196 '<tt>and</tt>' operation will always be a zero for that bit, no matter what
2197 the corresponding bit from the '<tt>undef</tt>' is. As such, it is unsafe to
2198 optimize or assume that the result of the '<tt>and</tt>' is '<tt>undef</tt>'.
2199 However, it is safe to assume that all bits of the '<tt>undef</tt>' could be
2200 0, and optimize the '<tt>and</tt>' to 0. Likewise, it is safe to assume that
2201 all the bits of the '<tt>undef</tt>' operand to the '<tt>or</tt>' could be
2202 set, allowing the '<tt>or</tt>' to be folded to -1.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2203
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2204<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2205 %A = select undef, %X, %Y
2206 %B = select undef, 42, %Y
2207 %C = select %X, %Y, undef
2208Safe:
2209 %A = %X (or %Y)
2210 %B = 42 (or %Y)
2211 %C = %Y
2212Unsafe:
2213 %A = undef
2214 %B = undef
2215 %C = undef
2216</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2217
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2218<p>This set of examples shows that undefined '<tt>select</tt>' (and conditional
2219 branch) conditions can go <em>either way</em>, but they have to come from one
2220 of the two operands. In the <tt>%A</tt> example, if <tt>%X</tt> and
2221 <tt>%Y</tt> were both known to have a clear low bit, then <tt>%A</tt> would
2222 have to have a cleared low bit. However, in the <tt>%C</tt> example, the
2223 optimizer is allowed to assume that the '<tt>undef</tt>' operand could be the
2224 same as <tt>%Y</tt>, allowing the whole '<tt>select</tt>' to be
2225 eliminated.</p>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2226
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2227<pre class="doc_code">
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2228 %A = xor undef, undef
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2229
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2230 %B = undef
2231 %C = xor %B, %B
2232
2233 %D = undef
2234 %E = icmp lt %D, 4
2235 %F = icmp gte %D, 4
2236
2237Safe:
2238 %A = undef
2239 %B = undef
2240 %C = undef
2241 %D = undef
2242 %E = undef
2243 %F = undef
2244</pre>
Chris Lattnerec72b9b2009-09-07 22:52:39 +0000[diff] [blame]2245
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2246<p>This example points out that two '<tt>undef</tt>' operands are not
2247 necessarily the same. This can be surprising to people (and also matches C
2248 semantics) where they assume that "<tt>X^X</tt>" is always zero, even
2249 if <tt>X</tt> is undefined. This isn't true for a number of reasons, but the
2250 short answer is that an '<tt>undef</tt>' "variable" can arbitrarily change
2251 its value over its "live range". This is true because the variable doesn't
2252 actually <em>have a live range</em>. Instead, the value is logically read
2253 from arbitrary registers that happen to be around when needed, so the value
2254 is not necessarily consistent over time. In fact, <tt>%A</tt> and <tt>%C</tt>
2255 need to have the same semantics or the core LLVM "replace all uses with"
2256 concept would not hold.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2257
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2258<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2259 %A = fdiv undef, %X
2260 %B = fdiv %X, undef
2261Safe:
2262 %A = undef
2263b: unreachable
2264</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2265
2266<p>These examples show the crucial difference between an <em>undefined
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2267 value</em> and <em>undefined behavior</em>. An undefined value (like
2268 '<tt>undef</tt>') is allowed to have an arbitrary bit-pattern. This means that
2269 the <tt>%A</tt> operation can be constant folded to '<tt>undef</tt>', because
2270 the '<tt>undef</tt>' could be an SNaN, and <tt>fdiv</tt> is not (currently)
2271 defined on SNaN's. However, in the second example, we can make a more
2272 aggressive assumption: because the <tt>undef</tt> is allowed to be an
2273 arbitrary value, we are allowed to assume that it could be zero. Since a
2274 divide by zero has <em>undefined behavior</em>, we are allowed to assume that
2275 the operation does not execute at all. This allows us to delete the divide and
2276 all code after it. Because the undefined operation "can't happen", the
2277 optimizer can assume that it occurs in dead code.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2278
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2279<pre class="doc_code">
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2280a: store undef -> %X
2281b: store %X -> undef
2282Safe:
2283a: &lt;deleted&gt;
2284b: unreachable
2285</pre>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2286
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2287<p>These examples reiterate the <tt>fdiv</tt> example: a store <em>of</em> an
2288 undefined value can be assumed to not have any effect; we can assume that the
2289 value is overwritten with bits that happen to match what was already there.
2290 However, a store <em>to</em> an undefined location could clobber arbitrary
2291 memory, therefore, it has undefined behavior.</p>
Chris Lattnera34a7182009-09-07 23:33:52 +0000[diff] [blame]2292
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2293</div>
2294
2295<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2296<h3>
2297 <a name="trapvalues">Trap Values</a>
2298</h3>
2299
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2300<div>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2301
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2302<p>Trap values are similar to <a href="#undefvalues">undef values</a>, however
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2303 instead of representing an unspecified bit pattern, they represent the
2304 fact that an instruction or constant expression which cannot evoke side
2305 effects has nevertheless detected a condition which results in undefined
Dan Gohmanb2a709b2010-04-26 20:21:21 +0000[diff] [blame]2306 behavior.</p>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2307
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2308<p>There is currently no way of representing a trap value in the IR; they
Dan Gohmanac355aa2010-05-03 14:51:43 +0000[diff] [blame]2309 only exist when produced by operations such as
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2310 <a href="#i_add"><tt>add</tt></a> with the <tt>nsw</tt> flag.</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2311
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2312<p>Trap value behavior is defined in terms of value <i>dependence</i>:</p>
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2313
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2314<ul>
2315<li>Values other than <a href="#i_phi"><tt>phi</tt></a> nodes depend on
2316 their operands.</li>
2317
2318<li><a href="#i_phi"><tt>Phi</tt></a> nodes depend on the operand corresponding
2319 to their dynamic predecessor basic block.</li>
2320
2321<li>Function arguments depend on the corresponding actual argument values in
2322 the dynamic callers of their functions.</li>
2323
2324<li><a href="#i_call"><tt>Call</tt></a> instructions depend on the
2325 <a href="#i_ret"><tt>ret</tt></a> instructions that dynamically transfer
2326 control back to them.</li>
2327
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2328<li><a href="#i_invoke"><tt>Invoke</tt></a> instructions depend on the
2329 <a href="#i_ret"><tt>ret</tt></a>, <a href="#i_unwind"><tt>unwind</tt></a>,
2330 or exception-throwing call instructions that dynamically transfer control
2331 back to them.</li>
2332
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2333<li>Non-volatile loads and stores depend on the most recent stores to all of the
2334 referenced memory addresses, following the order in the IR
2335 (including loads and stores implied by intrinsics such as
2336 <a href="#int_memcpy"><tt>@llvm.memcpy</tt></a>.)</li>
2337
Dan Gohman3513ea52010-05-03 14:59:34 +0000[diff] [blame]2338<!-- TODO: In the case of multiple threads, this only applies if the store
2339 "happens-before" the load or store. -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2340
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2341<!-- TODO: floating-point exception state -->
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2342
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2343<li>An instruction with externally visible side effects depends on the most
2344 recent preceding instruction with externally visible side effects, following
Dan Gohman6c858db2010-07-06 15:26:33 +0000[diff] [blame]2345 the order in the IR. (This includes
2346 <a href="#volatile">volatile operations</a>.)</li>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2347
Dan Gohman7292a752010-05-03 14:55:22 +0000[diff] [blame]2348<li>An instruction <i>control-depends</i> on a
2349 <a href="#terminators">terminator instruction</a>
2350 if the terminator instruction has multiple successors and the instruction
2351 is always executed when control transfers to one of the successors, and
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2352 may not be executed when control is transferred to another.</li>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2353
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2354<li>Additionally, an instruction also <i>control-depends</i> on a terminator
2355 instruction if the set of instructions it otherwise depends on would be
Chris Lattner0ab5e2c2011-04-15 05:18:47 +0000[diff] [blame]2356 different if the terminator had transferred control to a different
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2357 successor.</li>
2358
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2359<li>Dependence is transitive.</li>
2360
2361</ul>
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2362
2363<p>Whenever a trap value is generated, all values which depend on it evaluate
2364 to trap. If they have side effects, the evoke their side effects as if each
2365 operand with a trap value were undef. If they have externally-visible side
2366 effects, the behavior is undefined.</p>
2367
2368<p>Here are some examples:</p>
Dan Gohman48a25882010-04-26 20:54:53 +0000[diff] [blame]2369
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2370<pre class="doc_code">
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2371entry:
2372 %trap = sub nuw i32 0, 1 ; Results in a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2373 %still_trap = and i32 %trap, 0 ; Whereas (and i32 undef, 0) would return 0.
2374 %trap_yet_again = getelementptr i32* @h, i32 %still_trap
2375 store i32 0, i32* %trap_yet_again ; undefined behavior
2376
2377 store i32 %trap, i32* @g ; Trap value conceptually stored to memory.
2378 %trap2 = load i32* @g ; Returns a trap value, not just undef.
2379
2380 volatile store i32 %trap, i32* @g ; External observation; undefined behavior.
2381
2382 %narrowaddr = bitcast i32* @g to i16*
2383 %wideaddr = bitcast i32* @g to i64*
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2384 %trap3 = load i16* %narrowaddr ; Returns a trap value.
2385 %trap4 = load i64* %wideaddr ; Returns a trap value.
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2386
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2387 %cmp = icmp slt i32 %trap, 0 ; Returns a trap value.
2388 br i1 %cmp, label %true, label %end ; Branch to either destination.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2389
2390true:
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2391 volatile store i32 0, i32* @g ; This is control-dependent on %cmp, so
2392 ; it has undefined behavior.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2393 br label %end
2394
2395end:
2396 %p = phi i32 [ 0, %entry ], [ 1, %true ]
2397 ; Both edges into this PHI are
2398 ; control-dependent on %cmp, so this
Dan Gohman2f1ae062010-04-28 00:49:41 +0000[diff] [blame]2399 ; always results in a trap value.
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2400
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2401 volatile store i32 0, i32* @g ; This would depend on the store in %true
2402 ; if %cmp is true, or the store in %entry
2403 ; otherwise, so this is undefined behavior.
2404
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2405 br i1 %cmp, label %second_true, label %second_end
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2406 ; The same branch again, but this time the
2407 ; true block doesn't have side effects.
2408
2409second_true:
2410 ; No side effects!
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2411 ret void
Dan Gohmanc8454ee2011-04-12 23:05:59 +0000[diff] [blame]2412
2413second_end:
2414 volatile store i32 0, i32* @g ; This time, the instruction always depends
2415 ; on the store in %end. Also, it is
2416 ; control-equivalent to %end, so this is
Nick Lewycky9c876bf2011-05-16 19:29:30 +0000[diff] [blame]2417 ; well-defined (again, ignoring earlier
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2418 ; undefined behavior in this example).
Dan Gohmanb8b85c12010-04-26 23:36:52 +0000[diff] [blame]2419</pre>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2420
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]2421</div>
2422
2423<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2424<h3>
2425 <a name="blockaddress">Addresses of Basic Blocks</a>
2426</h3>
2427
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2428<div>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2429
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2430<p><b><tt>blockaddress(@function, %block)</tt></b></p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2431
2432<p>The '<tt>blockaddress</tt>' constant computes the address of the specified
Chris Lattner5c5f0ac2009-10-27 21:49:40 +0000[diff] [blame]2433 basic block in the specified function, and always has an i8* type. Taking
Chris Lattneraa99c942009-11-01 01:27:45 +0000[diff] [blame]2434 the address of the entry block is illegal.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2435
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2436<p>This value only has defined behavior when used as an operand to the
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2437 '<a href="#i_indirectbr"><tt>indirectbr</tt></a>' instruction, or for
2438 comparisons against null. Pointer equality tests between labels addresses
2439 results in undefined behavior &mdash; though, again, comparison against null
2440 is ok, and no label is equal to the null pointer. This may be passed around
2441 as an opaque pointer sized value as long as the bits are not inspected. This
2442 allows <tt>ptrtoint</tt> and arithmetic to be performed on these values so
2443 long as the original value is reconstituted before the <tt>indirectbr</tt>
2444 instruction.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]2445
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2446<p>Finally, some targets may provide defined semantics when using the value as
2447 the operand to an inline assembly, but that is target specific.</p>
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]2448
2449</div>
2450
2451
2452<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2453<h3>
2454 <a name="constantexprs">Constant Expressions</a>
2455</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2456
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2457<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2458
2459<p>Constant expressions are used to allow expressions involving other constants
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2460 to be used as constants. Constant expressions may be of
2461 any <a href="#t_firstclass">first class</a> type and may involve any LLVM
2462 operation that does not have side effects (e.g. load and call are not
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]2463 supported). The following is the syntax for constant expressions:</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2464
2465<dl>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2466 <dt><b><tt>trunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2467 <dd>Truncate a constant to another type. The bit size of CST must be larger
2468 than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2469
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2470 <dt><b><tt>zext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2471 <dd>Zero extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2472 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2473
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2474 <dt><b><tt>sext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2475 <dd>Sign extend a constant to another type. The bit size of CST must be
Duncan Sandsa522e562010-07-13 12:06:14 +0000[diff] [blame]2476 smaller than the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2477
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2478 <dt><b><tt>fptrunc (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2479 <dd>Truncate a floating point constant to another floating point type. The
2480 size of CST must be larger than the size of TYPE. Both types must be
2481 floating point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2482
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2483 <dt><b><tt>fpext (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2484 <dd>Floating point extend a constant to another type. The size of CST must be
2485 smaller or equal to the size of TYPE. Both types must be floating
2486 point.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2487
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2488 <dt><b><tt>fptoui (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2489 <dd>Convert a floating point constant to the corresponding unsigned integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2490 constant. TYPE must be a scalar or vector integer type. CST must be of
2491 scalar or vector floating point type. Both CST and TYPE must be scalars,
2492 or vectors of the same number of elements. If the value won't fit in the
2493 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2494
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2495 <dt><b><tt>fptosi (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2496 <dd>Convert a floating point constant to the corresponding signed integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2497 constant. TYPE must be a scalar or vector integer type. CST must be of
2498 scalar or vector floating point type. Both CST and TYPE must be scalars,
2499 or vectors of the same number of elements. If the value won't fit in the
2500 integer type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2501
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2502 <dt><b><tt>uitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2503 <dd>Convert an unsigned integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2504 constant. TYPE must be a scalar or vector floating point type. CST must be
2505 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2506 vectors of the same number of elements. If the value won't fit in the
2507 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2508
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2509 <dt><b><tt>sitofp (CST to TYPE)</tt></b></dt>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2510 <dd>Convert a signed integer constant to the corresponding floating point
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2511 constant. TYPE must be a scalar or vector floating point type. CST must be
2512 of scalar or vector integer type. Both CST and TYPE must be scalars, or
2513 vectors of the same number of elements. If the value won't fit in the
2514 floating point type, the results are undefined.</dd>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]2515
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2516 <dt><b><tt>ptrtoint (CST to TYPE)</tt></b></dt>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2517 <dd>Convert a pointer typed constant to the corresponding integer constant
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2518 <tt>TYPE</tt> must be an integer type. <tt>CST</tt> must be of pointer
2519 type. The <tt>CST</tt> value is zero extended, truncated, or unchanged to
2520 make it fit in <tt>TYPE</tt>.</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2521
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2522 <dt><b><tt>inttoptr (CST to TYPE)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2523 <dd>Convert a integer constant to a pointer constant. TYPE must be a pointer
2524 type. CST must be of integer type. The CST value is zero extended,
2525 truncated, or unchanged to make it fit in a pointer size. This one is
2526 <i>really</i> dangerous!</dd>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]2527
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2528 <dt><b><tt>bitcast (CST to TYPE)</tt></b></dt>
Chris Lattner789dee32009-02-28 18:27:03 +0000[diff] [blame]2529 <dd>Convert a constant, CST, to another TYPE. The constraints of the operands
2530 are the same as those for the <a href="#i_bitcast">bitcast
2531 instruction</a>.</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2532
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2533 <dt><b><tt>getelementptr (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
2534 <dt><b><tt>getelementptr inbounds (CSTPTR, IDX0, IDX1, ...)</tt></b></dt>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2535 <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2536 constants. As with the <a href="#i_getelementptr">getelementptr</a>
2537 instruction, the index list may have zero or more indexes, which are
2538 required to make sense for the type of "CSTPTR".</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2539
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2540 <dt><b><tt>select (COND, VAL1, VAL2)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2541 <dd>Perform the <a href="#i_select">select operation</a> on constants.</dd>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2542
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2543 <dt><b><tt>icmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2544 <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
2545
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2546 <dt><b><tt>fcmp COND (VAL1, VAL2)</tt></b></dt>
Reid Spencer9965ee72006-12-04 19:23:19 +0000[diff] [blame]2547 <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2548
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2549 <dt><b><tt>extractelement (VAL, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2550 <dd>Perform the <a href="#i_extractelement">extractelement operation</a> on
2551 constants.</dd>
Robert Bocchino7e97a6d2006-01-10 19:31:34 +0000[diff] [blame]2552
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2553 <dt><b><tt>insertelement (VAL, ELT, IDX)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2554 <dd>Perform the <a href="#i_insertelement">insertelement operation</a> on
2555 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2556
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2557 <dt><b><tt>shufflevector (VEC1, VEC2, IDXMASK)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2558 <dd>Perform the <a href="#i_shufflevector">shufflevector operation</a> on
2559 constants.</dd>
Chris Lattner016a0e52006-04-08 00:13:41 +0000[diff] [blame]2560
Nick Lewycky9ab9a7f2010-05-29 06:44:15 +0000[diff] [blame]2561 <dt><b><tt>extractvalue (VAL, IDX0, IDX1, ...)</tt></b></dt>
2562 <dd>Perform the <a href="#i_extractvalue">extractvalue operation</a> on
2563 constants. The index list is interpreted in a similar manner as indices in
2564 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2565 index value must be specified.</dd>
2566
2567 <dt><b><tt>insertvalue (VAL, ELT, IDX0, IDX1, ...)</tt></b></dt>
2568 <dd>Perform the <a href="#i_insertvalue">insertvalue operation</a> on
2569 constants. The index list is interpreted in a similar manner as indices in
2570 a '<a href="#i_getelementptr">getelementptr</a>' operation. At least one
2571 index value must be specified.</dd>
2572
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]2573 <dt><b><tt>OPCODE (LHS, RHS)</tt></b></dt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2574 <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
2575 be any of the <a href="#binaryops">binary</a>
2576 or <a href="#bitwiseops">bitwise binary</a> operations. The constraints
2577 on operands are the same as those for the corresponding instruction
2578 (e.g. no bitwise operations on floating point values are allowed).</dd>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2579</dl>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2580
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2581</div>
Chris Lattnerb1652612004-03-08 16:49:10 +0000[diff] [blame]2582
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2583</div>
2584
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2585<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2586<h2><a name="othervalues">Other Values</a></h2>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2587<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2588<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2589<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2590<h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2591<a name="inlineasm">Inline Assembler Expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2592</h3>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2593
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2594<div>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2595
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2596<p>LLVM supports inline assembler expressions (as opposed
2597 to <a href="#moduleasm"> Module-Level Inline Assembly</a>) through the use of
2598 a special value. This value represents the inline assembler as a string
2599 (containing the instructions to emit), a list of operand constraints (stored
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2600 as a string), a flag that indicates whether or not the inline asm
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2601 expression has side effects, and a flag indicating whether the function
2602 containing the asm needs to align its stack conservatively. An example
2603 inline assembler expression is:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2604
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2605<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2606i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2607</pre>
2608
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2609<p>Inline assembler expressions may <b>only</b> be used as the callee operand of
2610 a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we
2611 have:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2612
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2613<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2614%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2615</pre>
2616
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2617<p>Inline asms with side effects not visible in the constraint list must be
2618 marked as having side effects. This is done through the use of the
2619 '<tt>sideeffect</tt>' keyword, like so:</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2620
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2621<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]2622call void asm sideeffect "eieio", ""()
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2623</pre>
2624
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2625<p>In some cases inline asms will contain code that will not work unless the
2626 stack is aligned in some way, such as calls or SSE instructions on x86,
2627 yet will not contain code that does that alignment within the asm.
2628 The compiler should make conservative assumptions about what the asm might
2629 contain and should generate its usual stack alignment code in the prologue
2630 if the '<tt>alignstack</tt>' keyword is present:</p>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2631
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2632<pre class="doc_code">
Dale Johannesen1cfb9582009-10-21 23:28:00 +0000[diff] [blame]2633call void asm alignstack "eieio", ""()
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2634</pre>
Dale Johannesen63c94fe2009-10-13 21:56:55 +0000[diff] [blame]2635
2636<p>If both keywords appear the '<tt>sideeffect</tt>' keyword must come
2637 first.</p>
2638
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2639<p>TODO: The format of the asm and constraints string still need to be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2640 documented here. Constraints on what can be done (e.g. duplication, moving,
2641 etc need to be documented). This is probably best done by reference to
2642 another document that covers inline asm from a holistic perspective.</p>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2643
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2644<h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2645<a name="inlineasm_md">Inline Asm Metadata</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2646</h4>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2647
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2648<div>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2649
2650<p>The call instructions that wrap inline asm nodes may have a "!srcloc" MDNode
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2651 attached to it that contains a list of constant integers. If present, the
2652 code generator will use the integer as the location cookie value when report
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2653 errors through the LLVMContext error reporting mechanisms. This allows a
Dan Gohman61110ae2010-04-28 00:36:01 +0000[diff] [blame]2654 front-end to correlate backend errors that occur with inline asm back to the
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2655 source code that produced it. For example:</p>
2656
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2657<pre class="doc_code">
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2658call void asm sideeffect "something bad", ""()<b>, !srcloc !42</b>
2659...
2660!42 = !{ i32 1234567 }
2661</pre>
Chris Lattner51065562010-04-07 05:38:05 +0000[diff] [blame]2662
2663<p>It is up to the front-end to make sense of the magic numbers it places in the
Chris Lattner79ffdc72010-11-17 08:20:42 +0000[diff] [blame]2664 IR. If the MDNode contains multiple constants, the code generator will use
2665 the one that corresponds to the line of the asm that the error occurs on.</p>
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2666
2667</div>
2668
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2669</div>
2670
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2671<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2672<h3>
2673 <a name="metadata">Metadata Nodes and Metadata Strings</a>
2674</h3>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2675
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2676<div>
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2677
2678<p>LLVM IR allows metadata to be attached to instructions in the program that
2679 can convey extra information about the code to the optimizers and code
2680 generator. One example application of metadata is source-level debug
2681 information. There are two metadata primitives: strings and nodes. All
2682 metadata has the <tt>metadata</tt> type and is identified in syntax by a
2683 preceding exclamation point ('<tt>!</tt>').</p>
2684
2685<p>A metadata string is a string surrounded by double quotes. It can contain
2686 any character by escaping non-printable characters with "\xx" where "xx" is
2687 the two digit hex code. For example: "<tt>!"test\00"</tt>".</p>
2688
2689<p>Metadata nodes are represented with notation similar to structure constants
2690 (a comma separated list of elements, surrounded by braces and preceded by an
2691 exclamation point). For example: "<tt>!{ metadata !"test\00", i32
2692 10}</tt>". Metadata nodes can have any values as their operand.</p>
2693
2694<p>A <a href="#namedmetadatastructure">named metadata</a> is a collection of
2695 metadata nodes, which can be looked up in the module symbol table. For
2696 example: "<tt>!foo = metadata !{!4, !3}</tt>".
2697
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2698<p>Metadata can be used as function arguments. Here <tt>llvm.dbg.value</tt>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2699 function is using two metadata arguments.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2700
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2701<div class="doc_code">
2702<pre>
2703call void @llvm.dbg.value(metadata !24, i64 0, metadata !25)
2704</pre>
2705</div>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2706
2707<p>Metadata can be attached with an instruction. Here metadata <tt>!21</tt> is
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]2708 attached with <tt>add</tt> instruction using <tt>!dbg</tt> identifier.</p>
Devang Patel9984bd62010-03-04 23:44:48 +0000[diff] [blame]2709
Bill Wendlingc0e10672011-03-02 02:17:11 +0000[diff] [blame]2710<div class="doc_code">
2711<pre>
2712%indvar.next = add i64 %indvar, 1, !dbg !21
2713</pre>
2714</div>
2715
Chris Lattnerc2f8f162010-01-15 21:50:19 +0000[diff] [blame]2716</div>
2717
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2718</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2719
2720<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2721<h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2722 <a name="intrinsic_globals">Intrinsic Global Variables</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2723</h2>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2724<!-- *********************************************************************** -->
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2725<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2726<p>LLVM has a number of "magic" global variables that contain data that affect
2727code generation or other IR semantics. These are documented here. All globals
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2728of this sort should have a section specified as "<tt>llvm.metadata</tt>". This
2729section and all globals that start with "<tt>llvm.</tt>" are reserved for use
2730by LLVM.</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2731
2732<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2733<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2734<a name="intg_used">The '<tt>llvm.used</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2735</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2736
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2737<div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2738
2739<p>The <tt>@llvm.used</tt> global is an array with i8* element type which has <a
2740href="#linkage_appending">appending linkage</a>. This array contains a list of
2741pointers to global variables and functions which may optionally have a pointer
2742cast formed of bitcast or getelementptr. For example, a legal use of it is:</p>
2743
2744<pre>
2745 @X = global i8 4
2746 @Y = global i32 123
2747
2748 @llvm.used = appending global [2 x i8*] [
2749 i8* @X,
2750 i8* bitcast (i32* @Y to i8*)
2751 ], section "llvm.metadata"
2752</pre>
2753
2754<p>If a global variable appears in the <tt>@llvm.used</tt> list, then the
2755compiler, assembler, and linker are required to treat the symbol as if there is
2756a reference to the global that it cannot see. For example, if a variable has
2757internal linkage and no references other than that from the <tt>@llvm.used</tt>
2758list, it cannot be deleted. This is commonly used to represent references from
2759inline asms and other things the compiler cannot "see", and corresponds to
2760"attribute((used))" in GNU C.</p>
2761
2762<p>On some targets, the code generator must emit a directive to the assembler or
2763object file to prevent the assembler and linker from molesting the symbol.</p>
2764
2765</div>
2766
2767<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2768<h3>
2769 <a name="intg_compiler_used">
2770 The '<tt>llvm.compiler.used</tt>' Global Variable
2771 </a>
2772</h3>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2773
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2774<div>
Chris Lattner58f9bb22009-07-20 06:14:25 +0000[diff] [blame]2775
2776<p>The <tt>@llvm.compiler.used</tt> directive is the same as the
2777<tt>@llvm.used</tt> directive, except that it only prevents the compiler from
2778touching the symbol. On targets that support it, this allows an intelligent
2779linker to optimize references to the symbol without being impeded as it would be
2780by <tt>@llvm.used</tt>.</p>
2781
2782<p>This is a rare construct that should only be used in rare circumstances, and
2783should not be exposed to source languages.</p>
2784
2785</div>
2786
2787<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2788<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2789<a name="intg_global_ctors">The '<tt>llvm.global_ctors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2790</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2791
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2792<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2793<pre>
2794%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2795@llvm.global_ctors = appending global [1 x %0] [%0 { i32 65535, void ()* @ctor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2796</pre>
2797<p>The <tt>@llvm.global_ctors</tt> array contains a list of constructor functions and associated priorities. The functions referenced by this array will be called in ascending order of priority (i.e. lowest first) when the module is loaded. The order of functions with the same priority is not defined.
2798</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2799
2800</div>
2801
2802<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2803<h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2804<a name="intg_global_dtors">The '<tt>llvm.global_dtors</tt>' Global Variable</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2805</h3>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2806
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2807<div>
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2808<pre>
2809%0 = type { i32, void ()* }
David Chisnallb492b812010-04-30 19:27:35 +0000[diff] [blame]2810@llvm.global_dtors = appending global [1 x %0] [%0 { i32 65535, void ()* @dtor }]
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2811</pre>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2812
David Chisnalla9d4a6f2010-04-30 19:23:49 +0000[diff] [blame]2813<p>The <tt>@llvm.global_dtors</tt> array contains a list of destructor functions and associated priorities. The functions referenced by this array will be called in descending order of priority (i.e. highest first) when the module is loaded. The order of functions with the same priority is not defined.
2814</p>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2815
2816</div>
2817
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2818</div>
Chris Lattnerae76db52009-07-20 05:55:19 +0000[diff] [blame]2819
Chris Lattner98f013c2006-01-25 23:47:57 +0000[diff] [blame]2820<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2821<h2><a name="instref">Instruction Reference</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2822<!-- *********************************************************************** -->
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2823
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2824<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2825
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2826<p>The LLVM instruction set consists of several different classifications of
2827 instructions: <a href="#terminators">terminator
2828 instructions</a>, <a href="#binaryops">binary instructions</a>,
2829 <a href="#bitwiseops">bitwise binary instructions</a>,
2830 <a href="#memoryops">memory instructions</a>, and
2831 <a href="#otherops">other instructions</a>.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2832
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2833<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2834<h3>
2835 <a name="terminators">Terminator Instructions</a>
2836</h3>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2837
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2838<div>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2839
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2840<p>As mentioned <a href="#functionstructure">previously</a>, every basic block
2841 in a program ends with a "Terminator" instruction, which indicates which
2842 block should be executed after the current block is finished. These
2843 terminator instructions typically yield a '<tt>void</tt>' value: they produce
2844 control flow, not values (the one exception being the
2845 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
2846
Duncan Sands626b0242010-04-15 20:35:54 +0000[diff] [blame]2847<p>There are seven different terminator instructions: the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2848 '<a href="#i_ret"><tt>ret</tt></a>' instruction, the
2849 '<a href="#i_br"><tt>br</tt></a>' instruction, the
2850 '<a href="#i_switch"><tt>switch</tt></a>' instruction, the
Bill Wendling33fef7e2009-11-02 00:25:26 +0000[diff] [blame]2851 '<a href="#i_indirectbr">'<tt>indirectbr</tt></a>' Instruction, the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2852 '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the
2853 '<a href="#i_unwind"><tt>unwind</tt></a>' instruction, and the
2854 '<a href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner74d3f822004-12-09 17:30:23 +0000[diff] [blame]2855
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2856<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2857<h4>
2858 <a name="i_ret">'<tt>ret</tt>' Instruction</a>
2859</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2860
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2861<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2862
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2863<h5>Syntax:</h5>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2864<pre>
2865 ret &lt;type&gt; &lt;value&gt; <i>; Return a value from a non-void function</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2866 ret void <i>; Return from void function</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2867</pre>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2868
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2869<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2870<p>The '<tt>ret</tt>' instruction is used to return control flow (and optionally
2871 a value) from a function back to the caller.</p>
2872
2873<p>There are two forms of the '<tt>ret</tt>' instruction: one that returns a
2874 value and then causes control flow, and one that just causes control flow to
2875 occur.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2876
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2877<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2878<p>The '<tt>ret</tt>' instruction optionally accepts a single argument, the
2879 return value. The type of the return value must be a
2880 '<a href="#t_firstclass">first class</a>' type.</p>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]2881
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2882<p>A function is not <a href="#wellformed">well formed</a> if it it has a
2883 non-void return type and contains a '<tt>ret</tt>' instruction with no return
2884 value or a return value with a type that does not match its type, or if it
2885 has a void return type and contains a '<tt>ret</tt>' instruction with a
2886 return value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2887
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2888<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2889<p>When the '<tt>ret</tt>' instruction is executed, control flow returns back to
2890 the calling function's context. If the caller is a
2891 "<a href="#i_call"><tt>call</tt></a>" instruction, execution continues at the
2892 instruction after the call. If the caller was an
2893 "<a href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues at
2894 the beginning of the "normal" destination block. If the instruction returns
2895 a value, that value shall set the call or invoke instruction's return
2896 value.</p>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2897
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2898<h5>Example:</h5>
Chris Lattnerda508ac2008-04-23 04:59:35 +0000[diff] [blame]2899<pre>
2900 ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]2901 ret void <i>; Return from a void function</i>
Bill Wendling050ee8f2009-02-28 22:12:54 +0000[diff] [blame]2902 ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2903</pre>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]2904
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2905</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2906<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2907<h4>
2908 <a name="i_br">'<tt>br</tt>' Instruction</a>
2909</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2910
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2911<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2912
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2913<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2914<pre>
2915 br i1 &lt;cond&gt;, label &lt;iftrue&gt;, label &lt;iffalse&gt;<br> br label &lt;dest&gt; <i>; Unconditional branch</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2916</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2917
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2918<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2919<p>The '<tt>br</tt>' instruction is used to cause control flow to transfer to a
2920 different basic block in the current function. There are two forms of this
2921 instruction, corresponding to a conditional branch and an unconditional
2922 branch.</p>
2923
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2924<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2925<p>The conditional branch form of the '<tt>br</tt>' instruction takes a single
2926 '<tt>i1</tt>' value and two '<tt>label</tt>' values. The unconditional form
2927 of the '<tt>br</tt>' instruction takes a single '<tt>label</tt>' value as a
2928 target.</p>
2929
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2930<h5>Semantics:</h5>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2931<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2932 argument is evaluated. If the value is <tt>true</tt>, control flows to the
2933 '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
2934 control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
2935
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2936<h5>Example:</h5>
Bill Wendling30235112009-07-20 02:39:26 +0000[diff] [blame]2937<pre>
2938Test:
2939 %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b
2940 br i1 %cond, label %IfEqual, label %IfUnequal
2941IfEqual:
2942 <a href="#i_ret">ret</a> i32 1
2943IfUnequal:
2944 <a href="#i_ret">ret</a> i32 0
2945</pre>
2946
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]2947</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2948
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2949<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2950<h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2951 <a name="i_switch">'<tt>switch</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]2952</h4>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2953
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]2954<div>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2955
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2956<h5>Syntax:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2957<pre>
2958 switch &lt;intty&gt; &lt;value&gt;, label &lt;defaultdest&gt; [ &lt;intty&gt; &lt;val&gt;, label &lt;dest&gt; ... ]
2959</pre>
2960
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2961<h5>Overview:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2962<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2963 several different places. It is a generalization of the '<tt>br</tt>'
2964 instruction, allowing a branch to occur to one of many possible
2965 destinations.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2967<h5>Arguments:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2968<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2969 comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination,
2970 and an array of pairs of comparison value constants and '<tt>label</tt>'s.
2971 The table is not allowed to contain duplicate constant entries.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2972
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2973<h5>Semantics:</h5>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]2974<p>The <tt>switch</tt> instruction specifies a table of values and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2975 destinations. When the '<tt>switch</tt>' instruction is executed, this table
2976 is searched for the given value. If the value is found, control flow is
Benjamin Kramer0f420382009-10-12 14:46:08 +0000[diff] [blame]2977 transferred to the corresponding destination; otherwise, control flow is
2978 transferred to the default destination.</p>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2979
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2980<h5>Implementation:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2981<p>Depending on properties of the target machine and the particular
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]2982 <tt>switch</tt> instruction, this instruction may be code generated in
2983 different ways. For example, it could be generated as a series of chained
2984 conditional branches or with a lookup table.</p>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2985
2986<h5>Example:</h5>
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2987<pre>
2988 <i>; Emulate a conditional br instruction</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]2989 %Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2990 switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2991
2992 <i>; Emulate an unconditional br instruction</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]2993 switch i32 0, label %dest [ ]
Chris Lattnercf96c6c2004-02-24 04:54:45 +0000[diff] [blame]2994
2995 <i>; Implement a jump table:</i>
Dan Gohman623806e2009-01-04 23:44:43 +0000[diff] [blame]2996 switch i32 %val, label %otherwise [ i32 0, label %onzero
2997 i32 1, label %onone
2998 i32 2, label %ontwo ]
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]2999</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3000
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3001</div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3002
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3003
3004<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3005<h4>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3006 <a name="i_indirectbr">'<tt>indirectbr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3007</h4>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3008
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3009<div>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3010
3011<h5>Syntax:</h5>
3012<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3013 indirectbr &lt;somety&gt;* &lt;address&gt;, [ label &lt;dest1&gt;, label &lt;dest2&gt;, ... ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3014</pre>
3015
3016<h5>Overview:</h5>
3017
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3018<p>The '<tt>indirectbr</tt>' instruction implements an indirect branch to a label
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3019 within the current function, whose address is specified by
Chris Lattnere4801f72009-10-27 21:01:34 +0000[diff] [blame]3020 "<tt>address</tt>". Address must be derived from a <a
3021 href="#blockaddress">blockaddress</a> constant.</p>
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3022
3023<h5>Arguments:</h5>
3024
3025<p>The '<tt>address</tt>' argument is the address of the label to jump to. The
3026 rest of the arguments indicate the full set of possible destinations that the
3027 address may point to. Blocks are allowed to occur multiple times in the
3028 destination list, though this isn't particularly useful.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3029
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3030<p>This destination list is required so that dataflow analysis has an accurate
3031 understanding of the CFG.</p>
3032
3033<h5>Semantics:</h5>
3034
3035<p>Control transfers to the block specified in the address argument. All
3036 possible destination blocks must be listed in the label list, otherwise this
3037 instruction has undefined behavior. This implies that jumps to labels
3038 defined in other functions have undefined behavior as well.</p>
3039
3040<h5>Implementation:</h5>
3041
3042<p>This is typically implemented with a jump through a register.</p>
3043
3044<h5>Example:</h5>
3045<pre>
Chris Lattnerd04cb6d2009-10-28 00:19:10 +0000[diff] [blame]3046 indirectbr i8* %Addr, [ label %bb1, label %bb2, label %bb3 ]
Chris Lattner3ed871f2009-10-27 19:13:16 +0000[diff] [blame]3047</pre>
3048
3049</div>
3050
3051
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3052<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3053<h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3054 <a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3055</h4>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3056
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3057<div>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3058
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3059<h5>Syntax:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3060<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3061 &lt;result&gt; = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ptr to function ty&gt; &lt;function ptr val&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner6b7a0082006-05-14 18:23:06 +0000[diff] [blame]3062 to label &lt;normal label&gt; unwind label &lt;exception label&gt;
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3063</pre>
3064
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]3065<h5>Overview:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3066<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3067 function, with the possibility of control flow transfer to either the
3068 '<tt>normal</tt>' label or the '<tt>exception</tt>' label. If the callee
3069 function returns with the "<tt><a href="#i_ret">ret</a></tt>" instruction,
3070 control flow will return to the "normal" label. If the callee (or any
3071 indirect callees) returns with the "<a href="#i_unwind"><tt>unwind</tt></a>"
3072 instruction, control is interrupted and continued at the dynamically nearest
3073 "exception" label.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3074
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3075<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3076<p>This instruction requires several arguments:</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3077
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3078<ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3079 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
3080 convention</a> the call should use. If none is specified, the call
3081 defaults to using C calling conventions.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3082
3083 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3084 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
3085 '<tt>inreg</tt>' attributes are valid here.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]3086
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3087 <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3088 function value being invoked. In most cases, this is a direct function
3089 invocation, but indirect <tt>invoke</tt>s are just as possible, branching
3090 off an arbitrary pointer to function value.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3091
3092 <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3093 function to be invoked. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3094
3095 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]3096 signature argument types and parameter attributes. All arguments must be
3097 of <a href="#t_firstclass">first class</a> type. If the function
3098 signature indicates the function accepts a variable number of arguments,
3099 the extra arguments can be specified.</li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3100
3101 <li>'<tt>normal label</tt>': the label reached when the called function
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3102 executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3103
3104 <li>'<tt>exception label</tt>': the label reached when a callee returns with
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3105 the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3106
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]3107 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3108 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
3109 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3110</ol>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3111
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3112<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3113<p>This instruction is designed to operate as a standard
3114 '<tt><a href="#i_call">call</a></tt>' instruction in most regards. The
3115 primary difference is that it establishes an association with a label, which
3116 is used by the runtime library to unwind the stack.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3117
3118<p>This instruction is used in languages with destructors to ensure that proper
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3119 cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
3120 exception. Additionally, this is important for implementation of
3121 '<tt>catch</tt>' clauses in high-level languages that support them.</p>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3122
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3123<p>For the purposes of the SSA form, the definition of the value returned by the
3124 '<tt>invoke</tt>' instruction is deemed to occur on the edge from the current
3125 block to the "normal" label. If the callee unwinds then no return value is
3126 available.</p>
Dan Gohman9069d892009-05-22 21:47:08 +0000[diff] [blame]3127
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3128<p>Note that the code generator does not yet completely support unwind, and
3129that the invoke/unwind semantics are likely to change in future versions.</p>
3130
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3131<h5>Example:</h5>
Chris Lattner0132aff2005-05-06 22:57:40 +0000[diff] [blame]3132<pre>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3133 %retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3134 unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky084ab472008-03-16 07:18:12 +0000[diff] [blame]3135 %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3136 unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3137</pre>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3138
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3139</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3140
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3141<!-- _______________________________________________________________________ -->
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3142
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3143<h4>
3144 <a name="i_unwind">'<tt>unwind</tt>' Instruction</a>
3145</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3146
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3147<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3148
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3149<h5>Syntax:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3150<pre>
3151 unwind
3152</pre>
3153
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3154<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3155<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3156 at the first callee in the dynamic call stack which used
3157 an <a href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call.
3158 This is primarily used to implement exception handling.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3159
Chris Lattner5ed60612003-09-03 00:41:47 +0000[diff] [blame]3160<h5>Semantics:</h5>
Chris Lattnerfe8519c2008-04-19 21:01:16 +0000[diff] [blame]3161<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3162 immediately halt. The dynamic call stack is then searched for the
3163 first <a href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack.
3164 Once found, execution continues at the "exceptional" destination block
3165 specified by the <tt>invoke</tt> instruction. If there is no <tt>invoke</tt>
3166 instruction in the dynamic call chain, undefined behavior results.</p>
3167
Chris Lattner97257f82010-01-15 18:08:37 +0000[diff] [blame]3168<p>Note that the code generator does not yet completely support unwind, and
3169that the invoke/unwind semantics are likely to change in future versions.</p>
3170
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3171</div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3172
3173<!-- _______________________________________________________________________ -->
3174
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3175<h4>
3176 <a name="i_unreachable">'<tt>unreachable</tt>' Instruction</a>
3177</h4>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3178
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3179<div>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3180
3181<h5>Syntax:</h5>
3182<pre>
3183 unreachable
3184</pre>
3185
3186<h5>Overview:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3187<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3188 instruction is used to inform the optimizer that a particular portion of the
3189 code is not reachable. This can be used to indicate that the code after a
3190 no-return function cannot be reached, and other facts.</p>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3191
3192<h5>Semantics:</h5>
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3193<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3194
Chris Lattner08b7d5b2004-10-16 18:04:13 +0000[diff] [blame]3195</div>
3196
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3197</div>
3198
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3199<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3200<h3>
3201 <a name="binaryops">Binary Operations</a>
3202</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3203
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3204<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3205
3206<p>Binary operators are used to do most of the computation in a program. They
3207 require two operands of the same type, execute an operation on them, and
3208 produce a single value. The operands might represent multiple data, as is
3209 the case with the <a href="#t_vector">vector</a> data type. The result value
3210 has the same type as its operands.</p>
3211
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3212<p>There are several different binary operators:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3213
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3214<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3215<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3216 <a name="i_add">'<tt>add</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3217</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3218
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3219<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3220
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3221<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3222<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3223 &lt;result&gt; = add &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3224 &lt;result&gt; = add nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3225 &lt;result&gt; = add nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3226 &lt;result&gt; = add nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3227</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3228
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3229<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3230<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3231
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3232<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3233<p>The two arguments to the '<tt>add</tt>' instruction must
3234 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3235 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3236
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3237<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3238<p>The value produced is the integer sum of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3239
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3240<p>If the sum has unsigned overflow, the result returned is the mathematical
3241 result modulo 2<sup>n</sup>, where n is the bit width of the result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3242
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3243<p>Because LLVM integers use a two's complement representation, this instruction
3244 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3245
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3246<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3247 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3248 <tt>nsw</tt> keywords are present, the result value of the <tt>add</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3249 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3250 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3251
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3252<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3253<pre>
3254 &lt;result&gt; = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3255</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3256
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3257</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3258
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3259<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3260<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3261 <a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3262</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3263
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3264<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3265
3266<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3267<pre>
3268 &lt;result&gt; = fadd &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3269</pre>
3270
3271<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3272<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
3273
3274<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3275<p>The two arguments to the '<tt>fadd</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3276 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3277 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3278
3279<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3280<p>The value produced is the floating point sum of the two operands.</p>
3281
3282<h5>Example:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3283<pre>
3284 &lt;result&gt; = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
3285</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3286
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3287</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3288
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3289<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3290<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3291 <a name="i_sub">'<tt>sub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3292</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3293
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3294<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3295
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3296<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3297<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3298 &lt;result&gt; = sub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3299 &lt;result&gt; = sub nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3300 &lt;result&gt; = sub nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3301 &lt;result&gt; = sub nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3302</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3303
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3304<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3305<p>The '<tt>sub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3306 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3307
3308<p>Note that the '<tt>sub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3309 '<tt>neg</tt>' instruction present in most other intermediate
3310 representations.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3311
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3312<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3313<p>The two arguments to the '<tt>sub</tt>' instruction must
3314 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3315 integer values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3316
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3317<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3318<p>The value produced is the integer difference of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3319
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3320<p>If the difference has unsigned overflow, the result returned is the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3321 mathematical result modulo 2<sup>n</sup>, where n is the bit width of the
3322 result.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3323
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3324<p>Because LLVM integers use a two's complement representation, this instruction
3325 is appropriate for both signed and unsigned integers.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3326
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3327<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3328 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3329 <tt>nsw</tt> keywords are present, the result value of the <tt>sub</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3330 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3331 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3332
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3333<h5>Example:</h5>
Bill Wendling2d8b9a82007-05-29 09:42:13 +0000[diff] [blame]3334<pre>
3335 &lt;result&gt; = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3336 &lt;result&gt; = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3337</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3338
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3339</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3340
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3341<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3342<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3343 <a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3344</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3345
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3346<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3347
3348<h5>Syntax:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3349<pre>
3350 &lt;result&gt; = fsub &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3351</pre>
3352
3353<h5>Overview:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3354<p>The '<tt>fsub</tt>' instruction returns the difference of its two
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3355 operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3356
3357<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3358 '<tt>fneg</tt>' instruction present in most other intermediate
3359 representations.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3360
3361<h5>Arguments:</h5>
Bill Wendling972b7202009-07-20 02:32:41 +0000[diff] [blame]3362<p>The two arguments to the '<tt>fsub</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3363 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3364 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3365
3366<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3367<p>The value produced is the floating point difference of the two operands.</p>
3368
3369<h5>Example:</h5>
3370<pre>
3371 &lt;result&gt; = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
3372 &lt;result&gt; = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
3373</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3374
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3375</div>
3376
3377<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3378<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3379 <a name="i_mul">'<tt>mul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3380</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3381
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3382<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3383
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3384<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3385<pre>
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3386 &lt;result&gt; = mul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3387 &lt;result&gt; = mul nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3388 &lt;result&gt; = mul nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3389 &lt;result&gt; = mul nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3390</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3391
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3392<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3393<p>The '<tt>mul</tt>' instruction returns the product of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3394
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3395<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3396<p>The two arguments to the '<tt>mul</tt>' instruction must
3397 be <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3398 integer values. Both arguments must have identical types.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3399
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3400<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3401<p>The value produced is the integer product of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3402
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3403<p>If the result of the multiplication has unsigned overflow, the result
3404 returned is the mathematical result modulo 2<sup>n</sup>, where n is the bit
3405 width of the result.</p>
3406
3407<p>Because LLVM integers use a two's complement representation, and the result
3408 is the same width as the operands, this instruction returns the correct
3409 result for both signed and unsigned integers. If a full product
3410 (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands should
3411 be sign-extended or zero-extended as appropriate to the width of the full
3412 product.</p>
3413
Dan Gohman902dfff2009-07-22 22:44:56 +0000[diff] [blame]3414<p><tt>nuw</tt> and <tt>nsw</tt> stand for &quot;No Unsigned Wrap&quot;
3415 and &quot;No Signed Wrap&quot;, respectively. If the <tt>nuw</tt> and/or
3416 <tt>nsw</tt> keywords are present, the result value of the <tt>mul</tt>
Dan Gohmanffc9a6b2010-04-22 23:14:21 +0000[diff] [blame]3417 is a <a href="#trapvalues">trap value</a> if unsigned and/or signed overflow,
3418 respectively, occurs.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3419
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3420<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3421<pre>
3422 &lt;result&gt; = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3423</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3424
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3425</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3426
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3427<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3428<h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3429 <a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3430</h4>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3431
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3432<div>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3433
3434<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3435<pre>
3436 &lt;result&gt; = fmul &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3437</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3438
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3439<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3440<p>The '<tt>fmul</tt>' instruction returns the product of its two operands.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3441
3442<h5>Arguments:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3443<p>The two arguments to the '<tt>fmul</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3444 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3445 floating point values. Both arguments must have identical types.</p>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3446
3447<h5>Semantics:</h5>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3448<p>The value produced is the floating point product of the two operands.</p>
3449
3450<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3451<pre>
3452 &lt;result&gt; = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3453</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3454
Dan Gohmana5b96452009-06-04 22:49:04 +0000[diff] [blame]3455</div>
3456
3457<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3458<h4>
3459 <a name="i_udiv">'<tt>udiv</tt>' Instruction</a>
3460</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3461
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3462<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3463
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3464<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3465<pre>
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3466 &lt;result&gt; = udiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3467 &lt;result&gt; = udiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3468</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3469
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3470<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3471<p>The '<tt>udiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3472
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3473<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3474<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3475 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3476 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3477
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3478<h5>Semantics:</h5>
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3479<p>The value produced is the unsigned integer quotient of the two operands.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3480
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3481<p>Note that unsigned integer division and signed integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3482 operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
3483
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3484<p>Division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3485
Chris Lattner35315d02011-02-06 21:44:57 +0000[diff] [blame]3486<p>If the <tt>exact</tt> keyword is present, the result value of the
3487 <tt>udiv</tt> is a <a href="#trapvalues">trap value</a> if %op1 is not a
3488 multiple of %op2 (as such, "((a udiv exact b) mul b) == a").</p>
3489
3490
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3491<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3492<pre>
3493 &lt;result&gt; = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3494</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3495
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3496</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3497
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3498<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3499<h4>
3500 <a name="i_sdiv">'<tt>sdiv</tt>' Instruction</a>
3501</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3502
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3503<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3504
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3505<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3506<pre>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3507 &lt;result&gt; = sdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Dan Gohman957b1312009-09-02 17:31:42 +0000[diff] [blame]3508 &lt;result&gt; = sdiv exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3509</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3510
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3511<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3512<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3513
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3514<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3515<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3516 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3517 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3518
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3519<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3520<p>The value produced is the signed integer quotient of the two operands rounded
3521 towards zero.</p>
3522
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3523<p>Note that signed integer division and unsigned integer division are distinct
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3524 operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
3525
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3526<p>Division by zero leads to undefined behavior. Overflow also leads to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3527 undefined behavior; this is a rare case, but can occur, for example, by doing
3528 a 32-bit division of -2147483648 by -1.</p>
3529
Dan Gohman71dfd782009-07-22 00:04:19 +0000[diff] [blame]3530<p>If the <tt>exact</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]3531 <tt>sdiv</tt> is a <a href="#trapvalues">trap value</a> if the result would
Dan Gohmane501ff72010-07-11 00:08:34 +0000[diff] [blame]3532 be rounded.</p>
Dan Gohmanb07de442009-07-20 22:41:19 +0000[diff] [blame]3533
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3534<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3535<pre>
3536 &lt;result&gt; = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3537</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3538
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3539</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3540
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3541<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3542<h4>
3543 <a name="i_fdiv">'<tt>fdiv</tt>' Instruction</a>
3544</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3545
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3546<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3547
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3548<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3549<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3550 &lt;result&gt; = fdiv &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3551</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3552
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3553<h5>Overview:</h5>
3554<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3555
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3556<h5>Arguments:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]3557<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3558 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3559 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3560
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3561<h5>Semantics:</h5>
Reid Spencer7e80b0b2006-10-26 06:15:43 +0000[diff] [blame]3562<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3563
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3564<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3565<pre>
3566 &lt;result&gt; = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3567</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3568
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3569</div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3570
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3571<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3572<h4>
3573 <a name="i_urem">'<tt>urem</tt>' Instruction</a>
3574</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3575
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3576<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3577
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3578<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3579<pre>
3580 &lt;result&gt; = urem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3581</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3582
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3583<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3584<p>The '<tt>urem</tt>' instruction returns the remainder from the unsigned
3585 division of its two arguments.</p>
3586
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3587<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3588<p>The two arguments to the '<tt>urem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3589 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3590 values. Both arguments must have identical types.</p>
3591
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3592<h5>Semantics:</h5>
3593<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3594 This instruction always performs an unsigned division to get the
3595 remainder.</p>
3596
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3597<p>Note that unsigned integer remainder and signed integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3598 distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
3599
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3600<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3601
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3602<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3603<pre>
3604 &lt;result&gt; = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3605</pre>
3606
3607</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3608
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3609<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3610<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3611 <a name="i_srem">'<tt>srem</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3612</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3613
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3614<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3615
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3616<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3617<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3618 &lt;result&gt; = srem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3619</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3620
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3621<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3622<p>The '<tt>srem</tt>' instruction returns the remainder from the signed
3623 division of its two operands. This instruction can also take
3624 <a href="#t_vector">vector</a> versions of the values in which case the
3625 elements must be integers.</p>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]3626
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3627<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3628<p>The two arguments to the '<tt>srem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3629 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3630 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3631
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3632<h5>Semantics:</h5>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3633<p>This instruction returns the <i>remainder</i> of a division (where the result
Duncan Sands2769c6e2011-03-07 09:12:24 +0000[diff] [blame]3634 is either zero or has the same sign as the dividend, <tt>op1</tt>), not the
3635 <i>modulo</i> operator (where the result is either zero or has the same sign
3636 as the divisor, <tt>op2</tt>) of a value.
3637 For more information about the difference,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3638 see <a href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
3639 Math Forum</a>. For a table of how this is implemented in various languages,
3640 please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
3641 Wikipedia: modulo operation</a>.</p>
3642
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3643<p>Note that signed integer remainder and unsigned integer remainder are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3644 distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
3645
Chris Lattner2f2427e2008-01-28 00:36:27 +0000[diff] [blame]3646<p>Taking the remainder of a division by zero leads to undefined behavior.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3647 Overflow also leads to undefined behavior; this is a rare case, but can
3648 occur, for example, by taking the remainder of a 32-bit division of
3649 -2147483648 by -1. (The remainder doesn't actually overflow, but this rule
3650 lets srem be implemented using instructions that return both the result of
3651 the division and the remainder.)</p>
3652
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3653<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3654<pre>
3655 &lt;result&gt; = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3656</pre>
3657
3658</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3659
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3660<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3661<h4>
3662 <a name="i_frem">'<tt>frem</tt>' Instruction</a>
3663</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3664
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3665<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3666
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3667<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3668<pre>
3669 &lt;result&gt; = frem &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3670</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3671
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3672<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3673<p>The '<tt>frem</tt>' instruction returns the remainder from the division of
3674 its two operands.</p>
3675
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3676<h5>Arguments:</h5>
3677<p>The two arguments to the '<tt>frem</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3678 <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
3679 floating point values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3680
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3681<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3682<p>This instruction returns the <i>remainder</i> of a division. The remainder
3683 has the same sign as the dividend.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3684
Reid Spencer7eb55b32006-11-02 01:53:59 +0000[diff] [blame]3685<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3686<pre>
3687 &lt;result&gt; = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3688</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3689
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3690</div>
Robert Bocchino820bc75b2006-02-17 21:18:08 +0000[diff] [blame]3691
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3692</div>
3693
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3694<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3695<h3>
3696 <a name="bitwiseops">Bitwise Binary Operations</a>
3697</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3698
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3699<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3700
3701<p>Bitwise binary operators are used to do various forms of bit-twiddling in a
3702 program. They are generally very efficient instructions and can commonly be
3703 strength reduced from other instructions. They require two operands of the
3704 same type, execute an operation on them, and produce a single value. The
3705 resulting value is the same type as its operands.</p>
3706
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3707<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3708<h4>
3709 <a name="i_shl">'<tt>shl</tt>' Instruction</a>
3710</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3711
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3712<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3713
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3714<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3715<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3716 &lt;result&gt; = shl &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3717 &lt;result&gt; = shl nuw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3718 &lt;result&gt; = shl nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3719 &lt;result&gt; = shl nuw nsw &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3720</pre>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3721
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3722<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3723<p>The '<tt>shl</tt>' instruction returns the first operand shifted to the left
3724 a specified number of bits.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3725
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3726<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3727<p>Both arguments to the '<tt>shl</tt>' instruction must be the
3728 same <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
3729 integer type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3730
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3731<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3732<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod
3733 2<sup>n</sup>, where <tt>n</tt> is the width of the result. If <tt>op2</tt>
3734 is (statically or dynamically) negative or equal to or larger than the number
3735 of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3736 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3737 shift amount in <tt>op2</tt>.</p>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3738
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3739<p>If the <tt>nuw</tt> keyword is present, then the shift produces a
3740 <a href="#trapvalues">trap value</a> if it shifts out any non-zero bits. If
Chris Lattnerf10dfdc2011-02-09 16:44:44 +0000[diff] [blame]3741 the <tt>nsw</tt> keyword is present, then the shift produces a
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3742 <a href="#trapvalues">trap value</a> if it shifts out any bits that disagree
3743 with the resultant sign bit. As such, NUW/NSW have the same semantics as
3744 they would if the shift were expressed as a mul instruction with the same
3745 nsw/nuw bits in (mul %op1, (shl 1, %op2)).</p>
3746
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3747<h5>Example:</h5>
3748<pre>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3749 &lt;result&gt; = shl i32 4, %var <i>; yields {i32}: 4 &lt;&lt; %var</i>
3750 &lt;result&gt; = shl i32 4, 2 <i>; yields {i32}: 16</i>
3751 &lt;result&gt; = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3752 &lt;result&gt; = shl i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3753 &lt;result&gt; = shl &lt;2 x i32&gt; &lt; i32 1, i32 1&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 2, i32 4&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3754</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3755
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3756</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3757
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3758<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3759<h4>
3760 <a name="i_lshr">'<tt>lshr</tt>' Instruction</a>
3761</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3763<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3764
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3765<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3766<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3767 &lt;result&gt; = lshr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3768 &lt;result&gt; = lshr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3769</pre>
3770
3771<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3772<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
3773 operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3774
3775<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3776<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3777 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3778 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3779
3780<h5>Semantics:</h5>
3781<p>This instruction always performs a logical shift right operation. The most
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3782 significant bits of the result will be filled with zero bits after the shift.
3783 If <tt>op2</tt> is (statically or dynamically) equal to or larger than the
3784 number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
3785 vectors, each vector element of <tt>op1</tt> is shifted by the corresponding
3786 shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3787
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3788<p>If the <tt>exact</tt> keyword is present, the result value of the
3789 <tt>lshr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3790 shifted out are non-zero.</p>
3791
3792
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3793<h5>Example:</h5>
3794<pre>
3795 &lt;result&gt; = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
3796 &lt;result&gt; = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
3797 &lt;result&gt; = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
3798 &lt;result&gt; = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3799 &lt;result&gt; = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3800 &lt;result&gt; = lshr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 2&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 0x7FFFFFFF, i32 1&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3801</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3802
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3803</div>
3804
Reid Spencer2ab01932007-02-02 13:57:07 +0000[diff] [blame]3805<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3806<h4>
3807 <a name="i_ashr">'<tt>ashr</tt>' Instruction</a>
3808</h4>
3809
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3810<div>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3811
3812<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3813<pre>
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3814 &lt;result&gt; = ashr &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3815 &lt;result&gt; = ashr exact &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3816</pre>
3817
3818<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3819<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
3820 operand shifted to the right a specified number of bits with sign
3821 extension.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3822
3823<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3824<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3825 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3826 type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3827
3828<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3829<p>This instruction always performs an arithmetic shift right operation, The
3830 most significant bits of the result will be filled with the sign bit
3831 of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
3832 larger than the number of bits in <tt>op1</tt>, the result is undefined. If
3833 the arguments are vectors, each vector element of <tt>op1</tt> is shifted by
3834 the corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3835
Chris Lattnera676c0f2011-02-07 16:40:21 +0000[diff] [blame]3836<p>If the <tt>exact</tt> keyword is present, the result value of the
3837 <tt>ashr</tt> is a <a href="#trapvalues">trap value</a> if any of the bits
3838 shifted out are non-zero.</p>
3839
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3840<h5>Example:</h5>
3841<pre>
3842 &lt;result&gt; = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
3843 &lt;result&gt; = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
3844 &lt;result&gt; = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
3845 &lt;result&gt; = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattnerf0e50112007-10-03 21:01:14 +0000[diff] [blame]3846 &lt;result&gt; = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang4dd832d2008-12-09 05:46:39 +0000[diff] [blame]3847 &lt;result&gt; = ashr &lt;2 x i32&gt; &lt; i32 -2, i32 4&gt;, &lt; i32 1, i32 3&gt; <i>; yields: result=&lt;2 x i32&gt; &lt; i32 -1, i32 0&gt;</i>
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3848</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3849
Reid Spencer04e259b2007-01-31 21:39:12 +0000[diff] [blame]3850</div>
3851
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3852<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3853<h4>
3854 <a name="i_and">'<tt>and</tt>' Instruction</a>
3855</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3856
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3857<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3858
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3859<h5>Syntax:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3860<pre>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]3861 &lt;result&gt; = and &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3862</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3863
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3864<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3865<p>The '<tt>and</tt>' instruction returns the bitwise logical and of its two
3866 operands.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3867
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3868<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3869<p>The two arguments to the '<tt>and</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3870 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3871 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3872
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3873<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3874<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3875
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3876<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3877 <tbody>
3878 <tr>
3879 <td>In0</td>
3880 <td>In1</td>
3881 <td>Out</td>
3882 </tr>
3883 <tr>
3884 <td>0</td>
3885 <td>0</td>
3886 <td>0</td>
3887 </tr>
3888 <tr>
3889 <td>0</td>
3890 <td>1</td>
3891 <td>0</td>
3892 </tr>
3893 <tr>
3894 <td>1</td>
3895 <td>0</td>
3896 <td>0</td>
3897 </tr>
3898 <tr>
3899 <td>1</td>
3900 <td>1</td>
3901 <td>1</td>
3902 </tr>
3903 </tbody>
3904</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3905
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3906<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3907<pre>
3908 &lt;result&gt; = and i32 4, %var <i>; yields {i32}:result = 4 &amp; %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3909 &lt;result&gt; = and i32 15, 40 <i>; yields {i32}:result = 8</i>
3910 &lt;result&gt; = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3911</pre>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3912</div>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3913<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3914<h4>
3915 <a name="i_or">'<tt>or</tt>' Instruction</a>
3916</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3917
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3918<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3919
3920<h5>Syntax:</h5>
3921<pre>
3922 &lt;result&gt; = or &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
3923</pre>
3924
3925<h5>Overview:</h5>
3926<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive or of its
3927 two operands.</p>
3928
3929<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3930<p>The two arguments to the '<tt>or</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3931 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3932 values. Both arguments must have identical types.</p>
3933
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3934<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3935<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3936
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]3937<table border="1" cellspacing="0" cellpadding="4">
3938 <tbody>
3939 <tr>
3940 <td>In0</td>
3941 <td>In1</td>
3942 <td>Out</td>
3943 </tr>
3944 <tr>
3945 <td>0</td>
3946 <td>0</td>
3947 <td>0</td>
3948 </tr>
3949 <tr>
3950 <td>0</td>
3951 <td>1</td>
3952 <td>1</td>
3953 </tr>
3954 <tr>
3955 <td>1</td>
3956 <td>0</td>
3957 <td>1</td>
3958 </tr>
3959 <tr>
3960 <td>1</td>
3961 <td>1</td>
3962 <td>1</td>
3963 </tr>
3964 </tbody>
3965</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3966
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3967<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3968<pre>
3969 &lt;result&gt; = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]3970 &lt;result&gt; = or i32 15, 40 <i>; yields {i32}:result = 47</i>
3971 &lt;result&gt; = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3972</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3973
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3974</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3975
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3976<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]3977<h4>
3978 <a name="i_xor">'<tt>xor</tt>' Instruction</a>
3979</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3980
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]3981<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3982
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3983<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3984<pre>
3985 &lt;result&gt; = xor &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {ty}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3986</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3987
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3988<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3989<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive or of
3990 its two operands. The <tt>xor</tt> is used to implement the "one's
3991 complement" operation, which is the "~" operator in C.</p>
3992
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3993<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]3994<p>The two arguments to the '<tt>xor</tt>' instruction must be
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]3995 <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
3996 values. Both arguments must have identical types.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]3997
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]3998<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]3999<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4000
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4001<table border="1" cellspacing="0" cellpadding="4">
4002 <tbody>
4003 <tr>
4004 <td>In0</td>
4005 <td>In1</td>
4006 <td>Out</td>
4007 </tr>
4008 <tr>
4009 <td>0</td>
4010 <td>0</td>
4011 <td>0</td>
4012 </tr>
4013 <tr>
4014 <td>0</td>
4015 <td>1</td>
4016 <td>1</td>
4017 </tr>
4018 <tr>
4019 <td>1</td>
4020 <td>0</td>
4021 <td>1</td>
4022 </tr>
4023 <tr>
4024 <td>1</td>
4025 <td>1</td>
4026 <td>0</td>
4027 </tr>
4028 </tbody>
4029</table>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4030
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4031<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4032<pre>
4033 &lt;result&gt; = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4034 &lt;result&gt; = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
4035 &lt;result&gt; = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
4036 &lt;result&gt; = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4037</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4038
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4039</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4040
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4041</div>
4042
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4043<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4044<h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4045 <a name="vectorops">Vector Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4046</h3>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4047
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4048<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4049
4050<p>LLVM supports several instructions to represent vector operations in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4051 target-independent manner. These instructions cover the element-access and
4052 vector-specific operations needed to process vectors effectively. While LLVM
4053 does directly support these vector operations, many sophisticated algorithms
4054 will want to use target-specific intrinsics to take full advantage of a
4055 specific target.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4056
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4057<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4058<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4059 <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4060</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4061
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4062<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4063
4064<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4065<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4066 &lt;result&gt; = extractelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, i32 &lt;idx&gt; <i>; yields &lt;ty&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4067</pre>
4068
4069<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4070<p>The '<tt>extractelement</tt>' instruction extracts a single scalar element
4071 from a vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4072
4073
4074<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4075<p>The first operand of an '<tt>extractelement</tt>' instruction is a value
4076 of <a href="#t_vector">vector</a> type. The second operand is an index
4077 indicating the position from which to extract the element. The index may be
4078 a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4079
4080<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4081<p>The result is a scalar of the same type as the element type of
4082 <tt>val</tt>. Its value is the value at position <tt>idx</tt> of
4083 <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4084 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4085
4086<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4087<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4088 &lt;result&gt; = extractelement &lt;4 x i32&gt; %vec, i32 0 <i>; yields i32</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4089</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4090
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4091</div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4092
4093<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4094<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4095 <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4096</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4097
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4098<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4099
4100<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4101<pre>
Dan Gohman43ba0672008-05-12 23:38:42 +0000[diff] [blame]4102 &lt;result&gt; = insertelement &lt;n x &lt;ty&gt;&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, i32 &lt;idx&gt; <i>; yields &lt;n x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4103</pre>
4104
4105<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4106<p>The '<tt>insertelement</tt>' instruction inserts a scalar element into a
4107 vector at a specified index.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4108
4109<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4110<p>The first operand of an '<tt>insertelement</tt>' instruction is a value
4111 of <a href="#t_vector">vector</a> type. The second operand is a scalar value
4112 whose type must equal the element type of the first operand. The third
4113 operand is an index indicating the position at which to insert the value.
4114 The index may be a variable.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4115
4116<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4117<p>The result is a vector of the same type as <tt>val</tt>. Its element values
4118 are those of <tt>val</tt> except at position <tt>idx</tt>, where it gets the
4119 value <tt>elt</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
4120 results are undefined.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4121
4122<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4123<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4124 &lt;result&gt; = insertelement &lt;4 x i32&gt; %vec, i32 1, i32 0 <i>; yields &lt;4 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4125</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4126
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4127</div>
4128
4129<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4130<h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4131 <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4132</h4>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4133
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4134<div>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4135
4136<h5>Syntax:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4137<pre>
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4138 &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;m x i32&gt; &lt;mask&gt; <i>; yields &lt;m x &lt;ty&gt;&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4139</pre>
4140
4141<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4142<p>The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
4143 from two input vectors, returning a vector with the same element type as the
4144 input and length that is the same as the shuffle mask.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4145
4146<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4147<p>The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
4148 with types that match each other. The third argument is a shuffle mask whose
4149 element type is always 'i32'. The result of the instruction is a vector
4150 whose length is the same as the shuffle mask and whose element type is the
4151 same as the element type of the first two operands.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4152
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4153<p>The shuffle mask operand is required to be a constant vector with either
4154 constant integer or undef values.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4155
4156<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4157<p>The elements of the two input vectors are numbered from left to right across
4158 both of the vectors. The shuffle mask operand specifies, for each element of
4159 the result vector, which element of the two input vectors the result element
4160 gets. The element selector may be undef (meaning "don't care") and the
4161 second operand may be undef if performing a shuffle from only one vector.</p>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4162
4163<h5>Example:</h5>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4164<pre>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4165 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4166 &lt;4 x i32&gt; &lt;i32 0, i32 4, i32 1, i32 5&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4167 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; undef,
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4168 &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.
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4169 &lt;result&gt; = shufflevector &lt;8 x i32&gt; %v1, &lt;8 x i32&gt; undef,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4170 &lt;4 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3&gt; <i>; yields &lt;4 x i32&gt;</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4171 &lt;result&gt; = shufflevector &lt;4 x i32&gt; %v1, &lt;4 x i32&gt; %v2,
Mon P Wang25f01062008-11-10 04:46:22 +0000[diff] [blame]4172 &lt;8 x i32&gt; &lt;i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 &gt; <i>; yields &lt;8 x i32&gt;</i>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4173</pre>
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4174
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4175</div>
Tanya Lattnerb138bbe2006-04-14 19:24:33 +0000[diff] [blame]4176
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4177</div>
4178
Chris Lattnerce83bff2006-04-08 23:07:04 +0000[diff] [blame]4179<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4180<h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4181 <a name="aggregateops">Aggregate Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4182</h3>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4183
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4184<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4185
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4186<p>LLVM supports several instructions for working with
4187 <a href="#t_aggregate">aggregate</a> values.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4188
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4189<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4190<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4191 <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4192</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4193
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4194<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4195
4196<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4197<pre>
4198 &lt;result&gt; = extractvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;idx&gt;{, &lt;idx&gt;}*
4199</pre>
4200
4201<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4202<p>The '<tt>extractvalue</tt>' instruction extracts the value of a member field
4203 from an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4204
4205<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4206<p>The first operand of an '<tt>extractvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4207 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4208 <a href="#t_array">array</a> type. The operands are constant indices to
4209 specify which value to extract in a similar manner as indices in a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4210 '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.</p>
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4211 <p>The major differences to <tt>getelementptr</tt> indexing are:</p>
4212 <ul>
4213 <li>Since the value being indexed is not a pointer, the first index is
4214 omitted and assumed to be zero.</li>
4215 <li>At least one index must be specified.</li>
4216 <li>Not only struct indices but also array indices must be in
4217 bounds.</li>
4218 </ul>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4219
4220<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4221<p>The result is the value at the position in the aggregate specified by the
4222 index operands.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4223
4224<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4225<pre>
Gabor Greif03ab4dc2009-10-28 13:14:50 +0000[diff] [blame]4226 &lt;result&gt; = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4227</pre>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4228
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4229</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4230
4231<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4232<h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4233 <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4234</h4>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4235
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4236<div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4237
4238<h5>Syntax:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4239<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4240 &lt;result&gt; = insertvalue &lt;aggregate type&gt; &lt;val&gt;, &lt;ty&gt; &lt;elt&gt;, &lt;idx&gt;{, <idx>}* <i>; yields &lt;aggregate type&gt;</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4241</pre>
4242
4243<h5>Overview:</h5>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4244<p>The '<tt>insertvalue</tt>' instruction inserts a value into a member field
4245 in an <a href="#t_aggregate">aggregate</a> value.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4246
4247<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4248<p>The first operand of an '<tt>insertvalue</tt>' instruction is a value
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4249 of <a href="#t_struct">struct</a> or
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4250 <a href="#t_array">array</a> type. The second operand is a first-class
4251 value to insert. The following operands are constant indices indicating
4252 the position at which to insert the value in a similar manner as indices in a
Frits van Bommel7cf63ac2010-12-05 20:54:38 +0000[diff] [blame]4253 '<tt><a href="#i_extractvalue">extractvalue</a></tt>' instruction. The
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4254 value to insert must have the same type as the value identified by the
4255 indices.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4256
4257<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4258<p>The result is an aggregate of the same type as <tt>val</tt>. Its value is
4259 that of <tt>val</tt> except that the value at the position specified by the
4260 indices is that of <tt>elt</tt>.</p>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4261
4262<h5>Example:</h5>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4263<pre>
Chris Lattnerc2e85402011-05-22 07:18:08 +0000[diff] [blame]4264 %agg1 = insertvalue {i32, float} undef, i32 1, 0 <i>; yields {i32 1, float undef}</i>
4265 %agg2 = insertvalue {i32, float} %agg1, float %val, 1 <i>; yields {i32 1, float %val}</i>
4266 %agg3 = insertvalue {i32, {float}} %agg1, float %val, 1, 0 <i>; yields {i32 1, float %val}</i>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4267</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4268
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4269</div>
4270
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4271</div>
Dan Gohmanb9d66602008-05-12 23:51:09 +0000[diff] [blame]4272
4273<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4274<h3>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4275 <a name="memoryops">Memory Access and Addressing Operations</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4276</h3>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4277
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4278<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4279
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4280<p>A key design point of an SSA-based representation is how it represents
4281 memory. In LLVM, no memory locations are in SSA form, which makes things
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]4282 very simple. This section describes how to read, write, and allocate
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4283 memory in LLVM.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4284
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4285<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4286<h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4287 <a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4288</h4>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4289
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4290<div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4291
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4292<h5>Syntax:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4293<pre>
Dan Gohman2140a742010-05-28 01:14:11 +0000[diff] [blame]4294 &lt;result&gt; = alloca &lt;type&gt;[, &lt;ty&gt; &lt;NumElements&gt;][, align &lt;alignment&gt;] <i>; yields {type*}:result</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4295</pre>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4296
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4297<h5>Overview:</h5>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4298<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4299 currently executing function, to be automatically released when this function
4300 returns to its caller. The object is always allocated in the generic address
4301 space (address space zero).</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4302
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4303<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4304<p>The '<tt>alloca</tt>' instruction
4305 allocates <tt>sizeof(&lt;type&gt;)*NumElements</tt> bytes of memory on the
4306 runtime stack, returning a pointer of the appropriate type to the program.
4307 If "NumElements" is specified, it is the number of elements allocated,
4308 otherwise "NumElements" is defaulted to be one. If a constant alignment is
4309 specified, the value result of the allocation is guaranteed to be aligned to
4310 at least that boundary. If not specified, or if zero, the target can choose
4311 to align the allocation on any convenient boundary compatible with the
4312 type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4313
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4314<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4315
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4316<h5>Semantics:</h5>
Bill Wendling9ee6a312009-05-08 20:49:29 +0000[diff] [blame]4317<p>Memory is allocated; a pointer is returned. The operation is undefined if
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4318 there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
4319 memory is automatically released when the function returns. The
4320 '<tt>alloca</tt>' instruction is commonly used to represent automatic
4321 variables that must have an address available. When the function returns
4322 (either with the <tt><a href="#i_ret">ret</a></tt>
4323 or <tt><a href="#i_unwind">unwind</a></tt> instructions), the memory is
4324 reclaimed. Allocating zero bytes is legal, but the result is undefined.</p>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4325
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4326<h5>Example:</h5>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4327<pre>
Dan Gohman7a5acb52009-01-04 23:49:44 +0000[diff] [blame]4328 %ptr = alloca i32 <i>; yields {i32*}:ptr</i>
4329 %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
4330 %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
4331 %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4332</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4333
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4334</div>
Chris Lattner54611b42005-11-06 08:02:57 +0000[diff] [blame]4335
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4336<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4337<h4>
4338 <a name="i_load">'<tt>load</tt>' Instruction</a>
4339</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4340
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4341<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4342
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4343<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4344<pre>
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4345 &lt;result&gt; = load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4346 &lt;result&gt; = volatile load &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;]
4347 !&lt;index&gt; = !{ i32 1 }
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4348</pre>
4349
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4350<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4351<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4352
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4353<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4354<p>The argument to the '<tt>load</tt>' instruction specifies the memory address
4355 from which to load. The pointer must point to
4356 a <a href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
4357 marked as <tt>volatile</tt>, then the optimizer is not allowed to modify the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4358 number or order of execution of this <tt>load</tt> with other <a
4359 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4360
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4361<p>The optional constant <tt>align</tt> argument specifies the alignment of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4362 operation (that is, the alignment of the memory address). A value of 0 or an
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4363 omitted <tt>align</tt> argument means that the operation has the preferential
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4364 alignment for the target. It is the responsibility of the code emitter to
4365 ensure that the alignment information is correct. Overestimating the
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4366 alignment results in undefined behavior. Underestimating the alignment may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4367 produce less efficient code. An alignment of 1 is always safe.</p>
4368
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4369<p>The optional <tt>!nontemporal</tt> metadata must reference a single
4370 metatadata name &lt;index&gt; corresponding to a metadata node with
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4371 one <tt>i32</tt> entry of value 1. The existence of
Bill Wendlingbc4024f2010-02-25 21:23:24 +0000[diff] [blame]4372 the <tt>!nontemporal</tt> metatadata on the instruction tells the optimizer
4373 and code generator that this load is not expected to be reused in the cache.
4374 The code generator may select special instructions to save cache bandwidth,
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4375 such as the <tt>MOVNT</tt> instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4376
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4377<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4378<p>The location of memory pointed to is loaded. If the value being loaded is of
4379 scalar type then the number of bytes read does not exceed the minimum number
4380 of bytes needed to hold all bits of the type. For example, loading an
4381 <tt>i24</tt> reads at most three bytes. When loading a value of a type like
4382 <tt>i20</tt> with a size that is not an integral number of bytes, the result
4383 is undefined if the value was not originally written using a store of the
4384 same type.</p>
4385
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4386<h5>Examples:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4387<pre>
4388 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
4389 <a href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4390 %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4391</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4392
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4393</div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4394
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4395<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4396<h4>
4397 <a name="i_store">'<tt>store</tt>' Instruction</a>
4398</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4399
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4400<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4401
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4402<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4403<pre>
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4404 store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
4405 volatile store &lt;ty&gt; &lt;value&gt;, &lt;ty&gt;* &lt;pointer&gt;[, align &lt;alignment&gt;][, !nontemporal !&lt;index&gt;] <i>; yields {void}</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4406</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4407
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4408<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4409<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4410
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4411<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4412<p>There are two arguments to the '<tt>store</tt>' instruction: a value to store
4413 and an address at which to store it. The type of the
4414 '<tt>&lt;pointer&gt;</tt>' operand must be a pointer to
4415 the <a href="#t_firstclass">first class</a> type of the
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]4416 '<tt>&lt;value&gt;</tt>' operand. If the <tt>store</tt> is marked as
4417 <tt>volatile</tt>, then the optimizer is not allowed to modify the number or
4418 order of execution of this <tt>store</tt> with other <a
4419 href="#volatile">volatile operations</a>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4420
4421<p>The optional constant "align" argument specifies the alignment of the
4422 operation (that is, the alignment of the memory address). A value of 0 or an
4423 omitted "align" argument means that the operation has the preferential
4424 alignment for the target. It is the responsibility of the code emitter to
4425 ensure that the alignment information is correct. Overestimating the
4426 alignment results in an undefined behavior. Underestimating the alignment may
4427 produce less efficient code. An alignment of 1 is always safe.</p>
4428
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4429<p>The optional !nontemporal metadata must reference a single metatadata
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4430 name &lt;index&gt; corresponding to a metadata node with one i32 entry of
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4431 value 1. The existence of the !nontemporal metatadata on the
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4432 instruction tells the optimizer and code generator that this load is
4433 not expected to be reused in the cache. The code generator may
4434 select special instructions to save cache bandwidth, such as the
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]4435 MOVNT instruction on x86.</p>
David Greene9641d062010-02-16 20:50:18 +0000[diff] [blame]4436
4437
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]4438<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4439<p>The contents of memory are updated to contain '<tt>&lt;value&gt;</tt>' at the
4440 location specified by the '<tt>&lt;pointer&gt;</tt>' operand. If
4441 '<tt>&lt;value&gt;</tt>' is of scalar type then the number of bytes written
4442 does not exceed the minimum number of bytes needed to hold all bits of the
4443 type. For example, storing an <tt>i24</tt> writes at most three bytes. When
4444 writing a value of a type like <tt>i20</tt> with a size that is not an
4445 integral number of bytes, it is unspecified what happens to the extra bits
4446 that do not belong to the type, but they will typically be overwritten.</p>
4447
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4448<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4449<pre>
4450 %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling8830ffe2007-10-22 05:10:05 +0000[diff] [blame]4451 store i32 3, i32* %ptr <i>; yields {void}</i>
4452 %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4453</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4454
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4455</div>
4456
Chris Lattner095735d2002-05-06 03:03:22 +0000[diff] [blame]4457<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4458<h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4459 <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4460</h4>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4461
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4462<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4463
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4464<h5>Syntax:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4465<pre>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4466 &lt;result&gt; = getelementptr &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4467 &lt;result&gt; = getelementptr inbounds &lt;pty&gt;* &lt;ptrval&gt;{, &lt;ty&gt; &lt;idx&gt;}*
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4468</pre>
4469
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4470<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4471<p>The '<tt>getelementptr</tt>' instruction is used to get the address of a
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4472 subelement of an <a href="#t_aggregate">aggregate</a> data structure.
4473 It performs address calculation only and does not access memory.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4474
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4475<h5>Arguments:</h5>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4476<p>The first argument is always a pointer, and forms the basis of the
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4477 calculation. The remaining arguments are indices that indicate which of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4478 elements of the aggregate object are indexed. The interpretation of each
4479 index is dependent on the type being indexed into. The first index always
4480 indexes the pointer value given as the first argument, the second index
4481 indexes a value of the type pointed to (not necessarily the value directly
4482 pointed to, since the first index can be non-zero), etc. The first type
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4483 indexed into must be a pointer value, subsequent types can be arrays,
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4484 vectors, and structs. Note that subsequent types being indexed into
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4485 can never be pointers, since that would require loading the pointer before
4486 continuing calculation.</p>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4487
4488<p>The type of each index argument depends on the type it is indexing into.
Chris Lattner13ee7952010-08-28 04:09:24 +0000[diff] [blame]4489 When indexing into a (optionally packed) structure, only <tt>i32</tt>
Chris Lattner392be582010-02-12 20:49:41 +0000[diff] [blame]4490 integer <b>constants</b> are allowed. When indexing into an array, pointer
4491 or vector, integers of any width are allowed, and they are not required to be
Chris Lattnera40b9122009-07-29 06:44:13 +0000[diff] [blame]4492 constant.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4493
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4494<p>For example, let's consider a C code fragment and how it gets compiled to
4495 LLVM:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4496
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4497<pre class="doc_code">
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4498struct RT {
4499 char A;
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4500 int B[10][20];
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4501 char C;
4502};
4503struct ST {
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4504 int X;
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4505 double Y;
4506 struct RT Z;
4507};
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4508
Chris Lattnera446f1b2007-05-29 15:43:56 +0000[diff] [blame]4509int *foo(struct ST *s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4510 return &amp;s[1].Z.B[5][13];
4511}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4512</pre>
4513
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4514<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4515
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]4516<pre class="doc_code">
Chris Lattnerbc088212009-01-11 20:53:49 +0000[diff] [blame]4517%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
4518%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4519
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4520define i32* @foo(%ST* %s) {
Bill Wendling3716c5d2007-05-29 09:04:49 +0000[diff] [blame]4521entry:
4522 %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
4523 ret i32* %reg
4524}
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4525</pre>
4526
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4527<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]4528<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4529 type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
4530 }</tt>' type, a structure. The second index indexes into the third element
4531 of the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
4532 i8 }</tt>' type, another structure. The third index indexes into the second
4533 element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
4534 array. The two dimensions of the array are subscripted into, yielding an
4535 '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a
4536 pointer to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4537
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4538<p>Note that it is perfectly legal to index partially through a structure,
4539 returning a pointer to an inner element. Because of this, the LLVM code for
4540 the given testcase is equivalent to:</p>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4541
4542<pre>
Dan Gohman6b867702009-07-25 02:23:48 +0000[diff] [blame]4543 define i32* @foo(%ST* %s) {
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4544 %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen5819f182007-04-22 01:17:39 +0000[diff] [blame]4545 %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
4546 %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4547 %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
4548 %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
4549 ret i32* %t5
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4550 }
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4551</pre>
Chris Lattnerc0ad71e2005-06-24 17:22:57 +0000[diff] [blame]4552
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4553<p>If the <tt>inbounds</tt> keyword is present, the result value of the
Dan Gohman57255802010-04-23 15:23:32 +0000[diff] [blame]4554 <tt>getelementptr</tt> is a <a href="#trapvalues">trap value</a> if the
4555 base pointer is not an <i>in bounds</i> address of an allocated object,
4556 or if any of the addresses that would be formed by successive addition of
4557 the offsets implied by the indices to the base address with infinitely
4558 precise arithmetic are not an <i>in bounds</i> address of that allocated
4559 object. The <i>in bounds</i> addresses for an allocated object are all
4560 the addresses that point into the object, plus the address one byte past
4561 the end.</p>
Dan Gohman1639c392009-07-27 21:53:46 +0000[diff] [blame]4562
4563<p>If the <tt>inbounds</tt> keyword is not present, the offsets are added to
4564 the base address with silently-wrapping two's complement arithmetic, and
4565 the result value of the <tt>getelementptr</tt> may be outside the object
4566 pointed to by the base pointer. The result value may not necessarily be
4567 used to access memory though, even if it happens to point into allocated
4568 storage. See the <a href="#pointeraliasing">Pointer Aliasing Rules</a>
4569 section for more information.</p>
4570
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4571<p>The getelementptr instruction is often confusing. For some more insight into
4572 how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p>
Chris Lattner6ab66722006-08-15 00:45:58 +0000[diff] [blame]4573
Chris Lattner590645f2002-04-14 06:13:44 +0000[diff] [blame]4574<h5>Example:</h5>
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4575<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4576 <i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4577 %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
4578 <i>; yields i8*:vptr</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4579 %vptr = getelementptr {i32, &lt;2 x i8&gt;}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman0e268272008-10-13 13:44:15 +0000[diff] [blame]4580 <i>; yields i8*:eptr</i>
4581 %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta0c155e62009-04-25 07:27:44 +0000[diff] [blame]4582 <i>; yields i32*:iptr</i>
Sanjiv Gupta77abea02009-04-24 16:38:13 +0000[diff] [blame]4583 %iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4584</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4585
Chris Lattner33fd7022004-04-05 01:30:49 +0000[diff] [blame]4586</div>
Reid Spencer443460a2006-11-09 21:15:49 +0000[diff] [blame]4587
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4588</div>
4589
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]4590<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4591<h3>
4592 <a name="convertops">Conversion Operations</a>
4593</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4594
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4595<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4596
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]4597<p>The instructions in this category are the conversion instructions (casting)
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4598 which all take a single operand and a type. They perform various bit
4599 conversions on the operand.</p>
4600
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4601<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4602<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4603 <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4604</h4>
4605
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4606<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4607
4608<h5>Syntax:</h5>
4609<pre>
4610 &lt;result&gt; = trunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4611</pre>
4612
4613<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4614<p>The '<tt>trunc</tt>' instruction truncates its operand to the
4615 type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4616
4617<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4618<p>The '<tt>trunc</tt>' instruction takes a value to trunc, and a type to trunc it to.
4619 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4620 of the same number of integers.
4621 The bit size of the <tt>value</tt> must be larger than
4622 the bit size of the destination type, <tt>ty2</tt>.
4623 Equal sized types are not allowed.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4624
4625<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4626<p>The '<tt>trunc</tt>' instruction truncates the high order bits
4627 in <tt>value</tt> and converts the remaining bits to <tt>ty2</tt>. Since the
4628 source size must be larger than the destination size, <tt>trunc</tt> cannot
4629 be a <i>no-op cast</i>. It will always truncate bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4630
4631<h5>Example:</h5>
4632<pre>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4633 %X = trunc i32 257 to i8 <i>; yields i8:1</i>
4634 %Y = trunc i32 123 to i1 <i>; yields i1:true</i>
4635 %Z = trunc i32 122 to i1 <i>; yields i1:false</i>
4636 %W = trunc &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i8&gt; <i>; yields &lt;i8 8, i8 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4637</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4638
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4639</div>
4640
4641<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4642<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4643 <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4644</h4>
4645
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4646<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4647
4648<h5>Syntax:</h5>
4649<pre>
4650 &lt;result&gt; = zext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4651</pre>
4652
4653<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4654<p>The '<tt>zext</tt>' instruction zero extends its operand to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4655 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4656
4657
4658<h5>Arguments:</h5>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4659<p>The '<tt>zext</tt>' instruction takes a value to cast, and a type to cast it to.
4660 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4661 of the same number of integers.
4662 The bit size of the <tt>value</tt> must be smaller than
4663 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4664 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4665
4666<h5>Semantics:</h5>
4667<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4668 bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4669
Reid Spencer07c9c682007-01-12 15:46:11 +0000[diff] [blame]4670<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4671
4672<h5>Example:</h5>
4673<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4674 %X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4675 %Y = zext i1 true to i32 <i>; yields i32:1</i>
Nadav Rotem25f2ac92011-02-20 12:37:50 +0000[diff] [blame]4676 %Z = zext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4677</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4678
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4679</div>
4680
4681<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4682<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4683 <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4684</h4>
4685
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4686<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4687
4688<h5>Syntax:</h5>
4689<pre>
4690 &lt;result&gt; = sext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4691</pre>
4692
4693<h5>Overview:</h5>
4694<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
4695
4696<h5>Arguments:</h5>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4697<p>The '<tt>sext</tt>' instruction takes a value to cast, and a type to cast it to.
4698 Both types must be of <a href="#t_integer">integer</a> types, or vectors
4699 of the same number of integers.
4700 The bit size of the <tt>value</tt> must be smaller than
4701 the bit size of the destination type,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4702 <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4703
4704<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4705<p>The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
4706 bit (highest order bit) of the <tt>value</tt> until it reaches the bit size
4707 of the type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4708
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4709<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4710
4711<h5>Example:</h5>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4712<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4713 %X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4714 %Y = sext i1 true to i32 <i>; yields i32:-1</i>
Nadav Rotem502f1b92011-02-24 21:01:34 +0000[diff] [blame]4715 %Z = sext &lt;2 x i16&gt; &lt;i16 8, i16 7&gt; to &lt;2 x i32&gt; <i>; yields &lt;i32 8, i32 7&gt;</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4716</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4717
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4718</div>
4719
4720<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4721<h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4722 <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4723</h4>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4724
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4725<div>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4726
4727<h5>Syntax:</h5>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4728<pre>
4729 &lt;result&gt; = fptrunc &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4730</pre>
4731
4732<h5>Overview:</h5>
4733<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4734 <tt>ty2</tt>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4735
4736<h5>Arguments:</h5>
4737<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4738 point</a> value to cast and a <a href="#t_floating">floating point</a> type
4739 to cast it to. The size of <tt>value</tt> must be larger than the size of
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4740 <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4741 <i>no-op cast</i>.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4742
4743<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4744<p>The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4745 <a href="#t_floating">floating point</a> type to a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4746 <a href="#t_floating">floating point</a> type. If the value cannot fit
4747 within the destination type, <tt>ty2</tt>, then the results are
4748 undefined.</p>
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4749
4750<h5>Example:</h5>
4751<pre>
4752 %X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
4753 %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
4754</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4755
Reid Spencer2e2740d2006-11-09 21:48:10 +0000[diff] [blame]4756</div>
4757
4758<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4759<h4>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4760 <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4761</h4>
4762
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4763<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4764
4765<h5>Syntax:</h5>
4766<pre>
4767 &lt;result&gt; = fpext &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4768</pre>
4769
4770<h5>Overview:</h5>
4771<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4772 floating point value.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4773
4774<h5>Arguments:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4775<p>The '<tt>fpext</tt>' instruction takes a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4776 <a href="#t_floating">floating point</a> <tt>value</tt> to cast, and
4777 a <a href="#t_floating">floating point</a> type to cast it to. The source
4778 type must be smaller than the destination type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4779
4780<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4781<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4782 <a href="#t_floating">floating point</a> type to a larger
4783 <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
4784 used to make a <i>no-op cast</i> because it always changes bits. Use
4785 <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4786
4787<h5>Example:</h5>
4788<pre>
Nick Lewycky9feca672011-03-31 18:20:19 +0000[diff] [blame]4789 %X = fpext float 3.125 to double <i>; yields double:3.125000e+00</i>
4790 %Y = fpext double %X to fp128 <i>; yields fp128:0xL00000000000000004000900000000000</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4791</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4792
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4793</div>
4794
4795<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4796<h4>
Reid Spencer2eadb532007-01-21 00:29:26 +0000[diff] [blame]4797 <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4798</h4>
4799
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4800<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4801
4802<h5>Syntax:</h5>
4803<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4804 &lt;result&gt; = fptoui &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4805</pre>
4806
4807<h5>Overview:</h5>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4808<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4809 unsigned integer equivalent of type <tt>ty2</tt>.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4810
4811<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4812<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
4813 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4814 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4815 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4816 vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4817
4818<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4819<p>The '<tt>fptoui</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4820 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4821 towards zero) unsigned integer value. If the value cannot fit
4822 in <tt>ty2</tt>, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4823
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4824<h5>Example:</h5>
4825<pre>
Reid Spencer753163d2007-07-31 14:40:14 +0000[diff] [blame]4826 %X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4827 %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4828 %Z = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4829</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4830
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4831</div>
4832
4833<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4834<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4835 <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4836</h4>
4837
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4838<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4839
4840<h5>Syntax:</h5>
4841<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4842 &lt;result&gt; = fptosi &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4843</pre>
4844
4845<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4846<p>The '<tt>fptosi</tt>' instruction converts
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4847 <a href="#t_floating">floating point</a> <tt>value</tt> to
4848 type <tt>ty2</tt>.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4849
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4850<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4851<p>The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
4852 scalar or vector <a href="#t_floating">floating point</a> value, and a type
4853 to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
4854 type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
4855 vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4856
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]4857<h5>Semantics:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]4858<p>The '<tt>fptosi</tt>' instruction converts its
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4859 <a href="#t_floating">floating point</a> operand into the nearest (rounding
4860 towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
4861 the results are undefined.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4862
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]4863<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]4864<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]4865 %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner5b95a172007-09-22 03:17:52 +0000[diff] [blame]4866 %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]4867 %Z = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4868</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4869
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4870</div>
4871
4872<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4873<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4874 <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4875</h4>
4876
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4877<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4878
4879<h5>Syntax:</h5>
4880<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4881 &lt;result&gt; = uitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4882</pre>
4883
4884<h5>Overview:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4885<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4886 integer and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4887
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4888<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4889<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4890 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4891 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4892 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4893 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4894
4895<h5>Semantics:</h5>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4896<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4897 integer quantity and converts it to the corresponding floating point
4898 value. If the value cannot fit in the floating point value, the results are
4899 undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4900
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4901<h5>Example:</h5>
4902<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4903 %X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4904 %Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4905</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4906
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4907</div>
4908
4909<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4910<h4>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4911 <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4912</h4>
4913
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4914<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4915
4916<h5>Syntax:</h5>
4917<pre>
Reid Spencer51b07252006-11-09 23:03:26 +0000[diff] [blame]4918 &lt;result&gt; = sitofp &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4919</pre>
4920
4921<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4922<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed integer
4923 and converts that value to the <tt>ty2</tt> type.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4924
4925<h5>Arguments:</h5>
Nate Begemand4d45c22007-11-17 03:58:34 +0000[diff] [blame]4926<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4927 scalar or vector <a href="#t_integer">integer</a> value, and a type to cast
4928 it to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
4929 type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
4930 floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4931
4932<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4933<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed integer
4934 quantity and converts it to the corresponding floating point value. If the
4935 value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4936
4937<h5>Example:</h5>
4938<pre>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]4939 %X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]4940 %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4941</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4942
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]4943</div>
4944
4945<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4946<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4947 <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4948</h4>
4949
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4950<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4951
4952<h5>Syntax:</h5>
4953<pre>
4954 &lt;result&gt; = ptrtoint &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4955</pre>
4956
4957<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4958<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
4959 the integer type <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4960
4961<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4962<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
4963 must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
4964 <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4965
4966<h5>Semantics:</h5>
4967<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4968 <tt>ty2</tt> by interpreting the pointer value as an integer and either
4969 truncating or zero extending that value to the size of the integer type. If
4970 <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
4971 <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
4972 are the same size, then nothing is done (<i>no-op cast</i>) other than a type
4973 change.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4974
4975<h5>Example:</h5>
4976<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]4977 %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
4978 %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4979</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4980
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4981</div>
4982
4983<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4984<h4>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4985 <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]4986</h4>
4987
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]4988<div>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4989
4990<h5>Syntax:</h5>
4991<pre>
4992 &lt;result&gt; = inttoptr &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
4993</pre>
4994
4995<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]4996<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to a
4997 pointer type, <tt>ty2</tt>.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]4998
4999<h5>Arguments:</h5>
Duncan Sands16f122e2007-03-30 12:22:09 +0000[diff] [blame]5000<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5001 value to cast, and a type to cast it to, which must be a
5002 <a href="#t_pointer">pointer</a> type.</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5003
5004<h5>Semantics:</h5>
5005<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5006 <tt>ty2</tt> by applying either a zero extension or a truncation depending on
5007 the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
5008 size of a pointer then a truncation is done. If <tt>value</tt> is smaller
5009 than the size of a pointer then a zero extension is done. If they are the
5010 same size, nothing is done (<i>no-op cast</i>).</p>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5011
5012<h5>Example:</h5>
5013<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5014 %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
Gabor Greiff50fd572009-10-28 09:21:30 +0000[diff] [blame]5015 %Y = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
5016 %Z = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5017</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5018
Reid Spencerb7344ff2006-11-11 21:00:47 +0000[diff] [blame]5019</div>
5020
5021<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5022<h4>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5023 <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5024</h4>
5025
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5026<div>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5027
5028<h5>Syntax:</h5>
5029<pre>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5030 &lt;result&gt; = bitcast &lt;ty&gt; &lt;value&gt; to &lt;ty2&gt; <i>; yields ty2</i>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5031</pre>
5032
5033<h5>Overview:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5034<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5035 <tt>ty2</tt> without changing any bits.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5036
5037<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5038<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be a
5039 non-aggregate first class value, and a type to cast it to, which must also be
5040 a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes
5041 of <tt>value</tt> and the destination type, <tt>ty2</tt>, must be
5042 identical. If the source type is a pointer, the destination type must also be
5043 a pointer. This instruction supports bitwise conversion of vectors to
5044 integers and to vectors of other types (as long as they have the same
5045 size).</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5046
5047<h5>Semantics:</h5>
Reid Spencer5b950642006-11-11 23:08:07 +0000[diff] [blame]5048<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5049 <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
5050 this conversion. The conversion is done as if the <tt>value</tt> had been
5051 stored to memory and read back as type <tt>ty2</tt>. Pointer types may only
5052 be converted to other pointer types with this instruction. To convert
5053 pointers to other types, use the <a href="#i_inttoptr">inttoptr</a> or
5054 <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer59b6b7d2006-11-08 01:11:31 +0000[diff] [blame]5055
5056<h5>Example:</h5>
5057<pre>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5058 %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5059 %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5060 %Z = bitcast &lt;2 x int&gt; %V to i64; <i>; yields i64: %V</i>
Chris Lattner70de6632001-07-09 00:26:23 +0000[diff] [blame]5061</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5062
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5063</div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5064
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5065</div>
5066
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5067<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5068<h3>
5069 <a name="otherops">Other Operations</a>
5070</h3>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5071
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5072<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5073
5074<p>The instructions in this category are the "miscellaneous" instructions, which
5075 defy better classification.</p>
5076
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5077<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5078<h4>
5079 <a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
5080</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5081
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5082<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5083
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5084<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5085<pre>
5086 &lt;result&gt; = icmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5087</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5088
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5089<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5090<p>The '<tt>icmp</tt>' instruction returns a boolean value or a vector of
5091 boolean values based on comparison of its two integer, integer vector, or
5092 pointer operands.</p>
5093
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5094<h5>Arguments:</h5>
5095<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5096 the condition code indicating the kind of comparison to perform. It is not a
5097 value, just a keyword. The possible condition code are:</p>
5098
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5099<ol>
5100 <li><tt>eq</tt>: equal</li>
5101 <li><tt>ne</tt>: not equal </li>
5102 <li><tt>ugt</tt>: unsigned greater than</li>
5103 <li><tt>uge</tt>: unsigned greater or equal</li>
5104 <li><tt>ult</tt>: unsigned less than</li>
5105 <li><tt>ule</tt>: unsigned less or equal</li>
5106 <li><tt>sgt</tt>: signed greater than</li>
5107 <li><tt>sge</tt>: signed greater or equal</li>
5108 <li><tt>slt</tt>: signed less than</li>
5109 <li><tt>sle</tt>: signed less or equal</li>
5110</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5111
Chris Lattnerc0f423a2007-01-15 01:54:13 +0000[diff] [blame]5112<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5113 <a href="#t_pointer">pointer</a> or integer <a href="#t_vector">vector</a>
5114 typed. They must also be identical types.</p>
5115
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5116<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5117<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to the
5118 condition code given as <tt>cond</tt>. The comparison performed always yields
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5119 either an <a href="#t_integer"><tt>i1</tt></a> or vector of <tt>i1</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5120 result, as follows:</p>
5121
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5122<ol>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5123 <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5124 <tt>false</tt> otherwise. No sign interpretation is necessary or
5125 performed.</li>
5126
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5127 <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5128 <tt>false</tt> otherwise. No sign interpretation is necessary or
5129 performed.</li>
5130
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5131 <li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5132 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5133
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5134 <li><tt>uge</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5135 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5136 to <tt>op2</tt>.</li>
5137
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5138 <li><tt>ult</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5139 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5140
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5141 <li><tt>ule</tt>: interprets the operands as unsigned values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5142 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5143
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5144 <li><tt>sgt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5145 <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5146
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5147 <li><tt>sge</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5148 <tt>true</tt> if <tt>op1</tt> is greater than or equal
5149 to <tt>op2</tt>.</li>
5150
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5151 <li><tt>slt</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5152 <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
5153
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5154 <li><tt>sle</tt>: interprets the operands as signed values and yields
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5155 <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5156</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5157
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5158<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5159 values are compared as if they were integers.</p>
5160
5161<p>If the operands are integer vectors, then they are compared element by
5162 element. The result is an <tt>i1</tt> vector with the same number of elements
5163 as the values being compared. Otherwise, the result is an <tt>i1</tt>.</p>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5164
5165<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5166<pre>
5167 &lt;result&gt; = icmp eq i32 4, 5 <i>; yields: result=false</i>
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5168 &lt;result&gt; = icmp ne float* %X, %X <i>; yields: result=false</i>
5169 &lt;result&gt; = icmp ult i16 4, 5 <i>; yields: result=true</i>
5170 &lt;result&gt; = icmp sgt i16 4, 5 <i>; yields: result=false</i>
5171 &lt;result&gt; = icmp ule i16 -4, 5 <i>; yields: result=false</i>
5172 &lt;result&gt; = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5173</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5174
5175<p>Note that the code generator does not yet support vector types with
5176 the <tt>icmp</tt> instruction.</p>
5177
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5178</div>
5179
5180<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5181<h4>
5182 <a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
5183</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5184
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5185<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5186
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5187<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5188<pre>
5189 &lt;result&gt; = fcmp &lt;cond&gt; &lt;ty&gt; &lt;op1&gt;, &lt;op2&gt; <i>; yields {i1} or {&lt;N x i1&gt;}:result</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5190</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5191
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5192<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5193<p>The '<tt>fcmp</tt>' instruction returns a boolean value or vector of boolean
5194 values based on comparison of its operands.</p>
5195
5196<p>If the operands are floating point scalars, then the result type is a boolean
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5197(<a href="#t_integer"><tt>i1</tt></a>).</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5198
5199<p>If the operands are floating point vectors, then the result type is a vector
5200 of boolean with the same number of elements as the operands being
5201 compared.</p>
5202
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5203<h5>Arguments:</h5>
5204<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5205 the condition code indicating the kind of comparison to perform. It is not a
5206 value, just a keyword. The possible condition code are:</p>
5207
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5208<ol>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5209 <li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5210 <li><tt>oeq</tt>: ordered and equal</li>
5211 <li><tt>ogt</tt>: ordered and greater than </li>
5212 <li><tt>oge</tt>: ordered and greater than or equal</li>
5213 <li><tt>olt</tt>: ordered and less than </li>
5214 <li><tt>ole</tt>: ordered and less than or equal</li>
5215 <li><tt>one</tt>: ordered and not equal</li>
5216 <li><tt>ord</tt>: ordered (no nans)</li>
5217 <li><tt>ueq</tt>: unordered or equal</li>
5218 <li><tt>ugt</tt>: unordered or greater than </li>
5219 <li><tt>uge</tt>: unordered or greater than or equal</li>
5220 <li><tt>ult</tt>: unordered or less than </li>
5221 <li><tt>ule</tt>: unordered or less than or equal</li>
5222 <li><tt>une</tt>: unordered or not equal</li>
5223 <li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5224 <li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5225</ol>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5226
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5227<p><i>Ordered</i> means that neither operand is a QNAN while
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5228 <i>unordered</i> means that either operand may be a QNAN.</p>
5229
5230<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be either
5231 a <a href="#t_floating">floating point</a> type or
5232 a <a href="#t_vector">vector</a> of floating point type. They must have
5233 identical types.</p>
5234
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5235<h5>Semantics:</h5>
Gabor Greif0f75ad02008-08-07 21:46:00 +0000[diff] [blame]5236<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5237 according to the condition code given as <tt>cond</tt>. If the operands are
5238 vectors, then the vectors are compared element by element. Each comparison
Nick Lewycky84a1eeb2009-09-27 00:45:11 +0000[diff] [blame]5239 performed always yields an <a href="#t_integer">i1</a> result, as
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5240 follows:</p>
5241
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5242<ol>
5243 <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5244
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5245 <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5246 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5247
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5248 <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5249 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5250
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5251 <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5252 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5253
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5254 <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5255 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5256
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5257 <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5258 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5259
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5260 <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5261 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5262
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5263 <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5264
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5265 <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5266 <tt>op1</tt> is equal to <tt>op2</tt>.</li>
5267
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5268 <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5269 <tt>op1</tt> is greater than <tt>op2</tt>.</li>
5270
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5271 <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5272 <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
5273
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5274 <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5275 <tt>op1</tt> is less than <tt>op2</tt>.</li>
5276
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5277 <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5278 <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
5279
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5280 <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5281 <tt>op1</tt> is not equal to <tt>op2</tt>.</li>
5282
Reid Spencerf69acf32006-11-19 03:00:14 +0000[diff] [blame]5283 <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5284
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5285 <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
5286</ol>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5287
5288<h5>Example:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5289<pre>
5290 &lt;result&gt; = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5291 &lt;result&gt; = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
5292 &lt;result&gt; = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
5293 &lt;result&gt; = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5294</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5295
5296<p>Note that the code generator does not yet support vector types with
5297 the <tt>fcmp</tt> instruction.</p>
5298
Reid Spencerc828a0e2006-11-18 21:50:54 +0000[diff] [blame]5299</div>
5300
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5301<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5302<h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5303 <a name="i_phi">'<tt>phi</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5304</h4>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5305
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5306<div>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5307
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5308<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5309<pre>
5310 &lt;result&gt; = phi &lt;ty&gt; [ &lt;val0&gt;, &lt;label0&gt;], ...
5311</pre>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5312
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5313<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5314<p>The '<tt>phi</tt>' instruction is used to implement the &#966; node in the
5315 SSA graph representing the function.</p>
5316
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5317<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5318<p>The type of the incoming values is specified with the first type field. After
5319 this, the '<tt>phi</tt>' instruction takes a list of pairs as arguments, with
5320 one pair for each predecessor basic block of the current block. Only values
5321 of <a href="#t_firstclass">first class</a> type may be used as the value
5322 arguments to the PHI node. Only labels may be used as the label
5323 arguments.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5324
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5325<p>There must be no non-phi instructions between the start of a basic block and
5326 the PHI instructions: i.e. PHI instructions must be first in a basic
5327 block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5328
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5329<p>For the purposes of the SSA form, the use of each incoming value is deemed to
5330 occur on the edge from the corresponding predecessor block to the current
5331 block (but after any definition of an '<tt>invoke</tt>' instruction's return
5332 value on the same edge).</p>
Jay Foad1a4eea52009-06-03 10:20:10 +0000[diff] [blame]5333
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5334<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5335<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5336 specified by the pair corresponding to the predecessor basic block that
5337 executed just prior to the current block.</p>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5338
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5339<h5>Example:</h5>
Chris Lattnerb54c30f2008-05-20 20:48:21 +0000[diff] [blame]5340<pre>
5341Loop: ; Infinite loop that counts from 0 on up...
5342 %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
5343 %nextindvar = add i32 %indvar, 1
5344 br label %Loop
5345</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5346
Reid Spencer97c5fa42006-11-08 01:18:52 +0000[diff] [blame]5347</div>
5348
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5349<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5350<h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5351 <a name="i_select">'<tt>select</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5352</h4>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5353
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5354<div>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5355
5356<h5>Syntax:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5357<pre>
Dan Gohmanc579d972008-09-09 01:02:47 +0000[diff] [blame]5358 &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>
5359
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5360 <i>selty</i> is either i1 or {&lt;N x i1&gt;}
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5361</pre>
5362
5363<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5364<p>The '<tt>select</tt>' instruction is used to choose one value based on a
5365 condition, without branching.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5366
5367
5368<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5369<p>The '<tt>select</tt>' instruction requires an 'i1' value or a vector of 'i1'
5370 values indicating the condition, and two values of the
5371 same <a href="#t_firstclass">first class</a> type. If the val1/val2 are
5372 vectors and the condition is a scalar, then entire vectors are selected, not
5373 individual elements.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5374
5375<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5376<p>If the condition is an i1 and it evaluates to 1, the instruction returns the
5377 first value argument; otherwise, it returns the second value argument.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5378
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5379<p>If the condition is a vector of i1, then the value arguments must be vectors
5380 of the same size, and the selection is done element by element.</p>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5381
5382<h5>Example:</h5>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5383<pre>
Reid Spencer36a15422007-01-12 03:35:51 +0000[diff] [blame]5384 %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5385</pre>
Dan Gohmana5127ab2009-01-22 01:39:38 +0000[diff] [blame]5386
5387<p>Note that the code generator does not yet support conditions
5388 with vector type.</p>
5389
Chris Lattnerb53c28d2004-03-12 05:50:16 +0000[diff] [blame]5390</div>
5391
Robert Bocchinof72fdfe2006-01-15 20:48:27 +0000[diff] [blame]5392<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5393<h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5394 <a name="i_call">'<tt>call</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5395</h4>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5396
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5397<div>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5398
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5399<h5>Syntax:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5400<pre>
Devang Patel02256232008-10-07 17:48:33 +0000[diff] [blame]5401 &lt;result&gt; = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] &lt;ty&gt; [&lt;fnty&gt;*] &lt;fnptrval&gt;(&lt;function args&gt;) [<a href="#fnattrs">fn attrs</a>]
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5402</pre>
5403
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5404<h5>Overview:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5405<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5406
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5407<h5>Arguments:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5408<p>This instruction requires several arguments:</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5409
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5410<ol>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5411 <li>The optional "tail" marker indicates that the callee function does not
5412 access any allocas or varargs in the caller. Note that calls may be
5413 marked "tail" even if they do not occur before
5414 a <a href="#i_ret"><tt>ret</tt></a> instruction. If the "tail" marker is
5415 present, the function call is eligible for tail call optimization,
5416 but <a href="CodeGenerator.html#tailcallopt">might not in fact be
Evan Cheng59676492010-03-08 21:05:02 +0000[diff] [blame]5417 optimized into a jump</a>. The code generator may optimize calls marked
5418 "tail" with either 1) automatic <a href="CodeGenerator.html#sibcallopt">
5419 sibling call optimization</a> when the caller and callee have
5420 matching signatures, or 2) forced tail call optimization when the
5421 following extra requirements are met:
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5422 <ul>
5423 <li>Caller and callee both have the calling
5424 convention <tt>fastcc</tt>.</li>
5425 <li>The call is in tail position (ret immediately follows call and ret
5426 uses value of call or is void).</li>
5427 <li>Option <tt>-tailcallopt</tt> is enabled,
Dan Gohman6232f732010-03-02 01:08:11 +0000[diff] [blame]5428 or <code>llvm::GuaranteedTailCallOpt</code> is <code>true</code>.</li>
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5429 <li><a href="CodeGenerator.html#tailcallopt">Platform specific
5430 constraints are met.</a></li>
5431 </ul>
5432 </li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5433
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5434 <li>The optional "cconv" marker indicates which <a href="#callingconv">calling
5435 convention</a> the call should use. If none is specified, the call
Jeffrey Yasskinb8677462010-01-09 19:44:16 +0000[diff] [blame]5436 defaults to using C calling conventions. The calling convention of the
5437 call must match the calling convention of the target function, or else the
5438 behavior is undefined.</li>
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5439
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5440 <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
5441 return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', and
5442 '<tt>inreg</tt>' attributes are valid here.</li>
5443
5444 <li>'<tt>ty</tt>': the type of the call instruction itself which is also the
5445 type of the return value. Functions that return no value are marked
5446 <tt><a href="#t_void">void</a></tt>.</li>
5447
5448 <li>'<tt>fnty</tt>': shall be the signature of the pointer to function value
5449 being invoked. The argument types must match the types implied by this
5450 signature. This type can be omitted if the function is not varargs and if
5451 the function type does not return a pointer to a function.</li>
5452
5453 <li>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
5454 be invoked. In most cases, this is a direct function invocation, but
5455 indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
5456 to function value.</li>
5457
5458 <li>'<tt>function args</tt>': argument list whose types match the function
Chris Lattner47f2a832010-03-02 06:36:51 +0000[diff] [blame]5459 signature argument types and parameter attributes. All arguments must be
5460 of <a href="#t_firstclass">first class</a> type. If the function
5461 signature indicates the function accepts a variable number of arguments,
5462 the extra arguments can be specified.</li>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5463
5464 <li>The optional <a href="#fnattrs">function attributes</a> list. Only
5465 '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
5466 '<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattnera8292f32002-05-06 22:08:29 +0000[diff] [blame]5467</ol>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5468
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5469<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5470<p>The '<tt>call</tt>' instruction is used to cause control flow to transfer to
5471 a specified function, with its incoming arguments bound to the specified
5472 values. Upon a '<tt><a href="#i_ret">ret</a></tt>' instruction in the called
5473 function, control flow continues with the instruction after the function
5474 call, and the return value of the function is bound to the result
5475 argument.</p>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5476
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]5477<h5>Example:</h5>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5478<pre>
Nick Lewyckya9b13d52007-09-08 13:57:50 +0000[diff] [blame]5479 %retval = call i32 @test(i32 %argc)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5480 call i32 (i8*, ...)* @printf(i8* %msg, i32 12, i8 42) <i>; yields i32</i>
Chris Lattnerfb7c88d2008-03-21 17:24:17 +0000[diff] [blame]5481 %X = tail call i32 @foo() <i>; yields i32</i>
5482 %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
5483 call void %foo(i8 97 signext)
Devang Pateld6cff512008-03-10 20:49:15 +0000[diff] [blame]5484
5485 %struct.A = type { i32, i8 }
Devang Patel7e9b05e2008-10-06 18:50:38 +0000[diff] [blame]5486 %r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohmancc3132e2008-10-04 19:00:07 +0000[diff] [blame]5487 %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
5488 %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner6cbe8e92008-10-08 06:26:11 +0000[diff] [blame]5489 %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijmaneefa7df2008-10-07 10:03:45 +0000[diff] [blame]5490 %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattnere23c1392005-05-06 05:47:36 +0000[diff] [blame]5491</pre>
5492
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5493<p>llvm treats calls to some functions with names and arguments that match the
Dale Johannesen722212d2009-09-25 17:04:42 +0000[diff] [blame]5494standard C99 library as being the C99 library functions, and may perform
5495optimizations or generate code for them under that assumption. This is
5496something we'd like to change in the future to provide better support for
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]5497freestanding environments and non-C-based languages.</p>
Dale Johannesen68f971b2009-09-24 18:38:21 +0000[diff] [blame]5498
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5499</div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5500
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5501<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5502<h4>
Chris Lattner33337472006-01-13 23:26:01 +0000[diff] [blame]5503 <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5504</h4>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5505
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5506<div>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5507
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5508<h5>Syntax:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5509<pre>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5510 &lt;resultval&gt; = va_arg &lt;va_list*&gt; &lt;arglist&gt;, &lt;argty&gt;
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5511</pre>
5512
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5513<h5>Overview:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5514<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5515 the "variable argument" area of a function call. It is used to implement the
5516 <tt>va_arg</tt> macro in C.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5517
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5518<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5519<p>This instruction takes a <tt>va_list*</tt> value and the type of the
5520 argument. It returns a value of the specified argument type and increments
5521 the <tt>va_list</tt> to point to the next argument. The actual type
5522 of <tt>va_list</tt> is target specific.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5523
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5524<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5525<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified type
5526 from the specified <tt>va_list</tt> and causes the <tt>va_list</tt> to point
5527 to the next argument. For more information, see the variable argument
5528 handling <a href="#int_varargs">Intrinsic Functions</a>.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5529
5530<p>It is legal for this instruction to be called in a function which does not
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5531 take a variable number of arguments, for example, the <tt>vfprintf</tt>
5532 function.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5533
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5534<p><tt>va_arg</tt> is an LLVM instruction instead of
5535 an <a href="#intrinsics">intrinsic function</a> because it takes a type as an
5536 argument.</p>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5537
Chris Lattner26ca62e2003-10-18 05:51:36 +0000[diff] [blame]5538<h5>Example:</h5>
Chris Lattner6a4a0492004-09-27 21:51:25 +0000[diff] [blame]5539<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
5540
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5541<p>Note that the code generator does not yet fully support va_arg on many
5542 targets. Also, it does not currently support va_arg with aggregate types on
5543 any target.</p>
Dan Gohman3065b612009-01-12 23:12:39 +0000[diff] [blame]5544
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5545</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5546
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5547</div>
5548
5549</div>
5550
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5551<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5552<h2><a name="intrinsics">Intrinsic Functions</a></h2>
Chris Lattner48b383b02003-11-25 01:02:51 +0000[diff] [blame]5553<!-- *********************************************************************** -->
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5554
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5555<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5556
5557<p>LLVM supports the notion of an "intrinsic function". These functions have
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5558 well known names and semantics and are required to follow certain
5559 restrictions. Overall, these intrinsics represent an extension mechanism for
5560 the LLVM language that does not require changing all of the transformations
5561 in LLVM when adding to the language (or the bitcode reader/writer, the
5562 parser, etc...).</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5563
John Criswell88190562005-05-16 16:17:45 +0000[diff] [blame]5564<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5565 prefix is reserved in LLVM for intrinsic names; thus, function names may not
5566 begin with this prefix. Intrinsic functions must always be external
5567 functions: you cannot define the body of intrinsic functions. Intrinsic
5568 functions may only be used in call or invoke instructions: it is illegal to
5569 take the address of an intrinsic function. Additionally, because intrinsic
5570 functions are part of the LLVM language, it is required if any are added that
5571 they be documented here.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5572
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5573<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents a
5574 family of functions that perform the same operation but on different data
5575 types. Because LLVM can represent over 8 million different integer types,
5576 overloading is used commonly to allow an intrinsic function to operate on any
5577 integer type. One or more of the argument types or the result type can be
5578 overloaded to accept any integer type. Argument types may also be defined as
5579 exactly matching a previous argument's type or the result type. This allows
5580 an intrinsic function which accepts multiple arguments, but needs all of them
5581 to be of the same type, to only be overloaded with respect to a single
5582 argument or the result.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5583
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5584<p>Overloaded intrinsics will have the names of its overloaded argument types
5585 encoded into its function name, each preceded by a period. Only those types
5586 which are overloaded result in a name suffix. Arguments whose type is matched
5587 against another type do not. For example, the <tt>llvm.ctpop</tt> function
5588 can take an integer of any width and returns an integer of exactly the same
5589 integer width. This leads to a family of functions such as
5590 <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29
5591 %val)</tt>. Only one type, the return type, is overloaded, and only one type
5592 suffix is required. Because the argument's type is matched against the return
5593 type, it does not require its own name suffix.</p>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]5594
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]5595<p>To learn how to add an intrinsic function, please see the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5596 <a href="ExtendingLLVM.html">Extending LLVM Guide</a>.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5597
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5598<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5599<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5600 <a name="int_varargs">Variable Argument Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5601</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5602
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5603<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5604
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5605<p>Variable argument support is defined in LLVM with
5606 the <a href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
5607 intrinsic functions. These functions are related to the similarly named
5608 macros defined in the <tt>&lt;stdarg.h&gt;</tt> header file.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5609
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5610<p>All of these functions operate on arguments that use a target-specific value
5611 type "<tt>va_list</tt>". The LLVM assembly language reference manual does
5612 not define what this type is, so all transformations should be prepared to
5613 handle these functions regardless of the type used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5614
Chris Lattner30b868d2006-05-15 17:26:46 +0000[diff] [blame]5615<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5616 instruction and the variable argument handling intrinsic functions are
5617 used.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5618
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]5619<pre class="doc_code">
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5620define i32 @test(i32 %X, ...) {
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5621 ; Initialize variable argument processing
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5622 %ap = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5623 %ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5624 call void @llvm.va_start(i8* %ap2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5625
5626 ; Read a single integer argument
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5627 %tmp = va_arg i8** %ap, i32
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5628
5629 ; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5630 %aq = alloca i8*
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5631 %aq2 = bitcast i8** %aq to i8*
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5632 call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5633 call void @llvm.va_end(i8* %aq2)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5634
5635 ; Stop processing of arguments.
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5636 call void @llvm.va_end(i8* %ap2)
Reid Spencerb5ebf3d2006-12-31 07:07:53 +0000[diff] [blame]5637 ret i32 %tmp
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5638}
Anton Korobeynikov640bbe02007-03-21 23:58:04 +0000[diff] [blame]5639
5640declare void @llvm.va_start(i8*)
5641declare void @llvm.va_copy(i8*, i8*)
5642declare void @llvm.va_end(i8*)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5643</pre>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5644
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5645<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5646<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5647 <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5648</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5649
5650
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5651<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5652
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5653<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5654<pre>
5655 declare void %llvm.va_start(i8* &lt;arglist&gt;)
5656</pre>
5657
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5658<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5659<p>The '<tt>llvm.va_start</tt>' intrinsic initializes <tt>*&lt;arglist&gt;</tt>
5660 for subsequent use by <tt><a href="#i_va_arg">va_arg</a></tt>.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5661
5662<h5>Arguments:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5663<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5664
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5665<h5>Semantics:</h5>
Dan Gohmanef9462f2008-10-14 16:51:45 +0000[diff] [blame]5666<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5667 macro available in C. In a target-dependent way, it initializes
5668 the <tt>va_list</tt> element to which the argument points, so that the next
5669 call to <tt>va_arg</tt> will produce the first variable argument passed to
5670 the function. Unlike the C <tt>va_start</tt> macro, this intrinsic does not
5671 need to know the last argument of the function as the compiler can figure
5672 that out.</p>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5673
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5674</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5675
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5676<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5677<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5678 <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5679</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5680
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5681<div>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5682
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5683<h5>Syntax:</h5>
5684<pre>
5685 declare void @llvm.va_end(i8* &lt;arglist&gt;)
5686</pre>
5687
5688<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5689<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*&lt;arglist&gt;</tt>,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5690 which has been initialized previously
5691 with <tt><a href="#int_va_start">llvm.va_start</a></tt>
5692 or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5693
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5694<h5>Arguments:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5695<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5696
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5697<h5>Semantics:</h5>
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5698<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5699 macro available in C. In a target-dependent way, it destroys
5700 the <tt>va_list</tt> element to which the argument points. Calls
5701 to <a href="#int_va_start"><tt>llvm.va_start</tt></a>
5702 and <a href="#int_va_copy"> <tt>llvm.va_copy</tt></a> must be matched exactly
5703 with calls to <tt>llvm.va_end</tt>.</p>
Chris Lattnerdb0790c2007-01-08 07:55:15 +0000[diff] [blame]5704
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5705</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5706
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5707<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5708<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5709 <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5710</h4>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5711
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5712<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5713
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5714<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5715<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5716 declare void @llvm.va_copy(i8* &lt;destarglist&gt;, i8* &lt;srcarglist&gt;)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5717</pre>
5718
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5719<h5>Overview:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5720<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5721 from the source argument list to the destination argument list.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5722
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5723<h5>Arguments:</h5>
Andrew Lenharth5fb787c2005-06-18 18:28:17 +0000[diff] [blame]5724<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5725 The second argument is a pointer to a <tt>va_list</tt> element to copy
5726 from.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5727
Chris Lattnerbd64b4e2003-05-08 04:57:36 +0000[diff] [blame]5728<h5>Semantics:</h5>
Jeff Cohen222a8a42007-04-29 01:07:00 +0000[diff] [blame]5729<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5730 macro available in C. In a target-dependent way, it copies the
5731 source <tt>va_list</tt> element into the destination <tt>va_list</tt>
5732 element. This intrinsic is necessary because
5733 the <tt><a href="#int_va_start"> llvm.va_start</a></tt> intrinsic may be
5734 arbitrarily complex and require, for example, memory allocation.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5735
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]5736</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]5737
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5738</div>
5739
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]5740<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5741<h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5742 <a name="int_gc">Accurate Garbage Collection Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5743</h3>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5744
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5745<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5746
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5747<p>LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner67c37d12008-08-05 18:29:16 +0000[diff] [blame]5748Collection</a> (GC) requires the implementation and generation of these
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5749intrinsics. These intrinsics allow identification of <a href="#int_gcroot">GC
5750roots on the stack</a>, as well as garbage collector implementations that
5751require <a href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a>
5752barriers. Front-ends for type-safe garbage collected languages should generate
5753these intrinsics to make use of the LLVM garbage collectors. For more details,
5754see <a href="GarbageCollection.html">Accurate Garbage Collection with
5755LLVM</a>.</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5756
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5757<p>The garbage collection intrinsics only operate on objects in the generic
5758 address space (address space zero).</p>
Christopher Lamb55c6d4f2007-12-17 01:00:21 +0000[diff] [blame]5759
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5760<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5761<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5762 <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5763</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5764
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5765<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5766
5767<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5768<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5769 declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5770</pre>
5771
5772<h5>Overview:</h5>
John Criswelldfe6a862004-12-10 15:51:16 +0000[diff] [blame]5773<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5774 the code generator, and allows some metadata to be associated with it.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5775
5776<h5>Arguments:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5777<p>The first argument specifies the address of a stack object that contains the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5778 root pointer. The second pointer (which must be either a constant or a
5779 global value address) contains the meta-data to be associated with the
5780 root.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5781
5782<h5>Semantics:</h5>
Chris Lattner851b7712008-04-24 05:59:56 +0000[diff] [blame]5783<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5784 location. At compile-time, the code generator generates information to allow
5785 the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
5786 intrinsic may only be used in a function which <a href="#gc">specifies a GC
5787 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5788
5789</div>
5790
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5791<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5792<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5793 <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5794</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5795
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5796<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5797
5798<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5799<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5800 declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5801</pre>
5802
5803<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5804<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5805 locations, allowing garbage collector implementations that require read
5806 barriers.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5807
5808<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5809<p>The second argument is the address to read from, which should be an address
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5810 allocated from the garbage collector. The first object is a pointer to the
5811 start of the referenced object, if needed by the language runtime (otherwise
5812 null).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5813
5814<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5815<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5816 instruction, but may be replaced with substantially more complex code by the
5817 garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
5818 may only be used in a function which <a href="#gc">specifies a GC
5819 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5820
5821</div>
5822
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5823<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5824<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5825 <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5826</h4>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5827
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5828<div>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5829
5830<h5>Syntax:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5831<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]5832 declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5833</pre>
5834
5835<h5>Overview:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5836<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5837 locations, allowing garbage collector implementations that require write
5838 barriers (such as generational or reference counting collectors).</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5839
5840<h5>Arguments:</h5>
Chris Lattnerf9228072006-03-14 20:02:51 +0000[diff] [blame]5841<p>The first argument is the reference to store, the second is the start of the
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5842 object to store it to, and the third is the address of the field of Obj to
5843 store to. If the runtime does not require a pointer to the object, Obj may
5844 be null.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5845
5846<h5>Semantics:</h5>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5847<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5848 instruction, but may be replaced with substantially more complex code by the
5849 garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
5850 may only be used in a function which <a href="#gc">specifies a GC
5851 algorithm</a>.</p>
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5852
5853</div>
5854
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5855</div>
5856
Chris Lattner757528b0b2004-05-23 21:06:01 +0000[diff] [blame]5857<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5858<h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5859 <a name="int_codegen">Code Generator Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5860</h3>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5861
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5862<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5863
5864<p>These intrinsics are provided by LLVM to expose special features that may
5865 only be implemented with code generator support.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5866
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5867<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5868<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5869 <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5870</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5871
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5872<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5873
5874<h5>Syntax:</h5>
5875<pre>
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]5876 declare i8 *@llvm.returnaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5877</pre>
5878
5879<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5880<p>The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
5881 target-specific value indicating the return address of the current function
5882 or one of its callers.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5883
5884<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5885<p>The argument to this intrinsic indicates which function to return the address
5886 for. Zero indicates the calling function, one indicates its caller, etc.
5887 The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5888
5889<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5890<p>The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer
5891 indicating the return address of the specified call frame, or zero if it
5892 cannot be identified. The value returned by this intrinsic is likely to be
5893 incorrect or 0 for arguments other than zero, so it should only be used for
5894 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5895
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5896<p>Note that calling this intrinsic does not prevent function inlining or other
5897 aggressive transformations, so the value returned may not be that of the
5898 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5899
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5900</div>
5901
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5902<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5903<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5904 <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5905</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5906
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5907<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5908
5909<h5>Syntax:</h5>
5910<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5911 declare i8* @llvm.frameaddress(i32 &lt;level&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5912</pre>
5913
5914<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5915<p>The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
5916 target-specific frame pointer value for the specified stack frame.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5917
5918<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5919<p>The argument to this intrinsic indicates which function to return the frame
5920 pointer for. Zero indicates the calling function, one indicates its caller,
5921 etc. The argument is <b>required</b> to be a constant integer value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5922
5923<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5924<p>The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer
5925 indicating the frame address of the specified call frame, or zero if it
5926 cannot be identified. The value returned by this intrinsic is likely to be
5927 incorrect or 0 for arguments other than zero, so it should only be used for
5928 debugging purposes.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5929
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5930<p>Note that calling this intrinsic does not prevent function inlining or other
5931 aggressive transformations, so the value returned may not be that of the
5932 obvious source-language caller.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5933
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]5934</div>
5935
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5936<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5937<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5938 <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5939</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5940
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5941<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5942
5943<h5>Syntax:</h5>
5944<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5945 declare i8* @llvm.stacksave()
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5946</pre>
5947
5948<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5949<p>The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state
5950 of the function stack, for use
5951 with <a href="#int_stackrestore"> <tt>llvm.stackrestore</tt></a>. This is
5952 useful for implementing language features like scoped automatic variable
5953 sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5954
5955<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5956<p>This intrinsic returns a opaque pointer value that can be passed
5957 to <a href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When
5958 an <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved
5959 from <tt>llvm.stacksave</tt>, it effectively restores the state of the stack
5960 to the state it was in when the <tt>llvm.stacksave</tt> intrinsic executed.
5961 In practice, this pops any <a href="#i_alloca">alloca</a> blocks from the
5962 stack that were allocated after the <tt>llvm.stacksave</tt> was executed.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5963
5964</div>
5965
5966<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5967<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5968 <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5969</h4>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5970
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5971<div>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5972
5973<h5>Syntax:</h5>
5974<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]5975 declare void @llvm.stackrestore(i8* %ptr)
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5976</pre>
5977
5978<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5979<p>The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
5980 the function stack to the state it was in when the
5981 corresponding <a href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic
5982 executed. This is useful for implementing language features like scoped
5983 automatic variable sized arrays in C99.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5984
5985<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]5986<p>See the description
5987 for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.</p>
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5988
5989</div>
5990
Chris Lattner2f0f0012006-01-13 02:03:13 +0000[diff] [blame]5991<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5992<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]5993 <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]5994</h4>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5995
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]5996<div>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]5997
5998<h5>Syntax:</h5>
5999<pre>
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6000 declare void @llvm.prefetch(i8* &lt;address&gt;, i32 &lt;rw&gt;, i32 &lt;locality&gt;, i32 &lt;cache type&gt;)
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6001</pre>
6002
6003<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6004<p>The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to
6005 insert a prefetch instruction if supported; otherwise, it is a noop.
6006 Prefetches have no effect on the behavior of the program but can change its
6007 performance characteristics.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6008
6009<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6010<p><tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the
6011 specifier determining if the fetch should be for a read (0) or write (1),
6012 and <tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Bruno Cardoso Lopesdc9ff3a2011-06-14 04:58:37 +0000[diff] [blame]6013 locality, to (3) - extremely local keep in cache. The <tt>cache type</tt>
6014 specifies whether the prefetch is performed on the data (1) or instruction (0)
6015 cache. The <tt>rw</tt>, <tt>locality</tt> and <tt>cache type</tt> arguments
6016 must be constant integers.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6017
6018<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6019<p>This intrinsic does not modify the behavior of the program. In particular,
6020 prefetches cannot trap and do not produce a value. On targets that support
6021 this intrinsic, the prefetch can provide hints to the processor cache for
6022 better performance.</p>
Chris Lattnerc8a2c222005-02-28 19:24:19 +0000[diff] [blame]6023
6024</div>
6025
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6026<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6027<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6028 <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6029</h4>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6030
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6031<div>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6032
6033<h5>Syntax:</h5>
6034<pre>
Chris Lattner12477732007-09-21 17:30:40 +0000[diff] [blame]6035 declare void @llvm.pcmarker(i32 &lt;id&gt;)
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6036</pre>
6037
6038<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6039<p>The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program
6040 Counter (PC) in a region of code to simulators and other tools. The method
6041 is target specific, but it is expected that the marker will use exported
6042 symbols to transmit the PC of the marker. The marker makes no guarantees
6043 that it will remain with any specific instruction after optimizations. It is
6044 possible that the presence of a marker will inhibit optimizations. The
6045 intended use is to be inserted after optimizations to allow correlations of
6046 simulation runs.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6047
6048<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6049<p><tt>id</tt> is a numerical id identifying the marker.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6050
6051<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6052<p>This intrinsic does not modify the behavior of the program. Backends that do
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6053 not support this intrinsic may ignore it.</p>
Andrew Lenharthb4427912005-03-28 20:05:49 +0000[diff] [blame]6054
6055</div>
6056
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6057<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6058<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6059 <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6060</h4>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6061
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6062<div>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6063
6064<h5>Syntax:</h5>
6065<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]6066 declare i64 @llvm.readcyclecounter()
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6067</pre>
6068
6069<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6070<p>The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
6071 counter register (or similar low latency, high accuracy clocks) on those
6072 targets that support it. On X86, it should map to RDTSC. On Alpha, it
6073 should map to RPCC. As the backing counters overflow quickly (on the order
6074 of 9 seconds on alpha), this should only be used for small timings.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6075
6076<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6077<p>When directly supported, reading the cycle counter should not modify any
6078 memory. Implementations are allowed to either return a application specific
6079 value or a system wide value. On backends without support, this is lowered
6080 to a constant 0.</p>
Andrew Lenharth01aa5632005-11-11 16:47:30 +0000[diff] [blame]6081
6082</div>
6083
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6084</div>
6085
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6086<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6087<h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6088 <a name="int_libc">Standard C Library Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6089</h3>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6090
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6091<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6092
6093<p>LLVM provides intrinsics for a few important standard C library functions.
6094 These intrinsics allow source-language front-ends to pass information about
6095 the alignment of the pointer arguments to the code generator, providing
6096 opportunity for more efficient code generation.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6097
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6098<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6099<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6100 <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6101</h4>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6102
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6103<div>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6104
6105<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6106<p>This is an overloaded intrinsic. You can use <tt>llvm.memcpy</tt> on any
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]6107 integer bit width and for different address spaces. Not all targets support
6108 all bit widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6109
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6110<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6111 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6112 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6113 declare void @llvm.memcpy.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6114 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6115</pre>
6116
6117<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6118<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6119 source location to the destination location.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6120
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6121<p>Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6122 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6123 and the pointers can be in specified address spaces.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6124
6125<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6126
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6127<p>The first argument is a pointer to the destination, the second is a pointer
6128 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6129 number of bytes to copy, the fourth argument is the alignment of the
6130 source and destination locations, and the fifth is a boolean indicating a
6131 volatile access.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6132
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6133<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6134 then the caller guarantees that both the source and destination pointers are
6135 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6136
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6137<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6138 <tt>llvm.memcpy</tt> call is a <a href="#volatile">volatile operation</a>.
6139 The detailed access behavior is not very cleanly specified and it is unwise
6140 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6141
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6142<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6143
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6144<p>The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the
6145 source location to the destination location, which are not allowed to
6146 overlap. It copies "len" bytes of memory over. If the argument is known to
6147 be aligned to some boundary, this can be specified as the fourth argument,
6148 otherwise it should be set to 0 or 1.</p>
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6149
Chris Lattnerfee11462004-02-12 17:01:32 +0000[diff] [blame]6150</div>
6151
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6152<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6153<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6154 <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6155</h4>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6156
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6157<div>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6158
6159<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6160<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
Mon P Wang508127b2010-04-07 06:35:53 +0000[diff] [blame]6161 width and for different address space. Not all targets support all bit
6162 widths however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6163
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6164<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6165 declare void @llvm.memmove.p0i8.p0i8.i32(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6166 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6167 declare void @llvm.memmove.p0i8.p0i8.i64(i8* &lt;dest&gt;, i8* &lt;src&gt;,
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6168 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6169</pre>
6170
6171<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6172<p>The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the
6173 source location to the destination location. It is similar to the
6174 '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to
6175 overlap.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6176
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6177<p>Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6178 intrinsics do not return a value, takes extra alignment/isvolatile arguments
6179 and the pointers can be in specified address spaces.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6180
6181<h5>Arguments:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6182
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6183<p>The first argument is a pointer to the destination, the second is a pointer
6184 to the source. The third argument is an integer argument specifying the
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6185 number of bytes to copy, the fourth argument is the alignment of the
6186 source and destination locations, and the fifth is a boolean indicating a
6187 volatile access.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6188
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6189<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6190 then the caller guarantees that the source and destination pointers are
6191 aligned to that boundary.</p>
Chris Lattner4c67c482004-02-12 21:18:15 +0000[diff] [blame]6192
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6193<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6194 <tt>llvm.memmove</tt> call is a <a href="#volatile">volatile operation</a>.
6195 The detailed access behavior is not very cleanly specified and it is unwise
6196 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6197
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6198<h5>Semantics:</h5>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6199
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6200<p>The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the
6201 source location to the destination location, which may overlap. It copies
6202 "len" bytes of memory over. If the argument is known to be aligned to some
6203 boundary, this can be specified as the fourth argument, otherwise it should
6204 be set to 0 or 1.</p>
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6205
Chris Lattnerf30152e2004-02-12 18:10:10 +0000[diff] [blame]6206</div>
6207
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6208<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6209<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6210 <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6211</h4>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6212
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6213<div>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6214
6215<h5>Syntax:</h5>
Chris Lattnerdd708342008-11-21 16:42:48 +0000[diff] [blame]6216<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6217 width and for different address spaces. However, not all targets support all
6218 bit widths.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6219
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6220<pre>
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6221 declare void @llvm.memset.p0i8.i32(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6222 i32 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Dan Gohmanaabfdb32010-05-28 17:13:49 +0000[diff] [blame]6223 declare void @llvm.memset.p0i8.i64(i8* &lt;dest&gt;, i8 &lt;val&gt;,
Chris Lattner685db9d2010-04-08 00:54:34 +0000[diff] [blame]6224 i64 &lt;len&gt;, i32 &lt;align&gt;, i1 &lt;isvolatile&gt;)
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6225</pre>
6226
6227<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6228<p>The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a
6229 particular byte value.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6230
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6231<p>Note that, unlike the standard libc function, the <tt>llvm.memset</tt>
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6232 intrinsic does not return a value and takes extra alignment/volatile
6233 arguments. Also, the destination can be in an arbitrary address space.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6234
6235<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6236<p>The first argument is a pointer to the destination to fill, the second is the
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6237 byte value with which to fill it, the third argument is an integer argument
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6238 specifying the number of bytes to fill, and the fourth argument is the known
John Criswellad05ae42010-07-30 16:30:28 +0000[diff] [blame]6239 alignment of the destination location.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6240
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]6241<p>If the call to this intrinsic has an alignment value that is not 0 or 1,
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6242 then the caller guarantees that the destination pointer is aligned to that
6243 boundary.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6244
Jeffrey Yasskin5d284ae2010-04-26 21:21:24 +0000[diff] [blame]6245<p>If the <tt>isvolatile</tt> parameter is <tt>true</tt>, the
6246 <tt>llvm.memset</tt> call is a <a href="#volatile">volatile operation</a>.
6247 The detailed access behavior is not very cleanly specified and it is unwise
6248 to depend on it.</p>
Chris Lattnerbd4ca622010-04-08 00:53:57 +0000[diff] [blame]6249
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6250<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6251<p>The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting
6252 at the destination location. If the argument is known to be aligned to some
6253 boundary, this can be specified as the fourth argument, otherwise it should
6254 be set to 0 or 1.</p>
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6255
Chris Lattner3649c3a2004-02-14 04:08:35 +0000[diff] [blame]6256</div>
6257
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6258<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6259<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6260 <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6261</h4>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6262
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6263<div>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6264
6265<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6266<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
6267 floating point or vector of floating point type. Not all targets support all
6268 types however.</p>
6269
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6270<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6271 declare float @llvm.sqrt.f32(float %Val)
6272 declare double @llvm.sqrt.f64(double %Val)
6273 declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
6274 declare fp128 @llvm.sqrt.f128(fp128 %Val)
6275 declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6276</pre>
6277
6278<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6279<p>The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
6280 returning the same value as the libm '<tt>sqrt</tt>' functions would.
6281 Unlike <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined
6282 behavior for negative numbers other than -0.0 (which allows for better
6283 optimization, because there is no need to worry about errno being
6284 set). <tt>llvm.sqrt(-0.0)</tt> is defined to return -0.0 like IEEE sqrt.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6285
6286<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6287<p>The argument and return value are floating point numbers of the same
6288 type.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6289
6290<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6291<p>This function returns the sqrt of the specified operand if it is a
6292 nonnegative floating point number.</p>
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6293
Chris Lattner8a8f2e52005-07-21 01:29:16 +0000[diff] [blame]6294</div>
6295
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6296<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6297<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6298 <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6299</h4>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6300
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6301<div>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6302
6303<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6304<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
6305 floating point or vector of floating point type. Not all targets support all
6306 types however.</p>
6307
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6308<pre>
Dale Johannesendd89d272007-10-02 17:47:38 +0000[diff] [blame]6309 declare float @llvm.powi.f32(float %Val, i32 %power)
6310 declare double @llvm.powi.f64(double %Val, i32 %power)
6311 declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
6312 declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
6313 declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6314</pre>
6315
6316<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6317<p>The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
6318 specified (positive or negative) power. The order of evaluation of
6319 multiplications is not defined. When a vector of floating point type is
6320 used, the second argument remains a scalar integer value.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6321
6322<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6323<p>The second argument is an integer power, and the first is a value to raise to
6324 that power.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6325
6326<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6327<p>This function returns the first value raised to the second power with an
6328 unspecified sequence of rounding operations.</p>
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6329
Chris Lattner33b73f92006-09-08 06:34:02 +0000[diff] [blame]6330</div>
6331
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6332<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6333<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6334 <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6335</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6336
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6337<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6338
6339<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6340<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
6341 floating point or vector of floating point type. Not all targets support all
6342 types however.</p>
6343
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6344<pre>
6345 declare float @llvm.sin.f32(float %Val)
6346 declare double @llvm.sin.f64(double %Val)
6347 declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
6348 declare fp128 @llvm.sin.f128(fp128 %Val)
6349 declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
6350</pre>
6351
6352<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6353<p>The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6354
6355<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6356<p>The argument and return value are floating point numbers of the same
6357 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6358
6359<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6360<p>This function returns the sine of the specified operand, returning the same
6361 values as the libm <tt>sin</tt> functions would, and handles error conditions
6362 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6363
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6364</div>
6365
6366<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6367<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6368 <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6369</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6370
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6371<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6372
6373<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6374<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
6375 floating point or vector of floating point type. Not all targets support all
6376 types however.</p>
6377
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6378<pre>
6379 declare float @llvm.cos.f32(float %Val)
6380 declare double @llvm.cos.f64(double %Val)
6381 declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
6382 declare fp128 @llvm.cos.f128(fp128 %Val)
6383 declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
6384</pre>
6385
6386<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6387<p>The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6388
6389<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6390<p>The argument and return value are floating point numbers of the same
6391 type.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6392
6393<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6394<p>This function returns the cosine of the specified operand, returning the same
6395 values as the libm <tt>cos</tt> functions would, and handles error conditions
6396 in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6397
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6398</div>
6399
6400<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6401<h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6402 <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6403</h4>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6404
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6405<div>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6406
6407<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6408<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
6409 floating point or vector of floating point type. Not all targets support all
6410 types however.</p>
6411
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6412<pre>
6413 declare float @llvm.pow.f32(float %Val, float %Power)
6414 declare double @llvm.pow.f64(double %Val, double %Power)
6415 declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
6416 declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
6417 declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
6418</pre>
6419
6420<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6421<p>The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
6422 specified (positive or negative) power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6423
6424<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6425<p>The second argument is a floating point power, and the first is a value to
6426 raise to that power.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6427
6428<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6429<p>This function returns the first value raised to the second power, returning
6430 the same values as the libm <tt>pow</tt> functions would, and handles error
6431 conditions in the same way.</p>
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6432
Dan Gohmanb6324c12007-10-15 20:30:11 +0000[diff] [blame]6433</div>
6434
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6435</div>
6436
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6437<!-- _______________________________________________________________________ -->
6438<h4>
6439 <a name="int_exp">'<tt>llvm.exp.*</tt>' Intrinsic</a>
6440</h4>
6441
6442<div>
6443
6444<h5>Syntax:</h5>
6445<p>This is an overloaded intrinsic. You can use <tt>llvm.exp</tt> on any
6446 floating point or vector of floating point type. Not all targets support all
6447 types however.</p>
6448
6449<pre>
6450 declare float @llvm.exp.f32(float %Val)
6451 declare double @llvm.exp.f64(double %Val)
6452 declare x86_fp80 @llvm.exp.f80(x86_fp80 %Val)
6453 declare fp128 @llvm.exp.f128(fp128 %Val)
6454 declare ppc_fp128 @llvm.exp.ppcf128(ppc_fp128 %Val)
6455</pre>
6456
6457<h5>Overview:</h5>
6458<p>The '<tt>llvm.exp.*</tt>' intrinsics perform the exp function.</p>
6459
6460<h5>Arguments:</h5>
6461<p>The argument and return value are floating point numbers of the same
6462 type.</p>
6463
6464<h5>Semantics:</h5>
6465<p>This function returns the same values as the libm <tt>exp</tt> functions
6466 would, and handles error conditions in the same way.</p>
6467
6468</div>
6469
6470<!-- _______________________________________________________________________ -->
6471<h4>
6472 <a name="int_log">'<tt>llvm.log.*</tt>' Intrinsic</a>
6473</h4>
6474
6475<div>
6476
6477<h5>Syntax:</h5>
6478<p>This is an overloaded intrinsic. You can use <tt>llvm.log</tt> on any
6479 floating point or vector of floating point type. Not all targets support all
6480 types however.</p>
6481
6482<pre>
6483 declare float @llvm.log.f32(float %Val)
6484 declare double @llvm.log.f64(double %Val)
6485 declare x86_fp80 @llvm.log.f80(x86_fp80 %Val)
6486 declare fp128 @llvm.log.f128(fp128 %Val)
6487 declare ppc_fp128 @llvm.log.ppcf128(ppc_fp128 %Val)
6488</pre>
6489
6490<h5>Overview:</h5>
6491<p>The '<tt>llvm.log.*</tt>' intrinsics perform the log function.</p>
6492
6493<h5>Arguments:</h5>
6494<p>The argument and return value are floating point numbers of the same
6495 type.</p>
6496
6497<h5>Semantics:</h5>
6498<p>This function returns the same values as the libm <tt>log</tt> functions
6499 would, and handles error conditions in the same way.</p>
6500
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6501<h4>
6502 <a name="int_fma">'<tt>llvm.fma.*</tt>' Intrinsic</a>
6503</h4>
6504
6505<div>
6506
6507<h5>Syntax:</h5>
6508<p>This is an overloaded intrinsic. You can use <tt>llvm.fma</tt> on any
6509 floating point or vector of floating point type. Not all targets support all
6510 types however.</p>
6511
6512<pre>
6513 declare float @llvm.fma.f32(float %a, float %b, float %c)
6514 declare double @llvm.fma.f64(double %a, double %b, double %c)
6515 declare x86_fp80 @llvm.fma.f80(x86_fp80 %a, x86_fp80 %b, x86_fp80 %c)
6516 declare fp128 @llvm.fma.f128(fp128 %a, fp128 %b, fp128 %c)
6517 declare ppc_fp128 @llvm.fma.ppcf128(ppc_fp128 %a, ppc_fp128 %b, ppc_fp128 %c)
6518</pre>
6519
6520<h5>Overview:</h5>
Cameron Zwaricha32fd212011-07-08 22:13:55 +0000[diff] [blame]6521<p>The '<tt>llvm.fma.*</tt>' intrinsics perform the fused multiply-add
Cameron Zwarichf03fa182011-07-08 21:39:21 +0000[diff] [blame]6522 operation.</p>
6523
6524<h5>Arguments:</h5>
6525<p>The argument and return value are floating point numbers of the same
6526 type.</p>
6527
6528<h5>Semantics:</h5>
6529<p>This function returns the same values as the libm <tt>fma</tt> functions
6530 would.</p>
6531
Dan Gohman911fa902011-05-23 21:13:03 +0000[diff] [blame]6532</div>
6533
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6534<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6535<h3>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6536 <a name="int_manip">Bit Manipulation Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6537</h3>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6538
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6539<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6540
6541<p>LLVM provides intrinsics for a few important bit manipulation operations.
6542 These allow efficient code generation for some algorithms.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6543
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6544<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6545<h4>
Reid Spencer96a5f022007-04-04 02:42:35 +0000[diff] [blame]6546 <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6547</h4>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6548
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6549<div>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6550
6551<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6552<p>This is an overloaded intrinsic function. You can use bswap on any integer
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6553 type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
6554
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6555<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6556 declare i16 @llvm.bswap.i16(i16 &lt;id&gt;)
6557 declare i32 @llvm.bswap.i32(i32 &lt;id&gt;)
6558 declare i64 @llvm.bswap.i64(i64 &lt;id&gt;)
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6559</pre>
6560
6561<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6562<p>The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
6563 values with an even number of bytes (positive multiple of 16 bits). These
6564 are useful for performing operations on data that is not in the target's
6565 native byte order.</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6566
6567<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6568<p>The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
6569 and low byte of the input i16 swapped. Similarly,
6570 the <tt>llvm.bswap.i32</tt> intrinsic returns an i32 value that has the four
6571 bytes of the input i32 swapped, so that if the input bytes are numbered 0, 1,
6572 2, 3 then the returned i32 will have its bytes in 3, 2, 1, 0 order.
6573 The <tt>llvm.bswap.i48</tt>, <tt>llvm.bswap.i64</tt> and other intrinsics
6574 extend this concept to additional even-byte lengths (6 bytes, 8 bytes and
6575 more, respectively).</p>
Nate Begeman0f223bb2006-01-13 23:26:38 +0000[diff] [blame]6576
6577</div>
6578
6579<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6580<h4>
Reid Spencerb4f9a6f2006-01-16 21:12:35 +0000[diff] [blame]6581 <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6582</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6583
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6584<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6585
6586<h5>Syntax:</h5>
Reid Spencer4eefaab2007-04-01 08:04:23 +0000[diff] [blame]6587<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6588 width, or on any vector with integer elements. Not all targets support all
6589 bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6590
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6591<pre>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6592 declare i8 @llvm.ctpop.i8(i8 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6593 declare i16 @llvm.ctpop.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6594 declare i32 @llvm.ctpop.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6595 declare i64 @llvm.ctpop.i64(i64 &lt;src&gt;)
6596 declare i256 @llvm.ctpop.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6597 declare &lt;2 x i32&gt; @llvm.ctpop.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6598</pre>
6599
6600<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6601<p>The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set
6602 in a value.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6603
6604<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6605<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6606 integer type, or a vector with integer elements.
6607 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6608
6609<h5>Semantics:</h5>
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6610<p>The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable, or within each
6611 element of a vector.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6612
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6613</div>
6614
6615<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6616<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6617 <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6618</h4>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6619
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6620<div>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6621
6622<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6623<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6624 integer bit width, or any vector whose elements are integers. Not all
6625 targets support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6626
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6627<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6628 declare i8 @llvm.ctlz.i8 (i8 &lt;src&gt;)
6629 declare i16 @llvm.ctlz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6630 declare i32 @llvm.ctlz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6631 declare i64 @llvm.ctlz.i64(i64 &lt;src&gt;)
6632 declare i256 @llvm.ctlz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6633 declare &lt;2 x i32&gt; @llvm.ctlz.v2i32(&lt;2 x i32&gt; &lt;src;gt)
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6634</pre>
6635
6636<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6637<p>The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
6638 leading zeros in a variable.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6639
6640<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6641<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6642 integer type, or any vector type with integer element type.
6643 The return type must match the argument type.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6644
6645<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6646<p>The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6647 zeros in a variable, or within each element of the vector if the operation
6648 is of vector type. If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6649 the type of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.</p>
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6650
Andrew Lenharth1d463522005-05-03 18:01:48 +0000[diff] [blame]6651</div>
Chris Lattner3b4f4372004-06-11 02:28:03 +0000[diff] [blame]6652
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6653<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6654<h4>
Chris Lattnerb748c672006-01-16 22:34:14 +0000[diff] [blame]6655 <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6656</h4>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6657
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6658<div>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6659
6660<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6661<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6662 integer bit width, or any vector of integer elements. Not all targets
6663 support all bit widths or vector types, however.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6664
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6665<pre>
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6666 declare i8 @llvm.cttz.i8 (i8 &lt;src&gt;)
6667 declare i16 @llvm.cttz.i16(i16 &lt;src&gt;)
Anton Korobeynikovbe9c93c2007-03-22 00:02:17 +0000[diff] [blame]6668 declare i32 @llvm.cttz.i32(i32 &lt;src&gt;)
Chandler Carruth7132e002007-08-04 01:51:18 +0000[diff] [blame]6669 declare i64 @llvm.cttz.i64(i64 &lt;src&gt;)
6670 declare i256 @llvm.cttz.i256(i256 &lt;src&gt;)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6671 declase &lt;2 x i32&gt; @llvm.cttz.v2i32(&lt;2 x i32&gt; &lt;src&gt;)
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6672</pre>
6673
6674<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6675<p>The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
6676 trailing zeros.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6677
6678<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6679<p>The only argument is the value to be counted. The argument may be of any
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6680 integer type, or a vectory with integer element type.. The return type
6681 must match the argument type.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6682
6683<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6684<p>The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant)
Owen Anderson2f37bdc2011-07-01 21:52:38 +0000[diff] [blame]6685 zeros in a variable, or within each element of a vector.
6686 If the src == 0 then the result is the size in bits of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6687 the type of src. For example, <tt>llvm.cttz(2) = 1</tt>.</p>
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6688
Chris Lattnerefa20fa2005-05-15 19:39:26 +0000[diff] [blame]6689</div>
6690
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6691</div>
6692
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6693<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6694<h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6695 <a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6696</h3>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6697
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6698<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6699
6700<p>LLVM provides intrinsics for some arithmetic with overflow operations.</p>
Bill Wendlingfd2bd722009-02-08 04:04:40 +0000[diff] [blame]6701
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6702<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6703<h4>
6704 <a name="int_sadd_overflow">
6705 '<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics
6706 </a>
6707</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6708
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6709<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6710
6711<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6712<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6713 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6714
6715<pre>
6716 declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
6717 declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6718 declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
6719</pre>
6720
6721<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6722<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6723 a signed addition of the two arguments, and indicate whether an overflow
6724 occurred during the signed summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6725
6726<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6727<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6728 be of integer types of any bit width, but they must have the same bit
6729 width. The second element of the result structure must be of
6730 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6731 undergo signed addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6732
6733<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6734<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6735 a signed addition of the two variables. They return a structure &mdash; the
6736 first element of which is the signed summation, and the second element of
6737 which is a bit specifying if the signed summation resulted in an
6738 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6739
6740<h5>Examples:</h5>
6741<pre>
6742 %res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
6743 %sum = extractvalue {i32, i1} %res, 0
6744 %obit = extractvalue {i32, i1} %res, 1
6745 br i1 %obit, label %overflow, label %normal
6746</pre>
6747
6748</div>
6749
6750<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6751<h4>
6752 <a name="int_uadd_overflow">
6753 '<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics
6754 </a>
6755</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6756
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6757<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6758
6759<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6760<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6761 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6762
6763<pre>
6764 declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
6765 declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6766 declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
6767</pre>
6768
6769<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6770<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6771 an unsigned addition of the two arguments, and indicate whether a carry
6772 occurred during the unsigned summation.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6773
6774<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6775<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6776 be of integer types of any bit width, but they must have the same bit
6777 width. The second element of the result structure must be of
6778 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6779 undergo unsigned addition.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6780
6781<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6782<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6783 an unsigned addition of the two arguments. They return a structure &mdash;
6784 the first element of which is the sum, and the second element of which is a
6785 bit specifying if the unsigned summation resulted in a carry.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6786
6787<h5>Examples:</h5>
6788<pre>
6789 %res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
6790 %sum = extractvalue {i32, i1} %res, 0
6791 %obit = extractvalue {i32, i1} %res, 1
6792 br i1 %obit, label %carry, label %normal
6793</pre>
6794
6795</div>
6796
6797<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6798<h4>
6799 <a name="int_ssub_overflow">
6800 '<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics
6801 </a>
6802</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6803
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6804<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6805
6806<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6807<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6808 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6809
6810<pre>
6811 declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
6812 declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6813 declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
6814</pre>
6815
6816<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6817<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6818 a signed subtraction of the two arguments, and indicate whether an overflow
6819 occurred during the signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6820
6821<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6822<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6823 be of integer types of any bit width, but they must have the same bit
6824 width. The second element of the result structure must be of
6825 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6826 undergo signed subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6827
6828<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6829<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6830 a signed subtraction of the two arguments. They return a structure &mdash;
6831 the first element of which is the subtraction, and the second element of
6832 which is a bit specifying if the signed subtraction resulted in an
6833 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6834
6835<h5>Examples:</h5>
6836<pre>
6837 %res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
6838 %sum = extractvalue {i32, i1} %res, 0
6839 %obit = extractvalue {i32, i1} %res, 1
6840 br i1 %obit, label %overflow, label %normal
6841</pre>
6842
6843</div>
6844
6845<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6846<h4>
6847 <a name="int_usub_overflow">
6848 '<tt>llvm.usub.with.overflow.*</tt>' Intrinsics
6849 </a>
6850</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6851
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6852<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6853
6854<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6855<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6856 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6857
6858<pre>
6859 declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
6860 declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6861 declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
6862</pre>
6863
6864<h5>Overview:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6865<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6866 an unsigned subtraction of the two arguments, and indicate whether an
6867 overflow occurred during the unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6868
6869<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6870<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6871 be of integer types of any bit width, but they must have the same bit
6872 width. The second element of the result structure must be of
6873 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6874 undergo unsigned subtraction.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6875
6876<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6877<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6878 an unsigned subtraction of the two arguments. They return a structure &mdash;
6879 the first element of which is the subtraction, and the second element of
6880 which is a bit specifying if the unsigned subtraction resulted in an
6881 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6882
6883<h5>Examples:</h5>
6884<pre>
6885 %res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
6886 %sum = extractvalue {i32, i1} %res, 0
6887 %obit = extractvalue {i32, i1} %res, 1
6888 br i1 %obit, label %overflow, label %normal
6889</pre>
6890
6891</div>
6892
6893<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6894<h4>
6895 <a name="int_smul_overflow">
6896 '<tt>llvm.smul.with.overflow.*</tt>' Intrinsics
6897 </a>
6898</h4>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6899
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6900<div>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6901
6902<h5>Syntax:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6903<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6904 on any integer bit width.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6905
6906<pre>
6907 declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
6908 declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6909 declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
6910</pre>
6911
6912<h5>Overview:</h5>
6913
6914<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6915 a signed multiplication of the two arguments, and indicate whether an
6916 overflow occurred during the signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6917
6918<h5>Arguments:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6919<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6920 be of integer types of any bit width, but they must have the same bit
6921 width. The second element of the result structure must be of
6922 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6923 undergo signed multiplication.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6924
6925<h5>Semantics:</h5>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6926<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6927 a signed multiplication of the two arguments. They return a structure &mdash;
6928 the first element of which is the multiplication, and the second element of
6929 which is a bit specifying if the signed multiplication resulted in an
6930 overflow.</p>
Bill Wendlingf4d70622009-02-08 01:40:31 +0000[diff] [blame]6931
6932<h5>Examples:</h5>
6933<pre>
6934 %res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
6935 %sum = extractvalue {i32, i1} %res, 0
6936 %obit = extractvalue {i32, i1} %res, 1
6937 br i1 %obit, label %overflow, label %normal
6938</pre>
6939
Reid Spencer5bf54c82007-04-11 23:23:49 +0000[diff] [blame]6940</div>
6941
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6942<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6943<h4>
6944 <a name="int_umul_overflow">
6945 '<tt>llvm.umul.with.overflow.*</tt>' Intrinsics
6946 </a>
6947</h4>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6948
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6949<div>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6950
6951<h5>Syntax:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6952<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6953 on any integer bit width.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6954
6955<pre>
6956 declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
6957 declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6958 declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
6959</pre>
6960
6961<h5>Overview:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6962<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6963 a unsigned multiplication of the two arguments, and indicate whether an
6964 overflow occurred during the unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6965
6966<h5>Arguments:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6967<p>The arguments (%a and %b) and the first element of the result structure may
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6968 be of integer types of any bit width, but they must have the same bit
6969 width. The second element of the result structure must be of
6970 type <tt>i1</tt>. <tt>%a</tt> and <tt>%b</tt> are the two values that will
6971 undergo unsigned multiplication.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6972
6973<h5>Semantics:</h5>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6974<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]6975 an unsigned multiplication of the two arguments. They return a structure
6976 &mdash; the first element of which is the multiplication, and the second
6977 element of which is a bit specifying if the unsigned multiplication resulted
6978 in an overflow.</p>
Bill Wendlingb9a73272009-02-08 23:00:09 +0000[diff] [blame]6979
6980<h5>Examples:</h5>
6981<pre>
6982 %res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
6983 %sum = extractvalue {i32, i1} %res, 0
6984 %obit = extractvalue {i32, i1} %res, 1
6985 br i1 %obit, label %overflow, label %normal
6986</pre>
6987
6988</div>
6989
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6990</div>
6991
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]6992<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6993<h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6994 <a name="int_fp16">Half Precision Floating Point Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]6995</h3>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6996
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]6997<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]6998
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]6999<p>Half precision floating point is a storage-only format. This means that it is
7000 a dense encoding (in memory) but does not support computation in the
7001 format.</p>
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7002
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7003<p>This means that code must first load the half-precision floating point
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7004 value as an i16, then convert it to float with <a
7005 href="#int_convert_from_fp16"><tt>llvm.convert.from.fp16</tt></a>.
7006 Computation can then be performed on the float value (including extending to
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7007 double etc). To store the value back to memory, it is first converted to
7008 float if needed, then converted to i16 with
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7009 <a href="#int_convert_to_fp16"><tt>llvm.convert.to.fp16</tt></a>, then
7010 storing as an i16 value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7011
7012<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7013<h4>
7014 <a name="int_convert_to_fp16">
7015 '<tt>llvm.convert.to.fp16</tt>' Intrinsic
7016 </a>
7017</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7018
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7019<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7020
7021<h5>Syntax:</h5>
7022<pre>
7023 declare i16 @llvm.convert.to.fp16(f32 %a)
7024</pre>
7025
7026<h5>Overview:</h5>
7027<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7028 a conversion from single precision floating point format to half precision
7029 floating point format.</p>
7030
7031<h5>Arguments:</h5>
7032<p>The intrinsic function contains single argument - the value to be
7033 converted.</p>
7034
7035<h5>Semantics:</h5>
7036<p>The '<tt>llvm.convert.to.fp16</tt>' intrinsic function performs
7037 a conversion from single precision floating point format to half precision
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7038 floating point format. The return value is an <tt>i16</tt> which
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7039 contains the converted number.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7040
7041<h5>Examples:</h5>
7042<pre>
7043 %res = call i16 @llvm.convert.to.fp16(f32 %a)
7044 store i16 %res, i16* @x, align 2
7045</pre>
7046
7047</div>
7048
7049<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7050<h4>
7051 <a name="int_convert_from_fp16">
7052 '<tt>llvm.convert.from.fp16</tt>' Intrinsic
7053 </a>
7054</h4>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7055
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7056<div>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7057
7058<h5>Syntax:</h5>
7059<pre>
7060 declare f32 @llvm.convert.from.fp16(i16 %a)
7061</pre>
7062
7063<h5>Overview:</h5>
7064<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs
7065 a conversion from half precision floating point format to single precision
7066 floating point format.</p>
7067
7068<h5>Arguments:</h5>
7069<p>The intrinsic function contains single argument - the value to be
7070 converted.</p>
7071
7072<h5>Semantics:</h5>
7073<p>The '<tt>llvm.convert.from.fp16</tt>' intrinsic function performs a
Chris Lattner022a9fb2010-03-15 04:12:21 +0000[diff] [blame]7074 conversion from half single precision floating point format to single
Chris Lattnerbbd8bd32010-03-14 23:03:31 +0000[diff] [blame]7075 precision floating point format. The input half-float value is represented by
7076 an <tt>i16</tt> value.</p>
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7077
7078<h5>Examples:</h5>
7079<pre>
7080 %a = load i16* @x, align 2
7081 %res = call f32 @llvm.convert.from.fp16(i16 %a)
7082</pre>
7083
7084</div>
7085
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7086</div>
7087
Anton Korobeynikovcd4dd9c2010-03-14 18:42:47 +0000[diff] [blame]7088<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7089<h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7090 <a name="int_debugger">Debugger Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7091</h3>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7092
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7093<div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7094
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7095<p>The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt>
7096 prefix), are described in
7097 the <a href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source
7098 Level Debugging</a> document.</p>
7099
7100</div>
Chris Lattner941515c2004-01-06 05:31:32 +0000[diff] [blame]7101
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7102<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7103<h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7104 <a name="int_eh">Exception Handling Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7105</h3>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7106
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7107<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7108
7109<p>The LLVM exception handling intrinsics (which all start with
7110 <tt>llvm.eh.</tt> prefix), are described in
7111 the <a href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
7112 Handling</a> document.</p>
7113
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7114</div>
7115
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7116<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7117<h3>
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7118 <a name="int_trampoline">Trampoline Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7119</h3>
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7120
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7121<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7122
7123<p>This intrinsic makes it possible to excise one parameter, marked with
Dan Gohman3770af52010-07-02 23:18:08 +0000[diff] [blame]7124 the <a href="#nest"><tt>nest</tt></a> attribute, from a function.
7125 The result is a callable
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7126 function pointer lacking the nest parameter - the caller does not need to
7127 provide a value for it. Instead, the value to use is stored in advance in a
7128 "trampoline", a block of memory usually allocated on the stack, which also
7129 contains code to splice the nest value into the argument list. This is used
7130 to implement the GCC nested function address extension.</p>
7131
7132<p>For example, if the function is
7133 <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
7134 pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as
7135 follows:</p>
7136
Benjamin Kramer79698be2010-07-13 12:26:09 +0000[diff] [blame]7137<pre class="doc_code">
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7138 %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
7139 %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7140 %p = call i8* @llvm.init.trampoline(i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval)
Duncan Sands86e01192007-09-11 14:10:23 +0000[diff] [blame]7141 %fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7142</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7143
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7144<p>The call <tt>%val = call i32 %fp(i32 %x, i32 %y)</tt> is then equivalent
7145 to <tt>%val = call i32 %f(i8* %nval, i32 %x, i32 %y)</tt>.</p>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7146
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7147<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7148<h4>
7149 <a name="int_it">
7150 '<tt>llvm.init.trampoline</tt>' Intrinsic
7151 </a>
7152</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7153
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7154<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7155
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7156<h5>Syntax:</h5>
7157<pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7158 declare i8* @llvm.init.trampoline(i8* &lt;tramp&gt;, i8* &lt;func&gt;, i8* &lt;nval&gt;)
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7159</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7160
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7161<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7162<p>This fills the memory pointed to by <tt>tramp</tt> with code and returns a
7163 function pointer suitable for executing it.</p>
7164
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7165<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7166<p>The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
7167 pointers. The <tt>tramp</tt> argument must point to a sufficiently large and
7168 sufficiently aligned block of memory; this memory is written to by the
7169 intrinsic. Note that the size and the alignment are target-specific - LLVM
7170 currently provides no portable way of determining them, so a front-end that
7171 generates this intrinsic needs to have some target-specific knowledge.
7172 The <tt>func</tt> argument must hold a function bitcast to
7173 an <tt>i8*</tt>.</p>
7174
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7175<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7176<p>The block of memory pointed to by <tt>tramp</tt> is filled with target
7177 dependent code, turning it into a function. A pointer to this function is
7178 returned, but needs to be bitcast to an <a href="#int_trampoline">appropriate
7179 function pointer type</a> before being called. The new function's signature
7180 is the same as that of <tt>func</tt> with any arguments marked with
7181 the <tt>nest</tt> attribute removed. At most one such <tt>nest</tt> argument
7182 is allowed, and it must be of pointer type. Calling the new function is
7183 equivalent to calling <tt>func</tt> with the same argument list, but
7184 with <tt>nval</tt> used for the missing <tt>nest</tt> argument. If, after
7185 calling <tt>llvm.init.trampoline</tt>, the memory pointed to
7186 by <tt>tramp</tt> is modified, then the effect of any later call to the
7187 returned function pointer is undefined.</p>
7188
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7189</div>
7190
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7191</div>
7192
Duncan Sands644f9172007-07-27 12:58:54 +0000[diff] [blame]7193<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7194<h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7195 <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7196</h3>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7197
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7198<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7199
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7200<p>These intrinsic functions expand the "universal IR" of LLVM to represent
7201 hardware constructs for atomic operations and memory synchronization. This
7202 provides an interface to the hardware, not an interface to the programmer. It
7203 is aimed at a low enough level to allow any programming models or APIs
7204 (Application Programming Interfaces) which need atomic behaviors to map
7205 cleanly onto it. It is also modeled primarily on hardware behavior. Just as
7206 hardware provides a "universal IR" for source languages, it also provides a
7207 starting point for developing a "universal" atomic operation and
7208 synchronization IR.</p>
7209
7210<p>These do <em>not</em> form an API such as high-level threading libraries,
7211 software transaction memory systems, atomic primitives, and intrinsic
7212 functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
7213 application libraries. The hardware interface provided by LLVM should allow
7214 a clean implementation of all of these APIs and parallel programming models.
7215 No one model or paradigm should be selected above others unless the hardware
7216 itself ubiquitously does so.</p>
7217
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7218<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7219<h4>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7220 <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7221</h4>
7222
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7223<div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7224<h5>Syntax:</h5>
7225<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7226 declare void @llvm.memory.barrier(i1 &lt;ll&gt;, i1 &lt;ls&gt;, i1 &lt;sl&gt;, i1 &lt;ss&gt;, i1 &lt;device&gt;)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7227</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7228
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7229<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7230<p>The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
7231 specific pairs of memory access types.</p>
7232
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7233<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7234<p>The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
7235 The first four arguments enables a specific barrier as listed below. The
Dan Gohmana269a0a2010-03-01 17:41:39 +0000[diff] [blame]7236 fifth argument specifies that the barrier applies to io or device or uncached
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7237 memory.</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7238
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7239<ul>
7240 <li><tt>ll</tt>: load-load barrier</li>
7241 <li><tt>ls</tt>: load-store barrier</li>
7242 <li><tt>sl</tt>: store-load barrier</li>
7243 <li><tt>ss</tt>: store-store barrier</li>
7244 <li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
7245</ul>
7246
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7247<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7248<p>This intrinsic causes the system to enforce some ordering constraints upon
7249 the loads and stores of the program. This barrier does not
7250 indicate <em>when</em> any events will occur, it only enforces
7251 an <em>order</em> in which they occur. For any of the specified pairs of load
7252 and store operations (f.ex. load-load, or store-load), all of the first
7253 operations preceding the barrier will complete before any of the second
7254 operations succeeding the barrier begin. Specifically the semantics for each
7255 pairing is as follows:</p>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7256
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7257<ul>
7258 <li><tt>ll</tt>: All loads before the barrier must complete before any load
7259 after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7260 <li><tt>ls</tt>: All loads before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7261 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7262 <li><tt>ss</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7263 store after the barrier begins.</li>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7264 <li><tt>sl</tt>: All stores before the barrier must complete before any
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7265 load after the barrier begins.</li>
7266</ul>
7267
7268<p>These semantics are applied with a logical "and" behavior when more than one
7269 is enabled in a single memory barrier intrinsic.</p>
7270
7271<p>Backends may implement stronger barriers than those requested when they do
7272 not support as fine grained a barrier as requested. Some architectures do
7273 not need all types of barriers and on such architectures, these become
7274 noops.</p>
7275
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7276<h5>Example:</h5>
7277<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7278%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7279%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7280 store i32 4, %ptr
7281
7282%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
Evan Cheng0ac49c62011-06-29 17:14:00 +0000[diff] [blame]7283 call void @llvm.memory.barrier(i1 false, i1 true, i1 false, i1 false, i1 true)
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7284 <i>; guarantee the above finishes</i>
7285 store i32 8, %ptr <i>; before this begins</i>
7286</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7287
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7288</div>
7289
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7290<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7291<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7292 <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7293</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7294
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7295<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7296
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7297<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7298<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
7299 any integer bit width and for different address spaces. Not all targets
7300 support all bit widths however.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7301
7302<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7303 declare i8 @llvm.atomic.cmp.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;cmp&gt;, i8 &lt;val&gt;)
7304 declare i16 @llvm.atomic.cmp.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;cmp&gt;, i16 &lt;val&gt;)
7305 declare i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;cmp&gt;, i32 &lt;val&gt;)
7306 declare i64 @llvm.atomic.cmp.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;cmp&gt;, i64 &lt;val&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7307</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7308
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7309<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7310<p>This loads a value in memory and compares it to a given value. If they are
7311 equal, it stores a new value into the memory.</p>
7312
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7313<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7314<p>The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result
7315 as well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
7316 same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
7317 this integer type. While any bit width integer may be used, targets may only
7318 lower representations they support in hardware.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7319
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7320<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7321<p>This entire intrinsic must be executed atomically. It first loads the value
7322 in memory pointed to by <tt>ptr</tt> and compares it with the
7323 value <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the
7324 memory. The loaded value is yielded in all cases. This provides the
7325 equivalent of an atomic compare-and-swap operation within the SSA
7326 framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7327
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7328<h5>Examples:</h5>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7329<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7330%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7331%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7332 store i32 4, %ptr
7333
7334%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7335%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 4, %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7336 <i>; yields {i32}:result1 = 4</i>
7337%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7338%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7339
7340%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7341%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32(i32* %ptr, i32 5, %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7342 <i>; yields {i32}:result2 = 8</i>
7343%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
7344
7345%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
7346</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7347
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7348</div>
7349
7350<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7351<h4>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7352 <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7353</h4>
7354
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7355<div>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7356<h5>Syntax:</h5>
7357
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7358<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
7359 integer bit width. Not all targets support all bit widths however.</p>
7360
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7361<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7362 declare i8 @llvm.atomic.swap.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;val&gt;)
7363 declare i16 @llvm.atomic.swap.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;val&gt;)
7364 declare i32 @llvm.atomic.swap.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;val&gt;)
7365 declare i64 @llvm.atomic.swap.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;val&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7366</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7367
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7368<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7369<p>This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
7370 the value from memory. It then stores the value in <tt>val</tt> in the memory
7371 at <tt>ptr</tt>.</p>
7372
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7373<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7374<p>The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both
7375 the <tt>val</tt> argument and the result must be integers of the same bit
7376 width. The first argument, <tt>ptr</tt>, must be a pointer to a value of this
7377 integer type. The targets may only lower integer representations they
7378 support.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7379
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7380<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7381<p>This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
7382 stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
7383 equivalent of an atomic swap operation within the SSA framework.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7384
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7385<h5>Examples:</h5>
7386<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7387%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7388%ptr = bitcast i8* %mallocP to i32*
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7389 store i32 4, %ptr
7390
7391%val1 = add i32 4, 4
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7392%result1 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val1)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7393 <i>; yields {i32}:result1 = 4</i>
7394%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
7395%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
7396
7397%val2 = add i32 1, 1
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7398%result2 = call i32 @llvm.atomic.swap.i32.p0i32(i32* %ptr, i32 %val2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7399 <i>; yields {i32}:result2 = 8</i>
7400
7401%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
7402%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
7403</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7404
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7405</div>
7406
7407<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7408<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7409 <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7410</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7411
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7412<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7413
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7414<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7415<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on
7416 any integer bit width. Not all targets support all bit widths however.</p>
7417
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7418<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7419 declare i8 @llvm.atomic.load.add.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7420 declare i16 @llvm.atomic.load.add.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7421 declare i32 @llvm.atomic.load.add.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7422 declare i64 @llvm.atomic.load.add.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7423</pre>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7424
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7425<h5>Overview:</h5>
7426<p>This intrinsic adds <tt>delta</tt> to the value stored in memory
7427 at <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7428
7429<h5>Arguments:</h5>
7430<p>The intrinsic takes two arguments, the first a pointer to an integer value
7431 and the second an integer value. The result is also an integer value. These
7432 integer types can have any bit width, but they must all have the same bit
7433 width. The targets may only lower integer representations they support.</p>
7434
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7435<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7436<p>This intrinsic does a series of operations atomically. It first loads the
7437 value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
7438 to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.</p>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7439
7440<h5>Examples:</h5>
7441<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7442%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7443%ptr = bitcast i8* %mallocP to i32*
7444 store i32 4, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7445%result1 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 4)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7446 <i>; yields {i32}:result1 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7447%result2 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 2)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7448 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7449%result3 = call i32 @llvm.atomic.load.add.i32.p0i32(i32* %ptr, i32 5)
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7450 <i>; yields {i32}:result3 = 10</i>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7451%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7452</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7453
Andrew Lenharth95528942008-02-21 06:45:13 +0000[diff] [blame]7454</div>
7455
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7456<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7457<h4>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7458 <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7459</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7460
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7461<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7462
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7463<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7464<p>This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
7465 any integer bit width and for different address spaces. Not all targets
7466 support all bit widths however.</p>
7467
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7468<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7469 declare i8 @llvm.atomic.load.sub.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7470 declare i16 @llvm.atomic.load.sub.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7471 declare i32 @llvm.atomic.load.sub.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7472 declare i64 @llvm.atomic.load.sub.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7473</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7474
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7475<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7476<p>This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7477 <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.</p>
7478
7479<h5>Arguments:</h5>
7480<p>The intrinsic takes two arguments, the first a pointer to an integer value
7481 and the second an integer value. The result is also an integer value. These
7482 integer types can have any bit width, but they must all have the same bit
7483 width. The targets may only lower integer representations they support.</p>
7484
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7485<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7486<p>This intrinsic does a series of operations atomically. It first loads the
7487 value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
7488 result to <tt>ptr</tt>. It yields the original value stored
7489 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7490
7491<h5>Examples:</h5>
7492<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7493%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7494%ptr = bitcast i8* %mallocP to i32*
7495 store i32 8, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7496%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 4)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7497 <i>; yields {i32}:result1 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7498%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7499 <i>; yields {i32}:result2 = 4</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7500%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32(i32* %ptr, i32 5)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7501 <i>; yields {i32}:result3 = 2</i>
7502%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
7503</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7504
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7505</div>
7506
7507<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7508<h4>
7509 <a name="int_atomic_load_and">
7510 '<tt>llvm.atomic.load.and.*</tt>' Intrinsic
7511 </a>
7512 <br>
7513 <a name="int_atomic_load_nand">
7514 '<tt>llvm.atomic.load.nand.*</tt>' Intrinsic
7515 </a>
7516 <br>
7517 <a name="int_atomic_load_or">
7518 '<tt>llvm.atomic.load.or.*</tt>' Intrinsic
7519 </a>
7520 <br>
7521 <a name="int_atomic_load_xor">
7522 '<tt>llvm.atomic.load.xor.*</tt>' Intrinsic
7523 </a>
7524</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7525
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7526<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7527
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7528<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7529<p>These are overloaded intrinsics. You can
7530 use <tt>llvm.atomic.load_and</tt>, <tt>llvm.atomic.load_nand</tt>,
7531 <tt>llvm.atomic.load_or</tt>, and <tt>llvm.atomic.load_xor</tt> on any integer
7532 bit width and for different address spaces. Not all targets support all bit
7533 widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7534
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7535<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7536 declare i8 @llvm.atomic.load.and.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7537 declare i16 @llvm.atomic.load.and.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7538 declare i32 @llvm.atomic.load.and.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7539 declare i64 @llvm.atomic.load.and.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7540</pre>
7541
7542<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7543 declare i8 @llvm.atomic.load.or.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7544 declare i16 @llvm.atomic.load.or.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7545 declare i32 @llvm.atomic.load.or.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7546 declare i64 @llvm.atomic.load.or.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7547</pre>
7548
7549<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7550 declare i8 @llvm.atomic.load.nand.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7551 declare i16 @llvm.atomic.load.nand.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7552 declare i32 @llvm.atomic.load.nand.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7553 declare i64 @llvm.atomic.load.nand.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7554</pre>
7555
7556<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7557 declare i8 @llvm.atomic.load.xor.i8.p0i32(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7558 declare i16 @llvm.atomic.load.xor.i16.p0i32(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7559 declare i32 @llvm.atomic.load.xor.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7560 declare i64 @llvm.atomic.load.xor.i64.p0i32(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7561</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7562
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7563<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7564<p>These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
7565 the value stored in memory at <tt>ptr</tt>. It yields the original value
7566 at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7567
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7568<h5>Arguments:</h5>
7569<p>These intrinsics take two arguments, the first a pointer to an integer value
7570 and the second an integer value. The result is also an integer value. These
7571 integer types can have any bit width, but they must all have the same bit
7572 width. The targets may only lower integer representations they support.</p>
7573
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7574<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7575<p>These intrinsics does a series of operations atomically. They first load the
7576 value stored at <tt>ptr</tt>. They then do the bitwise
7577 operation <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the
7578 original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7579
7580<h5>Examples:</h5>
7581<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7582%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7583%ptr = bitcast i8* %mallocP to i32*
7584 store i32 0x0F0F, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7585%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7586 <i>; yields {i32}:result0 = 0x0F0F</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7587%result1 = call i32 @llvm.atomic.load.and.i32.p0i32(i32* %ptr, i32 0xFF)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7588 <i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7589%result2 = call i32 @llvm.atomic.load.or.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7590 <i>; yields {i32}:result2 = 0xF0</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7591%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32(i32* %ptr, i32 0F)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7592 <i>; yields {i32}:result3 = FF</i>
7593%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
7594</pre>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7595
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7596</div>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7597
7598<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7599<h4>
7600 <a name="int_atomic_load_max">
7601 '<tt>llvm.atomic.load.max.*</tt>' Intrinsic
7602 </a>
7603 <br>
7604 <a name="int_atomic_load_min">
7605 '<tt>llvm.atomic.load.min.*</tt>' Intrinsic
7606 </a>
7607 <br>
7608 <a name="int_atomic_load_umax">
7609 '<tt>llvm.atomic.load.umax.*</tt>' Intrinsic
7610 </a>
7611 <br>
7612 <a name="int_atomic_load_umin">
7613 '<tt>llvm.atomic.load.umin.*</tt>' Intrinsic
7614 </a>
7615</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7616
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7617<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7618
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7619<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7620<p>These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
7621 <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
7622 <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
7623 address spaces. Not all targets support all bit widths however.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7624
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7625<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7626 declare i8 @llvm.atomic.load.max.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7627 declare i16 @llvm.atomic.load.max.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7628 declare i32 @llvm.atomic.load.max.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7629 declare i64 @llvm.atomic.load.max.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7630</pre>
7631
7632<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7633 declare i8 @llvm.atomic.load.min.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7634 declare i16 @llvm.atomic.load.min.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7635 declare i32 @llvm.atomic.load.min.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7636 declare i64 @llvm.atomic.load.min.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7637</pre>
7638
7639<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7640 declare i8 @llvm.atomic.load.umax.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7641 declare i16 @llvm.atomic.load.umax.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7642 declare i32 @llvm.atomic.load.umax.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7643 declare i64 @llvm.atomic.load.umax.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7644</pre>
7645
7646<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7647 declare i8 @llvm.atomic.load.umin.i8.p0i8(i8* &lt;ptr&gt;, i8 &lt;delta&gt;)
7648 declare i16 @llvm.atomic.load.umin.i16.p0i16(i16* &lt;ptr&gt;, i16 &lt;delta&gt;)
7649 declare i32 @llvm.atomic.load.umin.i32.p0i32(i32* &lt;ptr&gt;, i32 &lt;delta&gt;)
7650 declare i64 @llvm.atomic.load.umin.i64.p0i64(i64* &lt;ptr&gt;, i64 &lt;delta&gt;)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7651</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7652
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7653<h5>Overview:</h5>
Eric Christopher455c5772009-12-05 02:46:03 +0000[diff] [blame]7654<p>These intrinsics takes the signed or unsigned minimum or maximum of
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7655 <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
7656 original value at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7657
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7658<h5>Arguments:</h5>
7659<p>These intrinsics take two arguments, the first a pointer to an integer value
7660 and the second an integer value. The result is also an integer value. These
7661 integer types can have any bit width, but they must all have the same bit
7662 width. The targets may only lower integer representations they support.</p>
7663
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7664<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7665<p>These intrinsics does a series of operations atomically. They first load the
7666 value stored at <tt>ptr</tt>. They then do the signed or unsigned min or
7667 max <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They
7668 yield the original value stored at <tt>ptr</tt>.</p>
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7669
7670<h5>Examples:</h5>
7671<pre>
Victor Hernandeza70c6df2009-10-26 23:44:29 +0000[diff] [blame]7672%mallocP = tail call i8* @malloc(i32 ptrtoint (i32* getelementptr (i32* null, i32 1) to i32))
7673%ptr = bitcast i8* %mallocP to i32*
7674 store i32 7, %ptr
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7675%result0 = call i32 @llvm.atomic.load.min.i32.p0i32(i32* %ptr, i32 -2)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7676 <i>; yields {i32}:result0 = 7</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7677%result1 = call i32 @llvm.atomic.load.max.i32.p0i32(i32* %ptr, i32 8)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7678 <i>; yields {i32}:result1 = -2</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7679%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32(i32* %ptr, i32 10)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7680 <i>; yields {i32}:result2 = 8</i>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7681%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32(i32* %ptr, i32 30)
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7682 <i>; yields {i32}:result3 = 8</i>
7683%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
7684</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7685
Mon P Wang6a490372008-06-25 08:15:39 +0000[diff] [blame]7686</div>
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7687
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7688</div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7689
7690<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7691<h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7692 <a name="int_memorymarkers">Memory Use Markers</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7693</h3>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7694
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7695<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7696
7697<p>This class of intrinsics exists to information about the lifetime of memory
7698 objects and ranges where variables are immutable.</p>
7699
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7700<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7701<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7702 <a name="int_lifetime_start">'<tt>llvm.lifetime.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7703</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7704
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7705<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7706
7707<h5>Syntax:</h5>
7708<pre>
7709 declare void @llvm.lifetime.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7710</pre>
7711
7712<h5>Overview:</h5>
7713<p>The '<tt>llvm.lifetime.start</tt>' intrinsic specifies the start of a memory
7714 object's lifetime.</p>
7715
7716<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7717<p>The first argument is a constant integer representing the size of the
7718 object, or -1 if it is variable sized. The second argument is a pointer to
7719 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7720
7721<h5>Semantics:</h5>
7722<p>This intrinsic indicates that before this point in the code, the value of the
7723 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
Nick Lewyckyd20fd592009-10-27 16:56:58 +0000[diff] [blame]7724 never be used and has an undefined value. A load from the pointer that
7725 precedes this intrinsic can be replaced with
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7726 <tt>'<a href="#undefvalues">undef</a>'</tt>.</p>
7727
7728</div>
7729
7730<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7731<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7732 <a name="int_lifetime_end">'<tt>llvm.lifetime.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7733</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7734
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7735<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7736
7737<h5>Syntax:</h5>
7738<pre>
7739 declare void @llvm.lifetime.end(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7740</pre>
7741
7742<h5>Overview:</h5>
7743<p>The '<tt>llvm.lifetime.end</tt>' intrinsic specifies the end of a memory
7744 object's lifetime.</p>
7745
7746<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7747<p>The first argument is a constant integer representing the size of the
7748 object, or -1 if it is variable sized. The second argument is a pointer to
7749 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7750
7751<h5>Semantics:</h5>
7752<p>This intrinsic indicates that after this point in the code, the value of the
7753 memory pointed to by <tt>ptr</tt> is dead. This means that it is known to
7754 never be used and has an undefined value. Any stores into the memory object
7755 following this intrinsic may be removed as dead.
7756
7757</div>
7758
7759<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7760<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7761 <a name="int_invariant_start">'<tt>llvm.invariant.start</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7762</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7763
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7764<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7765
7766<h5>Syntax:</h5>
7767<pre>
Nick Lewycky2965d3e2010-11-30 04:13:41 +0000[diff] [blame]7768 declare {}* @llvm.invariant.start(i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7769</pre>
7770
7771<h5>Overview:</h5>
7772<p>The '<tt>llvm.invariant.start</tt>' intrinsic specifies that the contents of
7773 a memory object will not change.</p>
7774
7775<h5>Arguments:</h5>
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7776<p>The first argument is a constant integer representing the size of the
7777 object, or -1 if it is variable sized. The second argument is a pointer to
7778 the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7779
7780<h5>Semantics:</h5>
7781<p>This intrinsic indicates that until an <tt>llvm.invariant.end</tt> that uses
7782 the return value, the referenced memory location is constant and
7783 unchanging.</p>
7784
7785</div>
7786
7787<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7788<h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7789 <a name="int_invariant_end">'<tt>llvm.invariant.end</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7790</h4>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7791
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7792<div>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7793
7794<h5>Syntax:</h5>
7795<pre>
7796 declare void @llvm.invariant.end({}* &lt;start&gt;, i64 &lt;size&gt;, i8* nocapture &lt;ptr&gt;)
7797</pre>
7798
7799<h5>Overview:</h5>
7800<p>The '<tt>llvm.invariant.end</tt>' intrinsic specifies that the contents of
7801 a memory object are mutable.</p>
7802
7803<h5>Arguments:</h5>
7804<p>The first argument is the matching <tt>llvm.invariant.start</tt> intrinsic.
Nick Lewycky9bc89042009-10-13 07:57:33 +0000[diff] [blame]7805 The second argument is a constant integer representing the size of the
7806 object, or -1 if it is variable sized and the third argument is a pointer
7807 to the object.</p>
Nick Lewycky6f7d8342009-10-13 07:03:23 +0000[diff] [blame]7808
7809<h5>Semantics:</h5>
7810<p>This intrinsic indicates that the memory is mutable again.</p>
7811
7812</div>
7813
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7814</div>
7815
Andrew Lenharth9b254ee2008-02-16 01:24:58 +0000[diff] [blame]7816<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7817<h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7818 <a name="int_general">General Intrinsics</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7819</h3>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7820
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7821<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7822
7823<p>This class of intrinsics is designed to be generic and has no specific
7824 purpose.</p>
7825
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7826<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7827<h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7828 <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7829</h4>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7830
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7831<div>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7832
7833<h5>Syntax:</h5>
7834<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7835 declare void @llvm.var.annotation(i8* &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7836</pre>
7837
7838<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7839<p>The '<tt>llvm.var.annotation</tt>' intrinsic.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7840
7841<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7842<p>The first argument is a pointer to a value, the second is a pointer to a
7843 global string, the third is a pointer to a global string which is the source
7844 file name, and the last argument is the line number.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7845
7846<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7847<p>This intrinsic allows annotation of local variables with arbitrary strings.
7848 This can be useful for special purpose optimizations that want to look for
7849 these annotations. These have no other defined use, they are ignored by code
7850 generation and optimization.</p>
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7851
Tanya Lattnercb1b9602007-06-15 20:50:54 +0000[diff] [blame]7852</div>
7853
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7854<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7855<h4>
Tanya Lattner0186a652007-09-21 23:57:59 +0000[diff] [blame]7856 <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7857</h4>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7858
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7859<div>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7860
7861<h5>Syntax:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7862<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
7863 any integer bit width.</p>
7864
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7865<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7866 declare i8 @llvm.annotation.i8(i8 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7867 declare i16 @llvm.annotation.i16(i16 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7868 declare i32 @llvm.annotation.i32(i32 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7869 declare i64 @llvm.annotation.i64(i64 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
7870 declare i256 @llvm.annotation.i256(i256 &lt;val&gt;, i8* &lt;str&gt;, i8* &lt;str&gt;, i32 &lt;int&gt;)
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7871</pre>
7872
7873<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7874<p>The '<tt>llvm.annotation</tt>' intrinsic.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7875
7876<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7877<p>The first argument is an integer value (result of some expression), the
7878 second is a pointer to a global string, the third is a pointer to a global
7879 string which is the source file name, and the last argument is the line
7880 number. It returns the value of the first argument.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7881
7882<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7883<p>This intrinsic allows annotations to be put on arbitrary expressions with
7884 arbitrary strings. This can be useful for special purpose optimizations that
7885 want to look for these annotations. These have no other defined use, they
7886 are ignored by code generation and optimization.</p>
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7887
Tanya Lattner293c0372007-09-21 22:59:12 +0000[diff] [blame]7888</div>
Jim Laskey2211f492007-03-14 19:31:19 +0000[diff] [blame]7889
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7890<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7891<h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7892 <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7893</h4>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7894
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7895<div>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7896
7897<h5>Syntax:</h5>
7898<pre>
7899 declare void @llvm.trap()
7900</pre>
7901
7902<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7903<p>The '<tt>llvm.trap</tt>' intrinsic.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7904
7905<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7906<p>None.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7907
7908<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7909<p>This intrinsics is lowered to the target dependent trap instruction. If the
7910 target does not have a trap instruction, this intrinsic will be lowered to
7911 the call of the <tt>abort()</tt> function.</p>
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7912
Anton Korobeynikov06cbb652008-01-15 22:31:34 +0000[diff] [blame]7913</div>
7914
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7915<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7916<h4>
Misha Brukman50de2b22008-11-22 23:55:29 +0000[diff] [blame]7917 <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7918</h4>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7919
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7920<div>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7921
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7922<h5>Syntax:</h5>
7923<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7924 declare void @llvm.stackprotector(i8* &lt;guard&gt;, i8** &lt;slot&gt;)
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7925</pre>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7926
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7927<h5>Overview:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7928<p>The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and
7929 stores it onto the stack at <tt>slot</tt>. The stack slot is adjusted to
7930 ensure that it is placed on the stack before local variables.</p>
7931
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7932<h5>Arguments:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7933<p>The <tt>llvm.stackprotector</tt> intrinsic requires two pointer
7934 arguments. The first argument is the value loaded from the stack
7935 guard <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt>
7936 that has enough space to hold the value of the guard.</p>
7937
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7938<h5>Semantics:</h5>
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7939<p>This intrinsic causes the prologue/epilogue inserter to force the position of
7940 the <tt>AllocaInst</tt> stack slot to be before local variables on the
7941 stack. This is to ensure that if a local variable on the stack is
7942 overwritten, it will destroy the value of the guard. When the function exits,
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7943 the guard on the stack is checked against the original guard. If they are
Bill Wendlingd9a66f72009-07-20 02:29:24 +0000[diff] [blame]7944 different, then the program aborts by calling the <tt>__stack_chk_fail()</tt>
7945 function.</p>
7946
Bill Wendling14313312008-11-19 05:56:17 +0000[diff] [blame]7947</div>
7948
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7949<!-- _______________________________________________________________________ -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7950<h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7951 <a name="int_objectsize">'<tt>llvm.objectsize</tt>' Intrinsic</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]7952</h4>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7953
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7954<div>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7955
7956<h5>Syntax:</h5>
7957<pre>
Dan Gohmand6a6f612010-05-28 17:07:41 +0000[diff] [blame]7958 declare i32 @llvm.objectsize.i32(i8* &lt;object&gt;, i1 &lt;type&gt;)
7959 declare i64 @llvm.objectsize.i64(i8* &lt;object&gt;, i1 &lt;type&gt;)
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7960</pre>
7961
7962<h5>Overview:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7963<p>The <tt>llvm.objectsize</tt> intrinsic is designed to provide information to
7964 the optimizers to determine at compile time whether a) an operation (like
7965 memcpy) will overflow a buffer that corresponds to an object, or b) that a
7966 runtime check for overflow isn't necessary. An object in this context means
7967 an allocation of a specific class, structure, array, or other object.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7968
7969<h5>Arguments:</h5>
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7970<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7971 argument is a pointer to or into the <tt>object</tt>. The second argument
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7972 is a boolean 0 or 1. This argument determines whether you want the
7973 maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or
Eric Christopher31e39bd2009-12-23 00:29:49 +0000[diff] [blame]7974 1, variables are not allowed.</p>
7975
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7976<h5>Semantics:</h5>
7977<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant
Bill Wendling6bbe0912010-10-27 01:07:41 +0000[diff] [blame]7978 representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>,
7979 depending on the <tt>type</tt> argument, if the size cannot be determined at
7980 compile time.</p>
Eric Christopher73484322009-11-30 08:03:53 +0000[diff] [blame]7981
7982</div>
7983
NAKAMURA Takumiaa3d6242011-04-23 00:30:22 +0000[diff] [blame]7984</div>
7985
7986</div>
7987
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7988<!-- *********************************************************************** -->
Chris Lattner2f7c9632001-06-06 20:29:01 +0000[diff] [blame]7989<hr>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7990<address>
7991 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7992 src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7993 <a href="http://validator.w3.org/check/referer"><img
Misha Brukman86242e12008-12-11 17:34:48 +0000[diff] [blame]7994 src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7995
7996 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]7997 <a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Misha Brukmanc501f552004-03-01 17:47:27 +0000[diff] [blame]7998 Last modified: $Date$
7999</address>
Chris Lattnerb8f816e2008-01-04 04:33:49 +0000[diff] [blame]8000
Misha Brukman76307852003-11-08 01:05:38 +0000[diff] [blame]8001</body>
8002</html>