Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 1 | <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" |
| 2 | "http://www.w3.org/TR/html4/strict.dtd"> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3 | <html> |
| 4 | <head> |
| 5 | <title>LLVM Assembly Language Reference Manual</title> |
Reid Spencer | 3921c74 | 2004-08-26 20:44:00 +0000 | [diff] [blame] | 6 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
| 7 | <meta name="author" content="Chris Lattner"> |
| 8 | <meta name="description" |
| 9 | content="LLVM Assembly Language Reference Manual."> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 10 | <link rel="stylesheet" href="llvm.css" type="text/css"> |
| 11 | </head> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 12 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 13 | <body> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 14 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 15 | <div class="doc_title"> LLVM Language Reference Manual </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 16 | <ol> |
Misha Brukman | 9d0919f | 2003-11-08 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 Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 20 | <li><a href="#highlevel">High Level Structure</a> |
| 21 | <ol> |
| 22 | <li><a href="#modulestructure">Module Structure</a></li> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 23 | <li><a href="#linkage">Linkage Types</a></li> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 24 | <li><a href="#callingconv">Calling Conventions</a></li> |
Chris Lattner | e7886e4 | 2009-01-11 20:53:49 +0000 | [diff] [blame] | 25 | <li><a href="#namedtypes">Named Types</a></li> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 26 | <li><a href="#globalvars">Global Variables</a></li> |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 27 | <li><a href="#functionstructure">Functions</a></li> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 28 | <li><a href="#aliasstructure">Aliases</a></li> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 29 | <li><a href="#paramattrs">Parameter Attributes</a></li> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 30 | <li><a href="#fnattrs">Function Attributes</a></li> |
Gordon Henriksen | 80a75bf | 2007-12-10 03:18:06 +0000 | [diff] [blame] | 31 | <li><a href="#gc">Garbage Collector Names</a></li> |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 32 | <li><a href="#moduleasm">Module-Level Inline Assembly</a></li> |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 33 | <li><a href="#datalayout">Data Layout</a></li> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 34 | </ol> |
| 35 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 36 | <li><a href="#typesystem">Type System</a> |
| 37 | <ol> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 38 | <li><a href="#t_classifications">Type Classifications</a></li> |
Robert Bocchino | 7b81c75 | 2006-02-17 21:18:08 +0000 | [diff] [blame] | 39 | <li><a href="#t_primitive">Primitive Types</a> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 40 | <ol> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 41 | <li><a href="#t_floating">Floating Point Types</a></li> |
| 42 | <li><a href="#t_void">Void Type</a></li> |
| 43 | <li><a href="#t_label">Label Type</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 44 | </ol> |
| 45 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 46 | <li><a href="#t_derived">Derived Types</a> |
| 47 | <ol> |
Chris Lattner | b9488a6 | 2007-12-18 06:18:21 +0000 | [diff] [blame] | 48 | <li><a href="#t_integer">Integer Type</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 49 | <li><a href="#t_array">Array Type</a></li> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 50 | <li><a href="#t_function">Function Type</a></li> |
| 51 | <li><a href="#t_pointer">Pointer Type</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 52 | <li><a href="#t_struct">Structure Type</a></li> |
Andrew Lenharth | 75e1068 | 2006-12-08 17:13:00 +0000 | [diff] [blame] | 53 | <li><a href="#t_pstruct">Packed Structure Type</a></li> |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 54 | <li><a href="#t_vector">Vector Type</a></li> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 55 | <li><a href="#t_opaque">Opaque Type</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 56 | </ol> |
| 57 | </li> |
| 58 | </ol> |
| 59 | </li> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 60 | <li><a href="#constants">Constants</a> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 61 | <ol> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 62 | <li><a href="#simpleconstants">Simple Constants</a></li> |
| 63 | <li><a href="#aggregateconstants">Aggregate Constants</a></li> |
| 64 | <li><a href="#globalconstants">Global Variable and Function Addresses</a></li> |
| 65 | <li><a href="#undefvalues">Undefined Values</a></li> |
| 66 | <li><a href="#constantexprs">Constant Expressions</a></li> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 67 | </ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 68 | </li> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 69 | <li><a href="#othervalues">Other Values</a> |
| 70 | <ol> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 71 | <li><a href="#inlineasm">Inline Assembler Expressions</a></li> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 72 | </ol> |
| 73 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 74 | <li><a href="#instref">Instruction Reference</a> |
| 75 | <ol> |
| 76 | <li><a href="#terminators">Terminator Instructions</a> |
| 77 | <ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 78 | <li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li> |
| 79 | <li><a href="#i_br">'<tt>br</tt>' Instruction</a></li> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 80 | <li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li> |
| 81 | <li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 82 | <li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 83 | <li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 84 | </ol> |
| 85 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 86 | <li><a href="#binaryops">Binary Operations</a> |
| 87 | <ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 88 | <li><a href="#i_add">'<tt>add</tt>' Instruction</a></li> |
| 89 | <li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li> |
| 90 | <li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 91 | <li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li> |
| 92 | <li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li> |
| 93 | <li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 94 | <li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li> |
| 95 | <li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li> |
| 96 | <li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 97 | </ol> |
| 98 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 99 | <li><a href="#bitwiseops">Bitwise Binary Operations</a> |
| 100 | <ol> |
Reid Spencer | 8e11bf8 | 2007-02-02 13:57:07 +0000 | [diff] [blame] | 101 | <li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li> |
| 102 | <li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li> |
| 103 | <li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 104 | <li><a href="#i_and">'<tt>and</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 105 | <li><a href="#i_or">'<tt>or</tt>' Instruction</a></li> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 106 | <li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 107 | </ol> |
| 108 | </li> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 109 | <li><a href="#vectorops">Vector Operations</a> |
| 110 | <ol> |
| 111 | <li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li> |
| 112 | <li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li> |
| 113 | <li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 114 | </ol> |
| 115 | </li> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 116 | <li><a href="#aggregateops">Aggregate Operations</a> |
| 117 | <ol> |
| 118 | <li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li> |
| 119 | <li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li> |
| 120 | </ol> |
| 121 | </li> |
Chris Lattner | 884a970 | 2006-08-15 00:45:58 +0000 | [diff] [blame] | 122 | <li><a href="#memoryops">Memory Access and Addressing Operations</a> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 123 | <ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 124 | <li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li> |
| 125 | <li><a href="#i_free">'<tt>free</tt>' Instruction</a></li> |
| 126 | <li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li> |
Robert Bocchino | 7b81c75 | 2006-02-17 21:18:08 +0000 | [diff] [blame] | 127 | <li><a href="#i_load">'<tt>load</tt>' Instruction</a></li> |
| 128 | <li><a href="#i_store">'<tt>store</tt>' Instruction</a></li> |
| 129 | <li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 130 | </ol> |
| 131 | </li> |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 132 | <li><a href="#convertops">Conversion Operations</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 133 | <ol> |
| 134 | <li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li> |
| 135 | <li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li> |
| 136 | <li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li> |
| 137 | <li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li> |
| 138 | <li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 139 | <li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li> |
| 140 | <li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li> |
| 141 | <li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li> |
| 142 | <li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 143 | <li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li> |
| 144 | <li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li> |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 145 | <li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 146 | </ol> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 147 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 148 | <li><a href="#otherops">Other Operations</a> |
| 149 | <ol> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 150 | <li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li> |
| 151 | <li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 152 | <li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li> |
| 153 | <li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 154 | <li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 155 | <li><a href="#i_select">'<tt>select</tt>' Instruction</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 156 | <li><a href="#i_call">'<tt>call</tt>' Instruction</a></li> |
Chris Lattner | fb6977d | 2006-01-13 23:26:01 +0000 | [diff] [blame] | 157 | <li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 158 | </ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 159 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 160 | </ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 161 | </li> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 162 | <li><a href="#intrinsics">Intrinsic Functions</a> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 163 | <ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 164 | <li><a href="#int_varargs">Variable Argument Handling Intrinsics</a> |
| 165 | <ol> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 166 | <li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li> |
| 167 | <li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li> |
| 168 | <li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 169 | </ol> |
| 170 | </li> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 171 | <li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a> |
| 172 | <ol> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 173 | <li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li> |
| 174 | <li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li> |
| 175 | <li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 176 | </ol> |
| 177 | </li> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 178 | <li><a href="#int_codegen">Code Generator Intrinsics</a> |
| 179 | <ol> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 180 | <li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li> |
| 181 | <li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li> |
| 182 | <li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li> |
| 183 | <li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li> |
| 184 | <li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li> |
| 185 | <li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li> |
| 186 | <li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li> |
John Criswell | 7123e27 | 2004-04-09 16:43:20 +0000 | [diff] [blame] | 187 | </ol> |
| 188 | </li> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 189 | <li><a href="#int_libc">Standard C Library Intrinsics</a> |
| 190 | <ol> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 191 | <li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li> |
| 192 | <li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li> |
| 193 | <li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li> |
| 194 | <li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li> |
| 195 | <li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 196 | <li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li> |
| 197 | <li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li> |
| 198 | <li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 199 | </ol> |
| 200 | </li> |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 201 | <li><a href="#int_manip">Bit Manipulation Intrinsics</a> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 202 | <ol> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 203 | <li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li> |
Chris Lattner | 8a886be | 2006-01-16 22:34:14 +0000 | [diff] [blame] | 204 | <li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li> |
| 205 | <li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li> |
| 206 | <li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li> |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 207 | <li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li> |
| 208 | <li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 209 | </ol> |
| 210 | </li> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 211 | <li><a href="#int_debugger">Debugger intrinsics</a></li> |
Jim Laskey | dd4ef1b | 2007-03-14 19:31:19 +0000 | [diff] [blame] | 212 | <li><a href="#int_eh">Exception Handling intrinsics</a></li> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 213 | <li><a href="#int_trampoline">Trampoline Intrinsic</a> |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 214 | <ol> |
| 215 | <li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li> |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 216 | </ol> |
| 217 | </li> |
Bill Wendling | 3c44f5b | 2008-11-18 22:10:53 +0000 | [diff] [blame] | 218 | <li><a href="#int_atomics">Atomic intrinsics</a> |
| 219 | <ol> |
| 220 | <li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li> |
| 221 | <li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li> |
| 222 | <li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li> |
| 223 | <li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li> |
| 224 | <li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li> |
| 225 | <li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li> |
| 226 | <li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li> |
| 227 | <li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li> |
| 228 | <li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li> |
| 229 | <li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li> |
| 230 | <li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li> |
| 231 | <li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li> |
| 232 | <li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li> |
| 233 | </ol> |
| 234 | </li> |
Reid Spencer | 2067764 | 2007-07-20 19:59:11 +0000 | [diff] [blame] | 235 | <li><a href="#int_general">General intrinsics</a> |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 236 | <ol> |
Reid Spencer | 2067764 | 2007-07-20 19:59:11 +0000 | [diff] [blame] | 237 | <li><a href="#int_var_annotation"> |
Bill Wendling | 69e4adb | 2008-11-19 05:56:17 +0000 | [diff] [blame] | 238 | '<tt>llvm.var.annotation</tt>' Intrinsic</a></li> |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 239 | <li><a href="#int_annotation"> |
Bill Wendling | 69e4adb | 2008-11-19 05:56:17 +0000 | [diff] [blame] | 240 | '<tt>llvm.annotation.*</tt>' Intrinsic</a></li> |
Anton Korobeynikov | 4cb8618 | 2008-01-15 22:31:34 +0000 | [diff] [blame] | 241 | <li><a href="#int_trap"> |
Bill Wendling | 69e4adb | 2008-11-19 05:56:17 +0000 | [diff] [blame] | 242 | '<tt>llvm.trap</tt>' Intrinsic</a></li> |
| 243 | <li><a href="#int_stackprotector"> |
| 244 | '<tt>llvm.stackprotector</tt>' Intrinsic</a></li> |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 245 | </ol> |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 246 | </li> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 247 | </ol> |
| 248 | </li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 249 | </ol> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 250 | |
| 251 | <div class="doc_author"> |
| 252 | <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a> |
| 253 | and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 254 | </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 255 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 256 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 257 | <div class="doc_section"> <a name="abstract">Abstract </a></div> |
| 258 | <!-- *********************************************************************** --> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 259 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 260 | <div class="doc_text"> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 261 | <p>This document is a reference manual for the LLVM assembly language. |
Bill Wendling | 837f39b | 2008-08-05 22:29:16 +0000 | [diff] [blame] | 262 | LLVM is a Static Single Assignment (SSA) based representation that provides |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 263 | type safety, low-level operations, flexibility, and the capability of |
| 264 | representing 'all' high-level languages cleanly. It is the common code |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 265 | representation used throughout all phases of the LLVM compilation |
| 266 | strategy.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 267 | </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 268 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 269 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 270 | <div class="doc_section"> <a name="introduction">Introduction</a> </div> |
| 271 | <!-- *********************************************************************** --> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 272 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 273 | <div class="doc_text"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 274 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 275 | <p>The LLVM code representation is designed to be used in three |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 276 | different forms: as an in-memory compiler IR, as an on-disk bitcode |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 277 | representation (suitable for fast loading by a Just-In-Time compiler), |
| 278 | and as a human readable assembly language representation. This allows |
| 279 | LLVM to provide a powerful intermediate representation for efficient |
| 280 | compiler transformations and analysis, while providing a natural means |
| 281 | to debug and visualize the transformations. The three different forms |
| 282 | of LLVM are all equivalent. This document describes the human readable |
| 283 | representation and notation.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 284 | |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 285 | <p>The LLVM representation aims to be light-weight and low-level |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 286 | while being expressive, typed, and extensible at the same time. It |
| 287 | aims to be a "universal IR" of sorts, by being at a low enough level |
| 288 | that high-level ideas may be cleanly mapped to it (similar to how |
| 289 | microprocessors are "universal IR's", allowing many source languages to |
| 290 | be mapped to them). By providing type information, LLVM can be used as |
| 291 | the target of optimizations: for example, through pointer analysis, it |
| 292 | can be proven that a C automatic variable is never accessed outside of |
| 293 | the current function... allowing it to be promoted to a simple SSA |
| 294 | value instead of a memory location.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 295 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 296 | </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 297 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 298 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 299 | <div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 300 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 301 | <div class="doc_text"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 302 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 303 | <p>It is important to note that this document describes 'well formed' |
| 304 | LLVM assembly language. There is a difference between what the parser |
| 305 | accepts and what is considered 'well formed'. For example, the |
| 306 | following instruction is syntactically okay, but not well formed:</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 307 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 308 | <div class="doc_code"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 309 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 310 | %x = <a href="#i_add">add</a> i32 1, %x |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 311 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 312 | </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 313 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 314 | <p>...because the definition of <tt>%x</tt> does not dominate all of |
| 315 | its uses. The LLVM infrastructure provides a verification pass that may |
| 316 | be used to verify that an LLVM module is well formed. This pass is |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 317 | automatically run by the parser after parsing input assembly and by |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 318 | the optimizer before it outputs bitcode. The violations pointed out |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 319 | by the verifier pass indicate bugs in transformation passes or input to |
| 320 | the parser.</p> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 321 | </div> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 322 | |
Chris Lattner | cc68939 | 2007-10-03 17:34:29 +0000 | [diff] [blame] | 323 | <!-- Describe the typesetting conventions here. --> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 324 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 325 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 326 | <div class="doc_section"> <a name="identifiers">Identifiers</a> </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 327 | <!-- *********************************************************************** --> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 328 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 329 | <div class="doc_text"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 330 | |
Reid Spencer | 2c45228 | 2007-08-07 14:34:28 +0000 | [diff] [blame] | 331 | <p>LLVM identifiers come in two basic types: global and local. Global |
| 332 | identifiers (functions, global variables) begin with the @ character. Local |
| 333 | identifiers (register names, types) begin with the % character. Additionally, |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 334 | there are three different formats for identifiers, for different purposes:</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 335 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 336 | <ol> |
Reid Spencer | 2c45228 | 2007-08-07 14:34:28 +0000 | [diff] [blame] | 337 | <li>Named values are represented as a string of characters with their prefix. |
| 338 | For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual |
| 339 | regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'. |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 340 | Identifiers which require other characters in their names can be surrounded |
Daniel Dunbar | 76dea95 | 2008-10-14 23:51:43 +0000 | [diff] [blame] | 341 | with quotes. Special characters may be escaped using "\xx" where xx is the |
| 342 | ASCII code for the character in hexadecimal. In this way, any character can |
| 343 | be used in a name value, even quotes themselves. |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 344 | |
Reid Spencer | 2c45228 | 2007-08-07 14:34:28 +0000 | [diff] [blame] | 345 | <li>Unnamed values are represented as an unsigned numeric value with their |
| 346 | prefix. For example, %12, @2, %44.</li> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 347 | |
Reid Spencer | cc16dc3 | 2004-12-09 18:02:53 +0000 | [diff] [blame] | 348 | <li>Constants, which are described in a <a href="#constants">section about |
| 349 | constants</a>, below.</li> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 350 | </ol> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 351 | |
Reid Spencer | 2c45228 | 2007-08-07 14:34:28 +0000 | [diff] [blame] | 352 | <p>LLVM requires that values start with a prefix for two reasons: Compilers |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 353 | don't need to worry about name clashes with reserved words, and the set of |
| 354 | reserved words may be expanded in the future without penalty. Additionally, |
| 355 | unnamed identifiers allow a compiler to quickly come up with a temporary |
| 356 | variable without having to avoid symbol table conflicts.</p> |
| 357 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 358 | <p>Reserved words in LLVM are very similar to reserved words in other |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 359 | languages. There are keywords for different opcodes |
| 360 | ('<tt><a href="#i_add">add</a></tt>', |
| 361 | '<tt><a href="#i_bitcast">bitcast</a></tt>', |
| 362 | '<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 363 | href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...), |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 364 | and others. These reserved words cannot conflict with variable names, because |
Reid Spencer | 2c45228 | 2007-08-07 14:34:28 +0000 | [diff] [blame] | 365 | none of them start with a prefix character ('%' or '@').</p> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 366 | |
| 367 | <p>Here is an example of LLVM code to multiply the integer variable |
| 368 | '<tt>%X</tt>' by 8:</p> |
| 369 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 370 | <p>The easy way:</p> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 371 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 372 | <div class="doc_code"> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 373 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 374 | %result = <a href="#i_mul">mul</a> i32 %X, 8 |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 375 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 376 | </div> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 377 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 378 | <p>After strength reduction:</p> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 379 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 380 | <div class="doc_code"> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 381 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 382 | %result = <a href="#i_shl">shl</a> i32 %X, i8 3 |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 383 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 384 | </div> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 385 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 386 | <p>And the hard way:</p> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 387 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 388 | <div class="doc_code"> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 389 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 390 | <a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i> |
| 391 | <a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i> |
| 392 | %result = <a href="#i_add">add</a> i32 %1, %1 |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 393 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 394 | </div> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 395 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 396 | <p>This last way of multiplying <tt>%X</tt> by 8 illustrates several |
| 397 | important lexical features of LLVM:</p> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 398 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 399 | <ol> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 400 | |
| 401 | <li>Comments are delimited with a '<tt>;</tt>' and go until the end of |
| 402 | line.</li> |
| 403 | |
| 404 | <li>Unnamed temporaries are created when the result of a computation is not |
| 405 | assigned to a named value.</li> |
| 406 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 407 | <li>Unnamed temporaries are numbered sequentially</li> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 408 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 409 | </ol> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 410 | |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 411 | <p>...and it also shows a convention that we follow in this document. When |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 412 | demonstrating instructions, we will follow an instruction with a comment that |
| 413 | defines the type and name of value produced. Comments are shown in italic |
| 414 | text.</p> |
| 415 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 416 | </div> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 417 | |
| 418 | <!-- *********************************************************************** --> |
| 419 | <div class="doc_section"> <a name="highlevel">High Level Structure</a> </div> |
| 420 | <!-- *********************************************************************** --> |
| 421 | |
| 422 | <!-- ======================================================================= --> |
| 423 | <div class="doc_subsection"> <a name="modulestructure">Module Structure</a> |
| 424 | </div> |
| 425 | |
| 426 | <div class="doc_text"> |
| 427 | |
| 428 | <p>LLVM programs are composed of "Module"s, each of which is a |
| 429 | translation unit of the input programs. Each module consists of |
| 430 | functions, global variables, and symbol table entries. Modules may be |
| 431 | combined together with the LLVM linker, which merges function (and |
| 432 | global variable) definitions, resolves forward declarations, and merges |
| 433 | symbol table entries. Here is an example of the "hello world" module:</p> |
| 434 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 435 | <div class="doc_code"> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 436 | <pre><i>; Declare the string constant as a global constant...</i> |
Chris Lattner | a89e5f1 | 2007-06-12 17:00:26 +0000 | [diff] [blame] | 437 | <a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a |
| 438 | href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 439 | |
| 440 | <i>; External declaration of the puts function</i> |
Chris Lattner | a89e5f1 | 2007-06-12 17:00:26 +0000 | [diff] [blame] | 441 | <a href="#functionstructure">declare</a> i32 @puts(i8 *) <i>; i32(i8 *)* </i> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 442 | |
| 443 | <i>; Definition of main function</i> |
Chris Lattner | a89e5f1 | 2007-06-12 17:00:26 +0000 | [diff] [blame] | 444 | define i32 @main() { <i>; i32()* </i> |
Dan Gohman | 2a08c53 | 2009-01-04 23:44:43 +0000 | [diff] [blame] | 445 | <i>; Convert [13 x i8]* to i8 *...</i> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 446 | %cast210 = <a |
Dan Gohman | 2a08c53 | 2009-01-04 23:44:43 +0000 | [diff] [blame] | 447 | href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 448 | |
| 449 | <i>; Call puts function to write out the string to stdout...</i> |
| 450 | <a |
Chris Lattner | a89e5f1 | 2007-06-12 17:00:26 +0000 | [diff] [blame] | 451 | href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 452 | <a |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 453 | href="#i_ret">ret</a> i32 0<br>}<br> |
| 454 | </pre> |
| 455 | </div> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 456 | |
| 457 | <p>This example is made up of a <a href="#globalvars">global variable</a> |
| 458 | named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>" |
| 459 | function, and a <a href="#functionstructure">function definition</a> |
| 460 | for "<tt>main</tt>".</p> |
| 461 | |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 462 | <p>In general, a module is made up of a list of global values, |
| 463 | where both functions and global variables are global values. Global values are |
| 464 | represented by a pointer to a memory location (in this case, a pointer to an |
| 465 | array of char, and a pointer to a function), and have one of the following <a |
| 466 | href="#linkage">linkage types</a>.</p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 467 | |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 468 | </div> |
| 469 | |
| 470 | <!-- ======================================================================= --> |
| 471 | <div class="doc_subsection"> |
| 472 | <a name="linkage">Linkage Types</a> |
| 473 | </div> |
| 474 | |
| 475 | <div class="doc_text"> |
| 476 | |
| 477 | <p> |
| 478 | All Global Variables and Functions have one of the following types of linkage: |
| 479 | </p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 480 | |
| 481 | <dl> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 482 | |
Rafael Espindola | bb46f52 | 2009-01-15 20:18:42 +0000 | [diff] [blame] | 483 | <dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt> |
| 484 | |
| 485 | <dd>Global values with private linkage are only directly accessible by |
| 486 | objects in the current module. In particular, linking code into a module with |
| 487 | an private global value may cause the private to be renamed as necessary to |
| 488 | avoid collisions. Because the symbol is private to the module, all |
| 489 | references can be updated. This doesn't show up in any symbol table in the |
| 490 | object file. |
| 491 | </dd> |
| 492 | |
Dale Johannesen | 2307a7f | 2008-05-23 23:13:41 +0000 | [diff] [blame] | 493 | <dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 494 | |
Duncan Sands | 81d05c2 | 2009-01-16 09:29:46 +0000 | [diff] [blame] | 495 | <dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in |
Rafael Espindola | bb46f52 | 2009-01-15 20:18:42 +0000 | [diff] [blame] | 496 | the case of ELF) in the object file. This corresponds to the notion of the |
Chris Lattner | 4887bd8 | 2007-01-14 06:51:48 +0000 | [diff] [blame] | 497 | '<tt>static</tt>' keyword in C. |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 498 | </dd> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 499 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 500 | <dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 501 | |
Chris Lattner | 4887bd8 | 2007-01-14 06:51:48 +0000 | [diff] [blame] | 502 | <dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of |
| 503 | the same name when linkage occurs. This is typically used to implement |
| 504 | inline functions, templates, or other code which must be generated in each |
| 505 | translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are |
| 506 | allowed to be discarded. |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 507 | </dd> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 508 | |
Dale Johannesen | 2307a7f | 2008-05-23 23:13:41 +0000 | [diff] [blame] | 509 | <dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt> |
| 510 | |
| 511 | <dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt> |
| 512 | linkage, except that unreferenced <tt>common</tt> globals may not be |
| 513 | discarded. This is used for globals that may be emitted in multiple |
| 514 | translation units, but that are not guaranteed to be emitted into every |
| 515 | translation unit that uses them. One example of this is tentative |
| 516 | definitions in C, such as "<tt>int X;</tt>" at global scope. |
| 517 | </dd> |
| 518 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 519 | <dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 520 | |
Dale Johannesen | 2307a7f | 2008-05-23 23:13:41 +0000 | [diff] [blame] | 521 | <dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except |
| 522 | that some targets may choose to emit different assembly sequences for them |
| 523 | for target-dependent reasons. This is used for globals that are declared |
| 524 | "weak" in C source code. |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 525 | </dd> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 526 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 527 | <dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 528 | |
| 529 | <dd>"<tt>appending</tt>" linkage may only be applied to global variables of |
| 530 | pointer to array type. When two global variables with appending linkage are |
| 531 | linked together, the two global arrays are appended together. This is the |
| 532 | LLVM, typesafe, equivalent of having the system linker append together |
| 533 | "sections" with identical names when .o files are linked. |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 534 | </dd> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 535 | |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 536 | <dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt> |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 537 | <dd>The semantics of this linkage follow the ELF object file model: the |
| 538 | symbol is weak until linked, if not linked, the symbol becomes null instead |
| 539 | of being an undefined reference. |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 540 | </dd> |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 541 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 542 | <dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt> |
Chris Lattner | e5d947b | 2004-12-09 16:36:40 +0000 | [diff] [blame] | 543 | |
| 544 | <dd>If none of the above identifiers are used, the global is externally |
| 545 | visible, meaning that it participates in linkage and can be used to resolve |
| 546 | external symbol references. |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 547 | </dd> |
Reid Spencer | c891084 | 2007-04-11 23:49:50 +0000 | [diff] [blame] | 548 | </dl> |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 549 | |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 550 | <p> |
| 551 | The next two types of linkage are targeted for Microsoft Windows platform |
| 552 | only. They are designed to support importing (exporting) symbols from (to) |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 553 | DLLs (Dynamic Link Libraries). |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 554 | </p> |
| 555 | |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 556 | <dl> |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 557 | <dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt> |
| 558 | |
| 559 | <dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function |
| 560 | or variable via a global pointer to a pointer that is set up by the DLL |
| 561 | exporting the symbol. On Microsoft Windows targets, the pointer name is |
Dan Gohman | 7956412 | 2009-01-12 21:35:55 +0000 | [diff] [blame] | 562 | formed by combining <code>__imp_</code> and the function or variable name. |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 563 | </dd> |
| 564 | |
| 565 | <dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt> |
| 566 | |
| 567 | <dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global |
| 568 | pointer to a pointer in a DLL, so that it can be referenced with the |
| 569 | <tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer |
Dan Gohman | 7956412 | 2009-01-12 21:35:55 +0000 | [diff] [blame] | 570 | name is formed by combining <code>__imp_</code> and the function or variable |
Anton Korobeynikov | b74ed07 | 2006-09-14 18:23:27 +0000 | [diff] [blame] | 571 | name. |
| 572 | </dd> |
| 573 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 574 | </dl> |
| 575 | |
Dan Gohman | f003276 | 2008-11-24 17:18:39 +0000 | [diff] [blame] | 576 | <p>For example, since the "<tt>.LC0</tt>" |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 577 | variable is defined to be internal, if another module defined a "<tt>.LC0</tt>" |
| 578 | variable and was linked with this one, one of the two would be renamed, |
| 579 | preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are |
| 580 | external (i.e., lacking any linkage declarations), they are accessible |
Reid Spencer | ac8d276 | 2007-01-05 00:59:10 +0000 | [diff] [blame] | 581 | outside of the current module.</p> |
| 582 | <p>It is illegal for a function <i>declaration</i> |
| 583 | to have any linkage type other than "externally visible", <tt>dllimport</tt>, |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 584 | or <tt>extern_weak</tt>.</p> |
Anton Korobeynikov | 8b0a8c8 | 2007-04-25 14:27:10 +0000 | [diff] [blame] | 585 | <p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 586 | linkages.</p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 587 | </div> |
| 588 | |
| 589 | <!-- ======================================================================= --> |
| 590 | <div class="doc_subsection"> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 591 | <a name="callingconv">Calling Conventions</a> |
| 592 | </div> |
| 593 | |
| 594 | <div class="doc_text"> |
| 595 | |
| 596 | <p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a> |
| 597 | and <a href="#i_invoke">invokes</a> can all have an optional calling convention |
| 598 | specified for the call. The calling convention of any pair of dynamic |
| 599 | caller/callee must match, or the behavior of the program is undefined. The |
| 600 | following calling conventions are supported by LLVM, and more may be added in |
| 601 | the future:</p> |
| 602 | |
| 603 | <dl> |
| 604 | <dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt> |
| 605 | |
| 606 | <dd>This calling convention (the default if no other calling convention is |
| 607 | specified) matches the target C calling conventions. This calling convention |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 608 | supports varargs function calls and tolerates some mismatch in the declared |
Reid Spencer | c28d2bc | 2006-12-31 21:30:18 +0000 | [diff] [blame] | 609 | prototype and implemented declaration of the function (as does normal C). |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 610 | </dd> |
| 611 | |
| 612 | <dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt> |
| 613 | |
| 614 | <dd>This calling convention attempts to make calls as fast as possible |
| 615 | (e.g. by passing things in registers). This calling convention allows the |
| 616 | target to use whatever tricks it wants to produce fast code for the target, |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 617 | without having to conform to an externally specified ABI (Application Binary |
| 618 | Interface). Implementations of this convention should allow arbitrary |
Arnold Schwaighofer | 9097d14 | 2008-05-14 09:17:12 +0000 | [diff] [blame] | 619 | <a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be |
| 620 | supported. This calling convention does not support varargs and requires the |
| 621 | prototype of all callees to exactly match the prototype of the function |
| 622 | definition. |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 623 | </dd> |
| 624 | |
| 625 | <dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt> |
| 626 | |
| 627 | <dd>This calling convention attempts to make code in the caller as efficient |
| 628 | as possible under the assumption that the call is not commonly executed. As |
| 629 | such, these calls often preserve all registers so that the call does not break |
| 630 | any live ranges in the caller side. This calling convention does not support |
| 631 | varargs and requires the prototype of all callees to exactly match the |
| 632 | prototype of the function definition. |
| 633 | </dd> |
| 634 | |
Chris Lattner | cfe6b37 | 2005-05-07 01:46:40 +0000 | [diff] [blame] | 635 | <dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 636 | |
| 637 | <dd>Any calling convention may be specified by number, allowing |
| 638 | target-specific calling conventions to be used. Target specific calling |
| 639 | conventions start at 64. |
| 640 | </dd> |
Chris Lattner | cfe6b37 | 2005-05-07 01:46:40 +0000 | [diff] [blame] | 641 | </dl> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 642 | |
| 643 | <p>More calling conventions can be added/defined on an as-needed basis, to |
| 644 | support pascal conventions or any other well-known target-independent |
| 645 | convention.</p> |
| 646 | |
| 647 | </div> |
| 648 | |
| 649 | <!-- ======================================================================= --> |
| 650 | <div class="doc_subsection"> |
Anton Korobeynikov | 8cea37b | 2007-01-23 12:35:46 +0000 | [diff] [blame] | 651 | <a name="visibility">Visibility Styles</a> |
| 652 | </div> |
| 653 | |
| 654 | <div class="doc_text"> |
| 655 | |
| 656 | <p> |
| 657 | All Global Variables and Functions have one of the following visibility styles: |
| 658 | </p> |
| 659 | |
| 660 | <dl> |
| 661 | <dt><b>"<tt>default</tt>" - Default style</b>:</dt> |
| 662 | |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 663 | <dd>On targets that use the ELF object file format, default visibility means |
| 664 | that the declaration is visible to other |
Anton Korobeynikov | 8cea37b | 2007-01-23 12:35:46 +0000 | [diff] [blame] | 665 | modules and, in shared libraries, means that the declared entity may be |
| 666 | overridden. On Darwin, default visibility means that the declaration is |
| 667 | visible to other modules. Default visibility corresponds to "external |
| 668 | linkage" in the language. |
| 669 | </dd> |
| 670 | |
| 671 | <dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt> |
| 672 | |
| 673 | <dd>Two declarations of an object with hidden visibility refer to the same |
| 674 | object if they are in the same shared object. Usually, hidden visibility |
| 675 | indicates that the symbol will not be placed into the dynamic symbol table, |
| 676 | so no other module (executable or shared library) can reference it |
| 677 | directly. |
| 678 | </dd> |
| 679 | |
Anton Korobeynikov | 6f9896f | 2007-04-29 18:35:00 +0000 | [diff] [blame] | 680 | <dt><b>"<tt>protected</tt>" - Protected style</b>:</dt> |
| 681 | |
| 682 | <dd>On ELF, protected visibility indicates that the symbol will be placed in |
| 683 | the dynamic symbol table, but that references within the defining module will |
| 684 | bind to the local symbol. That is, the symbol cannot be overridden by another |
| 685 | module. |
| 686 | </dd> |
Anton Korobeynikov | 8cea37b | 2007-01-23 12:35:46 +0000 | [diff] [blame] | 687 | </dl> |
| 688 | |
| 689 | </div> |
| 690 | |
| 691 | <!-- ======================================================================= --> |
| 692 | <div class="doc_subsection"> |
Chris Lattner | e7886e4 | 2009-01-11 20:53:49 +0000 | [diff] [blame] | 693 | <a name="namedtypes">Named Types</a> |
| 694 | </div> |
| 695 | |
| 696 | <div class="doc_text"> |
| 697 | |
| 698 | <p>LLVM IR allows you to specify name aliases for certain types. This can make |
| 699 | it easier to read the IR and make the IR more condensed (particularly when |
| 700 | recursive types are involved). An example of a name specification is: |
| 701 | </p> |
| 702 | |
| 703 | <div class="doc_code"> |
| 704 | <pre> |
| 705 | %mytype = type { %mytype*, i32 } |
| 706 | </pre> |
| 707 | </div> |
| 708 | |
| 709 | <p>You may give a name to any <a href="#typesystem">type</a> except "<a |
| 710 | href="t_void">void</a>". Type name aliases may be used anywhere a type is |
| 711 | expected with the syntax "%mytype".</p> |
| 712 | |
| 713 | <p>Note that type names are aliases for the structural type that they indicate, |
| 714 | and that you can therefore specify multiple names for the same type. This often |
| 715 | leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses |
| 716 | structural typing, the name is not part of the type. When printing out LLVM IR, |
| 717 | the printer will pick <em>one name</em> to render all types of a particular |
| 718 | shape. This means that if you have code where two different source types end up |
| 719 | having the same LLVM type, that the dumper will sometimes print the "wrong" or |
| 720 | unexpected type. This is an important design point and isn't going to |
| 721 | change.</p> |
| 722 | |
| 723 | </div> |
| 724 | |
| 725 | |
| 726 | <!-- ======================================================================= --> |
| 727 | <div class="doc_subsection"> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 728 | <a name="globalvars">Global Variables</a> |
| 729 | </div> |
| 730 | |
| 731 | <div class="doc_text"> |
| 732 | |
Chris Lattner | 3689a34 | 2005-02-12 19:30:21 +0000 | [diff] [blame] | 733 | <p>Global variables define regions of memory allocated at compilation time |
Chris Lattner | 88f6c46 | 2005-11-12 00:45:07 +0000 | [diff] [blame] | 734 | instead of run-time. Global variables may optionally be initialized, may have |
Anton Korobeynikov | 8b0a8c8 | 2007-04-25 14:27:10 +0000 | [diff] [blame] | 735 | an explicit section to be placed in, and may have an optional explicit alignment |
| 736 | specified. A variable may be defined as "thread_local", which means that it |
| 737 | will not be shared by threads (each thread will have a separated copy of the |
| 738 | variable). A variable may be defined as a global "constant," which indicates |
| 739 | that the contents of the variable will <b>never</b> be modified (enabling better |
Chris Lattner | 3689a34 | 2005-02-12 19:30:21 +0000 | [diff] [blame] | 740 | optimization, allowing the global data to be placed in the read-only section of |
| 741 | an executable, etc). Note that variables that need runtime initialization |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 742 | cannot be marked "constant" as there is a store to the variable.</p> |
Chris Lattner | 3689a34 | 2005-02-12 19:30:21 +0000 | [diff] [blame] | 743 | |
| 744 | <p> |
| 745 | LLVM explicitly allows <em>declarations</em> of global variables to be marked |
| 746 | constant, even if the final definition of the global is not. This capability |
| 747 | can be used to enable slightly better optimization of the program, but requires |
| 748 | the language definition to guarantee that optimizations based on the |
| 749 | 'constantness' are valid for the translation units that do not include the |
| 750 | definition. |
| 751 | </p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 752 | |
| 753 | <p>As SSA values, global variables define pointer values that are in |
| 754 | scope (i.e. they dominate) all basic blocks in the program. Global |
| 755 | variables always define a pointer to their "content" type because they |
| 756 | describe a region of memory, and all memory objects in LLVM are |
| 757 | accessed through pointers.</p> |
| 758 | |
Christopher Lamb | 284d992 | 2007-12-11 09:31:00 +0000 | [diff] [blame] | 759 | <p>A global variable may be declared to reside in a target-specifc numbered |
| 760 | address space. For targets that support them, address spaces may affect how |
| 761 | optimizations are performed and/or what target instructions are used to access |
Christopher Lamb | d49e18d | 2007-12-12 08:44:39 +0000 | [diff] [blame] | 762 | the variable. The default address space is zero. The address space qualifier |
| 763 | must precede any other attributes.</p> |
Christopher Lamb | 284d992 | 2007-12-11 09:31:00 +0000 | [diff] [blame] | 764 | |
Chris Lattner | 88f6c46 | 2005-11-12 00:45:07 +0000 | [diff] [blame] | 765 | <p>LLVM allows an explicit section to be specified for globals. If the target |
| 766 | supports it, it will emit globals to the section specified.</p> |
| 767 | |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 768 | <p>An explicit alignment may be specified for a global. If not present, or if |
| 769 | the alignment is set to zero, the alignment of the global is set by the target |
| 770 | to whatever it feels convenient. If an explicit alignment is specified, the |
| 771 | global is forced to have at least that much alignment. All alignments must be |
| 772 | a power of 2.</p> |
| 773 | |
Christopher Lamb | 284d992 | 2007-12-11 09:31:00 +0000 | [diff] [blame] | 774 | <p>For example, the following defines a global in a numbered address space with |
| 775 | an initializer, section, and alignment:</p> |
Chris Lattner | 68027ea | 2007-01-14 00:27:09 +0000 | [diff] [blame] | 776 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 777 | <div class="doc_code"> |
Chris Lattner | 68027ea | 2007-01-14 00:27:09 +0000 | [diff] [blame] | 778 | <pre> |
Dan Gohman | 398873c | 2009-01-11 00:40:00 +0000 | [diff] [blame] | 779 | @G = addrspace(5) constant float 1.0, section "foo", align 4 |
Chris Lattner | 68027ea | 2007-01-14 00:27:09 +0000 | [diff] [blame] | 780 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 781 | </div> |
Chris Lattner | 68027ea | 2007-01-14 00:27:09 +0000 | [diff] [blame] | 782 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 783 | </div> |
| 784 | |
| 785 | |
| 786 | <!-- ======================================================================= --> |
| 787 | <div class="doc_subsection"> |
| 788 | <a name="functionstructure">Functions</a> |
| 789 | </div> |
| 790 | |
| 791 | <div class="doc_text"> |
| 792 | |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 793 | <p>LLVM function definitions consist of the "<tt>define</tt>" keyord, |
| 794 | an optional <a href="#linkage">linkage type</a>, an optional |
Anton Korobeynikov | 8cea37b | 2007-01-23 12:35:46 +0000 | [diff] [blame] | 795 | <a href="#visibility">visibility style</a>, an optional |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 796 | <a href="#callingconv">calling convention</a>, a return type, an optional |
| 797 | <a href="#paramattrs">parameter attribute</a> for the return type, a function |
| 798 | name, a (possibly empty) argument list (each with optional |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 799 | <a href="#paramattrs">parameter attributes</a>), optional |
| 800 | <a href="#fnattrs">function attributes</a>, an optional section, |
| 801 | an optional alignment, an optional <a href="#gc">garbage collector name</a>, |
Chris Lattner | 0c46a7d | 2008-10-04 18:10:21 +0000 | [diff] [blame] | 802 | an opening curly brace, a list of basic blocks, and a closing curly brace. |
Anton Korobeynikov | 8cea37b | 2007-01-23 12:35:46 +0000 | [diff] [blame] | 803 | |
| 804 | LLVM function declarations consist of the "<tt>declare</tt>" keyword, an |
| 805 | optional <a href="#linkage">linkage type</a>, an optional |
| 806 | <a href="#visibility">visibility style</a>, an optional |
| 807 | <a href="#callingconv">calling convention</a>, a return type, an optional |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 808 | <a href="#paramattrs">parameter attribute</a> for the return type, a function |
Gordon Henriksen | 80a75bf | 2007-12-10 03:18:06 +0000 | [diff] [blame] | 809 | name, a possibly empty list of arguments, an optional alignment, and an optional |
Gordon Henriksen | e754abe | 2007-12-10 03:30:21 +0000 | [diff] [blame] | 810 | <a href="#gc">garbage collector name</a>.</p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 811 | |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 812 | <p>A function definition contains a list of basic blocks, forming the CFG |
| 813 | (Control Flow Graph) for |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 814 | the function. Each basic block may optionally start with a label (giving the |
| 815 | basic block a symbol table entry), contains a list of instructions, and ends |
| 816 | with a <a href="#terminators">terminator</a> instruction (such as a branch or |
| 817 | function return).</p> |
| 818 | |
Chris Lattner | 4a3c901 | 2007-06-08 16:52:14 +0000 | [diff] [blame] | 819 | <p>The first basic block in a function is special in two ways: it is immediately |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 820 | executed on entrance to the function, and it is not allowed to have predecessor |
| 821 | basic blocks (i.e. there can not be any branches to the entry block of a |
| 822 | function). Because the block can have no predecessors, it also cannot have any |
| 823 | <a href="#i_phi">PHI nodes</a>.</p> |
| 824 | |
Chris Lattner | 88f6c46 | 2005-11-12 00:45:07 +0000 | [diff] [blame] | 825 | <p>LLVM allows an explicit section to be specified for functions. If the target |
| 826 | supports it, it will emit functions to the section specified.</p> |
| 827 | |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 828 | <p>An explicit alignment may be specified for a function. If not present, or if |
| 829 | the alignment is set to zero, the alignment of the function is set by the target |
| 830 | to whatever it feels convenient. If an explicit alignment is specified, the |
| 831 | function is forced to have at least that much alignment. All alignments must be |
| 832 | a power of 2.</p> |
| 833 | |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 834 | <h5>Syntax:</h5> |
| 835 | |
| 836 | <div class="doc_code"> |
Chris Lattner | 50ad45c | 2008-10-13 16:55:18 +0000 | [diff] [blame] | 837 | <tt> |
| 838 | define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>] |
| 839 | [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] |
| 840 | <ResultType> @<FunctionName> ([argument list]) |
| 841 | [<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N] |
| 842 | [<a href="#gc">gc</a>] { ... } |
| 843 | </tt> |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 844 | </div> |
| 845 | |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 846 | </div> |
| 847 | |
Anton Korobeynikov | 8b0a8c8 | 2007-04-25 14:27:10 +0000 | [diff] [blame] | 848 | |
| 849 | <!-- ======================================================================= --> |
| 850 | <div class="doc_subsection"> |
| 851 | <a name="aliasstructure">Aliases</a> |
| 852 | </div> |
| 853 | <div class="doc_text"> |
| 854 | <p>Aliases act as "second name" for the aliasee value (which can be either |
Anton Korobeynikov | 726d45c | 2008-03-22 08:36:14 +0000 | [diff] [blame] | 855 | function, global variable, another alias or bitcast of global value). Aliases |
| 856 | may have an optional <a href="#linkage">linkage type</a>, and an |
Anton Korobeynikov | 8b0a8c8 | 2007-04-25 14:27:10 +0000 | [diff] [blame] | 857 | optional <a href="#visibility">visibility style</a>.</p> |
| 858 | |
| 859 | <h5>Syntax:</h5> |
| 860 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 861 | <div class="doc_code"> |
Bill Wendling | aac388b | 2007-05-29 09:42:13 +0000 | [diff] [blame] | 862 | <pre> |
Duncan Sands | 0b23ac1 | 2008-09-12 20:48:21 +0000 | [diff] [blame] | 863 | @<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee> |
Bill Wendling | aac388b | 2007-05-29 09:42:13 +0000 | [diff] [blame] | 864 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 865 | </div> |
Anton Korobeynikov | 8b0a8c8 | 2007-04-25 14:27:10 +0000 | [diff] [blame] | 866 | |
| 867 | </div> |
| 868 | |
| 869 | |
| 870 | |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 871 | <!-- ======================================================================= --> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 872 | <div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div> |
| 873 | <div class="doc_text"> |
| 874 | <p>The return type and each parameter of a function type may have a set of |
| 875 | <i>parameter attributes</i> associated with them. Parameter attributes are |
| 876 | used to communicate additional information about the result or parameters of |
Duncan Sands | dc02467 | 2007-11-27 13:23:08 +0000 | [diff] [blame] | 877 | a function. Parameter attributes are considered to be part of the function, |
| 878 | not of the function type, so functions with different parameter attributes |
| 879 | can have the same function type.</p> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 880 | |
Reid Spencer | 950e9f8 | 2007-01-15 18:27:39 +0000 | [diff] [blame] | 881 | <p>Parameter attributes are simple keywords that follow the type specified. If |
| 882 | multiple parameter attributes are needed, they are space separated. For |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 883 | example:</p> |
| 884 | |
| 885 | <div class="doc_code"> |
| 886 | <pre> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 887 | declare i32 @printf(i8* noalias , ...) |
Chris Lattner | 66d922c | 2008-10-04 18:33:34 +0000 | [diff] [blame] | 888 | declare i32 @atoi(i8 zeroext) |
| 889 | declare signext i8 @returns_signed_char() |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 890 | </pre> |
| 891 | </div> |
| 892 | |
Duncan Sands | dc02467 | 2007-11-27 13:23:08 +0000 | [diff] [blame] | 893 | <p>Note that any attributes for the function result (<tt>nounwind</tt>, |
| 894 | <tt>readonly</tt>) come immediately after the argument list.</p> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 895 | |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 896 | <p>Currently, only the following parameter attributes are defined:</p> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 897 | <dl> |
Reid Spencer | 9445e9a | 2007-07-19 23:13:04 +0000 | [diff] [blame] | 898 | <dt><tt>zeroext</tt></dt> |
Chris Lattner | 66d922c | 2008-10-04 18:33:34 +0000 | [diff] [blame] | 899 | <dd>This indicates to the code generator that the parameter or return value |
| 900 | should be zero-extended to a 32-bit value by the caller (for a parameter) |
| 901 | or the callee (for a return value).</dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 902 | |
Reid Spencer | 9445e9a | 2007-07-19 23:13:04 +0000 | [diff] [blame] | 903 | <dt><tt>signext</tt></dt> |
Chris Lattner | 66d922c | 2008-10-04 18:33:34 +0000 | [diff] [blame] | 904 | <dd>This indicates to the code generator that the parameter or return value |
| 905 | should be sign-extended to a 32-bit value by the caller (for a parameter) |
| 906 | or the callee (for a return value).</dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 907 | |
Anton Korobeynikov | 34d6dea | 2007-01-28 14:30:45 +0000 | [diff] [blame] | 908 | <dt><tt>inreg</tt></dt> |
Dale Johannesen | c9c6da6 | 2008-09-25 20:47:45 +0000 | [diff] [blame] | 909 | <dd>This indicates that this parameter or return value should be treated |
| 910 | in a special target-dependent fashion during while emitting code for a |
| 911 | function call or return (usually, by putting it in a register as opposed |
Chris Lattner | 66d922c | 2008-10-04 18:33:34 +0000 | [diff] [blame] | 912 | to memory, though some targets use it to distinguish between two different |
| 913 | kinds of registers). Use of this attribute is target-specific.</dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 914 | |
Duncan Sands | edb05df | 2008-10-06 08:14:18 +0000 | [diff] [blame] | 915 | <dt><tt><a name="byval">byval</a></tt></dt> |
Chris Lattner | 0747baa | 2008-01-15 04:34:22 +0000 | [diff] [blame] | 916 | <dd>This indicates that the pointer parameter should really be passed by |
| 917 | value to the function. The attribute implies that a hidden copy of the |
| 918 | pointee is made between the caller and the callee, so the callee is unable |
Chris Lattner | ebec678 | 2008-08-05 18:21:08 +0000 | [diff] [blame] | 919 | to modify the value in the callee. This attribute is only valid on LLVM |
Chris Lattner | 0747baa | 2008-01-15 04:34:22 +0000 | [diff] [blame] | 920 | pointer arguments. It is generally used to pass structs and arrays by |
Duncan Sands | edb05df | 2008-10-06 08:14:18 +0000 | [diff] [blame] | 921 | value, but is also valid on pointers to scalars. The copy is considered to |
| 922 | belong to the caller not the callee (for example, |
| 923 | <tt><a href="#readonly">readonly</a></tt> functions should not write to |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 924 | <tt>byval</tt> parameters). This is not a valid attribute for return |
| 925 | values. </dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 926 | |
Anton Korobeynikov | 34d6dea | 2007-01-28 14:30:45 +0000 | [diff] [blame] | 927 | <dt><tt>sret</tt></dt> |
Duncan Sands | e26dec6 | 2008-02-18 04:19:38 +0000 | [diff] [blame] | 928 | <dd>This indicates that the pointer parameter specifies the address of a |
| 929 | structure that is the return value of the function in the source program. |
Chris Lattner | 66d922c | 2008-10-04 18:33:34 +0000 | [diff] [blame] | 930 | This pointer must be guaranteed by the caller to be valid: loads and stores |
| 931 | to the structure may be assumed by the callee to not to trap. This may only |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 932 | be applied to the first parameter. This is not a valid attribute for |
| 933 | return values. </dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 934 | |
Zhou Sheng | febca34 | 2007-06-05 05:28:26 +0000 | [diff] [blame] | 935 | <dt><tt>noalias</tt></dt> |
Nick Lewycky | 02ff308 | 2008-11-24 03:41:24 +0000 | [diff] [blame] | 936 | <dd>This indicates that the pointer does not alias any global or any other |
| 937 | parameter. The caller is responsible for ensuring that this is the |
Nick Lewycky | b2b32fd | 2008-11-24 05:00:44 +0000 | [diff] [blame] | 938 | case. On a function return value, <tt>noalias</tt> additionally indicates |
| 939 | that the pointer does not alias any other pointers visible to the |
Nick Lewycky | f23d0d3 | 2008-12-19 06:39:12 +0000 | [diff] [blame] | 940 | caller. For further details, please see the discussion of the NoAlias |
| 941 | response in |
| 942 | <a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias |
| 943 | analysis</a>.</dd> |
| 944 | |
| 945 | <dt><tt>nocapture</tt></dt> |
| 946 | <dd>This indicates that the callee does not make any copies of the pointer |
| 947 | that outlive the callee itself. This is not a valid attribute for return |
| 948 | values.</dd> |
Chris Lattner | 47507de | 2008-01-11 06:20:47 +0000 | [diff] [blame] | 949 | |
Duncan Sands | 50f19f5 | 2007-07-27 19:57:41 +0000 | [diff] [blame] | 950 | <dt><tt>nest</tt></dt> |
Duncan Sands | 0789b8b | 2008-07-08 09:27:25 +0000 | [diff] [blame] | 951 | <dd>This indicates that the pointer parameter can be excised using the |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 952 | <a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid |
| 953 | attribute for return values.</dd> |
Anton Korobeynikov | 7f70559 | 2007-01-12 19:20:47 +0000 | [diff] [blame] | 954 | </dl> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 955 | |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 956 | </div> |
| 957 | |
| 958 | <!-- ======================================================================= --> |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 959 | <div class="doc_subsection"> |
Gordon Henriksen | 80a75bf | 2007-12-10 03:18:06 +0000 | [diff] [blame] | 960 | <a name="gc">Garbage Collector Names</a> |
| 961 | </div> |
| 962 | |
| 963 | <div class="doc_text"> |
| 964 | <p>Each function may specify a garbage collector name, which is simply a |
| 965 | string.</p> |
| 966 | |
| 967 | <div class="doc_code"><pre |
| 968 | >define void @f() gc "name" { ...</pre></div> |
| 969 | |
| 970 | <p>The compiler declares the supported values of <i>name</i>. Specifying a |
| 971 | collector which will cause the compiler to alter its output in order to support |
| 972 | the named garbage collection algorithm.</p> |
| 973 | </div> |
| 974 | |
| 975 | <!-- ======================================================================= --> |
| 976 | <div class="doc_subsection"> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 977 | <a name="fnattrs">Function Attributes</a> |
Devang Patel | f8b9481 | 2008-09-04 23:05:13 +0000 | [diff] [blame] | 978 | </div> |
| 979 | |
| 980 | <div class="doc_text"> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 981 | |
| 982 | <p>Function attributes are set to communicate additional information about |
| 983 | a function. Function attributes are considered to be part of the function, |
| 984 | not of the function type, so functions with different parameter attributes |
| 985 | can have the same function type.</p> |
| 986 | |
| 987 | <p>Function attributes are simple keywords that follow the type specified. If |
| 988 | multiple attributes are needed, they are space separated. For |
| 989 | example:</p> |
Devang Patel | f8b9481 | 2008-09-04 23:05:13 +0000 | [diff] [blame] | 990 | |
| 991 | <div class="doc_code"> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 992 | <pre> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 993 | define void @f() noinline { ... } |
| 994 | define void @f() alwaysinline { ... } |
| 995 | define void @f() alwaysinline optsize { ... } |
| 996 | define void @f() optsize |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 997 | </pre> |
Devang Patel | f8b9481 | 2008-09-04 23:05:13 +0000 | [diff] [blame] | 998 | </div> |
| 999 | |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1000 | <dl> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1001 | <dt><tt>alwaysinline</tt></dt> |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1002 | <dd>This attribute indicates that the inliner should attempt to inline this |
| 1003 | function into callers whenever possible, ignoring any active inlining size |
| 1004 | threshold for this caller.</dd> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1005 | |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1006 | <dt><tt>noinline</tt></dt> |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1007 | <dd>This attribute indicates that the inliner should never inline this function |
Chris Lattner | 94b5f7d | 2008-10-05 17:14:59 +0000 | [diff] [blame] | 1008 | in any situation. This attribute may not be used together with the |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1009 | <tt>alwaysinline</tt> attribute.</dd> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1010 | |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1011 | <dt><tt>optsize</tt></dt> |
Devang Patel | 66c6c65 | 2008-09-29 18:34:44 +0000 | [diff] [blame] | 1012 | <dd>This attribute suggests that optimization passes and code generator passes |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1013 | make choices that keep the code size of this function low, and otherwise do |
| 1014 | optimizations specifically to reduce code size.</dd> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1015 | |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1016 | <dt><tt>noreturn</tt></dt> |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1017 | <dd>This function attribute indicates that the function never returns normally. |
| 1018 | This produces undefined behavior at runtime if the function ever does |
| 1019 | dynamically return.</dd> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1020 | |
| 1021 | <dt><tt>nounwind</tt></dt> |
Chris Lattner | 88d4b59 | 2008-10-04 18:23:17 +0000 | [diff] [blame] | 1022 | <dd>This function attribute indicates that the function never returns with an |
| 1023 | unwind or exceptional control flow. If the function does unwind, its runtime |
| 1024 | behavior is undefined.</dd> |
| 1025 | |
| 1026 | <dt><tt>readnone</tt></dt> |
Duncan Sands | edb05df | 2008-10-06 08:14:18 +0000 | [diff] [blame] | 1027 | <dd>This attribute indicates that the function computes its result (or the |
| 1028 | exception it throws) based strictly on its arguments, without dereferencing any |
| 1029 | pointer arguments or otherwise accessing any mutable state (e.g. memory, control |
| 1030 | registers, etc) visible to caller functions. It does not write through any |
| 1031 | pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and |
| 1032 | never changes any state visible to callers.</dd> |
Devang Patel | 2c9c3e7 | 2008-09-26 23:51:19 +0000 | [diff] [blame] | 1033 | |
Duncan Sands | edb05df | 2008-10-06 08:14:18 +0000 | [diff] [blame] | 1034 | <dt><tt><a name="readonly">readonly</a></tt></dt> |
| 1035 | <dd>This attribute indicates that the function does not write through any |
| 1036 | pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) |
| 1037 | or otherwise modify any state (e.g. memory, control registers, etc) visible to |
| 1038 | caller functions. It may dereference pointer arguments and read state that may |
| 1039 | be set in the caller. A readonly function always returns the same value (or |
| 1040 | throws the same exception) when called with the same set of arguments and global |
| 1041 | state.</dd> |
Bill Wendling | 31359ba | 2008-11-13 01:02:51 +0000 | [diff] [blame] | 1042 | |
| 1043 | <dt><tt><a name="ssp">ssp</a></tt></dt> |
Bill Wendling | baa39d8 | 2008-11-26 19:19:05 +0000 | [diff] [blame] | 1044 | <dd>This attribute indicates that the function should emit a stack smashing |
Bill Wendling | 31359ba | 2008-11-13 01:02:51 +0000 | [diff] [blame] | 1045 | protector. It is in the form of a "canary"—a random value placed on the |
| 1046 | stack before the local variables that's checked upon return from the function to |
| 1047 | see if it has been overwritten. A heuristic is used to determine if a function |
Bill Wendling | baa39d8 | 2008-11-26 19:19:05 +0000 | [diff] [blame] | 1048 | needs stack protectors or not. |
Bill Wendling | 31359ba | 2008-11-13 01:02:51 +0000 | [diff] [blame] | 1049 | |
Bill Wendling | fbaa7ed | 2008-11-26 19:07:40 +0000 | [diff] [blame] | 1050 | <p>If a function that has an <tt>ssp</tt> attribute is inlined into a function |
| 1051 | that doesn't have an <tt>ssp</tt> attribute, then the resulting function will |
| 1052 | have an <tt>ssp</tt> attribute.</p></dd> |
| 1053 | |
| 1054 | <dt><tt>sspreq</tt></dt> |
Bill Wendling | baa39d8 | 2008-11-26 19:19:05 +0000 | [diff] [blame] | 1055 | <dd>This attribute indicates that the function should <em>always</em> emit a |
Bill Wendling | 31359ba | 2008-11-13 01:02:51 +0000 | [diff] [blame] | 1056 | stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt> |
Bill Wendling | baa39d8 | 2008-11-26 19:19:05 +0000 | [diff] [blame] | 1057 | function attribute. |
Bill Wendling | fbaa7ed | 2008-11-26 19:07:40 +0000 | [diff] [blame] | 1058 | |
| 1059 | <p>If a function that has an <tt>sspreq</tt> attribute is inlined into a |
| 1060 | function that doesn't have an <tt>sspreq</tt> attribute or which has |
| 1061 | an <tt>ssp</tt> attribute, then the resulting function will have |
| 1062 | an <tt>sspreq</tt> attribute.</p></dd> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1063 | </dl> |
| 1064 | |
Devang Patel | f8b9481 | 2008-09-04 23:05:13 +0000 | [diff] [blame] | 1065 | </div> |
| 1066 | |
| 1067 | <!-- ======================================================================= --> |
| 1068 | <div class="doc_subsection"> |
Chris Lattner | 1eeeb0c | 2006-04-08 04:40:53 +0000 | [diff] [blame] | 1069 | <a name="moduleasm">Module-Level Inline Assembly</a> |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 1070 | </div> |
| 1071 | |
| 1072 | <div class="doc_text"> |
| 1073 | <p> |
| 1074 | Modules may contain "module-level inline asm" blocks, which corresponds to the |
| 1075 | GCC "file scope inline asm" blocks. These blocks are internally concatenated by |
| 1076 | LLVM and treated as a single unit, but may be separated in the .ll file if |
| 1077 | desired. The syntax is very simple: |
| 1078 | </p> |
| 1079 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1080 | <div class="doc_code"> |
| 1081 | <pre> |
| 1082 | module asm "inline asm code goes here" |
| 1083 | module asm "more can go here" |
| 1084 | </pre> |
| 1085 | </div> |
Chris Lattner | 4e9aba7 | 2006-01-23 23:23:47 +0000 | [diff] [blame] | 1086 | |
| 1087 | <p>The strings can contain any character by escaping non-printable characters. |
| 1088 | The escape sequence used is simply "\xx" where "xx" is the two digit hex code |
| 1089 | for the number. |
| 1090 | </p> |
| 1091 | |
| 1092 | <p> |
| 1093 | The inline asm code is simply printed to the machine code .s file when |
| 1094 | assembly code is generated. |
| 1095 | </p> |
| 1096 | </div> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 1097 | |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1098 | <!-- ======================================================================= --> |
| 1099 | <div class="doc_subsection"> |
| 1100 | <a name="datalayout">Data Layout</a> |
| 1101 | </div> |
| 1102 | |
| 1103 | <div class="doc_text"> |
| 1104 | <p>A module may specify a target specific data layout string that specifies how |
Reid Spencer | c891084 | 2007-04-11 23:49:50 +0000 | [diff] [blame] | 1105 | data is to be laid out in memory. The syntax for the data layout is simply:</p> |
| 1106 | <pre> target datalayout = "<i>layout specification</i>"</pre> |
| 1107 | <p>The <i>layout specification</i> consists of a list of specifications |
| 1108 | separated by the minus sign character ('-'). Each specification starts with a |
| 1109 | letter and may include other information after the letter to define some |
| 1110 | aspect of the data layout. The specifications accepted are as follows: </p> |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1111 | <dl> |
| 1112 | <dt><tt>E</tt></dt> |
| 1113 | <dd>Specifies that the target lays out data in big-endian form. That is, the |
| 1114 | bits with the most significance have the lowest address location.</dd> |
| 1115 | <dt><tt>e</tt></dt> |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 1116 | <dd>Specifies that the target lays out data in little-endian form. That is, |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1117 | the bits with the least significance have the lowest address location.</dd> |
| 1118 | <dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt> |
| 1119 | <dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and |
| 1120 | <i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i> |
| 1121 | alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted |
| 1122 | too.</dd> |
| 1123 | <dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt> |
| 1124 | <dd>This specifies the alignment for an integer type of a given bit |
| 1125 | <i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd> |
| 1126 | <dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt> |
| 1127 | <dd>This specifies the alignment for a vector type of a given bit |
| 1128 | <i>size</i>.</dd> |
| 1129 | <dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt> |
| 1130 | <dd>This specifies the alignment for a floating point type of a given bit |
| 1131 | <i>size</i>. The value of <i>size</i> must be either 32 (float) or 64 |
| 1132 | (double).</dd> |
| 1133 | <dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt> |
| 1134 | <dd>This specifies the alignment for an aggregate type of a given bit |
| 1135 | <i>size</i>.</dd> |
| 1136 | </dl> |
| 1137 | <p>When constructing the data layout for a given target, LLVM starts with a |
| 1138 | default set of specifications which are then (possibly) overriden by the |
| 1139 | specifications in the <tt>datalayout</tt> keyword. The default specifications |
| 1140 | are given in this list:</p> |
| 1141 | <ul> |
| 1142 | <li><tt>E</tt> - big endian</li> |
| 1143 | <li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li> |
| 1144 | <li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li> |
| 1145 | <li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li> |
| 1146 | <li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li> |
| 1147 | <li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li> |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 1148 | <li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1149 | alignment of 64-bits</li> |
| 1150 | <li><tt>f32:32:32</tt> - float is 32-bit aligned</li> |
| 1151 | <li><tt>f64:64:64</tt> - double is 64-bit aligned</li> |
| 1152 | <li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li> |
| 1153 | <li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li> |
| 1154 | <li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li> |
| 1155 | </ul> |
Chris Lattner | ebec678 | 2008-08-05 18:21:08 +0000 | [diff] [blame] | 1156 | <p>When LLVM is determining the alignment for a given type, it uses the |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 1157 | following rules:</p> |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1158 | <ol> |
| 1159 | <li>If the type sought is an exact match for one of the specifications, that |
| 1160 | specification is used.</li> |
| 1161 | <li>If no match is found, and the type sought is an integer type, then the |
| 1162 | smallest integer type that is larger than the bitwidth of the sought type is |
| 1163 | used. If none of the specifications are larger than the bitwidth then the the |
| 1164 | largest integer type is used. For example, given the default specifications |
| 1165 | above, the i7 type will use the alignment of i8 (next largest) while both |
| 1166 | i65 and i256 will use the alignment of i64 (largest specified).</li> |
| 1167 | <li>If no match is found, and the type sought is a vector type, then the |
| 1168 | largest vector type that is smaller than the sought vector type will be used |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 1169 | as a fall back. This happens because <128 x double> can be implemented |
| 1170 | in terms of 64 <2 x double>, for example.</li> |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 1171 | </ol> |
| 1172 | </div> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 1173 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1174 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1175 | <div class="doc_section"> <a name="typesystem">Type System</a> </div> |
| 1176 | <!-- *********************************************************************** --> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 1177 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1178 | <div class="doc_text"> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 1179 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1180 | <p>The LLVM type system is one of the most important features of the |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1181 | intermediate representation. Being typed enables a number of |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 1182 | optimizations to be performed on the intermediate representation directly, |
| 1183 | without having to do |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1184 | extra analyses on the side before the transformation. A strong type |
| 1185 | system makes it easier to read the generated code and enables novel |
| 1186 | analyses and transformations that are not feasible to perform on normal |
| 1187 | three address code representations.</p> |
Chris Lattner | fa73021 | 2004-12-09 16:11:40 +0000 | [diff] [blame] | 1188 | |
| 1189 | </div> |
| 1190 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1191 | <!-- ======================================================================= --> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1192 | <div class="doc_subsection"> <a name="t_classifications">Type |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1193 | Classifications</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1194 | <div class="doc_text"> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1195 | <p>The types fall into a few useful |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1196 | classifications:</p> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 1197 | |
| 1198 | <table border="1" cellspacing="0" cellpadding="4"> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1199 | <tbody> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1200 | <tr><th>Classification</th><th>Types</th></tr> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1201 | <tr> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1202 | <td><a href="#t_integer">integer</a></td> |
Reid Spencer | 2b91631 | 2007-05-16 18:44:01 +0000 | [diff] [blame] | 1203 | <td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1204 | </tr> |
| 1205 | <tr> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1206 | <td><a href="#t_floating">floating point</a></td> |
| 1207 | <td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1208 | </tr> |
| 1209 | <tr> |
| 1210 | <td><a name="t_firstclass">first class</a></td> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1211 | <td><a href="#t_integer">integer</a>, |
| 1212 | <a href="#t_floating">floating point</a>, |
| 1213 | <a href="#t_pointer">pointer</a>, |
Dan Gohman | 0066db6 | 2008-06-18 18:42:13 +0000 | [diff] [blame] | 1214 | <a href="#t_vector">vector</a>, |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 1215 | <a href="#t_struct">structure</a>, |
| 1216 | <a href="#t_array">array</a>, |
Dan Gohman | ade5faa | 2008-05-23 22:50:26 +0000 | [diff] [blame] | 1217 | <a href="#t_label">label</a>. |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1218 | </td> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1219 | </tr> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1220 | <tr> |
| 1221 | <td><a href="#t_primitive">primitive</a></td> |
| 1222 | <td><a href="#t_label">label</a>, |
| 1223 | <a href="#t_void">void</a>, |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1224 | <a href="#t_floating">floating point</a>.</td> |
| 1225 | </tr> |
| 1226 | <tr> |
| 1227 | <td><a href="#t_derived">derived</a></td> |
| 1228 | <td><a href="#t_integer">integer</a>, |
| 1229 | <a href="#t_array">array</a>, |
| 1230 | <a href="#t_function">function</a>, |
| 1231 | <a href="#t_pointer">pointer</a>, |
| 1232 | <a href="#t_struct">structure</a>, |
| 1233 | <a href="#t_pstruct">packed structure</a>, |
| 1234 | <a href="#t_vector">vector</a>, |
| 1235 | <a href="#t_opaque">opaque</a>. |
Dan Gohman | 01ac101 | 2008-10-14 16:32:04 +0000 | [diff] [blame] | 1236 | </td> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1237 | </tr> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1238 | </tbody> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1239 | </table> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 1240 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1241 | <p>The <a href="#t_firstclass">first class</a> types are perhaps the |
| 1242 | most important. Values of these types are the only ones which can be |
| 1243 | produced by instructions, passed as arguments, or used as operands to |
Dan Gohman | c4b49eb | 2008-05-23 21:53:15 +0000 | [diff] [blame] | 1244 | instructions.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1245 | </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1246 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1247 | <!-- ======================================================================= --> |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1248 | <div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div> |
Chris Lattner | 8f8c7b7 | 2008-01-04 04:34:14 +0000 | [diff] [blame] | 1249 | |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1250 | <div class="doc_text"> |
| 1251 | <p>The primitive types are the fundamental building blocks of the LLVM |
| 1252 | system.</p> |
| 1253 | |
Chris Lattner | 8f8c7b7 | 2008-01-04 04:34:14 +0000 | [diff] [blame] | 1254 | </div> |
| 1255 | |
Chris Lattner | 4f69f46 | 2008-01-04 04:32:38 +0000 | [diff] [blame] | 1256 | <!-- _______________________________________________________________________ --> |
| 1257 | <div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div> |
| 1258 | |
| 1259 | <div class="doc_text"> |
| 1260 | <table> |
| 1261 | <tbody> |
| 1262 | <tr><th>Type</th><th>Description</th></tr> |
| 1263 | <tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr> |
| 1264 | <tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr> |
| 1265 | <tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr> |
| 1266 | <tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr> |
| 1267 | <tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr> |
| 1268 | </tbody> |
| 1269 | </table> |
| 1270 | </div> |
| 1271 | |
| 1272 | <!-- _______________________________________________________________________ --> |
| 1273 | <div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div> |
| 1274 | |
| 1275 | <div class="doc_text"> |
| 1276 | <h5>Overview:</h5> |
| 1277 | <p>The void type does not represent any value and has no size.</p> |
| 1278 | |
| 1279 | <h5>Syntax:</h5> |
| 1280 | |
| 1281 | <pre> |
| 1282 | void |
| 1283 | </pre> |
| 1284 | </div> |
| 1285 | |
| 1286 | <!-- _______________________________________________________________________ --> |
| 1287 | <div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div> |
| 1288 | |
| 1289 | <div class="doc_text"> |
| 1290 | <h5>Overview:</h5> |
| 1291 | <p>The label type represents code labels.</p> |
| 1292 | |
| 1293 | <h5>Syntax:</h5> |
| 1294 | |
| 1295 | <pre> |
| 1296 | label |
| 1297 | </pre> |
| 1298 | </div> |
| 1299 | |
| 1300 | |
| 1301 | <!-- ======================================================================= --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1302 | <div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1303 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1304 | <div class="doc_text"> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1305 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1306 | <p>The real power in LLVM comes from the derived types in the system. |
| 1307 | This is what allows a programmer to represent arrays, functions, |
| 1308 | pointers, and other useful types. Note that these derived types may be |
| 1309 | recursive: For example, it is possible to have a two dimensional array.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1310 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1311 | </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1312 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1313 | <!-- _______________________________________________________________________ --> |
Reid Spencer | 2b91631 | 2007-05-16 18:44:01 +0000 | [diff] [blame] | 1314 | <div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div> |
| 1315 | |
| 1316 | <div class="doc_text"> |
| 1317 | |
| 1318 | <h5>Overview:</h5> |
| 1319 | <p>The integer type is a very simple derived type that simply specifies an |
| 1320 | arbitrary bit width for the integer type desired. Any bit width from 1 bit to |
| 1321 | 2^23-1 (about 8 million) can be specified.</p> |
| 1322 | |
| 1323 | <h5>Syntax:</h5> |
| 1324 | |
| 1325 | <pre> |
| 1326 | iN |
| 1327 | </pre> |
| 1328 | |
| 1329 | <p>The number of bits the integer will occupy is specified by the <tt>N</tt> |
| 1330 | value.</p> |
| 1331 | |
| 1332 | <h5>Examples:</h5> |
| 1333 | <table class="layout"> |
Chris Lattner | b9488a6 | 2007-12-18 06:18:21 +0000 | [diff] [blame] | 1334 | <tbody> |
| 1335 | <tr> |
| 1336 | <td><tt>i1</tt></td> |
| 1337 | <td>a single-bit integer.</td> |
| 1338 | </tr><tr> |
| 1339 | <td><tt>i32</tt></td> |
| 1340 | <td>a 32-bit integer.</td> |
| 1341 | </tr><tr> |
| 1342 | <td><tt>i1942652</tt></td> |
| 1343 | <td>a really big integer of over 1 million bits.</td> |
Reid Spencer | 2b91631 | 2007-05-16 18:44:01 +0000 | [diff] [blame] | 1344 | </tr> |
Chris Lattner | b9488a6 | 2007-12-18 06:18:21 +0000 | [diff] [blame] | 1345 | </tbody> |
Reid Spencer | 2b91631 | 2007-05-16 18:44:01 +0000 | [diff] [blame] | 1346 | </table> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1347 | </div> |
Reid Spencer | 2b91631 | 2007-05-16 18:44:01 +0000 | [diff] [blame] | 1348 | |
| 1349 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1350 | <div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1351 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1352 | <div class="doc_text"> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1353 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1354 | <h5>Overview:</h5> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1355 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1356 | <p>The array type is a very simple derived type that arranges elements |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1357 | sequentially in memory. The array type requires a size (number of |
| 1358 | elements) and an underlying data type.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1359 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 1360 | <h5>Syntax:</h5> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1361 | |
| 1362 | <pre> |
| 1363 | [<# elements> x <elementtype>] |
| 1364 | </pre> |
| 1365 | |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 1366 | <p>The number of elements is a constant integer value; elementtype may |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1367 | be any type with a size.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1368 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 1369 | <h5>Examples:</h5> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1370 | <table class="layout"> |
| 1371 | <tr class="layout"> |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1372 | <td class="left"><tt>[40 x i32]</tt></td> |
| 1373 | <td class="left">Array of 40 32-bit integer values.</td> |
| 1374 | </tr> |
| 1375 | <tr class="layout"> |
| 1376 | <td class="left"><tt>[41 x i32]</tt></td> |
| 1377 | <td class="left">Array of 41 32-bit integer values.</td> |
| 1378 | </tr> |
| 1379 | <tr class="layout"> |
| 1380 | <td class="left"><tt>[4 x i8]</tt></td> |
| 1381 | <td class="left">Array of 4 8-bit integer values.</td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1382 | </tr> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1383 | </table> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1384 | <p>Here are some examples of multidimensional arrays:</p> |
| 1385 | <table class="layout"> |
| 1386 | <tr class="layout"> |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1387 | <td class="left"><tt>[3 x [4 x i32]]</tt></td> |
| 1388 | <td class="left">3x4 array of 32-bit integer values.</td> |
| 1389 | </tr> |
| 1390 | <tr class="layout"> |
| 1391 | <td class="left"><tt>[12 x [10 x float]]</tt></td> |
| 1392 | <td class="left">12x10 array of single precision floating point values.</td> |
| 1393 | </tr> |
| 1394 | <tr class="layout"> |
| 1395 | <td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td> |
| 1396 | <td class="left">2x3x4 array of 16-bit integer values.</td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1397 | </tr> |
| 1398 | </table> |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 1399 | |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 1400 | <p>Note that 'variable sized arrays' can be implemented in LLVM with a zero |
| 1401 | length array. Normally, accesses past the end of an array are undefined in |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 1402 | LLVM (e.g. it is illegal to access the 5th element of a 3 element array). |
| 1403 | As a special case, however, zero length arrays are recognized to be variable |
| 1404 | length. This allows implementation of 'pascal style arrays' with the LLVM |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1405 | type "{ i32, [0 x float]}", for example.</p> |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 1406 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1407 | </div> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1408 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1409 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1410 | <div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1411 | <div class="doc_text"> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1412 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1413 | <h5>Overview:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1414 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1415 | <p>The function type can be thought of as a function signature. It |
Devang Patel | a582f40 | 2008-03-24 05:35:41 +0000 | [diff] [blame] | 1416 | consists of a return type and a list of formal parameter types. The |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1417 | return type of a function type is a scalar type, a void type, or a struct type. |
Devang Patel | 7a3ad1a | 2008-03-24 20:52:42 +0000 | [diff] [blame] | 1418 | If the return type is a struct type then all struct elements must be of first |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1419 | class types, and the struct must have at least one element.</p> |
Devang Patel | c3fc6df | 2008-03-10 20:49:15 +0000 | [diff] [blame] | 1420 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1421 | <h5>Syntax:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1422 | |
| 1423 | <pre> |
| 1424 | <returntype list> (<parameter list>) |
| 1425 | </pre> |
| 1426 | |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 1427 | <p>...where '<tt><parameter list></tt>' is a comma-separated list of type |
Misha Brukman | c24b758 | 2004-08-12 20:16:08 +0000 | [diff] [blame] | 1428 | specifiers. Optionally, the parameter list may include a type <tt>...</tt>, |
Chris Lattner | 27f71f2 | 2003-09-03 00:41:47 +0000 | [diff] [blame] | 1429 | which indicates that the function takes a variable number of arguments. |
| 1430 | Variable argument functions can access their arguments with the <a |
Devang Patel | c3fc6df | 2008-03-10 20:49:15 +0000 | [diff] [blame] | 1431 | href="#int_varargs">variable argument handling intrinsic</a> functions. |
| 1432 | '<tt><returntype list></tt>' is a comma-separated list of |
| 1433 | <a href="#t_firstclass">first class</a> type specifiers.</p> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 1434 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1435 | <h5>Examples:</h5> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1436 | <table class="layout"> |
| 1437 | <tr class="layout"> |
Reid Spencer | 92f8230 | 2006-12-31 07:18:34 +0000 | [diff] [blame] | 1438 | <td class="left"><tt>i32 (i32)</tt></td> |
| 1439 | <td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1440 | </td> |
Reid Spencer | 92f8230 | 2006-12-31 07:18:34 +0000 | [diff] [blame] | 1441 | </tr><tr class="layout"> |
Reid Spencer | 9445e9a | 2007-07-19 23:13:04 +0000 | [diff] [blame] | 1442 | <td class="left"><tt>float (i16 signext, i32 *) * |
Reid Spencer | f17a0b7 | 2006-12-31 07:20:23 +0000 | [diff] [blame] | 1443 | </tt></td> |
Reid Spencer | 92f8230 | 2006-12-31 07:18:34 +0000 | [diff] [blame] | 1444 | <td class="left"><a href="#t_pointer">Pointer</a> to a function that takes |
| 1445 | an <tt>i16</tt> that should be sign extended and a |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1446 | <a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning |
Reid Spencer | 92f8230 | 2006-12-31 07:18:34 +0000 | [diff] [blame] | 1447 | <tt>float</tt>. |
| 1448 | </td> |
| 1449 | </tr><tr class="layout"> |
| 1450 | <td class="left"><tt>i32 (i8*, ...)</tt></td> |
| 1451 | <td class="left">A vararg function that takes at least one |
Reid Spencer | a517338 | 2007-01-04 16:43:23 +0000 | [diff] [blame] | 1452 | <a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C), |
Reid Spencer | 92f8230 | 2006-12-31 07:18:34 +0000 | [diff] [blame] | 1453 | which returns an integer. This is the signature for <tt>printf</tt> in |
| 1454 | LLVM. |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1455 | </td> |
Devang Patel | a582f40 | 2008-03-24 05:35:41 +0000 | [diff] [blame] | 1456 | </tr><tr class="layout"> |
| 1457 | <td class="left"><tt>{i32, i32} (i32)</tt></td> |
Misha Brukman | b0a57aa | 2008-11-27 06:41:20 +0000 | [diff] [blame] | 1458 | <td class="left">A function taking an <tt>i32</tt>, returning two |
| 1459 | <tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt> |
Devang Patel | a582f40 | 2008-03-24 05:35:41 +0000 | [diff] [blame] | 1460 | </td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1461 | </tr> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1462 | </table> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 1463 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1464 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1465 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1466 | <div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1467 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1468 | <h5>Overview:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1469 | <p>The structure type is used to represent a collection of data members |
| 1470 | together in memory. The packing of the field types is defined to match |
| 1471 | the ABI of the underlying processor. The elements of a structure may |
| 1472 | be any type that has a size.</p> |
| 1473 | <p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> |
| 1474 | and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a |
| 1475 | field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' |
| 1476 | instruction.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1477 | <h5>Syntax:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1478 | <pre> { <type list> }<br></pre> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1479 | <h5>Examples:</h5> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1480 | <table class="layout"> |
| 1481 | <tr class="layout"> |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 1482 | <td class="left"><tt>{ i32, i32, i32 }</tt></td> |
| 1483 | <td class="left">A triple of three <tt>i32</tt> values</td> |
| 1484 | </tr><tr class="layout"> |
| 1485 | <td class="left"><tt>{ float, i32 (i32) * }</tt></td> |
| 1486 | <td class="left">A pair, where the first element is a <tt>float</tt> and the |
| 1487 | second element is a <a href="#t_pointer">pointer</a> to a |
| 1488 | <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning |
| 1489 | an <tt>i32</tt>.</td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1490 | </tr> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1491 | </table> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1492 | </div> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1493 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1494 | <!-- _______________________________________________________________________ --> |
Andrew Lenharth | 75e1068 | 2006-12-08 17:13:00 +0000 | [diff] [blame] | 1495 | <div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a> |
| 1496 | </div> |
| 1497 | <div class="doc_text"> |
| 1498 | <h5>Overview:</h5> |
| 1499 | <p>The packed structure type is used to represent a collection of data members |
| 1500 | together in memory. There is no padding between fields. Further, the alignment |
| 1501 | of a packed structure is 1 byte. The elements of a packed structure may |
| 1502 | be any type that has a size.</p> |
| 1503 | <p>Structures are accessed using '<tt><a href="#i_load">load</a></tt> |
| 1504 | and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a |
| 1505 | field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>' |
| 1506 | instruction.</p> |
| 1507 | <h5>Syntax:</h5> |
| 1508 | <pre> < { <type list> } > <br></pre> |
| 1509 | <h5>Examples:</h5> |
| 1510 | <table class="layout"> |
| 1511 | <tr class="layout"> |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 1512 | <td class="left"><tt>< { i32, i32, i32 } ></tt></td> |
| 1513 | <td class="left">A triple of three <tt>i32</tt> values</td> |
| 1514 | </tr><tr class="layout"> |
Bill Wendling | e36dccc | 2008-09-07 10:26:33 +0000 | [diff] [blame] | 1515 | <td class="left"> |
| 1516 | <tt>< { float, i32 (i32)* } ></tt></td> |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 1517 | <td class="left">A pair, where the first element is a <tt>float</tt> and the |
| 1518 | second element is a <a href="#t_pointer">pointer</a> to a |
| 1519 | <a href="#t_function">function</a> that takes an <tt>i32</tt>, returning |
| 1520 | an <tt>i32</tt>.</td> |
Andrew Lenharth | 75e1068 | 2006-12-08 17:13:00 +0000 | [diff] [blame] | 1521 | </tr> |
| 1522 | </table> |
| 1523 | </div> |
| 1524 | |
| 1525 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1526 | <div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1527 | <div class="doc_text"> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 1528 | <h5>Overview:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1529 | <p>As in many languages, the pointer type represents a pointer or |
Christopher Lamb | 284d992 | 2007-12-11 09:31:00 +0000 | [diff] [blame] | 1530 | reference to another object, which must live in memory. Pointer types may have |
| 1531 | an optional address space attribute defining the target-specific numbered |
| 1532 | address space where the pointed-to object resides. The default address space is |
| 1533 | zero.</p> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 1534 | <h5>Syntax:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1535 | <pre> <type> *<br></pre> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 1536 | <h5>Examples:</h5> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1537 | <table class="layout"> |
| 1538 | <tr class="layout"> |
Dan Gohman | 2a08c53 | 2009-01-04 23:44:43 +0000 | [diff] [blame] | 1539 | <td class="left"><tt>[4 x i32]*</tt></td> |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1540 | <td class="left">A <a href="#t_pointer">pointer</a> to <a |
| 1541 | href="#t_array">array</a> of four <tt>i32</tt> values.</td> |
| 1542 | </tr> |
| 1543 | <tr class="layout"> |
| 1544 | <td class="left"><tt>i32 (i32 *) *</tt></td> |
| 1545 | <td class="left"> A <a href="#t_pointer">pointer</a> to a <a |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1546 | href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1547 | <tt>i32</tt>.</td> |
| 1548 | </tr> |
| 1549 | <tr class="layout"> |
| 1550 | <td class="left"><tt>i32 addrspace(5)*</tt></td> |
| 1551 | <td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value |
| 1552 | that resides in address space #5.</td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1553 | </tr> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1554 | </table> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1555 | </div> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1556 | |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1557 | <!-- _______________________________________________________________________ --> |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1558 | <div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1559 | <div class="doc_text"> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1560 | |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1561 | <h5>Overview:</h5> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1562 | |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1563 | <p>A vector type is a simple derived type that represents a vector |
| 1564 | of elements. Vector types are used when multiple primitive data |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1565 | are operated in parallel using a single instruction (SIMD). |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1566 | A vector type requires a size (number of |
Chris Lattner | b8d172f | 2005-11-10 01:44:22 +0000 | [diff] [blame] | 1567 | elements) and an underlying primitive data type. Vectors must have a power |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1568 | of two length (1, 2, 4, 8, 16 ...). Vector types are |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1569 | considered <a href="#t_firstclass">first class</a>.</p> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1570 | |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1571 | <h5>Syntax:</h5> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1572 | |
| 1573 | <pre> |
| 1574 | < <# elements> x <elementtype> > |
| 1575 | </pre> |
| 1576 | |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 1577 | <p>The number of elements is a constant integer value; elementtype may |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 1578 | be any integer or floating point type.</p> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1579 | |
Chris Lattner | a58561b | 2004-08-12 19:12:28 +0000 | [diff] [blame] | 1580 | <h5>Examples:</h5> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1581 | |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1582 | <table class="layout"> |
| 1583 | <tr class="layout"> |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1584 | <td class="left"><tt><4 x i32></tt></td> |
| 1585 | <td class="left">Vector of 4 32-bit integer values.</td> |
| 1586 | </tr> |
| 1587 | <tr class="layout"> |
| 1588 | <td class="left"><tt><8 x float></tt></td> |
| 1589 | <td class="left">Vector of 8 32-bit floating-point values.</td> |
| 1590 | </tr> |
| 1591 | <tr class="layout"> |
| 1592 | <td class="left"><tt><2 x i64></tt></td> |
| 1593 | <td class="left">Vector of 2 64-bit integer values.</td> |
Reid Spencer | d3f876c | 2004-11-01 08:19:36 +0000 | [diff] [blame] | 1594 | </tr> |
| 1595 | </table> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1596 | </div> |
| 1597 | |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1598 | <!-- _______________________________________________________________________ --> |
| 1599 | <div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div> |
| 1600 | <div class="doc_text"> |
| 1601 | |
| 1602 | <h5>Overview:</h5> |
| 1603 | |
| 1604 | <p>Opaque types are used to represent unknown types in the system. This |
Gordon Henriksen | 8ac04ff | 2007-10-14 00:34:53 +0000 | [diff] [blame] | 1605 | corresponds (for example) to the C notion of a forward declared structure type. |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1606 | In LLVM, opaque types can eventually be resolved to any type (not just a |
| 1607 | structure type).</p> |
| 1608 | |
| 1609 | <h5>Syntax:</h5> |
| 1610 | |
| 1611 | <pre> |
| 1612 | opaque |
| 1613 | </pre> |
| 1614 | |
| 1615 | <h5>Examples:</h5> |
| 1616 | |
| 1617 | <table class="layout"> |
| 1618 | <tr class="layout"> |
Chris Lattner | 23ff1f9 | 2007-12-19 05:04:11 +0000 | [diff] [blame] | 1619 | <td class="left"><tt>opaque</tt></td> |
| 1620 | <td class="left">An opaque type.</td> |
Chris Lattner | 69c11bb | 2005-04-25 17:34:15 +0000 | [diff] [blame] | 1621 | </tr> |
| 1622 | </table> |
| 1623 | </div> |
| 1624 | |
| 1625 | |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1626 | <!-- *********************************************************************** --> |
| 1627 | <div class="doc_section"> <a name="constants">Constants</a> </div> |
| 1628 | <!-- *********************************************************************** --> |
| 1629 | |
| 1630 | <div class="doc_text"> |
| 1631 | |
| 1632 | <p>LLVM has several different basic types of constants. This section describes |
| 1633 | them all and their syntax.</p> |
| 1634 | |
| 1635 | </div> |
| 1636 | |
| 1637 | <!-- ======================================================================= --> |
Reid Spencer | cc16dc3 | 2004-12-09 18:02:53 +0000 | [diff] [blame] | 1638 | <div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1639 | |
| 1640 | <div class="doc_text"> |
| 1641 | |
| 1642 | <dl> |
| 1643 | <dt><b>Boolean constants</b></dt> |
| 1644 | |
| 1645 | <dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 1646 | constants of the <tt><a href="#t_primitive">i1</a></tt> type. |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1647 | </dd> |
| 1648 | |
| 1649 | <dt><b>Integer constants</b></dt> |
| 1650 | |
Reid Spencer | cc16dc3 | 2004-12-09 18:02:53 +0000 | [diff] [blame] | 1651 | <dd>Standard integers (such as '4') are constants of the <a |
Reid Spencer | a517338 | 2007-01-04 16:43:23 +0000 | [diff] [blame] | 1652 | href="#t_integer">integer</a> type. Negative numbers may be used with |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1653 | integer types. |
| 1654 | </dd> |
| 1655 | |
| 1656 | <dt><b>Floating point constants</b></dt> |
| 1657 | |
| 1658 | <dd>Floating point constants use standard decimal notation (e.g. 123.421), |
| 1659 | exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal |
Chris Lattner | a73afe0 | 2008-04-01 18:45:27 +0000 | [diff] [blame] | 1660 | notation (see below). The assembler requires the exact decimal value of |
| 1661 | a floating-point constant. For example, the assembler accepts 1.25 but |
| 1662 | rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point |
| 1663 | constants must have a <a href="#t_floating">floating point</a> type. </dd> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1664 | |
| 1665 | <dt><b>Null pointer constants</b></dt> |
| 1666 | |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 1667 | <dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1668 | and must be of <a href="#t_pointer">pointer type</a>.</dd> |
| 1669 | |
| 1670 | </dl> |
| 1671 | |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 1672 | <p>The one non-intuitive notation for constants is the optional hexadecimal form |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1673 | of floating point constants. For example, the form '<tt>double |
| 1674 | 0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double |
| 1675 | 4.5e+15</tt>'. The only time hexadecimal floating point constants are required |
Reid Spencer | cc16dc3 | 2004-12-09 18:02:53 +0000 | [diff] [blame] | 1676 | (and the only time that they are generated by the disassembler) is when a |
| 1677 | floating point constant must be emitted but it cannot be represented as a |
| 1678 | decimal floating point number. For example, NaN's, infinities, and other |
| 1679 | special values are represented in their IEEE hexadecimal format so that |
| 1680 | assembly and disassembly do not cause any bits to change in the constants.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1681 | |
| 1682 | </div> |
| 1683 | |
| 1684 | <!-- ======================================================================= --> |
| 1685 | <div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a> |
| 1686 | </div> |
| 1687 | |
| 1688 | <div class="doc_text"> |
Chris Lattner | d4f6b17 | 2005-03-07 22:13:59 +0000 | [diff] [blame] | 1689 | <p>Aggregate constants arise from aggregation of simple constants |
| 1690 | and smaller aggregate constants.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1691 | |
| 1692 | <dl> |
| 1693 | <dt><b>Structure constants</b></dt> |
| 1694 | |
| 1695 | <dd>Structure constants are represented with notation similar to structure |
| 1696 | type definitions (a comma separated list of elements, surrounded by braces |
Chris Lattner | 64910ee | 2007-12-25 20:34:52 +0000 | [diff] [blame] | 1697 | (<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>", |
| 1698 | where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants |
Chris Lattner | d4f6b17 | 2005-03-07 22:13:59 +0000 | [diff] [blame] | 1699 | must have <a href="#t_struct">structure type</a>, and the number and |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1700 | types of elements must match those specified by the type. |
| 1701 | </dd> |
| 1702 | |
| 1703 | <dt><b>Array constants</b></dt> |
| 1704 | |
| 1705 | <dd>Array constants are represented with notation similar to array type |
| 1706 | definitions (a comma separated list of elements, surrounded by square brackets |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1707 | (<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1708 | constants must have <a href="#t_array">array type</a>, and the number and |
| 1709 | types of elements must match those specified by the type. |
| 1710 | </dd> |
| 1711 | |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1712 | <dt><b>Vector constants</b></dt> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1713 | |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1714 | <dd>Vector constants are represented with notation similar to vector type |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1715 | definitions (a comma separated list of elements, surrounded by |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 1716 | less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42, |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 1717 | i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1718 | href="#t_vector">vector type</a>, and the number and types of elements must |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1719 | match those specified by the type. |
| 1720 | </dd> |
| 1721 | |
| 1722 | <dt><b>Zero initialization</b></dt> |
| 1723 | |
| 1724 | <dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a |
| 1725 | value to zero of <em>any</em> type, including scalar and aggregate types. |
| 1726 | This is often used to avoid having to print large zero initializers (e.g. for |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 1727 | large arrays) and is always exactly equivalent to using explicit zero |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1728 | initializers. |
| 1729 | </dd> |
| 1730 | </dl> |
| 1731 | |
| 1732 | </div> |
| 1733 | |
| 1734 | <!-- ======================================================================= --> |
| 1735 | <div class="doc_subsection"> |
| 1736 | <a name="globalconstants">Global Variable and Function Addresses</a> |
| 1737 | </div> |
| 1738 | |
| 1739 | <div class="doc_text"> |
| 1740 | |
| 1741 | <p>The addresses of <a href="#globalvars">global variables</a> and <a |
| 1742 | href="#functionstructure">functions</a> are always implicitly valid (link-time) |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 1743 | constants. These constants are explicitly referenced when the <a |
| 1744 | href="#identifiers">identifier for the global</a> is used and always have <a |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1745 | href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM |
| 1746 | file:</p> |
| 1747 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1748 | <div class="doc_code"> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1749 | <pre> |
Chris Lattner | a18a424 | 2007-06-06 18:28:13 +0000 | [diff] [blame] | 1750 | @X = global i32 17 |
| 1751 | @Y = global i32 42 |
| 1752 | @Z = global [2 x i32*] [ i32* @X, i32* @Y ] |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1753 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1754 | </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1755 | |
| 1756 | </div> |
| 1757 | |
| 1758 | <!-- ======================================================================= --> |
Reid Spencer | 2dc45b8 | 2004-12-09 18:13:12 +0000 | [diff] [blame] | 1759 | <div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1760 | <div class="doc_text"> |
Reid Spencer | 2dc45b8 | 2004-12-09 18:13:12 +0000 | [diff] [blame] | 1761 | <p>The string '<tt>undef</tt>' is recognized as a type-less constant that has |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 1762 | no specific value. Undefined values may be of any type and be used anywhere |
Reid Spencer | 2dc45b8 | 2004-12-09 18:13:12 +0000 | [diff] [blame] | 1763 | a constant is permitted.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1764 | |
Reid Spencer | 2dc45b8 | 2004-12-09 18:13:12 +0000 | [diff] [blame] | 1765 | <p>Undefined values indicate to the compiler that the program is well defined |
| 1766 | no matter what value is used, giving the compiler more freedom to optimize. |
| 1767 | </p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1768 | </div> |
| 1769 | |
| 1770 | <!-- ======================================================================= --> |
| 1771 | <div class="doc_subsection"><a name="constantexprs">Constant Expressions</a> |
| 1772 | </div> |
| 1773 | |
| 1774 | <div class="doc_text"> |
| 1775 | |
| 1776 | <p>Constant expressions are used to allow expressions involving other constants |
| 1777 | to be used as constants. Constant expressions may be of any <a |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 1778 | href="#t_firstclass">first class</a> type and may involve any LLVM operation |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1779 | that does not have side effects (e.g. load and call are not supported). The |
| 1780 | following is the syntax for constant expressions:</p> |
| 1781 | |
| 1782 | <dl> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1783 | <dt><b><tt>trunc ( CST to TYPE )</tt></b></dt> |
| 1784 | <dd>Truncate a constant to another type. The bit size of CST must be larger |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 1785 | than the bit size of TYPE. Both types must be integers.</dd> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1786 | |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1787 | <dt><b><tt>zext ( CST to TYPE )</tt></b></dt> |
| 1788 | <dd>Zero extend a constant to another type. The bit size of CST must be |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 1789 | smaller or equal to the bit size of TYPE. Both types must be integers.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1790 | |
| 1791 | <dt><b><tt>sext ( CST to TYPE )</tt></b></dt> |
| 1792 | <dd>Sign extend a constant to another type. The bit size of CST must be |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 1793 | smaller or equal to the bit size of TYPE. Both types must be integers.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1794 | |
| 1795 | <dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt> |
| 1796 | <dd>Truncate a floating point constant to another floating point type. The |
| 1797 | size of CST must be larger than the size of TYPE. Both types must be |
| 1798 | floating point.</dd> |
| 1799 | |
| 1800 | <dt><b><tt>fpext ( CST to TYPE )</tt></b></dt> |
| 1801 | <dd>Floating point extend a constant to another type. The size of CST must be |
| 1802 | smaller or equal to the size of TYPE. Both types must be floating point.</dd> |
| 1803 | |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 1804 | <dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1805 | <dd>Convert a floating point constant to the corresponding unsigned integer |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 1806 | constant. TYPE must be a scalar or vector integer type. CST must be of scalar |
| 1807 | or vector floating point type. Both CST and TYPE must be scalars, or vectors |
| 1808 | of the same number of elements. If the value won't fit in the integer type, |
| 1809 | the results are undefined.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1810 | |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 1811 | <dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1812 | <dd>Convert a floating point constant to the corresponding signed integer |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 1813 | constant. TYPE must be a scalar or vector integer type. CST must be of scalar |
| 1814 | or vector floating point type. Both CST and TYPE must be scalars, or vectors |
| 1815 | of the same number of elements. If the value won't fit in the integer type, |
| 1816 | the results are undefined.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1817 | |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 1818 | <dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1819 | <dd>Convert an unsigned integer constant to the corresponding floating point |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 1820 | constant. TYPE must be a scalar or vector floating point type. CST must be of |
| 1821 | scalar or vector integer type. Both CST and TYPE must be scalars, or vectors |
| 1822 | of the same number of elements. If the value won't fit in the floating point |
| 1823 | type, the results are undefined.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1824 | |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 1825 | <dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1826 | <dd>Convert a signed integer constant to the corresponding floating point |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 1827 | constant. TYPE must be a scalar or vector floating point type. CST must be of |
| 1828 | scalar or vector integer type. Both CST and TYPE must be scalars, or vectors |
| 1829 | of the same number of elements. If the value won't fit in the floating point |
| 1830 | type, the results are undefined.</dd> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1831 | |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 1832 | <dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt> |
| 1833 | <dd>Convert a pointer typed constant to the corresponding integer constant |
| 1834 | TYPE must be an integer type. CST must be of pointer type. The CST value is |
| 1835 | zero extended, truncated, or unchanged to make it fit in TYPE.</dd> |
| 1836 | |
| 1837 | <dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt> |
| 1838 | <dd>Convert a integer constant to a pointer constant. TYPE must be a |
| 1839 | pointer type. CST must be of integer type. The CST value is zero extended, |
| 1840 | truncated, or unchanged to make it fit in a pointer size. This one is |
| 1841 | <i>really</i> dangerous!</dd> |
| 1842 | |
| 1843 | <dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1844 | <dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be |
| 1845 | identical (same number of bits). The conversion is done as if the CST value |
| 1846 | was stored to memory and read back as TYPE. In other words, no bits change |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 1847 | with this operator, just the type. This can be used for conversion of |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 1848 | vector types to any other type, as long as they have the same bit width. For |
Dan Gohman | 500233a | 2008-09-08 16:45:59 +0000 | [diff] [blame] | 1849 | pointers it is only valid to cast to another pointer type. It is not valid |
| 1850 | to bitcast to or from an aggregate type. |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 1851 | </dd> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1852 | |
| 1853 | <dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt> |
| 1854 | |
| 1855 | <dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on |
| 1856 | constants. As with the <a href="#i_getelementptr">getelementptr</a> |
| 1857 | instruction, the index list may have zero or more indexes, which are required |
| 1858 | to make sense for the type of "CSTPTR".</dd> |
| 1859 | |
Robert Bocchino | 9fbe145 | 2006-01-10 19:31:34 +0000 | [diff] [blame] | 1860 | <dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt> |
| 1861 | |
| 1862 | <dd>Perform the <a href="#i_select">select operation</a> on |
Reid Spencer | 01c4259 | 2006-12-04 19:23:19 +0000 | [diff] [blame] | 1863 | constants.</dd> |
| 1864 | |
| 1865 | <dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt> |
| 1866 | <dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd> |
| 1867 | |
| 1868 | <dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt> |
| 1869 | <dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd> |
Robert Bocchino | 9fbe145 | 2006-01-10 19:31:34 +0000 | [diff] [blame] | 1870 | |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 1871 | <dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt> |
| 1872 | <dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd> |
| 1873 | |
| 1874 | <dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt> |
| 1875 | <dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd> |
| 1876 | |
Robert Bocchino | 9fbe145 | 2006-01-10 19:31:34 +0000 | [diff] [blame] | 1877 | <dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt> |
| 1878 | |
| 1879 | <dd>Perform the <a href="#i_extractelement">extractelement |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 1880 | operation</a> on constants.</dd> |
Robert Bocchino | 9fbe145 | 2006-01-10 19:31:34 +0000 | [diff] [blame] | 1881 | |
Robert Bocchino | 05ccd70 | 2006-01-15 20:48:27 +0000 | [diff] [blame] | 1882 | <dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt> |
| 1883 | |
| 1884 | <dd>Perform the <a href="#i_insertelement">insertelement |
Reid Spencer | 01c4259 | 2006-12-04 19:23:19 +0000 | [diff] [blame] | 1885 | operation</a> on constants.</dd> |
Robert Bocchino | 05ccd70 | 2006-01-15 20:48:27 +0000 | [diff] [blame] | 1886 | |
Chris Lattner | c198954 | 2006-04-08 00:13:41 +0000 | [diff] [blame] | 1887 | |
| 1888 | <dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt> |
| 1889 | |
| 1890 | <dd>Perform the <a href="#i_shufflevector">shufflevector |
Reid Spencer | 01c4259 | 2006-12-04 19:23:19 +0000 | [diff] [blame] | 1891 | operation</a> on constants.</dd> |
Chris Lattner | c198954 | 2006-04-08 00:13:41 +0000 | [diff] [blame] | 1892 | |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1893 | <dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt> |
| 1894 | |
Reid Spencer | 2dc45b8 | 2004-12-09 18:13:12 +0000 | [diff] [blame] | 1895 | <dd>Perform the specified operation of the LHS and RHS constants. OPCODE may |
| 1896 | be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1897 | binary</a> operations. The constraints on operands are the same as those for |
| 1898 | the corresponding instruction (e.g. no bitwise operations on floating point |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 1899 | values are allowed).</dd> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1900 | </dl> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1901 | </div> |
Chris Lattner | 9ee5d22 | 2004-03-08 16:49:10 +0000 | [diff] [blame] | 1902 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1903 | <!-- *********************************************************************** --> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1904 | <div class="doc_section"> <a name="othervalues">Other Values</a> </div> |
| 1905 | <!-- *********************************************************************** --> |
| 1906 | |
| 1907 | <!-- ======================================================================= --> |
| 1908 | <div class="doc_subsection"> |
| 1909 | <a name="inlineasm">Inline Assembler Expressions</a> |
| 1910 | </div> |
| 1911 | |
| 1912 | <div class="doc_text"> |
| 1913 | |
| 1914 | <p> |
| 1915 | LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm"> |
| 1916 | Module-Level Inline Assembly</a>) through the use of a special value. This |
| 1917 | value represents the inline assembler as a string (containing the instructions |
| 1918 | to emit), a list of operand constraints (stored as a string), and a flag that |
| 1919 | indicates whether or not the inline asm expression has side effects. An example |
| 1920 | inline assembler expression is: |
| 1921 | </p> |
| 1922 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1923 | <div class="doc_code"> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1924 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1925 | i32 (i32) asm "bswap $0", "=r,r" |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1926 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1927 | </div> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1928 | |
| 1929 | <p> |
| 1930 | Inline assembler expressions may <b>only</b> be used as the callee operand of |
| 1931 | a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have: |
| 1932 | </p> |
| 1933 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1934 | <div class="doc_code"> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1935 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1936 | %X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y) |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1937 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1938 | </div> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1939 | |
| 1940 | <p> |
| 1941 | Inline asms with side effects not visible in the constraint list must be marked |
| 1942 | as having side effects. This is done through the use of the |
| 1943 | '<tt>sideeffect</tt>' keyword, like so: |
| 1944 | </p> |
| 1945 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1946 | <div class="doc_code"> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1947 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1948 | call void asm sideeffect "eieio", ""() |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1949 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 1950 | </div> |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1951 | |
| 1952 | <p>TODO: The format of the asm and constraints string still need to be |
| 1953 | documented here. Constraints on what can be done (e.g. duplication, moving, etc |
Chris Lattner | 4f99335 | 2008-10-04 18:36:02 +0000 | [diff] [blame] | 1954 | need to be documented). This is probably best done by reference to another |
| 1955 | document that covers inline asm from a holistic perspective. |
Chris Lattner | e87d653 | 2006-01-25 23:47:57 +0000 | [diff] [blame] | 1956 | </p> |
| 1957 | |
| 1958 | </div> |
| 1959 | |
| 1960 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1961 | <div class="doc_section"> <a name="instref">Instruction Reference</a> </div> |
| 1962 | <!-- *********************************************************************** --> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1963 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1964 | <div class="doc_text"> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1965 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1966 | <p>The LLVM instruction set consists of several different |
| 1967 | classifications of instructions: <a href="#terminators">terminator |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 1968 | instructions</a>, <a href="#binaryops">binary instructions</a>, |
| 1969 | <a href="#bitwiseops">bitwise binary instructions</a>, <a |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1970 | href="#memoryops">memory instructions</a>, and <a href="#otherops">other |
| 1971 | instructions</a>.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1972 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1973 | </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1974 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1975 | <!-- ======================================================================= --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1976 | <div class="doc_subsection"> <a name="terminators">Terminator |
| 1977 | Instructions</a> </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1978 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1979 | <div class="doc_text"> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1980 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1981 | <p>As mentioned <a href="#functionstructure">previously</a>, every |
| 1982 | basic block in a program ends with a "Terminator" instruction, which |
| 1983 | indicates which block should be executed after the current block is |
| 1984 | finished. These terminator instructions typically yield a '<tt>void</tt>' |
| 1985 | value: they produce control flow, not values (the one exception being |
| 1986 | the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p> |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 1987 | <p>There are six different terminator instructions: the '<a |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1988 | href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>' |
| 1989 | instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction, |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 1990 | the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a |
| 1991 | href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a |
| 1992 | href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1993 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1994 | </div> |
Chris Lattner | c3f5976 | 2004-12-09 17:30:23 +0000 | [diff] [blame] | 1995 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 1996 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 1997 | <div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>' |
| 1998 | Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 1999 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2000 | <h5>Syntax:</h5> |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 2001 | <pre> |
| 2002 | ret <type> <value> <i>; Return a value from a non-void function</i> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 2003 | ret void <i>; Return from void function</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2004 | </pre> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2005 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2006 | <h5>Overview:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2007 | |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 2008 | <p>The '<tt>ret</tt>' instruction is used to return control flow (and |
| 2009 | optionally a value) from a function back to the caller.</p> |
John Criswell | 4457dc9 | 2004-04-09 16:48:45 +0000 | [diff] [blame] | 2010 | <p>There are two forms of the '<tt>ret</tt>' instruction: one that |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 2011 | returns a value and then causes control flow, and one that just causes |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2012 | control flow to occur.</p> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2013 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2014 | <h5>Arguments:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2015 | |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 2016 | <p>The '<tt>ret</tt>' instruction optionally accepts a single argument, |
| 2017 | the return value. The type of the return value must be a |
| 2018 | '<a href="#t_firstclass">first class</a>' type.</p> |
| 2019 | |
| 2020 | <p>A function is not <a href="#wellformed">well formed</a> if |
| 2021 | it it has a non-void return type and contains a '<tt>ret</tt>' |
| 2022 | instruction with no return value or a return value with a type that |
| 2023 | does not match its type, or if it has a void return type and contains |
| 2024 | a '<tt>ret</tt>' instruction with a return value.</p> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2025 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2026 | <h5>Semantics:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2027 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2028 | <p>When the '<tt>ret</tt>' instruction is executed, control flow |
| 2029 | returns back to the calling function's context. If the caller is a "<a |
John Criswell | fa08187 | 2004-06-25 15:16:57 +0000 | [diff] [blame] | 2030 | href="#i_call"><tt>call</tt></a>" instruction, execution continues at |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2031 | the instruction after the call. If the caller was an "<a |
| 2032 | href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 2033 | at the beginning of the "normal" destination block. If the instruction |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2034 | returns a value, that value shall set the call or invoke instruction's |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 2035 | return value.</p> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2036 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2037 | <h5>Example:</h5> |
Chris Lattner | f4cde4e | 2008-04-23 04:59:35 +0000 | [diff] [blame] | 2038 | |
| 2039 | <pre> |
| 2040 | ret i32 5 <i>; Return an integer value of 5</i> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 2041 | ret void <i>; Return from a void function</i> |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 2042 | ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2043 | </pre> |
Dan Gohman | f3e60bd | 2009-01-12 23:12:39 +0000 | [diff] [blame] | 2044 | |
| 2045 | <p>Note that the code generator does not yet fully support larger |
| 2046 | aggregate return values.</p> |
| 2047 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2048 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2049 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2050 | <div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2051 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2052 | <h5>Syntax:</h5> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 2053 | <pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2054 | </pre> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2055 | <h5>Overview:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2056 | <p>The '<tt>br</tt>' instruction is used to cause control flow to |
| 2057 | transfer to a different basic block in the current function. There are |
| 2058 | two forms of this instruction, corresponding to a conditional branch |
| 2059 | and an unconditional branch.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2060 | <h5>Arguments:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2061 | <p>The conditional branch form of the '<tt>br</tt>' instruction takes a |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 2062 | single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The |
Reid Spencer | de15194 | 2007-02-19 23:54:10 +0000 | [diff] [blame] | 2063 | unconditional form of the '<tt>br</tt>' instruction takes a single |
| 2064 | '<tt>label</tt>' value as a target.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2065 | <h5>Semantics:</h5> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 2066 | <p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>' |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2067 | argument is evaluated. If the value is <tt>true</tt>, control flows |
| 2068 | to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>, |
| 2069 | control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2070 | <h5>Example:</h5> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 2071 | <pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq, i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2072 | href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2073 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2074 | <!-- _______________________________________________________________________ --> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2075 | <div class="doc_subsubsection"> |
| 2076 | <a name="i_switch">'<tt>switch</tt>' Instruction</a> |
| 2077 | </div> |
| 2078 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2079 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2080 | <h5>Syntax:</h5> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2081 | |
| 2082 | <pre> |
| 2083 | switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ] |
| 2084 | </pre> |
| 2085 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2086 | <h5>Overview:</h5> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2087 | |
| 2088 | <p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of |
| 2089 | several different places. It is a generalization of the '<tt>br</tt>' |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2090 | instruction, allowing a branch to occur to one of many possible |
| 2091 | destinations.</p> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2092 | |
| 2093 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2094 | <h5>Arguments:</h5> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2095 | |
| 2096 | <p>The '<tt>switch</tt>' instruction uses three parameters: an integer |
| 2097 | comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and |
| 2098 | an array of pairs of comparison value constants and '<tt>label</tt>'s. The |
| 2099 | table is not allowed to contain duplicate constant entries.</p> |
| 2100 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2101 | <h5>Semantics:</h5> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2102 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2103 | <p>The <tt>switch</tt> instruction specifies a table of values and |
| 2104 | destinations. When the '<tt>switch</tt>' instruction is executed, this |
John Criswell | 8411475 | 2004-06-25 16:05:06 +0000 | [diff] [blame] | 2105 | table is searched for the given value. If the value is found, control flow is |
| 2106 | transfered to the corresponding destination; otherwise, control flow is |
| 2107 | transfered to the default destination.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2108 | |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2109 | <h5>Implementation:</h5> |
| 2110 | |
| 2111 | <p>Depending on properties of the target machine and the particular |
| 2112 | <tt>switch</tt> instruction, this instruction may be code generated in different |
John Criswell | 8411475 | 2004-06-25 16:05:06 +0000 | [diff] [blame] | 2113 | ways. For example, it could be generated as a series of chained conditional |
| 2114 | branches or with a lookup table.</p> |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2115 | |
| 2116 | <h5>Example:</h5> |
| 2117 | |
| 2118 | <pre> |
| 2119 | <i>; Emulate a conditional br instruction</i> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 2120 | %Val = <a href="#i_zext">zext</a> i1 %value to i32 |
Dan Gohman | 2a08c53 | 2009-01-04 23:44:43 +0000 | [diff] [blame] | 2121 | switch i32 %Val, label %truedest [ i32 0, label %falsedest ] |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2122 | |
| 2123 | <i>; Emulate an unconditional br instruction</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2124 | switch i32 0, label %dest [ ] |
Chris Lattner | c88c17b | 2004-02-24 04:54:45 +0000 | [diff] [blame] | 2125 | |
| 2126 | <i>; Implement a jump table:</i> |
Dan Gohman | 2a08c53 | 2009-01-04 23:44:43 +0000 | [diff] [blame] | 2127 | switch i32 %val, label %otherwise [ i32 0, label %onzero |
| 2128 | i32 1, label %onone |
| 2129 | i32 2, label %ontwo ] |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2130 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2131 | </div> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2132 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2133 | <!-- _______________________________________________________________________ --> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2134 | <div class="doc_subsubsection"> |
| 2135 | <a name="i_invoke">'<tt>invoke</tt>' Instruction</a> |
| 2136 | </div> |
| 2137 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2138 | <div class="doc_text"> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2139 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2140 | <h5>Syntax:</h5> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2141 | |
| 2142 | <pre> |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 2143 | <result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>] |
Chris Lattner | 76b8a33 | 2006-05-14 18:23:06 +0000 | [diff] [blame] | 2144 | to label <normal label> unwind label <exception label> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2145 | </pre> |
| 2146 | |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 2147 | <h5>Overview:</h5> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2148 | |
| 2149 | <p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified |
| 2150 | function, with the possibility of control flow transfer to either the |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 2151 | '<tt>normal</tt>' label or the |
| 2152 | '<tt>exception</tt>' label. If the callee function returns with the |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2153 | "<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the |
| 2154 | "normal" label. If the callee (or any indirect callees) returns with the "<a |
John Criswell | e4c57cc | 2005-05-12 16:52:32 +0000 | [diff] [blame] | 2155 | href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 2156 | continued at the dynamically nearest "exception" label.</p> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2157 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2158 | <h5>Arguments:</h5> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2159 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2160 | <p>This instruction requires several arguments:</p> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2161 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2162 | <ol> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2163 | <li> |
Duncan Sands | 8036ca4 | 2007-03-30 12:22:09 +0000 | [diff] [blame] | 2164 | The optional "cconv" marker indicates which <a href="#callingconv">calling |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2165 | convention</a> the call should use. If none is specified, the call defaults |
| 2166 | to using C calling conventions. |
| 2167 | </li> |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 2168 | |
| 2169 | <li>The optional <a href="#paramattrs">Parameter Attributes</a> list for |
| 2170 | return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', |
| 2171 | and '<tt>inreg</tt>' attributes are valid here.</li> |
| 2172 | |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2173 | <li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to |
| 2174 | function value being invoked. In most cases, this is a direct function |
| 2175 | invocation, but indirect <tt>invoke</tt>s are just as possible, branching off |
| 2176 | an arbitrary pointer to function value. |
| 2177 | </li> |
| 2178 | |
| 2179 | <li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a |
| 2180 | function to be invoked. </li> |
| 2181 | |
| 2182 | <li>'<tt>function args</tt>': argument list whose types match the function |
| 2183 | signature argument types. If the function signature indicates the function |
| 2184 | accepts a variable number of arguments, the extra arguments can be |
| 2185 | specified. </li> |
| 2186 | |
| 2187 | <li>'<tt>normal label</tt>': the label reached when the called function |
| 2188 | executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li> |
| 2189 | |
| 2190 | <li>'<tt>exception label</tt>': the label reached when a callee returns with |
| 2191 | the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li> |
| 2192 | |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 2193 | <li>The optional <a href="#fnattrs">function attributes</a> list. Only |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 2194 | '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and |
| 2195 | '<tt>readnone</tt>' attributes are valid here.</li> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2196 | </ol> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2197 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2198 | <h5>Semantics:</h5> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2199 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2200 | <p>This instruction is designed to operate as a standard '<tt><a |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2201 | href="#i_call">call</a></tt>' instruction in most regards. The primary |
| 2202 | difference is that it establishes an association with a label, which is used by |
| 2203 | the runtime library to unwind the stack.</p> |
| 2204 | |
| 2205 | <p>This instruction is used in languages with destructors to ensure that proper |
| 2206 | cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown |
| 2207 | exception. Additionally, this is important for implementation of |
| 2208 | '<tt>catch</tt>' clauses in high-level languages that support them.</p> |
| 2209 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2210 | <h5>Example:</h5> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 2211 | <pre> |
Nick Lewycky | d703f65 | 2008-03-16 07:18:12 +0000 | [diff] [blame] | 2212 | %retval = invoke i32 @Test(i32 15) to label %Continue |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2213 | unwind label %TestCleanup <i>; {i32}:retval set</i> |
Nick Lewycky | d703f65 | 2008-03-16 07:18:12 +0000 | [diff] [blame] | 2214 | %retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2215 | unwind label %TestCleanup <i>; {i32}:retval set</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2216 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2217 | </div> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2218 | |
| 2219 | |
Chris Lattner | 27f71f2 | 2003-09-03 00:41:47 +0000 | [diff] [blame] | 2220 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2221 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2222 | <div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>' |
| 2223 | Instruction</a> </div> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2224 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2225 | <div class="doc_text"> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2226 | |
Chris Lattner | 27f71f2 | 2003-09-03 00:41:47 +0000 | [diff] [blame] | 2227 | <h5>Syntax:</h5> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2228 | <pre> |
| 2229 | unwind |
| 2230 | </pre> |
| 2231 | |
Chris Lattner | 27f71f2 | 2003-09-03 00:41:47 +0000 | [diff] [blame] | 2232 | <h5>Overview:</h5> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2233 | |
| 2234 | <p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow |
| 2235 | at the first callee in the dynamic call stack which used an <a |
| 2236 | href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is |
| 2237 | primarily used to implement exception handling.</p> |
| 2238 | |
Chris Lattner | 27f71f2 | 2003-09-03 00:41:47 +0000 | [diff] [blame] | 2239 | <h5>Semantics:</h5> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2240 | |
Chris Lattner | 72ed200 | 2008-04-19 21:01:16 +0000 | [diff] [blame] | 2241 | <p>The '<tt>unwind</tt>' instruction causes execution of the current function to |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2242 | immediately halt. The dynamic call stack is then searched for the first <a |
| 2243 | href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found, |
| 2244 | execution continues at the "exceptional" destination block specified by the |
| 2245 | <tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the |
| 2246 | dynamic call chain, undefined behavior results.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2247 | </div> |
Chris Lattner | 35eca58 | 2004-10-16 18:04:13 +0000 | [diff] [blame] | 2248 | |
| 2249 | <!-- _______________________________________________________________________ --> |
| 2250 | |
| 2251 | <div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>' |
| 2252 | Instruction</a> </div> |
| 2253 | |
| 2254 | <div class="doc_text"> |
| 2255 | |
| 2256 | <h5>Syntax:</h5> |
| 2257 | <pre> |
| 2258 | unreachable |
| 2259 | </pre> |
| 2260 | |
| 2261 | <h5>Overview:</h5> |
| 2262 | |
| 2263 | <p>The '<tt>unreachable</tt>' instruction has no defined semantics. This |
| 2264 | instruction is used to inform the optimizer that a particular portion of the |
| 2265 | code is not reachable. This can be used to indicate that the code after a |
| 2266 | no-return function cannot be reached, and other facts.</p> |
| 2267 | |
| 2268 | <h5>Semantics:</h5> |
| 2269 | |
| 2270 | <p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p> |
| 2271 | </div> |
| 2272 | |
| 2273 | |
| 2274 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2275 | <!-- ======================================================================= --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2276 | <div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2277 | <div class="doc_text"> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2278 | <p>Binary operators are used to do most of the computation in a |
Chris Lattner | 5a15814 | 2008-04-01 18:47:32 +0000 | [diff] [blame] | 2279 | program. They require two operands of the same type, execute an operation on them, and |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 2280 | produce a single value. The operands might represent |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2281 | multiple data, as is the case with the <a href="#t_vector">vector</a> data type. |
Chris Lattner | 5a15814 | 2008-04-01 18:47:32 +0000 | [diff] [blame] | 2282 | The result value has the same type as its operands.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2283 | <p>There are several different binary operators:</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2284 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2285 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2286 | <div class="doc_subsubsection"> |
| 2287 | <a name="i_add">'<tt>add</tt>' Instruction</a> |
| 2288 | </div> |
| 2289 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2290 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2291 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2292 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2293 | |
| 2294 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2295 | <result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2296 | </pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2297 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2298 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2299 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2300 | <p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2301 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2302 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2303 | |
| 2304 | <p>The two arguments to the '<tt>add</tt>' instruction must be <a |
| 2305 | href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or |
| 2306 | <a href="#t_vector">vector</a> values. Both arguments must have identical |
| 2307 | types.</p> |
| 2308 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2309 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2310 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2311 | <p>The value produced is the integer or floating point sum of the two |
| 2312 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2313 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2314 | <p>If an integer sum has unsigned overflow, the result returned is the |
| 2315 | mathematical result modulo 2<sup>n</sup>, where n is the bit width of |
| 2316 | the result.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2317 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2318 | <p>Because LLVM integers use a two's complement representation, this |
| 2319 | instruction is appropriate for both signed and unsigned integers.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2320 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2321 | <h5>Example:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2322 | |
| 2323 | <pre> |
| 2324 | <result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2325 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2326 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2327 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2328 | <div class="doc_subsubsection"> |
| 2329 | <a name="i_sub">'<tt>sub</tt>' Instruction</a> |
| 2330 | </div> |
| 2331 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2332 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2333 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2334 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2335 | |
| 2336 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2337 | <result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2338 | </pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2339 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2340 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2341 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2342 | <p>The '<tt>sub</tt>' instruction returns the difference of its two |
| 2343 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2344 | |
| 2345 | <p>Note that the '<tt>sub</tt>' instruction is used to represent the |
| 2346 | '<tt>neg</tt>' instruction present in most other intermediate |
| 2347 | representations.</p> |
| 2348 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2349 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2350 | |
| 2351 | <p>The two arguments to the '<tt>sub</tt>' instruction must be <a |
| 2352 | href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, |
| 2353 | or <a href="#t_vector">vector</a> values. Both arguments must have identical |
| 2354 | types.</p> |
| 2355 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2356 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2357 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2358 | <p>The value produced is the integer or floating point difference of |
| 2359 | the two operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2360 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2361 | <p>If an integer difference has unsigned overflow, the result returned is the |
| 2362 | mathematical result modulo 2<sup>n</sup>, where n is the bit width of |
| 2363 | the result.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2364 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2365 | <p>Because LLVM integers use a two's complement representation, this |
| 2366 | instruction is appropriate for both signed and unsigned integers.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2367 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2368 | <h5>Example:</h5> |
Bill Wendling | aac388b | 2007-05-29 09:42:13 +0000 | [diff] [blame] | 2369 | <pre> |
| 2370 | <result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2371 | <result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2372 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2373 | </div> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2374 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2375 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2376 | <div class="doc_subsubsection"> |
| 2377 | <a name="i_mul">'<tt>mul</tt>' Instruction</a> |
| 2378 | </div> |
| 2379 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2380 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2381 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2382 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2383 | <pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2384 | </pre> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2385 | <h5>Overview:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2386 | <p>The '<tt>mul</tt>' instruction returns the product of its two |
| 2387 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2388 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2389 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2390 | |
| 2391 | <p>The two arguments to the '<tt>mul</tt>' instruction must be <a |
| 2392 | href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, |
| 2393 | or <a href="#t_vector">vector</a> values. Both arguments must have identical |
| 2394 | types.</p> |
| 2395 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2396 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2397 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2398 | <p>The value produced is the integer or floating point product of the |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2399 | two operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2400 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2401 | <p>If the result of an integer multiplication has unsigned overflow, |
| 2402 | the result returned is the mathematical result modulo |
| 2403 | 2<sup>n</sup>, where n is the bit width of the result.</p> |
| 2404 | <p>Because LLVM integers use a two's complement representation, and the |
| 2405 | result is the same width as the operands, this instruction returns the |
| 2406 | correct result for both signed and unsigned integers. If a full product |
| 2407 | (e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands |
| 2408 | should be sign-extended or zero-extended as appropriate to the |
| 2409 | width of the full product.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2410 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2411 | <pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2412 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2413 | </div> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2414 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2415 | <!-- _______________________________________________________________________ --> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2416 | <div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction |
| 2417 | </a></div> |
| 2418 | <div class="doc_text"> |
| 2419 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2420 | <pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2421 | </pre> |
| 2422 | <h5>Overview:</h5> |
| 2423 | <p>The '<tt>udiv</tt>' instruction returns the quotient of its two |
| 2424 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2425 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2426 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2427 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2428 | <p>The two arguments to the '<tt>udiv</tt>' instruction must be |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2429 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2430 | values. Both arguments must have identical types.</p> |
| 2431 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2432 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2433 | |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2434 | <p>The value produced is the unsigned integer quotient of the two operands.</p> |
| 2435 | <p>Note that unsigned integer division and signed integer division are distinct |
| 2436 | operations; for signed integer division, use '<tt>sdiv</tt>'.</p> |
| 2437 | <p>Division by zero leads to undefined behavior.</p> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2438 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2439 | <pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2440 | </pre> |
| 2441 | </div> |
| 2442 | <!-- _______________________________________________________________________ --> |
| 2443 | <div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction |
| 2444 | </a> </div> |
| 2445 | <div class="doc_text"> |
| 2446 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2447 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2448 | <result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2449 | </pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2450 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2451 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2452 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2453 | <p>The '<tt>sdiv</tt>' instruction returns the quotient of its two |
| 2454 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2455 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2456 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2457 | |
| 2458 | <p>The two arguments to the '<tt>sdiv</tt>' instruction must be |
| 2459 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2460 | values. Both arguments must have identical types.</p> |
| 2461 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2462 | <h5>Semantics:</h5> |
Chris Lattner | a73afe0 | 2008-04-01 18:45:27 +0000 | [diff] [blame] | 2463 | <p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p> |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2464 | <p>Note that signed integer division and unsigned integer division are distinct |
| 2465 | operations; for unsigned integer division, use '<tt>udiv</tt>'.</p> |
| 2466 | <p>Division by zero leads to undefined behavior. Overflow also leads to |
| 2467 | undefined behavior; this is a rare case, but can occur, for example, |
| 2468 | by doing a 32-bit division of -2147483648 by -1.</p> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2469 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2470 | <pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i> |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2471 | </pre> |
| 2472 | </div> |
| 2473 | <!-- _______________________________________________________________________ --> |
| 2474 | <div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>' |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2475 | Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2476 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2477 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2478 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2479 | <result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2480 | </pre> |
| 2481 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2482 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2483 | <p>The '<tt>fdiv</tt>' instruction returns the quotient of its two |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2484 | operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2485 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2486 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2487 | |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2488 | <p>The two arguments to the '<tt>fdiv</tt>' instruction must be |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2489 | <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> |
| 2490 | of floating point values. Both arguments must have identical types.</p> |
| 2491 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2492 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2493 | |
Reid Spencer | 1628cec | 2006-10-26 06:15:43 +0000 | [diff] [blame] | 2494 | <p>The value produced is the floating point quotient of the two operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2495 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2496 | <h5>Example:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2497 | |
| 2498 | <pre> |
| 2499 | <result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2500 | </pre> |
| 2501 | </div> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2502 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2503 | <!-- _______________________________________________________________________ --> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2504 | <div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a> |
| 2505 | </div> |
| 2506 | <div class="doc_text"> |
| 2507 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2508 | <pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2509 | </pre> |
| 2510 | <h5>Overview:</h5> |
| 2511 | <p>The '<tt>urem</tt>' instruction returns the remainder from the |
| 2512 | unsigned division of its two arguments.</p> |
| 2513 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2514 | <p>The two arguments to the '<tt>urem</tt>' instruction must be |
| 2515 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2516 | values. Both arguments must have identical types.</p> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2517 | <h5>Semantics:</h5> |
| 2518 | <p>This instruction returns the unsigned integer <i>remainder</i> of a division. |
Chris Lattner | a73afe0 | 2008-04-01 18:45:27 +0000 | [diff] [blame] | 2519 | This instruction always performs an unsigned division to get the remainder.</p> |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2520 | <p>Note that unsigned integer remainder and signed integer remainder are |
| 2521 | distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p> |
| 2522 | <p>Taking the remainder of a division by zero leads to undefined behavior.</p> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2523 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2524 | <pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2525 | </pre> |
| 2526 | |
| 2527 | </div> |
| 2528 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2529 | <div class="doc_subsubsection"> |
| 2530 | <a name="i_srem">'<tt>srem</tt>' Instruction</a> |
| 2531 | </div> |
| 2532 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2533 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2534 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2535 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2536 | |
| 2537 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2538 | <result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2539 | </pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2540 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2541 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2542 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2543 | <p>The '<tt>srem</tt>' instruction returns the remainder from the |
Dan Gohman | 8017631 | 2007-11-05 23:35:22 +0000 | [diff] [blame] | 2544 | signed division of its two operands. This instruction can also take |
| 2545 | <a href="#t_vector">vector</a> versions of the values in which case |
| 2546 | the elements must be integers.</p> |
Chris Lattner | c7d3ab3 | 2008-01-04 04:33:49 +0000 | [diff] [blame] | 2547 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2548 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2549 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2550 | <p>The two arguments to the '<tt>srem</tt>' instruction must be |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2551 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2552 | values. Both arguments must have identical types.</p> |
| 2553 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2554 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2555 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2556 | <p>This instruction returns the <i>remainder</i> of a division (where the result |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2557 | has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i> |
| 2558 | operator (where the result has the same sign as the divisor, <tt>op2</tt>) of |
Reid Spencer | c9fdfc8 | 2007-03-24 22:23:39 +0000 | [diff] [blame] | 2559 | a value. For more information about the difference, see <a |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2560 | href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The |
Reid Spencer | c9fdfc8 | 2007-03-24 22:23:39 +0000 | [diff] [blame] | 2561 | Math Forum</a>. For a table of how this is implemented in various languages, |
Reid Spencer | 64f5c6c | 2007-03-24 22:40:44 +0000 | [diff] [blame] | 2562 | please see <a href="http://en.wikipedia.org/wiki/Modulo_operation"> |
Reid Spencer | c9fdfc8 | 2007-03-24 22:23:39 +0000 | [diff] [blame] | 2563 | Wikipedia: modulo operation</a>.</p> |
Chris Lattner | 5ec8983 | 2008-01-28 00:36:27 +0000 | [diff] [blame] | 2564 | <p>Note that signed integer remainder and unsigned integer remainder are |
| 2565 | distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p> |
| 2566 | <p>Taking the remainder of a division by zero leads to undefined behavior. |
| 2567 | Overflow also leads to undefined behavior; this is a rare case, but can occur, |
| 2568 | for example, by taking the remainder of a 32-bit division of -2147483648 by -1. |
| 2569 | (The remainder doesn't actually overflow, but this rule lets srem be |
| 2570 | implemented using instructions that return both the result of the division |
| 2571 | and the remainder.)</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2572 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2573 | <pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2574 | </pre> |
| 2575 | |
| 2576 | </div> |
| 2577 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2578 | <div class="doc_subsubsection"> |
| 2579 | <a name="i_frem">'<tt>frem</tt>' Instruction</a> </div> |
| 2580 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2581 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2582 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2583 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2584 | <pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2585 | </pre> |
| 2586 | <h5>Overview:</h5> |
| 2587 | <p>The '<tt>frem</tt>' instruction returns the remainder from the |
| 2588 | division of its two operands.</p> |
| 2589 | <h5>Arguments:</h5> |
| 2590 | <p>The two arguments to the '<tt>frem</tt>' instruction must be |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2591 | <a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> |
| 2592 | of floating point values. Both arguments must have identical types.</p> |
| 2593 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2594 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2595 | |
Chris Lattner | a73afe0 | 2008-04-01 18:45:27 +0000 | [diff] [blame] | 2596 | <p>This instruction returns the <i>remainder</i> of a division. |
| 2597 | The remainder has the same sign as the dividend.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2598 | |
Reid Spencer | 0a783f7 | 2006-11-02 01:53:59 +0000 | [diff] [blame] | 2599 | <h5>Example:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2600 | |
| 2601 | <pre> |
| 2602 | <result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2603 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2604 | </div> |
Robert Bocchino | 7b81c75 | 2006-02-17 21:18:08 +0000 | [diff] [blame] | 2605 | |
Reid Spencer | 8e11bf8 | 2007-02-02 13:57:07 +0000 | [diff] [blame] | 2606 | <!-- ======================================================================= --> |
| 2607 | <div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary |
| 2608 | Operations</a> </div> |
| 2609 | <div class="doc_text"> |
| 2610 | <p>Bitwise binary operators are used to do various forms of |
| 2611 | bit-twiddling in a program. They are generally very efficient |
| 2612 | instructions and can commonly be strength reduced from other |
Chris Lattner | a73afe0 | 2008-04-01 18:45:27 +0000 | [diff] [blame] | 2613 | instructions. They require two operands of the same type, execute an operation on them, |
| 2614 | and produce a single value. The resulting value is the same type as its operands.</p> |
Reid Spencer | 8e11bf8 | 2007-02-02 13:57:07 +0000 | [diff] [blame] | 2615 | </div> |
| 2616 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2617 | <!-- _______________________________________________________________________ --> |
| 2618 | <div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>' |
| 2619 | Instruction</a> </div> |
| 2620 | <div class="doc_text"> |
| 2621 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2622 | <pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2623 | </pre> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2624 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2625 | <h5>Overview:</h5> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2626 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2627 | <p>The '<tt>shl</tt>' instruction returns the first operand shifted to |
| 2628 | the left a specified number of bits.</p> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2629 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2630 | <h5>Arguments:</h5> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2631 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2632 | <p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a |
Nate Begeman | 5bc1ea0 | 2008-07-29 15:49:41 +0000 | [diff] [blame] | 2633 | href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2634 | type. '<tt>op2</tt>' is treated as an unsigned value.</p> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2635 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2636 | <h5>Semantics:</h5> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2637 | |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2638 | <p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>, |
| 2639 | where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or |
Mon P Wang | 01f8d09 | 2008-12-10 08:55:09 +0000 | [diff] [blame] | 2640 | equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined. |
| 2641 | If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the |
| 2642 | corresponding shift amount in <tt>op2</tt>.</p> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2643 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2644 | <h5>Example:</h5><pre> |
| 2645 | <result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i> |
| 2646 | <result> = shl i32 4, 2 <i>; yields {i32}: 16</i> |
| 2647 | <result> = shl i32 1, 10 <i>; yields {i32}: 1024</i> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2648 | <result> = shl i32 1, 32 <i>; undefined</i> |
Mon P Wang | e9f1015 | 2008-12-09 05:46:39 +0000 | [diff] [blame] | 2649 | <result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2650 | </pre> |
| 2651 | </div> |
| 2652 | <!-- _______________________________________________________________________ --> |
| 2653 | <div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>' |
| 2654 | Instruction</a> </div> |
| 2655 | <div class="doc_text"> |
| 2656 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2657 | <pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2658 | </pre> |
| 2659 | |
| 2660 | <h5>Overview:</h5> |
| 2661 | <p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2662 | operand shifted to the right a specified number of bits with zero fill.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2663 | |
| 2664 | <h5>Arguments:</h5> |
| 2665 | <p>Both arguments to the '<tt>lshr</tt>' instruction must be the same |
Nate Begeman | 5bc1ea0 | 2008-07-29 15:49:41 +0000 | [diff] [blame] | 2666 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2667 | type. '<tt>op2</tt>' is treated as an unsigned value.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2668 | |
| 2669 | <h5>Semantics:</h5> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2670 | |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2671 | <p>This instruction always performs a logical shift right operation. The most |
| 2672 | significant bits of the result will be filled with zero bits after the |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2673 | shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than |
Mon P Wang | 01f8d09 | 2008-12-10 08:55:09 +0000 | [diff] [blame] | 2674 | the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are |
| 2675 | vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift |
| 2676 | amount in <tt>op2</tt>.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2677 | |
| 2678 | <h5>Example:</h5> |
| 2679 | <pre> |
| 2680 | <result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i> |
| 2681 | <result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i> |
| 2682 | <result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i> |
| 2683 | <result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2684 | <result> = lshr i32 1, 32 <i>; undefined</i> |
Mon P Wang | e9f1015 | 2008-12-09 05:46:39 +0000 | [diff] [blame] | 2685 | <result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2686 | </pre> |
| 2687 | </div> |
| 2688 | |
Reid Spencer | 8e11bf8 | 2007-02-02 13:57:07 +0000 | [diff] [blame] | 2689 | <!-- _______________________________________________________________________ --> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2690 | <div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>' |
| 2691 | Instruction</a> </div> |
| 2692 | <div class="doc_text"> |
| 2693 | |
| 2694 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2695 | <pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2696 | </pre> |
| 2697 | |
| 2698 | <h5>Overview:</h5> |
| 2699 | <p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2700 | operand shifted to the right a specified number of bits with sign extension.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2701 | |
| 2702 | <h5>Arguments:</h5> |
| 2703 | <p>Both arguments to the '<tt>ashr</tt>' instruction must be the same |
Nate Begeman | 5bc1ea0 | 2008-07-29 15:49:41 +0000 | [diff] [blame] | 2704 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2705 | type. '<tt>op2</tt>' is treated as an unsigned value.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2706 | |
| 2707 | <h5>Semantics:</h5> |
| 2708 | <p>This instruction always performs an arithmetic shift right operation, |
| 2709 | The most significant bits of the result will be filled with the sign bit |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2710 | of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or |
Mon P Wang | 01f8d09 | 2008-12-10 08:55:09 +0000 | [diff] [blame] | 2711 | larger than the number of bits in <tt>op1</tt>, the result is undefined. If the |
| 2712 | arguments are vectors, each vector element of <tt>op1</tt> is shifted by the |
| 2713 | corresponding shift amount in <tt>op2</tt>.</p> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2714 | |
| 2715 | <h5>Example:</h5> |
| 2716 | <pre> |
| 2717 | <result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i> |
| 2718 | <result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i> |
| 2719 | <result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i> |
| 2720 | <result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i> |
Chris Lattner | 6ccc2d5 | 2007-10-03 21:01:14 +0000 | [diff] [blame] | 2721 | <result> = ashr i32 1, 32 <i>; undefined</i> |
Mon P Wang | e9f1015 | 2008-12-09 05:46:39 +0000 | [diff] [blame] | 2722 | <result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i> |
Reid Spencer | 569f2fa | 2007-01-31 21:39:12 +0000 | [diff] [blame] | 2723 | </pre> |
| 2724 | </div> |
| 2725 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2726 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2727 | <div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>' |
| 2728 | Instruction</a> </div> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2729 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2730 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2731 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2732 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2733 | |
| 2734 | <pre> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2735 | <result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2736 | </pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2737 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2738 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2739 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2740 | <p>The '<tt>and</tt>' instruction returns the bitwise logical and of |
| 2741 | its two operands.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2742 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2743 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2744 | |
| 2745 | <p>The two arguments to the '<tt>and</tt>' instruction must be |
| 2746 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2747 | values. Both arguments must have identical types.</p> |
| 2748 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2749 | <h5>Semantics:</h5> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2750 | <p>The truth table used for the '<tt>and</tt>' instruction is:</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2751 | <p> </p> |
Bill Wendling | c7e4c4d | 2008-09-07 10:29:20 +0000 | [diff] [blame] | 2752 | <div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2753 | <table border="1" cellspacing="0" cellpadding="4"> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2754 | <tbody> |
| 2755 | <tr> |
| 2756 | <td>In0</td> |
| 2757 | <td>In1</td> |
| 2758 | <td>Out</td> |
| 2759 | </tr> |
| 2760 | <tr> |
| 2761 | <td>0</td> |
| 2762 | <td>0</td> |
| 2763 | <td>0</td> |
| 2764 | </tr> |
| 2765 | <tr> |
| 2766 | <td>0</td> |
| 2767 | <td>1</td> |
| 2768 | <td>0</td> |
| 2769 | </tr> |
| 2770 | <tr> |
| 2771 | <td>1</td> |
| 2772 | <td>0</td> |
| 2773 | <td>0</td> |
| 2774 | </tr> |
| 2775 | <tr> |
| 2776 | <td>1</td> |
| 2777 | <td>1</td> |
| 2778 | <td>1</td> |
| 2779 | </tr> |
| 2780 | </tbody> |
| 2781 | </table> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 2782 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2783 | <h5>Example:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2784 | <pre> |
| 2785 | <result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2786 | <result> = and i32 15, 40 <i>; yields {i32}:result = 8</i> |
| 2787 | <result> = and i32 4, 8 <i>; yields {i32}:result = 0</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2788 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2789 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2790 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2791 | <div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2792 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2793 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2794 | <pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2795 | </pre> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2796 | <h5>Overview:</h5> |
| 2797 | <p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive |
| 2798 | or of its two operands.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2799 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2800 | |
| 2801 | <p>The two arguments to the '<tt>or</tt>' instruction must be |
| 2802 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2803 | values. Both arguments must have identical types.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2804 | <h5>Semantics:</h5> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2805 | <p>The truth table used for the '<tt>or</tt>' instruction is:</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2806 | <p> </p> |
Bill Wendling | c7e4c4d | 2008-09-07 10:29:20 +0000 | [diff] [blame] | 2807 | <div> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2808 | <table border="1" cellspacing="0" cellpadding="4"> |
| 2809 | <tbody> |
| 2810 | <tr> |
| 2811 | <td>In0</td> |
| 2812 | <td>In1</td> |
| 2813 | <td>Out</td> |
| 2814 | </tr> |
| 2815 | <tr> |
| 2816 | <td>0</td> |
| 2817 | <td>0</td> |
| 2818 | <td>0</td> |
| 2819 | </tr> |
| 2820 | <tr> |
| 2821 | <td>0</td> |
| 2822 | <td>1</td> |
| 2823 | <td>1</td> |
| 2824 | </tr> |
| 2825 | <tr> |
| 2826 | <td>1</td> |
| 2827 | <td>0</td> |
| 2828 | <td>1</td> |
| 2829 | </tr> |
| 2830 | <tr> |
| 2831 | <td>1</td> |
| 2832 | <td>1</td> |
| 2833 | <td>1</td> |
| 2834 | </tr> |
| 2835 | </tbody> |
| 2836 | </table> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 2837 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2838 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2839 | <pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 | %var</i> |
| 2840 | <result> = or i32 15, 40 <i>; yields {i32}:result = 47</i> |
| 2841 | <result> = or i32 4, 8 <i>; yields {i32}:result = 12</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2842 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2843 | </div> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2844 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2845 | <div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>' |
| 2846 | Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2847 | <div class="doc_text"> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2848 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 2849 | <pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2850 | </pre> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2851 | <h5>Overview:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2852 | <p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive |
| 2853 | or of its two operands. The <tt>xor</tt> is used to implement the |
| 2854 | "one's complement" operation, which is the "~" operator in C.</p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2855 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2856 | <p>The two arguments to the '<tt>xor</tt>' instruction must be |
| 2857 | <a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer |
| 2858 | values. Both arguments must have identical types.</p> |
| 2859 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2860 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 2861 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2862 | <p>The truth table used for the '<tt>xor</tt>' instruction is:</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2863 | <p> </p> |
Bill Wendling | c7e4c4d | 2008-09-07 10:29:20 +0000 | [diff] [blame] | 2864 | <div> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2865 | <table border="1" cellspacing="0" cellpadding="4"> |
| 2866 | <tbody> |
| 2867 | <tr> |
| 2868 | <td>In0</td> |
| 2869 | <td>In1</td> |
| 2870 | <td>Out</td> |
| 2871 | </tr> |
| 2872 | <tr> |
| 2873 | <td>0</td> |
| 2874 | <td>0</td> |
| 2875 | <td>0</td> |
| 2876 | </tr> |
| 2877 | <tr> |
| 2878 | <td>0</td> |
| 2879 | <td>1</td> |
| 2880 | <td>1</td> |
| 2881 | </tr> |
| 2882 | <tr> |
| 2883 | <td>1</td> |
| 2884 | <td>0</td> |
| 2885 | <td>1</td> |
| 2886 | </tr> |
| 2887 | <tr> |
| 2888 | <td>1</td> |
| 2889 | <td>1</td> |
| 2890 | <td>0</td> |
| 2891 | </tr> |
| 2892 | </tbody> |
| 2893 | </table> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 2894 | </div> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 2895 | <p> </p> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2896 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2897 | <pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i> |
| 2898 | <result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i> |
| 2899 | <result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i> |
| 2900 | <result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2901 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 2902 | </div> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 2903 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 2904 | <!-- ======================================================================= --> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 2905 | <div class="doc_subsection"> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2906 | <a name="vectorops">Vector Operations</a> |
| 2907 | </div> |
| 2908 | |
| 2909 | <div class="doc_text"> |
| 2910 | |
| 2911 | <p>LLVM supports several instructions to represent vector operations in a |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 2912 | target-independent manner. These instructions cover the element-access and |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2913 | vector-specific operations needed to process vectors effectively. While LLVM |
| 2914 | does directly support these vector operations, many sophisticated algorithms |
| 2915 | will want to use target-specific intrinsics to take full advantage of a specific |
| 2916 | target.</p> |
| 2917 | |
| 2918 | </div> |
| 2919 | |
| 2920 | <!-- _______________________________________________________________________ --> |
| 2921 | <div class="doc_subsubsection"> |
| 2922 | <a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a> |
| 2923 | </div> |
| 2924 | |
| 2925 | <div class="doc_text"> |
| 2926 | |
| 2927 | <h5>Syntax:</h5> |
| 2928 | |
| 2929 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2930 | <result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2931 | </pre> |
| 2932 | |
| 2933 | <h5>Overview:</h5> |
| 2934 | |
| 2935 | <p> |
| 2936 | The '<tt>extractelement</tt>' instruction extracts a single scalar |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2937 | element from a vector at a specified index. |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2938 | </p> |
| 2939 | |
| 2940 | |
| 2941 | <h5>Arguments:</h5> |
| 2942 | |
| 2943 | <p> |
| 2944 | The first operand of an '<tt>extractelement</tt>' instruction is a |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2945 | value of <a href="#t_vector">vector</a> type. The second operand is |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2946 | an index indicating the position from which to extract the element. |
| 2947 | The index may be a variable.</p> |
| 2948 | |
| 2949 | <h5>Semantics:</h5> |
| 2950 | |
| 2951 | <p> |
| 2952 | The result is a scalar of the same type as the element type of |
| 2953 | <tt>val</tt>. Its value is the value at position <tt>idx</tt> of |
| 2954 | <tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the |
| 2955 | results are undefined. |
| 2956 | </p> |
| 2957 | |
| 2958 | <h5>Example:</h5> |
| 2959 | |
| 2960 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 2961 | %result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2962 | </pre> |
| 2963 | </div> |
| 2964 | |
| 2965 | |
| 2966 | <!-- _______________________________________________________________________ --> |
| 2967 | <div class="doc_subsubsection"> |
| 2968 | <a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a> |
| 2969 | </div> |
| 2970 | |
| 2971 | <div class="doc_text"> |
| 2972 | |
| 2973 | <h5>Syntax:</h5> |
| 2974 | |
| 2975 | <pre> |
Dan Gohman | f3480b9 | 2008-05-12 23:38:42 +0000 | [diff] [blame] | 2976 | <result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2977 | </pre> |
| 2978 | |
| 2979 | <h5>Overview:</h5> |
| 2980 | |
| 2981 | <p> |
| 2982 | The '<tt>insertelement</tt>' instruction inserts a scalar |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2983 | element into a vector at a specified index. |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2984 | </p> |
| 2985 | |
| 2986 | |
| 2987 | <h5>Arguments:</h5> |
| 2988 | |
| 2989 | <p> |
| 2990 | The first operand of an '<tt>insertelement</tt>' instruction is a |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2991 | value of <a href="#t_vector">vector</a> type. The second operand is a |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 2992 | scalar value whose type must equal the element type of the first |
| 2993 | operand. The third operand is an index indicating the position at |
| 2994 | which to insert the value. The index may be a variable.</p> |
| 2995 | |
| 2996 | <h5>Semantics:</h5> |
| 2997 | |
| 2998 | <p> |
Reid Spencer | 485bad1 | 2007-02-15 03:07:05 +0000 | [diff] [blame] | 2999 | The result is a vector of the same type as <tt>val</tt>. Its |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3000 | element values are those of <tt>val</tt> except at position |
| 3001 | <tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt> |
| 3002 | exceeds the length of <tt>val</tt>, the results are undefined. |
| 3003 | </p> |
| 3004 | |
| 3005 | <h5>Example:</h5> |
| 3006 | |
| 3007 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3008 | %result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3009 | </pre> |
| 3010 | </div> |
| 3011 | |
| 3012 | <!-- _______________________________________________________________________ --> |
| 3013 | <div class="doc_subsubsection"> |
| 3014 | <a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a> |
| 3015 | </div> |
| 3016 | |
| 3017 | <div class="doc_text"> |
| 3018 | |
| 3019 | <h5>Syntax:</h5> |
| 3020 | |
| 3021 | <pre> |
Mon P Wang | aeb06d2 | 2008-11-10 04:46:22 +0000 | [diff] [blame] | 3022 | <result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3023 | </pre> |
| 3024 | |
| 3025 | <h5>Overview:</h5> |
| 3026 | |
| 3027 | <p> |
| 3028 | The '<tt>shufflevector</tt>' instruction constructs a permutation of elements |
Mon P Wang | aeb06d2 | 2008-11-10 04:46:22 +0000 | [diff] [blame] | 3029 | from two input vectors, returning a vector with the same element type as |
| 3030 | the input and length that is the same as the shuffle mask. |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3031 | </p> |
| 3032 | |
| 3033 | <h5>Arguments:</h5> |
| 3034 | |
| 3035 | <p> |
Mon P Wang | aeb06d2 | 2008-11-10 04:46:22 +0000 | [diff] [blame] | 3036 | The first two operands of a '<tt>shufflevector</tt>' instruction are vectors |
| 3037 | with types that match each other. The third argument is a shuffle mask whose |
| 3038 | element type is always 'i32'. The result of the instruction is a vector whose |
| 3039 | length is the same as the shuffle mask and whose element type is the same as |
| 3040 | the element type of the first two operands. |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3041 | </p> |
| 3042 | |
| 3043 | <p> |
| 3044 | The shuffle mask operand is required to be a constant vector with either |
| 3045 | constant integer or undef values. |
| 3046 | </p> |
| 3047 | |
| 3048 | <h5>Semantics:</h5> |
| 3049 | |
| 3050 | <p> |
| 3051 | The elements of the two input vectors are numbered from left to right across |
| 3052 | both of the vectors. The shuffle mask operand specifies, for each element of |
Mon P Wang | aeb06d2 | 2008-11-10 04:46:22 +0000 | [diff] [blame] | 3053 | the result vector, which element of the two input vectors the result element |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3054 | gets. The element selector may be undef (meaning "don't care") and the second |
| 3055 | operand may be undef if performing a shuffle from only one vector. |
| 3056 | </p> |
| 3057 | |
| 3058 | <h5>Example:</h5> |
| 3059 | |
| 3060 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3061 | %result = shufflevector <4 x i32> %v1, <4 x i32> %v2, |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 3062 | <4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3063 | %result = shufflevector <4 x i32> %v1, <4 x i32> undef, |
| 3064 | <4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle. |
Mon P Wang | aeb06d2 | 2008-11-10 04:46:22 +0000 | [diff] [blame] | 3065 | %result = shufflevector <8 x i32> %v1, <8 x i32> undef, |
| 3066 | <4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> |
| 3067 | %result = shufflevector <4 x i32> %v1, <4 x i32> %v2, |
| 3068 | <8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i> |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3069 | </pre> |
| 3070 | </div> |
| 3071 | |
Tanya Lattner | 0947429 | 2006-04-14 19:24:33 +0000 | [diff] [blame] | 3072 | |
Chris Lattner | 3df241e | 2006-04-08 23:07:04 +0000 | [diff] [blame] | 3073 | <!-- ======================================================================= --> |
| 3074 | <div class="doc_subsection"> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3075 | <a name="aggregateops">Aggregate Operations</a> |
| 3076 | </div> |
| 3077 | |
| 3078 | <div class="doc_text"> |
| 3079 | |
| 3080 | <p>LLVM supports several instructions for working with aggregate values. |
| 3081 | </p> |
| 3082 | |
| 3083 | </div> |
| 3084 | |
| 3085 | <!-- _______________________________________________________________________ --> |
| 3086 | <div class="doc_subsubsection"> |
| 3087 | <a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a> |
| 3088 | </div> |
| 3089 | |
| 3090 | <div class="doc_text"> |
| 3091 | |
| 3092 | <h5>Syntax:</h5> |
| 3093 | |
| 3094 | <pre> |
| 3095 | <result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}* |
| 3096 | </pre> |
| 3097 | |
| 3098 | <h5>Overview:</h5> |
| 3099 | |
| 3100 | <p> |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3101 | The '<tt>extractvalue</tt>' instruction extracts the value of a struct field |
| 3102 | or array element from an aggregate value. |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3103 | </p> |
| 3104 | |
| 3105 | |
| 3106 | <h5>Arguments:</h5> |
| 3107 | |
| 3108 | <p> |
| 3109 | The first operand of an '<tt>extractvalue</tt>' instruction is a |
| 3110 | value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3111 | type. The operands are constant indices to specify which value to extract |
Dan Gohman | 81a0c0b | 2008-05-31 00:58:22 +0000 | [diff] [blame] | 3112 | in a similar manner as indices in a |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3113 | '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. |
| 3114 | </p> |
| 3115 | |
| 3116 | <h5>Semantics:</h5> |
| 3117 | |
| 3118 | <p> |
| 3119 | The result is the value at the position in the aggregate specified by |
| 3120 | the index operands. |
| 3121 | </p> |
| 3122 | |
| 3123 | <h5>Example:</h5> |
| 3124 | |
| 3125 | <pre> |
Dan Gohman | 81a0c0b | 2008-05-31 00:58:22 +0000 | [diff] [blame] | 3126 | %result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3127 | </pre> |
| 3128 | </div> |
| 3129 | |
| 3130 | |
| 3131 | <!-- _______________________________________________________________________ --> |
| 3132 | <div class="doc_subsubsection"> |
| 3133 | <a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a> |
| 3134 | </div> |
| 3135 | |
| 3136 | <div class="doc_text"> |
| 3137 | |
| 3138 | <h5>Syntax:</h5> |
| 3139 | |
| 3140 | <pre> |
Dan Gohman | 81a0c0b | 2008-05-31 00:58:22 +0000 | [diff] [blame] | 3141 | <result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3142 | </pre> |
| 3143 | |
| 3144 | <h5>Overview:</h5> |
| 3145 | |
| 3146 | <p> |
| 3147 | The '<tt>insertvalue</tt>' instruction inserts a value |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3148 | into a struct field or array element in an aggregate. |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3149 | </p> |
| 3150 | |
| 3151 | |
| 3152 | <h5>Arguments:</h5> |
| 3153 | |
| 3154 | <p> |
| 3155 | The first operand of an '<tt>insertvalue</tt>' instruction is a |
| 3156 | value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type. |
| 3157 | The second operand is a first-class value to insert. |
Dan Gohman | c4b49eb | 2008-05-23 21:53:15 +0000 | [diff] [blame] | 3158 | The following operands are constant indices |
Dan Gohman | 81a0c0b | 2008-05-31 00:58:22 +0000 | [diff] [blame] | 3159 | indicating the position at which to insert the value in a similar manner as |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3160 | indices in a |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3161 | '<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction. |
| 3162 | The value to insert must have the same type as the value identified |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3163 | by the indices. |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3164 | </p> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3165 | |
| 3166 | <h5>Semantics:</h5> |
| 3167 | |
| 3168 | <p> |
| 3169 | The result is an aggregate of the same type as <tt>val</tt>. Its |
| 3170 | value is that of <tt>val</tt> except that the value at the position |
Dan Gohman | c3dac5c | 2008-05-13 18:16:06 +0000 | [diff] [blame] | 3171 | specified by the indices is that of <tt>elt</tt>. |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3172 | </p> |
| 3173 | |
| 3174 | <h5>Example:</h5> |
| 3175 | |
| 3176 | <pre> |
Dan Gohman | 52bb2db | 2008-06-23 15:26:37 +0000 | [diff] [blame] | 3177 | %result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i> |
Dan Gohman | a334d5f | 2008-05-12 23:51:09 +0000 | [diff] [blame] | 3178 | </pre> |
| 3179 | </div> |
| 3180 | |
| 3181 | |
| 3182 | <!-- ======================================================================= --> |
| 3183 | <div class="doc_subsection"> |
Chris Lattner | 884a970 | 2006-08-15 00:45:58 +0000 | [diff] [blame] | 3184 | <a name="memoryops">Memory Access and Addressing Operations</a> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3185 | </div> |
| 3186 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3187 | <div class="doc_text"> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3188 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3189 | <p>A key design point of an SSA-based representation is how it |
| 3190 | represents memory. In LLVM, no memory locations are in SSA form, which |
| 3191 | makes things very simple. This section describes how to read, write, |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 3192 | allocate, and free memory in LLVM.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3193 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3194 | </div> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3195 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3196 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3197 | <div class="doc_subsubsection"> |
| 3198 | <a name="i_malloc">'<tt>malloc</tt>' Instruction</a> |
| 3199 | </div> |
| 3200 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3201 | <div class="doc_text"> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3202 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3203 | <h5>Syntax:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3204 | |
| 3205 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3206 | <result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3207 | </pre> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3208 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3209 | <h5>Overview:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3210 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3211 | <p>The '<tt>malloc</tt>' instruction allocates memory from the system |
Christopher Lamb | 303dae9 | 2007-12-17 01:00:21 +0000 | [diff] [blame] | 3212 | heap and returns a pointer to it. The object is always allocated in the generic |
| 3213 | address space (address space zero).</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3214 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3215 | <h5>Arguments:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3216 | |
| 3217 | <p>The '<tt>malloc</tt>' instruction allocates |
| 3218 | <tt>sizeof(<type>)*NumElements</tt> |
John Criswell | 6e4ca61 | 2004-02-24 16:13:56 +0000 | [diff] [blame] | 3219 | bytes of memory from the operating system and returns a pointer of the |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3220 | appropriate type to the program. If "NumElements" is specified, it is the |
Gabor Greif | 1acd2ee | 2008-02-09 22:24:34 +0000 | [diff] [blame] | 3221 | number of elements allocated, otherwise "NumElements" is defaulted to be one. |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3222 | If a constant alignment is specified, the value result of the allocation is guaranteed to |
Gabor Greif | 1acd2ee | 2008-02-09 22:24:34 +0000 | [diff] [blame] | 3223 | be aligned to at least that boundary. If not specified, or if zero, the target can |
| 3224 | choose to align the allocation on any convenient boundary.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3225 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3226 | <p>'<tt>type</tt>' must be a sized type.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3227 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3228 | <h5>Semantics:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3229 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3230 | <p>Memory is allocated using the system "<tt>malloc</tt>" function, and |
Nick Lewycky | 02ff308 | 2008-11-24 03:41:24 +0000 | [diff] [blame] | 3231 | a pointer is returned. The result of a zero byte allocation is undefined. The |
Chris Lattner | 72ed200 | 2008-04-19 21:01:16 +0000 | [diff] [blame] | 3232 | result is null if there is insufficient memory available.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3233 | |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3234 | <h5>Example:</h5> |
| 3235 | |
| 3236 | <pre> |
Dan Gohman | 81e2167 | 2009-01-04 23:49:44 +0000 | [diff] [blame] | 3237 | %array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3238 | |
Bill Wendling | aac388b | 2007-05-29 09:42:13 +0000 | [diff] [blame] | 3239 | %size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i> |
| 3240 | %array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i> |
| 3241 | %array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i> |
| 3242 | %array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i> |
| 3243 | %array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3244 | </pre> |
Dan Gohman | f3e60bd | 2009-01-12 23:12:39 +0000 | [diff] [blame] | 3245 | |
| 3246 | <p>Note that the code generator does not yet respect the |
| 3247 | alignment value.</p> |
| 3248 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3249 | </div> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3250 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3251 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3252 | <div class="doc_subsubsection"> |
| 3253 | <a name="i_free">'<tt>free</tt>' Instruction</a> |
| 3254 | </div> |
| 3255 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3256 | <div class="doc_text"> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3257 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3258 | <h5>Syntax:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3259 | |
| 3260 | <pre> |
Dan Gohman | 81e2167 | 2009-01-04 23:49:44 +0000 | [diff] [blame] | 3261 | free <type> <value> <i>; yields {void}</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3262 | </pre> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3263 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3264 | <h5>Overview:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3265 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3266 | <p>The '<tt>free</tt>' instruction returns memory back to the unused |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 3267 | memory heap to be reallocated in the future.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3268 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3269 | <h5>Arguments:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3270 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3271 | <p>'<tt>value</tt>' shall be a pointer value that points to a value |
| 3272 | that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>' |
| 3273 | instruction.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3274 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3275 | <h5>Semantics:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3276 | |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 3277 | <p>Access to the memory pointed to by the pointer is no longer defined |
Chris Lattner | e0db56d | 2008-04-19 22:41:32 +0000 | [diff] [blame] | 3278 | after this instruction executes. If the pointer is null, the operation |
| 3279 | is a noop.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3280 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3281 | <h5>Example:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3282 | |
| 3283 | <pre> |
Dan Gohman | 81e2167 | 2009-01-04 23:49:44 +0000 | [diff] [blame] | 3284 | %array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3285 | free [4 x i8]* %array |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3286 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3287 | </div> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3288 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3289 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3290 | <div class="doc_subsubsection"> |
| 3291 | <a name="i_alloca">'<tt>alloca</tt>' Instruction</a> |
| 3292 | </div> |
| 3293 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3294 | <div class="doc_text"> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3295 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3296 | <h5>Syntax:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3297 | |
| 3298 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3299 | <result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3300 | </pre> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3301 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3302 | <h5>Overview:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3303 | |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 3304 | <p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the |
| 3305 | currently executing function, to be automatically released when this function |
Christopher Lamb | 303dae9 | 2007-12-17 01:00:21 +0000 | [diff] [blame] | 3306 | returns to its caller. The object is always allocated in the generic address |
| 3307 | space (address space zero).</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3308 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3309 | <h5>Arguments:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3310 | |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 3311 | <p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3312 | bytes of memory on the runtime stack, returning a pointer of the |
Gabor Greif | 1acd2ee | 2008-02-09 22:24:34 +0000 | [diff] [blame] | 3313 | appropriate type to the program. If "NumElements" is specified, it is the |
| 3314 | number of elements allocated, otherwise "NumElements" is defaulted to be one. |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3315 | If a constant alignment is specified, the value result of the allocation is guaranteed |
Gabor Greif | 1acd2ee | 2008-02-09 22:24:34 +0000 | [diff] [blame] | 3316 | to be aligned to at least that boundary. If not specified, or if zero, the target |
| 3317 | can choose to align the allocation on any convenient boundary.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3318 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3319 | <p>'<tt>type</tt>' may be any sized type.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3320 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3321 | <h5>Semantics:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3322 | |
Chris Lattner | 72ed200 | 2008-04-19 21:01:16 +0000 | [diff] [blame] | 3323 | <p>Memory is allocated; a pointer is returned. The operation is undefiend if |
| 3324 | there is insufficient stack space for the allocation. '<tt>alloca</tt>'d |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3325 | memory is automatically released when the function returns. The '<tt>alloca</tt>' |
| 3326 | instruction is commonly used to represent automatic variables that must |
| 3327 | have an address available. When the function returns (either with the <tt><a |
John Criswell | dae2e93 | 2005-05-12 16:55:34 +0000 | [diff] [blame] | 3328 | href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt> |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3329 | instructions), the memory is reclaimed. Allocating zero bytes |
| 3330 | is legal, but the result is undefined.</p> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3331 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3332 | <h5>Example:</h5> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3333 | |
| 3334 | <pre> |
Dan Gohman | 81e2167 | 2009-01-04 23:49:44 +0000 | [diff] [blame] | 3335 | %ptr = alloca i32 <i>; yields {i32*}:ptr</i> |
| 3336 | %ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i> |
| 3337 | %ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i> |
| 3338 | %ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3339 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3340 | </div> |
Chris Lattner | 2cbdc45 | 2005-11-06 08:02:57 +0000 | [diff] [blame] | 3341 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3342 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3343 | <div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>' |
| 3344 | Instruction</a> </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3345 | <div class="doc_text"> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3346 | <h5>Syntax:</h5> |
Christopher Lamb | 2330e4d | 2007-04-21 08:16:25 +0000 | [diff] [blame] | 3347 | <pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3348 | <h5>Overview:</h5> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3349 | <p>The '<tt>load</tt>' instruction is used to read from memory.</p> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3350 | <h5>Arguments:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3351 | <p>The argument to the '<tt>load</tt>' instruction specifies the memory |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 3352 | address from which to load. The pointer must point to a <a |
Chris Lattner | e53e508 | 2004-06-03 22:57:15 +0000 | [diff] [blame] | 3353 | href="#t_firstclass">first class</a> type. If the <tt>load</tt> is |
John Criswell | 0ec250c | 2005-10-24 16:17:18 +0000 | [diff] [blame] | 3354 | marked as <tt>volatile</tt>, then the optimizer is not allowed to modify |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3355 | the number or order of execution of this <tt>load</tt> with other |
| 3356 | volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt> |
| 3357 | instructions. </p> |
Chris Lattner | a31d1d7 | 2008-01-06 21:04:43 +0000 | [diff] [blame] | 3358 | <p> |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3359 | The optional constant "align" argument specifies the alignment of the operation |
Chris Lattner | a31d1d7 | 2008-01-06 21:04:43 +0000 | [diff] [blame] | 3360 | (that is, the alignment of the memory address). A value of 0 or an |
| 3361 | omitted "align" argument means that the operation has the preferential |
| 3362 | alignment for the target. It is the responsibility of the code emitter |
| 3363 | to ensure that the alignment information is correct. Overestimating |
| 3364 | the alignment results in an undefined behavior. Underestimating the |
| 3365 | alignment may produce less efficient code. An alignment of 1 is always |
| 3366 | safe. |
| 3367 | </p> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3368 | <h5>Semantics:</h5> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3369 | <p>The location of memory pointed to is loaded.</p> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3370 | <h5>Examples:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3371 | <pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3372 | <a |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3373 | href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i> |
| 3374 | %val = load i32* %ptr <i>; yields {i32}:val = i32 3</i> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3375 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3376 | </div> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3377 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3378 | <div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>' |
| 3379 | Instruction</a> </div> |
Reid Spencer | 035ab57 | 2006-11-09 21:18:01 +0000 | [diff] [blame] | 3380 | <div class="doc_text"> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3381 | <h5>Syntax:</h5> |
Christopher Lamb | 2330e4d | 2007-04-21 08:16:25 +0000 | [diff] [blame] | 3382 | <pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i> |
| 3383 | volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3384 | </pre> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3385 | <h5>Overview:</h5> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3386 | <p>The '<tt>store</tt>' instruction is used to write to memory.</p> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3387 | <h5>Arguments:</h5> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3388 | <p>There are two arguments to the '<tt>store</tt>' instruction: a value |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 3389 | to store and an address at which to store it. The type of the '<tt><pointer></tt>' |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3390 | operand must be a pointer to the <a href="#t_firstclass">first class</a> type |
| 3391 | of the '<tt><value></tt>' |
John Criswell | c1f786c | 2005-05-13 22:25:59 +0000 | [diff] [blame] | 3392 | operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3393 | optimizer is not allowed to modify the number or order of execution of |
| 3394 | this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a |
| 3395 | href="#i_store">store</a></tt> instructions.</p> |
Chris Lattner | a31d1d7 | 2008-01-06 21:04:43 +0000 | [diff] [blame] | 3396 | <p> |
Chris Lattner | 4316dec | 2008-04-02 00:38:26 +0000 | [diff] [blame] | 3397 | The optional constant "align" argument specifies the alignment of the operation |
Chris Lattner | a31d1d7 | 2008-01-06 21:04:43 +0000 | [diff] [blame] | 3398 | (that is, the alignment of the memory address). A value of 0 or an |
| 3399 | omitted "align" argument means that the operation has the preferential |
| 3400 | alignment for the target. It is the responsibility of the code emitter |
| 3401 | to ensure that the alignment information is correct. Overestimating |
| 3402 | the alignment results in an undefined behavior. Underestimating the |
| 3403 | alignment may produce less efficient code. An alignment of 1 is always |
| 3404 | safe. |
| 3405 | </p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3406 | <h5>Semantics:</h5> |
| 3407 | <p>The contents of memory are updated to contain '<tt><value></tt>' |
| 3408 | at the location specified by the '<tt><pointer></tt>' operand.</p> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3409 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3410 | <pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i> |
Bill Wendling | 8c6c72d | 2007-10-22 05:10:05 +0000 | [diff] [blame] | 3411 | store i32 3, i32* %ptr <i>; yields {void}</i> |
| 3412 | %val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i> |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3413 | </pre> |
Reid Spencer | 47ce179 | 2006-11-09 21:15:49 +0000 | [diff] [blame] | 3414 | </div> |
| 3415 | |
Chris Lattner | 2b7d320 | 2002-05-06 03:03:22 +0000 | [diff] [blame] | 3416 | <!-- _______________________________________________________________________ --> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3417 | <div class="doc_subsubsection"> |
| 3418 | <a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a> |
| 3419 | </div> |
| 3420 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3421 | <div class="doc_text"> |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 3422 | <h5>Syntax:</h5> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3423 | <pre> |
Matthijs Kooijman | e49d0bc | 2008-10-13 13:44:15 +0000 | [diff] [blame] | 3424 | <result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}* |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3425 | </pre> |
| 3426 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 3427 | <h5>Overview:</h5> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3428 | |
| 3429 | <p> |
| 3430 | The '<tt>getelementptr</tt>' instruction is used to get the address of a |
Matthijs Kooijman | e49d0bc | 2008-10-13 13:44:15 +0000 | [diff] [blame] | 3431 | subelement of an aggregate data structure. It performs address calculation only |
| 3432 | and does not access memory.</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3433 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 3434 | <h5>Arguments:</h5> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3435 | |
Matthijs Kooijman | e49d0bc | 2008-10-13 13:44:15 +0000 | [diff] [blame] | 3436 | <p>The first argument is always a pointer, and forms the basis of the |
| 3437 | calculation. The remaining arguments are indices, that indicate which of the |
| 3438 | elements of the aggregate object are indexed. The interpretation of each index |
| 3439 | is dependent on the type being indexed into. The first index always indexes the |
| 3440 | pointer value given as the first argument, the second index indexes a value of |
| 3441 | the type pointed to (not necessarily the value directly pointed to, since the |
| 3442 | first index can be non-zero), etc. The first type indexed into must be a pointer |
| 3443 | value, subsequent types can be arrays, vectors and structs. Note that subsequent |
| 3444 | types being indexed into can never be pointers, since that would require loading |
| 3445 | the pointer before continuing calculation.</p> |
| 3446 | |
| 3447 | <p>The type of each index argument depends on the type it is indexing into. |
| 3448 | When indexing into a (packed) structure, only <tt>i32</tt> integer |
| 3449 | <b>constants</b> are allowed. When indexing into an array, pointer or vector, |
| 3450 | only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values |
| 3451 | will be sign extended to 64-bits if required.</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3452 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3453 | <p>For example, let's consider a C code fragment and how it gets |
| 3454 | compiled to LLVM:</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3455 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3456 | <div class="doc_code"> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3457 | <pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3458 | struct RT { |
| 3459 | char A; |
Chris Lattner | cabc846 | 2007-05-29 15:43:56 +0000 | [diff] [blame] | 3460 | int B[10][20]; |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3461 | char C; |
| 3462 | }; |
| 3463 | struct ST { |
Chris Lattner | cabc846 | 2007-05-29 15:43:56 +0000 | [diff] [blame] | 3464 | int X; |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3465 | double Y; |
| 3466 | struct RT Z; |
| 3467 | }; |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3468 | |
Chris Lattner | cabc846 | 2007-05-29 15:43:56 +0000 | [diff] [blame] | 3469 | int *foo(struct ST *s) { |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3470 | return &s[1].Z.B[5][13]; |
| 3471 | } |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3472 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3473 | </div> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3474 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3475 | <p>The LLVM code generated by the GCC frontend is:</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3476 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3477 | <div class="doc_code"> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3478 | <pre> |
Chris Lattner | e7886e4 | 2009-01-11 20:53:49 +0000 | [diff] [blame] | 3479 | %RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 } |
| 3480 | %ST = <a href="#namedtypes">type</a> { i32, double, %RT } |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3481 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3482 | define i32* %foo(%ST* %s) { |
| 3483 | entry: |
| 3484 | %reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13 |
| 3485 | ret i32* %reg |
| 3486 | } |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3487 | </pre> |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 3488 | </div> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3489 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 3490 | <h5>Semantics:</h5> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3491 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3492 | <p>In the example above, the first index is indexing into the '<tt>%ST*</tt>' |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3493 | type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3494 | }</tt>' type, a structure. The second index indexes into the third element of |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3495 | the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]], |
| 3496 | i8 }</tt>' type, another structure. The third index indexes into the second |
| 3497 | element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3498 | array. The two dimensions of the array are subscripted into, yielding an |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3499 | '<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer |
| 3500 | to this element, thus computing a value of '<tt>i32*</tt>' type.</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3501 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 3502 | <p>Note that it is perfectly legal to index partially through a |
| 3503 | structure, returning a pointer to an inner element. Because of this, |
| 3504 | the LLVM code for the given testcase is equivalent to:</p> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3505 | |
| 3506 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3507 | define i32* %foo(%ST* %s) { |
| 3508 | %t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i> |
Jeff Cohen | 6f1cc77 | 2007-04-22 01:17:39 +0000 | [diff] [blame] | 3509 | %t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i> |
| 3510 | %t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3511 | %t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i> |
| 3512 | %t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i> |
| 3513 | ret i32* %t5 |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3514 | } |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 3515 | </pre> |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 3516 | |
| 3517 | <p>Note that it is undefined to access an array out of bounds: array and |
| 3518 | pointer indexes must always be within the defined bounds of the array type. |
Chris Lattner | 05d6709 | 2008-04-24 05:59:56 +0000 | [diff] [blame] | 3519 | The one exception for this rule is zero length arrays. These arrays are |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 3520 | defined to be accessible as variable length arrays, which requires access |
| 3521 | beyond the zero'th element.</p> |
| 3522 | |
Chris Lattner | 884a970 | 2006-08-15 00:45:58 +0000 | [diff] [blame] | 3523 | <p>The getelementptr instruction is often confusing. For some more insight |
| 3524 | into how it works, see <a href="GetElementPtr.html">the getelementptr |
| 3525 | FAQ</a>.</p> |
| 3526 | |
Chris Lattner | 7faa883 | 2002-04-14 06:13:44 +0000 | [diff] [blame] | 3527 | <h5>Example:</h5> |
Chris Lattner | e67a951 | 2005-06-24 17:22:57 +0000 | [diff] [blame] | 3528 | |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3529 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3530 | <i>; yields [12 x i8]*:aptr</i> |
Matthijs Kooijman | e49d0bc | 2008-10-13 13:44:15 +0000 | [diff] [blame] | 3531 | %aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1 |
| 3532 | <i>; yields i8*:vptr</i> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3533 | %vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1 |
Matthijs Kooijman | e49d0bc | 2008-10-13 13:44:15 +0000 | [diff] [blame] | 3534 | <i>; yields i8*:eptr</i> |
| 3535 | %eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1 |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3536 | </pre> |
Chris Lattner | f74d5c7 | 2004-04-05 01:30:49 +0000 | [diff] [blame] | 3537 | </div> |
Reid Spencer | 47ce179 | 2006-11-09 21:15:49 +0000 | [diff] [blame] | 3538 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 3539 | <!-- ======================================================================= --> |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 3540 | <div class="doc_subsection"> <a name="convertops">Conversion Operations</a> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3541 | </div> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3542 | <div class="doc_text"> |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 3543 | <p>The instructions in this category are the conversion instructions (casting) |
| 3544 | which all take a single operand and a type. They perform various bit conversions |
| 3545 | on the operand.</p> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3546 | </div> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3547 | |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 3548 | <!-- _______________________________________________________________________ --> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3549 | <div class="doc_subsubsection"> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3550 | <a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a> |
| 3551 | </div> |
| 3552 | <div class="doc_text"> |
| 3553 | |
| 3554 | <h5>Syntax:</h5> |
| 3555 | <pre> |
| 3556 | <result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3557 | </pre> |
| 3558 | |
| 3559 | <h5>Overview:</h5> |
| 3560 | <p> |
| 3561 | The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>. |
| 3562 | </p> |
| 3563 | |
| 3564 | <h5>Arguments:</h5> |
| 3565 | <p> |
| 3566 | The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must |
| 3567 | be an <a href="#t_integer">integer</a> type, and a type that specifies the size |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 3568 | and type of the result, which must be an <a href="#t_integer">integer</a> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3569 | type. The bit size of <tt>value</tt> must be larger than the bit size of |
| 3570 | <tt>ty2</tt>. Equal sized types are not allowed.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3571 | |
| 3572 | <h5>Semantics:</h5> |
| 3573 | <p> |
| 3574 | The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3575 | and converts the remaining bits to <tt>ty2</tt>. Since the source size must be |
| 3576 | larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>. |
| 3577 | It will always truncate bits.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3578 | |
| 3579 | <h5>Example:</h5> |
| 3580 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3581 | %X = trunc i32 257 to i8 <i>; yields i8:1</i> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 3582 | %Y = trunc i32 123 to i1 <i>; yields i1:true</i> |
| 3583 | %Y = trunc i32 122 to i1 <i>; yields i1:false</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3584 | </pre> |
| 3585 | </div> |
| 3586 | |
| 3587 | <!-- _______________________________________________________________________ --> |
| 3588 | <div class="doc_subsubsection"> |
| 3589 | <a name="i_zext">'<tt>zext .. to</tt>' Instruction</a> |
| 3590 | </div> |
| 3591 | <div class="doc_text"> |
| 3592 | |
| 3593 | <h5>Syntax:</h5> |
| 3594 | <pre> |
| 3595 | <result> = zext <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3596 | </pre> |
| 3597 | |
| 3598 | <h5>Overview:</h5> |
| 3599 | <p>The '<tt>zext</tt>' instruction zero extends its operand to type |
| 3600 | <tt>ty2</tt>.</p> |
| 3601 | |
| 3602 | |
| 3603 | <h5>Arguments:</h5> |
| 3604 | <p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 3605 | <a href="#t_integer">integer</a> type, and a type to cast it to, which must |
| 3606 | also be of <a href="#t_integer">integer</a> type. The bit size of the |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3607 | <tt>value</tt> must be smaller than the bit size of the destination type, |
| 3608 | <tt>ty2</tt>.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3609 | |
| 3610 | <h5>Semantics:</h5> |
| 3611 | <p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero |
Chris Lattner | d1d2517 | 2007-05-24 19:13:27 +0000 | [diff] [blame] | 3612 | bits until it reaches the size of the destination type, <tt>ty2</tt>.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3613 | |
Reid Spencer | b592952 | 2007-01-12 15:46:11 +0000 | [diff] [blame] | 3614 | <p>When zero extending from i1, the result will always be either 0 or 1.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3615 | |
| 3616 | <h5>Example:</h5> |
| 3617 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3618 | %X = zext i32 257 to i64 <i>; yields i64:257</i> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 3619 | %Y = zext i1 true to i32 <i>; yields i32:1</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3620 | </pre> |
| 3621 | </div> |
| 3622 | |
| 3623 | <!-- _______________________________________________________________________ --> |
| 3624 | <div class="doc_subsubsection"> |
| 3625 | <a name="i_sext">'<tt>sext .. to</tt>' Instruction</a> |
| 3626 | </div> |
| 3627 | <div class="doc_text"> |
| 3628 | |
| 3629 | <h5>Syntax:</h5> |
| 3630 | <pre> |
| 3631 | <result> = sext <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3632 | </pre> |
| 3633 | |
| 3634 | <h5>Overview:</h5> |
| 3635 | <p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p> |
| 3636 | |
| 3637 | <h5>Arguments:</h5> |
| 3638 | <p> |
| 3639 | The '<tt>sext</tt>' instruction takes a value to cast, which must be of |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 3640 | <a href="#t_integer">integer</a> type, and a type to cast it to, which must |
| 3641 | also be of <a href="#t_integer">integer</a> type. The bit size of the |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3642 | <tt>value</tt> must be smaller than the bit size of the destination type, |
| 3643 | <tt>ty2</tt>.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3644 | |
| 3645 | <h5>Semantics:</h5> |
| 3646 | <p> |
| 3647 | The '<tt>sext</tt>' instruction performs a sign extension by copying the sign |
| 3648 | bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of |
Chris Lattner | d1d2517 | 2007-05-24 19:13:27 +0000 | [diff] [blame] | 3649 | the type <tt>ty2</tt>.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3650 | |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 3651 | <p>When sign extending from i1, the extension always results in -1 or 0.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3652 | |
| 3653 | <h5>Example:</h5> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3654 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3655 | %X = sext i8 -1 to i16 <i>; yields i16 :65535</i> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 3656 | %Y = sext i1 true to i32 <i>; yields i32:-1</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3657 | </pre> |
| 3658 | </div> |
| 3659 | |
| 3660 | <!-- _______________________________________________________________________ --> |
| 3661 | <div class="doc_subsubsection"> |
Reid Spencer | 3fa91b0 | 2006-11-09 21:48:10 +0000 | [diff] [blame] | 3662 | <a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a> |
| 3663 | </div> |
| 3664 | |
| 3665 | <div class="doc_text"> |
| 3666 | |
| 3667 | <h5>Syntax:</h5> |
| 3668 | |
| 3669 | <pre> |
| 3670 | <result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3671 | </pre> |
| 3672 | |
| 3673 | <h5>Overview:</h5> |
| 3674 | <p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type |
| 3675 | <tt>ty2</tt>.</p> |
| 3676 | |
| 3677 | |
| 3678 | <h5>Arguments:</h5> |
| 3679 | <p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating |
| 3680 | point</a> value to cast and a <a href="#t_floating">floating point</a> type to |
| 3681 | cast it to. The size of <tt>value</tt> must be larger than the size of |
| 3682 | <tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a |
| 3683 | <i>no-op cast</i>.</p> |
| 3684 | |
| 3685 | <h5>Semantics:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3686 | <p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger |
| 3687 | <a href="#t_floating">floating point</a> type to a smaller |
| 3688 | <a href="#t_floating">floating point</a> type. If the value cannot fit within |
| 3689 | the destination type, <tt>ty2</tt>, then the results are undefined.</p> |
Reid Spencer | 3fa91b0 | 2006-11-09 21:48:10 +0000 | [diff] [blame] | 3690 | |
| 3691 | <h5>Example:</h5> |
| 3692 | <pre> |
| 3693 | %X = fptrunc double 123.0 to float <i>; yields float:123.0</i> |
| 3694 | %Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i> |
| 3695 | </pre> |
| 3696 | </div> |
| 3697 | |
| 3698 | <!-- _______________________________________________________________________ --> |
| 3699 | <div class="doc_subsubsection"> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3700 | <a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a> |
| 3701 | </div> |
| 3702 | <div class="doc_text"> |
| 3703 | |
| 3704 | <h5>Syntax:</h5> |
| 3705 | <pre> |
| 3706 | <result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3707 | </pre> |
| 3708 | |
| 3709 | <h5>Overview:</h5> |
| 3710 | <p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger |
| 3711 | floating point value.</p> |
| 3712 | |
| 3713 | <h5>Arguments:</h5> |
| 3714 | <p>The '<tt>fpext</tt>' instruction takes a |
| 3715 | <a href="#t_floating">floating point</a> <tt>value</tt> to cast, |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3716 | and a <a href="#t_floating">floating point</a> type to cast it to. The source |
| 3717 | type must be smaller than the destination type.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3718 | |
| 3719 | <h5>Semantics:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3720 | <p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller |
Duncan Sands | 8036ca4 | 2007-03-30 12:22:09 +0000 | [diff] [blame] | 3721 | <a href="#t_floating">floating point</a> type to a larger |
| 3722 | <a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3723 | used to make a <i>no-op cast</i> because it always changes bits. Use |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3724 | <tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3725 | |
| 3726 | <h5>Example:</h5> |
| 3727 | <pre> |
| 3728 | %X = fpext float 3.1415 to double <i>; yields double:3.1415</i> |
| 3729 | %Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i> |
| 3730 | </pre> |
| 3731 | </div> |
| 3732 | |
| 3733 | <!-- _______________________________________________________________________ --> |
| 3734 | <div class="doc_subsubsection"> |
Reid Spencer | 24d6da5 | 2007-01-21 00:29:26 +0000 | [diff] [blame] | 3735 | <a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3736 | </div> |
| 3737 | <div class="doc_text"> |
| 3738 | |
| 3739 | <h5>Syntax:</h5> |
| 3740 | <pre> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3741 | <result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3742 | </pre> |
| 3743 | |
| 3744 | <h5>Overview:</h5> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3745 | <p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3746 | unsigned integer equivalent of type <tt>ty2</tt>. |
| 3747 | </p> |
| 3748 | |
| 3749 | <h5>Arguments:</h5> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3750 | <p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 3751 | scalar or vector <a href="#t_floating">floating point</a> value, and a type |
| 3752 | to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> |
| 3753 | type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a |
| 3754 | vector integer type with the same number of elements as <tt>ty</tt></p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3755 | |
| 3756 | <h5>Semantics:</h5> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3757 | <p> The '<tt>fptoui</tt>' instruction converts its |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3758 | <a href="#t_floating">floating point</a> operand into the nearest (rounding |
| 3759 | towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>, |
| 3760 | the results are undefined.</p> |
| 3761 | |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3762 | <h5>Example:</h5> |
| 3763 | <pre> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3764 | %X = fptoui double 123.0 to i32 <i>; yields i32:123</i> |
Chris Lattner | 8851904 | 2007-09-22 03:17:52 +0000 | [diff] [blame] | 3765 | %Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i> |
Reid Spencer | 1539a1c | 2007-07-31 14:40:14 +0000 | [diff] [blame] | 3766 | %X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3767 | </pre> |
| 3768 | </div> |
| 3769 | |
| 3770 | <!-- _______________________________________________________________________ --> |
| 3771 | <div class="doc_subsubsection"> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3772 | <a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3773 | </div> |
| 3774 | <div class="doc_text"> |
| 3775 | |
| 3776 | <h5>Syntax:</h5> |
| 3777 | <pre> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3778 | <result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3779 | </pre> |
| 3780 | |
| 3781 | <h5>Overview:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3782 | <p>The '<tt>fptosi</tt>' instruction converts |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3783 | <a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>. |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3784 | </p> |
| 3785 | |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 3786 | <h5>Arguments:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3787 | <p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 3788 | scalar or vector <a href="#t_floating">floating point</a> value, and a type |
| 3789 | to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> |
| 3790 | type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a |
| 3791 | vector integer type with the same number of elements as <tt>ty</tt></p> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3792 | |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 3793 | <h5>Semantics:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3794 | <p>The '<tt>fptosi</tt>' instruction converts its |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3795 | <a href="#t_floating">floating point</a> operand into the nearest (rounding |
| 3796 | towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>, |
| 3797 | the results are undefined.</p> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3798 | |
Chris Lattner | 33ba0d9 | 2001-07-09 00:26:23 +0000 | [diff] [blame] | 3799 | <h5>Example:</h5> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3800 | <pre> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 3801 | %X = fptosi double -123.0 to i32 <i>; yields i32:-123</i> |
Chris Lattner | 8851904 | 2007-09-22 03:17:52 +0000 | [diff] [blame] | 3802 | %Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3803 | %X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3804 | </pre> |
| 3805 | </div> |
| 3806 | |
| 3807 | <!-- _______________________________________________________________________ --> |
| 3808 | <div class="doc_subsubsection"> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3809 | <a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3810 | </div> |
| 3811 | <div class="doc_text"> |
| 3812 | |
| 3813 | <h5>Syntax:</h5> |
| 3814 | <pre> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3815 | <result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3816 | </pre> |
| 3817 | |
| 3818 | <h5>Overview:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3819 | <p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3820 | integer and converts that value to the <tt>ty2</tt> type.</p> |
| 3821 | |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3822 | <h5>Arguments:</h5> |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 3823 | <p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a |
| 3824 | scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it |
| 3825 | to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a> |
| 3826 | type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector |
| 3827 | floating point type with the same number of elements as <tt>ty</tt></p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3828 | |
| 3829 | <h5>Semantics:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3830 | <p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3831 | integer quantity and converts it to the corresponding floating point value. If |
Jeff Cohen | cb75731 | 2007-04-22 14:56:37 +0000 | [diff] [blame] | 3832 | the value cannot fit in the floating point value, the results are undefined.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3833 | |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3834 | <h5>Example:</h5> |
| 3835 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3836 | %X = uitofp i32 257 to float <i>; yields float:257.0</i> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3837 | %Y = uitofp i8 -1 to double <i>; yields double:255.0</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3838 | </pre> |
| 3839 | </div> |
| 3840 | |
| 3841 | <!-- _______________________________________________________________________ --> |
| 3842 | <div class="doc_subsubsection"> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3843 | <a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3844 | </div> |
| 3845 | <div class="doc_text"> |
| 3846 | |
| 3847 | <h5>Syntax:</h5> |
| 3848 | <pre> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3849 | <result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3850 | </pre> |
| 3851 | |
| 3852 | <h5>Overview:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3853 | <p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3854 | integer and converts that value to the <tt>ty2</tt> type.</p> |
| 3855 | |
| 3856 | <h5>Arguments:</h5> |
Nate Begeman | b348d18 | 2007-11-17 03:58:34 +0000 | [diff] [blame] | 3857 | <p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a |
| 3858 | scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it |
| 3859 | to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a> |
| 3860 | type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector |
| 3861 | floating point type with the same number of elements as <tt>ty</tt></p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3862 | |
| 3863 | <h5>Semantics:</h5> |
Reid Spencer | d444879 | 2006-11-09 23:03:26 +0000 | [diff] [blame] | 3864 | <p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3865 | integer quantity and converts it to the corresponding floating point value. If |
Jeff Cohen | cb75731 | 2007-04-22 14:56:37 +0000 | [diff] [blame] | 3866 | the value cannot fit in the floating point value, the results are undefined.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3867 | |
| 3868 | <h5>Example:</h5> |
| 3869 | <pre> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3870 | %X = sitofp i32 257 to float <i>; yields float:257.0</i> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3871 | %Y = sitofp i8 -1 to double <i>; yields double:-1.0</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3872 | </pre> |
| 3873 | </div> |
| 3874 | |
| 3875 | <!-- _______________________________________________________________________ --> |
| 3876 | <div class="doc_subsubsection"> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3877 | <a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a> |
| 3878 | </div> |
| 3879 | <div class="doc_text"> |
| 3880 | |
| 3881 | <h5>Syntax:</h5> |
| 3882 | <pre> |
| 3883 | <result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3884 | </pre> |
| 3885 | |
| 3886 | <h5>Overview:</h5> |
| 3887 | <p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to |
| 3888 | the integer type <tt>ty2</tt>.</p> |
| 3889 | |
| 3890 | <h5>Arguments:</h5> |
| 3891 | <p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which |
Duncan Sands | 8036ca4 | 2007-03-30 12:22:09 +0000 | [diff] [blame] | 3892 | must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3893 | <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3894 | |
| 3895 | <h5>Semantics:</h5> |
| 3896 | <p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type |
| 3897 | <tt>ty2</tt> by interpreting the pointer value as an integer and either |
| 3898 | truncating or zero extending that value to the size of the integer type. If |
| 3899 | <tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If |
| 3900 | <tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 3901 | are the same size, then nothing is done (<i>no-op cast</i>) other than a type |
| 3902 | change.</p> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3903 | |
| 3904 | <h5>Example:</h5> |
| 3905 | <pre> |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 3906 | %X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i> |
| 3907 | %Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3908 | </pre> |
| 3909 | </div> |
| 3910 | |
| 3911 | <!-- _______________________________________________________________________ --> |
| 3912 | <div class="doc_subsubsection"> |
| 3913 | <a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a> |
| 3914 | </div> |
| 3915 | <div class="doc_text"> |
| 3916 | |
| 3917 | <h5>Syntax:</h5> |
| 3918 | <pre> |
| 3919 | <result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i> |
| 3920 | </pre> |
| 3921 | |
| 3922 | <h5>Overview:</h5> |
| 3923 | <p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to |
| 3924 | a pointer type, <tt>ty2</tt>.</p> |
| 3925 | |
| 3926 | <h5>Arguments:</h5> |
Duncan Sands | 8036ca4 | 2007-03-30 12:22:09 +0000 | [diff] [blame] | 3927 | <p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3928 | value to cast, and a type to cast it to, which must be a |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3929 | <a href="#t_pointer">pointer</a> type.</p> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3930 | |
| 3931 | <h5>Semantics:</h5> |
| 3932 | <p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type |
| 3933 | <tt>ty2</tt> by applying either a zero extension or a truncation depending on |
| 3934 | the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the |
| 3935 | size of a pointer then a truncation is done. If <tt>value</tt> is smaller than |
| 3936 | the size of a pointer then a zero extension is done. If they are the same size, |
| 3937 | nothing is done (<i>no-op cast</i>).</p> |
| 3938 | |
| 3939 | <h5>Example:</h5> |
| 3940 | <pre> |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 3941 | %X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i> |
| 3942 | %X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i> |
| 3943 | %Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i> |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3944 | </pre> |
| 3945 | </div> |
| 3946 | |
| 3947 | <!-- _______________________________________________________________________ --> |
| 3948 | <div class="doc_subsubsection"> |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3949 | <a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3950 | </div> |
| 3951 | <div class="doc_text"> |
| 3952 | |
| 3953 | <h5>Syntax:</h5> |
| 3954 | <pre> |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3955 | <result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3956 | </pre> |
| 3957 | |
| 3958 | <h5>Overview:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 3959 | |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3960 | <p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3961 | <tt>ty2</tt> without changing any bits.</p> |
| 3962 | |
| 3963 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 3964 | |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3965 | <p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be |
Dan Gohman | 500233a | 2008-09-08 16:45:59 +0000 | [diff] [blame] | 3966 | a non-aggregate first class value, and a type to cast it to, which must also be |
| 3967 | a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of |
| 3968 | <tt>value</tt> |
Reid Spencer | 19b569f | 2007-01-09 20:08:58 +0000 | [diff] [blame] | 3969 | and the destination type, <tt>ty2</tt>, must be identical. If the source |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 3970 | type is a pointer, the destination type must also be a pointer. This |
| 3971 | instruction supports bitwise conversion of vectors to integers and to vectors |
| 3972 | of other types (as long as they have the same size).</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3973 | |
| 3974 | <h5>Semantics:</h5> |
Reid Spencer | 5c0ef47 | 2006-11-11 23:08:07 +0000 | [diff] [blame] | 3975 | <p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type |
Reid Spencer | 7267925 | 2006-11-11 21:00:47 +0000 | [diff] [blame] | 3976 | <tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with |
| 3977 | this conversion. The conversion is done as if the <tt>value</tt> had been |
| 3978 | stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be |
| 3979 | converted to other pointer types with this instruction. To convert pointers to |
| 3980 | other types, use the <a href="#i_inttoptr">inttoptr</a> or |
| 3981 | <a href="#i_ptrtoint">ptrtoint</a> instructions first.</p> |
Reid Spencer | 9dee3ac | 2006-11-08 01:11:31 +0000 | [diff] [blame] | 3982 | |
| 3983 | <h5>Example:</h5> |
| 3984 | <pre> |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 3985 | %X = bitcast i8 255 to i8 <i>; yields i8 :-1</i> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 3986 | %Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 3987 | %Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i> |
Chris Lattner | 33ba0d9 | 2001-07-09 00:26:23 +0000 | [diff] [blame] | 3988 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 3989 | </div> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 3990 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 3991 | <!-- ======================================================================= --> |
| 3992 | <div class="doc_subsection"> <a name="otherops">Other Operations</a> </div> |
| 3993 | <div class="doc_text"> |
| 3994 | <p>The instructions in this category are the "miscellaneous" |
| 3995 | instructions, which defy better classification.</p> |
| 3996 | </div> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 3997 | |
| 3998 | <!-- _______________________________________________________________________ --> |
| 3999 | <div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a> |
| 4000 | </div> |
| 4001 | <div class="doc_text"> |
| 4002 | <h5>Syntax:</h5> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4003 | <pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4004 | </pre> |
| 4005 | <h5>Overview:</h5> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4006 | <p>The '<tt>icmp</tt>' instruction returns a boolean value or |
| 4007 | a vector of boolean values based on comparison |
| 4008 | of its two integer, integer vector, or pointer operands.</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4009 | <h5>Arguments:</h5> |
| 4010 | <p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4011 | the condition code indicating the kind of comparison to perform. It is not |
| 4012 | a value, just a keyword. The possible condition code are: |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4013 | </p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4014 | <ol> |
| 4015 | <li><tt>eq</tt>: equal</li> |
| 4016 | <li><tt>ne</tt>: not equal </li> |
| 4017 | <li><tt>ugt</tt>: unsigned greater than</li> |
| 4018 | <li><tt>uge</tt>: unsigned greater or equal</li> |
| 4019 | <li><tt>ult</tt>: unsigned less than</li> |
| 4020 | <li><tt>ule</tt>: unsigned less or equal</li> |
| 4021 | <li><tt>sgt</tt>: signed greater than</li> |
| 4022 | <li><tt>sge</tt>: signed greater or equal</li> |
| 4023 | <li><tt>slt</tt>: signed less than</li> |
| 4024 | <li><tt>sle</tt>: signed less or equal</li> |
| 4025 | </ol> |
Chris Lattner | 3b19d65 | 2007-01-15 01:54:13 +0000 | [diff] [blame] | 4026 | <p>The remaining two arguments must be <a href="#t_integer">integer</a> or |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4027 | <a href="#t_pointer">pointer</a> |
| 4028 | or integer <a href="#t_vector">vector</a> typed. |
| 4029 | They must also be identical types.</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4030 | <h5>Semantics:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4031 | <p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4032 | the condition code given as <tt>cond</tt>. The comparison performed always |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4033 | yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows: |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4034 | </p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4035 | <ol> |
| 4036 | <li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal, |
| 4037 | <tt>false</tt> otherwise. No sign interpretation is necessary or performed. |
| 4038 | </li> |
| 4039 | <li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal, |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4040 | <tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4041 | <li><tt>ugt</tt>: interprets the operands as unsigned values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4042 | <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4043 | <li><tt>uge</tt>: interprets the operands as unsigned values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4044 | <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4045 | <li><tt>ult</tt>: interprets the operands as unsigned values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4046 | <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4047 | <li><tt>ule</tt>: interprets the operands as unsigned values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4048 | <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4049 | <li><tt>sgt</tt>: interprets the operands as signed values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4050 | <tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4051 | <li><tt>sge</tt>: interprets the operands as signed values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4052 | <tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4053 | <li><tt>slt</tt>: interprets the operands as signed values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4054 | <tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4055 | <li><tt>sle</tt>: interprets the operands as signed values and yields |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4056 | <tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4057 | </ol> |
| 4058 | <p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4059 | values are compared as if they were integers.</p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4060 | <p>If the operands are integer vectors, then they are compared |
| 4061 | element by element. The result is an <tt>i1</tt> vector with |
| 4062 | the same number of elements as the values being compared. |
| 4063 | Otherwise, the result is an <tt>i1</tt>. |
| 4064 | </p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4065 | |
| 4066 | <h5>Example:</h5> |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 4067 | <pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i> |
| 4068 | <result> = icmp ne float* %X, %X <i>; yields: result=false</i> |
| 4069 | <result> = icmp ult i16 4, 5 <i>; yields: result=true</i> |
| 4070 | <result> = icmp sgt i16 4, 5 <i>; yields: result=false</i> |
| 4071 | <result> = icmp ule i16 -4, 5 <i>; yields: result=false</i> |
| 4072 | <result> = icmp sge i16 4, 5 <i>; yields: result=false</i> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4073 | </pre> |
Dan Gohman | c766f72 | 2009-01-22 01:39:38 +0000 | [diff] [blame^] | 4074 | |
| 4075 | <p>Note that the code generator does not yet support vector types with |
| 4076 | the <tt>icmp</tt> instruction.</p> |
| 4077 | |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4078 | </div> |
| 4079 | |
| 4080 | <!-- _______________________________________________________________________ --> |
| 4081 | <div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a> |
| 4082 | </div> |
| 4083 | <div class="doc_text"> |
| 4084 | <h5>Syntax:</h5> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4085 | <pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4086 | </pre> |
| 4087 | <h5>Overview:</h5> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4088 | <p>The '<tt>fcmp</tt>' instruction returns a boolean value |
| 4089 | or vector of boolean values based on comparison |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4090 | of its operands.</p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4091 | <p> |
| 4092 | If the operands are floating point scalars, then the result |
| 4093 | type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>). |
| 4094 | </p> |
| 4095 | <p>If the operands are floating point vectors, then the result type |
| 4096 | is a vector of boolean with the same number of elements as the |
| 4097 | operands being compared.</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4098 | <h5>Arguments:</h5> |
| 4099 | <p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4100 | the condition code indicating the kind of comparison to perform. It is not |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4101 | a value, just a keyword. The possible condition code are:</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4102 | <ol> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4103 | <li><tt>false</tt>: no comparison, always returns false</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4104 | <li><tt>oeq</tt>: ordered and equal</li> |
| 4105 | <li><tt>ogt</tt>: ordered and greater than </li> |
| 4106 | <li><tt>oge</tt>: ordered and greater than or equal</li> |
| 4107 | <li><tt>olt</tt>: ordered and less than </li> |
| 4108 | <li><tt>ole</tt>: ordered and less than or equal</li> |
| 4109 | <li><tt>one</tt>: ordered and not equal</li> |
| 4110 | <li><tt>ord</tt>: ordered (no nans)</li> |
| 4111 | <li><tt>ueq</tt>: unordered or equal</li> |
| 4112 | <li><tt>ugt</tt>: unordered or greater than </li> |
| 4113 | <li><tt>uge</tt>: unordered or greater than or equal</li> |
| 4114 | <li><tt>ult</tt>: unordered or less than </li> |
| 4115 | <li><tt>ule</tt>: unordered or less than or equal</li> |
| 4116 | <li><tt>une</tt>: unordered or not equal</li> |
| 4117 | <li><tt>uno</tt>: unordered (either nans)</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4118 | <li><tt>true</tt>: no comparison, always returns true</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4119 | </ol> |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4120 | <p><i>Ordered</i> means that neither operand is a QNAN while |
Reid Spencer | 93a4985 | 2006-12-06 07:08:07 +0000 | [diff] [blame] | 4121 | <i>unordered</i> means that either operand may be a QNAN.</p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4122 | <p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be |
| 4123 | either a <a href="#t_floating">floating point</a> type |
| 4124 | or a <a href="#t_vector">vector</a> of floating point type. |
| 4125 | They must have identical types.</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4126 | <h5>Semantics:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4127 | <p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4128 | according to the condition code given as <tt>cond</tt>. |
| 4129 | If the operands are vectors, then the vectors are compared |
| 4130 | element by element. |
| 4131 | Each comparison performed |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4132 | always yields an <a href="#t_primitive">i1</a> result, as follows:</p> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4133 | <ol> |
| 4134 | <li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4135 | <li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4136 | <tt>op1</tt> is equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4137 | <li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4138 | <tt>op1</tt> is greather than <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4139 | <li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4140 | <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4141 | <li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4142 | <tt>op1</tt> is less than <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4143 | <li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4144 | <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4145 | <li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4146 | <tt>op1</tt> is not equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4147 | <li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li> |
| 4148 | <li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4149 | <tt>op1</tt> is equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4150 | <li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4151 | <tt>op1</tt> is greater than <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4152 | <li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4153 | <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4154 | <li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4155 | <tt>op1</tt> is less than <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4156 | <li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4157 | <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4158 | <li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4159 | <tt>op1</tt> is not equal to <tt>op2</tt>.</li> |
Reid Spencer | b7f2628 | 2006-11-19 03:00:14 +0000 | [diff] [blame] | 4160 | <li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4161 | <li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li> |
| 4162 | </ol> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4163 | |
| 4164 | <h5>Example:</h5> |
| 4165 | <pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4166 | <result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i> |
| 4167 | <result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i> |
| 4168 | <result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i> |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4169 | </pre> |
Dan Gohman | c766f72 | 2009-01-22 01:39:38 +0000 | [diff] [blame^] | 4170 | |
| 4171 | <p>Note that the code generator does not yet support vector types with |
| 4172 | the <tt>fcmp</tt> instruction.</p> |
| 4173 | |
Reid Spencer | f3a70a6 | 2006-11-18 21:50:54 +0000 | [diff] [blame] | 4174 | </div> |
| 4175 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4176 | <!-- _______________________________________________________________________ --> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4177 | <div class="doc_subsubsection"> |
| 4178 | <a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a> |
| 4179 | </div> |
| 4180 | <div class="doc_text"> |
| 4181 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4182 | <pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4183 | </pre> |
| 4184 | <h5>Overview:</h5> |
| 4185 | <p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on |
| 4186 | element-wise comparison of its two integer vector operands.</p> |
| 4187 | <h5>Arguments:</h5> |
| 4188 | <p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is |
| 4189 | the condition code indicating the kind of comparison to perform. It is not |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4190 | a value, just a keyword. The possible condition code are:</p> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4191 | <ol> |
| 4192 | <li><tt>eq</tt>: equal</li> |
| 4193 | <li><tt>ne</tt>: not equal </li> |
| 4194 | <li><tt>ugt</tt>: unsigned greater than</li> |
| 4195 | <li><tt>uge</tt>: unsigned greater or equal</li> |
| 4196 | <li><tt>ult</tt>: unsigned less than</li> |
| 4197 | <li><tt>ule</tt>: unsigned less or equal</li> |
| 4198 | <li><tt>sgt</tt>: signed greater than</li> |
| 4199 | <li><tt>sge</tt>: signed greater or equal</li> |
| 4200 | <li><tt>slt</tt>: signed less than</li> |
| 4201 | <li><tt>sle</tt>: signed less or equal</li> |
| 4202 | </ol> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4203 | <p>The remaining two arguments must be <a href="#t_vector">vector</a> or |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4204 | <a href="#t_integer">integer</a> typed. They must also be identical types.</p> |
| 4205 | <h5>Semantics:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4206 | <p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4207 | according to the condition code given as <tt>cond</tt>. The comparison yields a |
| 4208 | <a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of |
| 4209 | identical type as the values being compared. The most significant bit in each |
| 4210 | element is 1 if the element-wise comparison evaluates to true, and is 0 |
| 4211 | otherwise. All other bits of the result are undefined. The condition codes |
| 4212 | are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>' |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4213 | instruction</a>.</p> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4214 | |
| 4215 | <h5>Example:</h5> |
| 4216 | <pre> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4217 | <result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i> |
| 4218 | <result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4219 | </pre> |
| 4220 | </div> |
| 4221 | |
| 4222 | <!-- _______________________________________________________________________ --> |
| 4223 | <div class="doc_subsubsection"> |
| 4224 | <a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a> |
| 4225 | </div> |
| 4226 | <div class="doc_text"> |
| 4227 | <h5>Syntax:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4228 | <pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4229 | <h5>Overview:</h5> |
| 4230 | <p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on |
| 4231 | element-wise comparison of its two floating point vector operands. The output |
| 4232 | elements have the same width as the input elements.</p> |
| 4233 | <h5>Arguments:</h5> |
| 4234 | <p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is |
| 4235 | the condition code indicating the kind of comparison to perform. It is not |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4236 | a value, just a keyword. The possible condition code are:</p> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4237 | <ol> |
| 4238 | <li><tt>false</tt>: no comparison, always returns false</li> |
| 4239 | <li><tt>oeq</tt>: ordered and equal</li> |
| 4240 | <li><tt>ogt</tt>: ordered and greater than </li> |
| 4241 | <li><tt>oge</tt>: ordered and greater than or equal</li> |
| 4242 | <li><tt>olt</tt>: ordered and less than </li> |
| 4243 | <li><tt>ole</tt>: ordered and less than or equal</li> |
| 4244 | <li><tt>one</tt>: ordered and not equal</li> |
| 4245 | <li><tt>ord</tt>: ordered (no nans)</li> |
| 4246 | <li><tt>ueq</tt>: unordered or equal</li> |
| 4247 | <li><tt>ugt</tt>: unordered or greater than </li> |
| 4248 | <li><tt>uge</tt>: unordered or greater than or equal</li> |
| 4249 | <li><tt>ult</tt>: unordered or less than </li> |
| 4250 | <li><tt>ule</tt>: unordered or less than or equal</li> |
| 4251 | <li><tt>une</tt>: unordered or not equal</li> |
| 4252 | <li><tt>uno</tt>: unordered (either nans)</li> |
| 4253 | <li><tt>true</tt>: no comparison, always returns true</li> |
| 4254 | </ol> |
| 4255 | <p>The remaining two arguments must be <a href="#t_vector">vector</a> of |
| 4256 | <a href="#t_floating">floating point</a> typed. They must also be identical |
| 4257 | types.</p> |
| 4258 | <h5>Semantics:</h5> |
Gabor Greif | fb224a2 | 2008-08-07 21:46:00 +0000 | [diff] [blame] | 4259 | <p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4260 | according to the condition code given as <tt>cond</tt>. The comparison yields a |
| 4261 | <a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with |
| 4262 | an identical number of elements as the values being compared, and each element |
| 4263 | having identical with to the width of the floating point elements. The most |
| 4264 | significant bit in each element is 1 if the element-wise comparison evaluates to |
| 4265 | true, and is 0 otherwise. All other bits of the result are undefined. The |
| 4266 | condition codes are evaluated identically to the |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4267 | <a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4268 | |
| 4269 | <h5>Example:</h5> |
| 4270 | <pre> |
Chris Lattner | 50ad45c | 2008-10-13 16:55:18 +0000 | [diff] [blame] | 4271 | <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i> |
| 4272 | <result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > |
| 4273 | |
| 4274 | <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i> |
| 4275 | <result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> |
Nate Begeman | ac80ade | 2008-05-12 19:01:56 +0000 | [diff] [blame] | 4276 | </pre> |
| 4277 | </div> |
| 4278 | |
| 4279 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4280 | <div class="doc_subsubsection"> |
| 4281 | <a name="i_phi">'<tt>phi</tt>' Instruction</a> |
| 4282 | </div> |
| 4283 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4284 | <div class="doc_text"> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4285 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4286 | <h5>Syntax:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4287 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4288 | <pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre> |
| 4289 | <h5>Overview:</h5> |
| 4290 | <p>The '<tt>phi</tt>' instruction is used to implement the φ node in |
| 4291 | the SSA graph representing the function.</p> |
| 4292 | <h5>Arguments:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4293 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4294 | <p>The type of the incoming values is specified with the first type |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4295 | field. After this, the '<tt>phi</tt>' instruction takes a list of pairs |
| 4296 | as arguments, with one pair for each predecessor basic block of the |
| 4297 | current block. Only values of <a href="#t_firstclass">first class</a> |
| 4298 | type may be used as the value arguments to the PHI node. Only labels |
| 4299 | may be used as the label arguments.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4300 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4301 | <p>There must be no non-phi instructions between the start of a basic |
| 4302 | block and the PHI instructions: i.e. PHI instructions must be first in |
| 4303 | a basic block.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4304 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4305 | <h5>Semantics:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4306 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4307 | <p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value |
| 4308 | specified by the pair corresponding to the predecessor basic block that executed |
| 4309 | just prior to the current block.</p> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4310 | |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4311 | <h5>Example:</h5> |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4312 | <pre> |
| 4313 | Loop: ; Infinite loop that counts from 0 on up... |
| 4314 | %indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ] |
| 4315 | %nextindvar = add i32 %indvar, 1 |
| 4316 | br label %Loop |
| 4317 | </pre> |
Reid Spencer | 2fd21e6 | 2006-11-08 01:18:52 +0000 | [diff] [blame] | 4318 | </div> |
| 4319 | |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4320 | <!-- _______________________________________________________________________ --> |
| 4321 | <div class="doc_subsubsection"> |
| 4322 | <a name="i_select">'<tt>select</tt>' Instruction</a> |
| 4323 | </div> |
| 4324 | |
| 4325 | <div class="doc_text"> |
| 4326 | |
| 4327 | <h5>Syntax:</h5> |
| 4328 | |
| 4329 | <pre> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4330 | <result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i> |
| 4331 | |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4332 | <i>selty</i> is either i1 or {<N x i1>} |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4333 | </pre> |
| 4334 | |
| 4335 | <h5>Overview:</h5> |
| 4336 | |
| 4337 | <p> |
| 4338 | The '<tt>select</tt>' instruction is used to choose one value based on a |
| 4339 | condition, without branching. |
| 4340 | </p> |
| 4341 | |
| 4342 | |
| 4343 | <h5>Arguments:</h5> |
| 4344 | |
| 4345 | <p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4346 | The '<tt>select</tt>' instruction requires an 'i1' value or |
| 4347 | a vector of 'i1' values indicating the |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4348 | condition, and two values of the same <a href="#t_firstclass">first class</a> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4349 | type. If the val1/val2 are vectors and |
| 4350 | the condition is a scalar, then entire vectors are selected, not |
Chris Lattner | 5568e94 | 2008-05-20 20:48:21 +0000 | [diff] [blame] | 4351 | individual elements. |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4352 | </p> |
| 4353 | |
| 4354 | <h5>Semantics:</h5> |
| 4355 | |
| 4356 | <p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4357 | If the condition is an i1 and it evaluates to 1, the instruction returns the first |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 4358 | value argument; otherwise, it returns the second value argument. |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4359 | </p> |
Dan Gohman | f72fb67 | 2008-09-09 01:02:47 +0000 | [diff] [blame] | 4360 | <p> |
| 4361 | If the condition is a vector of i1, then the value arguments must |
| 4362 | be vectors of the same size, and the selection is done element |
| 4363 | by element. |
| 4364 | </p> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4365 | |
| 4366 | <h5>Example:</h5> |
| 4367 | |
| 4368 | <pre> |
Reid Spencer | c78f337 | 2007-01-12 03:35:51 +0000 | [diff] [blame] | 4369 | %X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i> |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4370 | </pre> |
Dan Gohman | c766f72 | 2009-01-22 01:39:38 +0000 | [diff] [blame^] | 4371 | |
| 4372 | <p>Note that the code generator does not yet support conditions |
| 4373 | with vector type.</p> |
| 4374 | |
Chris Lattner | cc37aae | 2004-03-12 05:50:16 +0000 | [diff] [blame] | 4375 | </div> |
| 4376 | |
Robert Bocchino | 05ccd70 | 2006-01-15 20:48:27 +0000 | [diff] [blame] | 4377 | |
| 4378 | <!-- _______________________________________________________________________ --> |
| 4379 | <div class="doc_subsubsection"> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4380 | <a name="i_call">'<tt>call</tt>' Instruction</a> |
| 4381 | </div> |
| 4382 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4383 | <div class="doc_text"> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4384 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 4385 | <h5>Syntax:</h5> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4386 | <pre> |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 4387 | <result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>] |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4388 | </pre> |
| 4389 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 4390 | <h5>Overview:</h5> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4391 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4392 | <p>The '<tt>call</tt>' instruction represents a simple function call.</p> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4393 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 4394 | <h5>Arguments:</h5> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4395 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4396 | <p>This instruction requires several arguments:</p> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4397 | |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 4398 | <ol> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4399 | <li> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 4400 | <p>The optional "tail" marker indicates whether the callee function accesses |
| 4401 | any allocas or varargs in the caller. If the "tail" marker is present, the |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4402 | function call is eligible for tail call optimization. Note that calls may |
| 4403 | be marked "tail" even if they do not occur before a <a |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4404 | href="#i_ret"><tt>ret</tt></a> instruction.</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4405 | </li> |
| 4406 | <li> |
Duncan Sands | 8036ca4 | 2007-03-30 12:22:09 +0000 | [diff] [blame] | 4407 | <p>The optional "cconv" marker indicates which <a href="#callingconv">calling |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 4408 | convention</a> the call should use. If none is specified, the call defaults |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4409 | to using C calling conventions.</p> |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 4410 | </li> |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 4411 | |
| 4412 | <li> |
| 4413 | <p>The optional <a href="#paramattrs">Parameter Attributes</a> list for |
| 4414 | return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>', |
| 4415 | and '<tt>inreg</tt>' attributes are valid here.</p> |
| 4416 | </li> |
| 4417 | |
Chris Lattner | bad10ee | 2005-05-06 22:57:40 +0000 | [diff] [blame] | 4418 | <li> |
Nick Lewycky | db7e3c9 | 2007-09-08 13:57:50 +0000 | [diff] [blame] | 4419 | <p>'<tt>ty</tt>': the type of the call instruction itself which is also |
| 4420 | the type of the return value. Functions that return no value are marked |
| 4421 | <tt><a href="#t_void">void</a></tt>.</p> |
| 4422 | </li> |
| 4423 | <li> |
| 4424 | <p>'<tt>fnty</tt>': shall be the signature of the pointer to function |
| 4425 | value being invoked. The argument types must match the types implied by |
| 4426 | this signature. This type can be omitted if the function is not varargs |
| 4427 | and if the function type does not return a pointer to a function.</p> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4428 | </li> |
| 4429 | <li> |
| 4430 | <p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to |
| 4431 | be invoked. In most cases, this is a direct function invocation, but |
| 4432 | indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 4433 | to function value.</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4434 | </li> |
| 4435 | <li> |
| 4436 | <p>'<tt>function args</tt>': argument list whose types match the |
Reid Spencer | a7e302a | 2005-05-01 22:22:57 +0000 | [diff] [blame] | 4437 | function signature argument types. All arguments must be of |
| 4438 | <a href="#t_firstclass">first class</a> type. If the function signature |
| 4439 | indicates the function accepts a variable number of arguments, the extra |
| 4440 | arguments can be specified.</p> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4441 | </li> |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 4442 | <li> |
Devang Patel | 307e8ab | 2008-10-07 17:48:33 +0000 | [diff] [blame] | 4443 | <p>The optional <a href="#fnattrs">function attributes</a> list. Only |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 4444 | '<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and |
| 4445 | '<tt>readnone</tt>' attributes are valid here.</p> |
| 4446 | </li> |
Chris Lattner | 6536cfe | 2002-05-06 22:08:29 +0000 | [diff] [blame] | 4447 | </ol> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4448 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 4449 | <h5>Semantics:</h5> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4450 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4451 | <p>The '<tt>call</tt>' instruction is used to cause control flow to |
| 4452 | transfer to a specified function, with its incoming arguments bound to |
| 4453 | the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>' |
| 4454 | instruction in the called function, control flow continues with the |
| 4455 | instruction after the function call, and the return value of the |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4456 | function is bound to the result argument.</p> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4457 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 4458 | <h5>Example:</h5> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4459 | |
| 4460 | <pre> |
Nick Lewycky | db7e3c9 | 2007-09-08 13:57:50 +0000 | [diff] [blame] | 4461 | %retval = call i32 @test(i32 %argc) |
Chris Lattner | 772fccf | 2008-03-21 17:24:17 +0000 | [diff] [blame] | 4462 | call i32 (i8 *, ...)* @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i> |
| 4463 | %X = tail call i32 @foo() <i>; yields i32</i> |
| 4464 | %Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i> |
| 4465 | call void %foo(i8 97 signext) |
Devang Patel | c3fc6df | 2008-03-10 20:49:15 +0000 | [diff] [blame] | 4466 | |
| 4467 | %struct.A = type { i32, i8 } |
Devang Patel | f642f47 | 2008-10-06 18:50:38 +0000 | [diff] [blame] | 4468 | %r = call %struct.A @foo() <i>; yields { 32, i8 }</i> |
Dan Gohman | b1e6b96 | 2008-10-04 19:00:07 +0000 | [diff] [blame] | 4469 | %gr = extractvalue %struct.A %r, 0 <i>; yields i32</i> |
| 4470 | %gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i> |
Chris Lattner | 85a350f | 2008-10-08 06:26:11 +0000 | [diff] [blame] | 4471 | %Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i> |
Matthijs Kooijman | cb73d19 | 2008-10-07 10:03:45 +0000 | [diff] [blame] | 4472 | %ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i> |
Chris Lattner | 2bff524 | 2005-05-06 05:47:36 +0000 | [diff] [blame] | 4473 | </pre> |
| 4474 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4475 | </div> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4476 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4477 | <!-- _______________________________________________________________________ --> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4478 | <div class="doc_subsubsection"> |
Chris Lattner | fb6977d | 2006-01-13 23:26:01 +0000 | [diff] [blame] | 4479 | <a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4480 | </div> |
| 4481 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4482 | <div class="doc_text"> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4483 | |
Chris Lattner | 8d1a81d | 2003-10-18 05:51:36 +0000 | [diff] [blame] | 4484 | <h5>Syntax:</h5> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4485 | |
| 4486 | <pre> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4487 | <resultval> = va_arg <va_list*> <arglist>, <argty> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4488 | </pre> |
| 4489 | |
Chris Lattner | 8d1a81d | 2003-10-18 05:51:36 +0000 | [diff] [blame] | 4490 | <h5>Overview:</h5> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4491 | |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4492 | <p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4493 | the "variable argument" area of a function call. It is used to implement the |
| 4494 | <tt>va_arg</tt> macro in C.</p> |
| 4495 | |
Chris Lattner | 8d1a81d | 2003-10-18 05:51:36 +0000 | [diff] [blame] | 4496 | <h5>Arguments:</h5> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4497 | |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4498 | <p>This instruction takes a <tt>va_list*</tt> value and the type of |
| 4499 | the argument. It returns a value of the specified argument type and |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4500 | increments the <tt>va_list</tt> to point to the next argument. The |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4501 | actual type of <tt>va_list</tt> is target specific.</p> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4502 | |
Chris Lattner | 8d1a81d | 2003-10-18 05:51:36 +0000 | [diff] [blame] | 4503 | <h5>Semantics:</h5> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4504 | |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4505 | <p>The '<tt>va_arg</tt>' instruction loads an argument of the specified |
| 4506 | type from the specified <tt>va_list</tt> and causes the |
| 4507 | <tt>va_list</tt> to point to the next argument. For more information, |
| 4508 | see the variable argument handling <a href="#int_varargs">Intrinsic |
| 4509 | Functions</a>.</p> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4510 | |
| 4511 | <p>It is legal for this instruction to be called in a function which does not |
| 4512 | take a variable number of arguments, for example, the <tt>vfprintf</tt> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4513 | function.</p> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4514 | |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4515 | <p><tt>va_arg</tt> is an LLVM instruction instead of an <a |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 4516 | href="#intrinsics">intrinsic function</a> because it takes a type as an |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4517 | argument.</p> |
| 4518 | |
Chris Lattner | 8d1a81d | 2003-10-18 05:51:36 +0000 | [diff] [blame] | 4519 | <h5>Example:</h5> |
Chris Lattner | e19d7a7 | 2004-09-27 21:51:25 +0000 | [diff] [blame] | 4520 | |
| 4521 | <p>See the <a href="#int_varargs">variable argument processing</a> section.</p> |
| 4522 | |
Dan Gohman | f3e60bd | 2009-01-12 23:12:39 +0000 | [diff] [blame] | 4523 | <p>Note that the code generator does not yet fully support va_arg |
| 4524 | on many targets. Also, it does not currently support va_arg with |
| 4525 | aggregate types on any target.</p> |
| 4526 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4527 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4528 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4529 | <!-- *********************************************************************** --> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4530 | <div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div> |
| 4531 | <!-- *********************************************************************** --> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4532 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4533 | <div class="doc_text"> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4534 | |
| 4535 | <p>LLVM supports the notion of an "intrinsic function". These functions have |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 4536 | well known names and semantics and are required to follow certain restrictions. |
| 4537 | Overall, these intrinsics represent an extension mechanism for the LLVM |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4538 | language that does not require changing all of the transformations in LLVM when |
Gabor Greif | 04367bf | 2007-07-06 22:07:22 +0000 | [diff] [blame] | 4539 | adding to the language (or the bitcode reader/writer, the parser, etc...).</p> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4540 | |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 4541 | <p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4542 | prefix is reserved in LLVM for intrinsic names; thus, function names may not |
| 4543 | begin with this prefix. Intrinsic functions must always be external functions: |
| 4544 | you cannot define the body of intrinsic functions. Intrinsic functions may |
| 4545 | only be used in call or invoke instructions: it is illegal to take the address |
| 4546 | of an intrinsic function. Additionally, because intrinsic functions are part |
| 4547 | of the LLVM language, it is required if any are added that they be documented |
| 4548 | here.</p> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4549 | |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 4550 | <p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents |
| 4551 | a family of functions that perform the same operation but on different data |
| 4552 | types. Because LLVM can represent over 8 million different integer types, |
| 4553 | overloading is used commonly to allow an intrinsic function to operate on any |
| 4554 | integer type. One or more of the argument types or the result type can be |
| 4555 | overloaded to accept any integer type. Argument types may also be defined as |
| 4556 | exactly matching a previous argument's type or the result type. This allows an |
| 4557 | intrinsic function which accepts multiple arguments, but needs all of them to |
| 4558 | be of the same type, to only be overloaded with respect to a single argument or |
| 4559 | the result.</p> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4560 | |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 4561 | <p>Overloaded intrinsics will have the names of its overloaded argument types |
| 4562 | encoded into its function name, each preceded by a period. Only those types |
| 4563 | which are overloaded result in a name suffix. Arguments whose type is matched |
| 4564 | against another type do not. For example, the <tt>llvm.ctpop</tt> function can |
| 4565 | take an integer of any width and returns an integer of exactly the same integer |
| 4566 | width. This leads to a family of functions such as |
| 4567 | <tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>. |
| 4568 | Only one type, the return type, is overloaded, and only one type suffix is |
| 4569 | required. Because the argument's type is matched against the return type, it |
| 4570 | does not require its own name suffix.</p> |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 4571 | |
| 4572 | <p>To learn how to add an intrinsic function, please see the |
| 4573 | <a href="ExtendingLLVM.html">Extending LLVM Guide</a>. |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4574 | </p> |
| 4575 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4576 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4577 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4578 | <!-- ======================================================================= --> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4579 | <div class="doc_subsection"> |
| 4580 | <a name="int_varargs">Variable Argument Handling Intrinsics</a> |
| 4581 | </div> |
| 4582 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4583 | <div class="doc_text"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4584 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4585 | <p>Variable argument support is defined in LLVM with the <a |
Chris Lattner | fb6977d | 2006-01-13 23:26:01 +0000 | [diff] [blame] | 4586 | href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4587 | intrinsic functions. These functions are related to the similarly |
| 4588 | named macros defined in the <tt><stdarg.h></tt> header file.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4589 | |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4590 | <p>All of these functions operate on arguments that use a |
| 4591 | target-specific value type "<tt>va_list</tt>". The LLVM assembly |
| 4592 | language reference manual does not define what this type is, so all |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4593 | transformations should be prepared to handle these functions regardless of |
| 4594 | the type used.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4595 | |
Chris Lattner | 374ab30 | 2006-05-15 17:26:46 +0000 | [diff] [blame] | 4596 | <p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4597 | instruction and the variable argument handling intrinsic functions are |
| 4598 | used.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4599 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 4600 | <div class="doc_code"> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4601 | <pre> |
Anton Korobeynikov | 5d522f3 | 2007-03-21 23:58:04 +0000 | [diff] [blame] | 4602 | define i32 @test(i32 %X, ...) { |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4603 | ; Initialize variable argument processing |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4604 | %ap = alloca i8* |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4605 | %ap2 = bitcast i8** %ap to i8* |
Anton Korobeynikov | 5d522f3 | 2007-03-21 23:58:04 +0000 | [diff] [blame] | 4606 | call void @llvm.va_start(i8* %ap2) |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4607 | |
| 4608 | ; Read a single integer argument |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4609 | %tmp = va_arg i8** %ap, i32 |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4610 | |
| 4611 | ; Demonstrate usage of llvm.va_copy and llvm.va_end |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4612 | %aq = alloca i8* |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4613 | %aq2 = bitcast i8** %aq to i8* |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4614 | call void @llvm.va_copy(i8* %aq2, i8* %ap2) |
Anton Korobeynikov | 5d522f3 | 2007-03-21 23:58:04 +0000 | [diff] [blame] | 4615 | call void @llvm.va_end(i8* %aq2) |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4616 | |
| 4617 | ; Stop processing of arguments. |
Anton Korobeynikov | 5d522f3 | 2007-03-21 23:58:04 +0000 | [diff] [blame] | 4618 | call void @llvm.va_end(i8* %ap2) |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 4619 | ret i32 %tmp |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4620 | } |
Anton Korobeynikov | 5d522f3 | 2007-03-21 23:58:04 +0000 | [diff] [blame] | 4621 | |
| 4622 | declare void @llvm.va_start(i8*) |
| 4623 | declare void @llvm.va_copy(i8*, i8*) |
| 4624 | declare void @llvm.va_end(i8*) |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4625 | </pre> |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4626 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4627 | |
Bill Wendling | 2f7a8b0 | 2007-05-29 09:04:49 +0000 | [diff] [blame] | 4628 | </div> |
| 4629 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4630 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4631 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4632 | <a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4633 | </div> |
| 4634 | |
| 4635 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4636 | <div class="doc_text"> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4637 | <h5>Syntax:</h5> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4638 | <pre> declare void %llvm.va_start(i8* <arglist>)<br></pre> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4639 | <h5>Overview:</h5> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4640 | <p>The '<tt>llvm.va_start</tt>' intrinsic initializes |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4641 | <tt>*<arglist></tt> for subsequent use by <tt><a |
| 4642 | href="#i_va_arg">va_arg</a></tt>.</p> |
| 4643 | |
| 4644 | <h5>Arguments:</h5> |
| 4645 | |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4646 | <p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4647 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4648 | <h5>Semantics:</h5> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4649 | |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 4650 | <p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4651 | macro available in C. In a target-dependent way, it initializes the |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4652 | <tt>va_list</tt> element to which the argument points, so that the next call to |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4653 | <tt>va_arg</tt> will produce the first variable argument passed to the function. |
| 4654 | Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4655 | last argument of the function as the compiler can figure that out.</p> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4656 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4657 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4658 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4659 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4660 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4661 | <a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4662 | </div> |
| 4663 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4664 | <div class="doc_text"> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4665 | <h5>Syntax:</h5> |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 4666 | <pre> declare void @llvm.va_end(i8* <arglist>)<br></pre> |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4667 | <h5>Overview:</h5> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4668 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4669 | <p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>, |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4670 | which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt> |
Chris Lattner | 261efe9 | 2003-11-25 01:02:51 +0000 | [diff] [blame] | 4671 | or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4672 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4673 | <h5>Arguments:</h5> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4674 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4675 | <p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4676 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4677 | <h5>Semantics:</h5> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4678 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4679 | <p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt> |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4680 | macro available in C. In a target-dependent way, it destroys the |
| 4681 | <tt>va_list</tt> element to which the argument points. Calls to <a |
| 4682 | href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy"> |
| 4683 | <tt>llvm.va_copy</tt></a> must be matched exactly with calls to |
| 4684 | <tt>llvm.va_end</tt>.</p> |
Chris Lattner | b75137d | 2007-01-08 07:55:15 +0000 | [diff] [blame] | 4685 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4686 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4687 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4688 | <!-- _______________________________________________________________________ --> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4689 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4690 | <a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4691 | </div> |
| 4692 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4693 | <div class="doc_text"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4694 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4695 | <h5>Syntax:</h5> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4696 | |
| 4697 | <pre> |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 4698 | declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>) |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4699 | </pre> |
| 4700 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4701 | <h5>Overview:</h5> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4702 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4703 | <p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position |
| 4704 | from the source argument list to the destination argument list.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4705 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4706 | <h5>Arguments:</h5> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4707 | |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4708 | <p>The first argument is a pointer to a <tt>va_list</tt> element to initialize. |
Andrew Lenharth | d0a4c62 | 2005-06-22 20:38:11 +0000 | [diff] [blame] | 4709 | The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p> |
Andrew Lenharth | 8bf607a | 2005-06-18 18:28:17 +0000 | [diff] [blame] | 4710 | |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4711 | |
Chris Lattner | d9ad5b3 | 2003-05-08 04:57:36 +0000 | [diff] [blame] | 4712 | <h5>Semantics:</h5> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4713 | |
Jeff Cohen | b627eab | 2007-04-29 01:07:00 +0000 | [diff] [blame] | 4714 | <p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt> |
| 4715 | macro available in C. In a target-dependent way, it copies the source |
| 4716 | <tt>va_list</tt> element into the destination <tt>va_list</tt> element. This |
| 4717 | intrinsic is necessary because the <tt><a href="#int_va_start"> |
| 4718 | llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for |
| 4719 | example, memory allocation.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4720 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 4721 | </div> |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 4722 | |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 4723 | <!-- ======================================================================= --> |
| 4724 | <div class="doc_subsection"> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4725 | <a name="int_gc">Accurate Garbage Collection Intrinsics</a> |
| 4726 | </div> |
| 4727 | |
| 4728 | <div class="doc_text"> |
| 4729 | |
| 4730 | <p> |
| 4731 | LLVM support for <a href="GarbageCollection.html">Accurate Garbage |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 4732 | Collection</a> (GC) requires the implementation and generation of these |
| 4733 | intrinsics. |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4734 | These intrinsics allow identification of <a href="#int_gcroot">GC roots on the |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4735 | stack</a>, as well as garbage collector implementations that require <a |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4736 | href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers. |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4737 | Front-ends for type-safe garbage collected languages should generate these |
| 4738 | intrinsics to make use of the LLVM garbage collectors. For more details, see <a |
| 4739 | href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>. |
| 4740 | </p> |
Christopher Lamb | 303dae9 | 2007-12-17 01:00:21 +0000 | [diff] [blame] | 4741 | |
| 4742 | <p>The garbage collection intrinsics only operate on objects in the generic |
| 4743 | address space (address space zero).</p> |
| 4744 | |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4745 | </div> |
| 4746 | |
| 4747 | <!-- _______________________________________________________________________ --> |
| 4748 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4749 | <a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4750 | </div> |
| 4751 | |
| 4752 | <div class="doc_text"> |
| 4753 | |
| 4754 | <h5>Syntax:</h5> |
| 4755 | |
| 4756 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 4757 | declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata) |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4758 | </pre> |
| 4759 | |
| 4760 | <h5>Overview:</h5> |
| 4761 | |
John Criswell | 9e2485c | 2004-12-10 15:51:16 +0000 | [diff] [blame] | 4762 | <p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4763 | the code generator, and allows some metadata to be associated with it.</p> |
| 4764 | |
| 4765 | <h5>Arguments:</h5> |
| 4766 | |
| 4767 | <p>The first argument specifies the address of a stack object that contains the |
| 4768 | root pointer. The second pointer (which must be either a constant or a global |
| 4769 | value address) contains the meta-data to be associated with the root.</p> |
| 4770 | |
| 4771 | <h5>Semantics:</h5> |
| 4772 | |
Chris Lattner | 05d6709 | 2008-04-24 05:59:56 +0000 | [diff] [blame] | 4773 | <p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc" |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4774 | location. At compile-time, the code generator generates information to allow |
Gordon Henriksen | e1433f2 | 2007-12-25 02:31:26 +0000 | [diff] [blame] | 4775 | the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>' |
| 4776 | intrinsic may only be used in a function which <a href="#gc">specifies a GC |
| 4777 | algorithm</a>.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4778 | |
| 4779 | </div> |
| 4780 | |
| 4781 | |
| 4782 | <!-- _______________________________________________________________________ --> |
| 4783 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4784 | <a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4785 | </div> |
| 4786 | |
| 4787 | <div class="doc_text"> |
| 4788 | |
| 4789 | <h5>Syntax:</h5> |
| 4790 | |
| 4791 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 4792 | declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr) |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4793 | </pre> |
| 4794 | |
| 4795 | <h5>Overview:</h5> |
| 4796 | |
| 4797 | <p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap |
| 4798 | locations, allowing garbage collector implementations that require read |
| 4799 | barriers.</p> |
| 4800 | |
| 4801 | <h5>Arguments:</h5> |
| 4802 | |
Chris Lattner | 80626e9 | 2006-03-14 20:02:51 +0000 | [diff] [blame] | 4803 | <p>The second argument is the address to read from, which should be an address |
| 4804 | allocated from the garbage collector. The first object is a pointer to the |
| 4805 | start of the referenced object, if needed by the language runtime (otherwise |
| 4806 | null).</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4807 | |
| 4808 | <h5>Semantics:</h5> |
| 4809 | |
| 4810 | <p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load |
| 4811 | instruction, but may be replaced with substantially more complex code by the |
Gordon Henriksen | e1433f2 | 2007-12-25 02:31:26 +0000 | [diff] [blame] | 4812 | garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic |
| 4813 | may only be used in a function which <a href="#gc">specifies a GC |
| 4814 | algorithm</a>.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4815 | |
| 4816 | </div> |
| 4817 | |
| 4818 | |
| 4819 | <!-- _______________________________________________________________________ --> |
| 4820 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4821 | <a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4822 | </div> |
| 4823 | |
| 4824 | <div class="doc_text"> |
| 4825 | |
| 4826 | <h5>Syntax:</h5> |
| 4827 | |
| 4828 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 4829 | declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2) |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4830 | </pre> |
| 4831 | |
| 4832 | <h5>Overview:</h5> |
| 4833 | |
| 4834 | <p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap |
| 4835 | locations, allowing garbage collector implementations that require write |
| 4836 | barriers (such as generational or reference counting collectors).</p> |
| 4837 | |
| 4838 | <h5>Arguments:</h5> |
| 4839 | |
Chris Lattner | 80626e9 | 2006-03-14 20:02:51 +0000 | [diff] [blame] | 4840 | <p>The first argument is the reference to store, the second is the start of the |
| 4841 | object to store it to, and the third is the address of the field of Obj to |
| 4842 | store to. If the runtime does not require a pointer to the object, Obj may be |
| 4843 | null.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4844 | |
| 4845 | <h5>Semantics:</h5> |
| 4846 | |
| 4847 | <p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store |
| 4848 | instruction, but may be replaced with substantially more complex code by the |
Gordon Henriksen | e1433f2 | 2007-12-25 02:31:26 +0000 | [diff] [blame] | 4849 | garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic |
| 4850 | may only be used in a function which <a href="#gc">specifies a GC |
| 4851 | algorithm</a>.</p> |
Chris Lattner | d792391 | 2004-05-23 21:06:01 +0000 | [diff] [blame] | 4852 | |
| 4853 | </div> |
| 4854 | |
| 4855 | |
| 4856 | |
| 4857 | <!-- ======================================================================= --> |
| 4858 | <div class="doc_subsection"> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4859 | <a name="int_codegen">Code Generator Intrinsics</a> |
| 4860 | </div> |
| 4861 | |
| 4862 | <div class="doc_text"> |
| 4863 | <p> |
| 4864 | These intrinsics are provided by LLVM to expose special features that may only |
| 4865 | be implemented with code generator support. |
| 4866 | </p> |
| 4867 | |
| 4868 | </div> |
| 4869 | |
| 4870 | <!-- _______________________________________________________________________ --> |
| 4871 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4872 | <a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4873 | </div> |
| 4874 | |
| 4875 | <div class="doc_text"> |
| 4876 | |
| 4877 | <h5>Syntax:</h5> |
| 4878 | <pre> |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 4879 | declare i8 *@llvm.returnaddress(i32 <level>) |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4880 | </pre> |
| 4881 | |
| 4882 | <h5>Overview:</h5> |
| 4883 | |
| 4884 | <p> |
Chris Lattner | 32b5d71 | 2006-10-15 20:05:59 +0000 | [diff] [blame] | 4885 | The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a |
| 4886 | target-specific value indicating the return address of the current function |
| 4887 | or one of its callers. |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4888 | </p> |
| 4889 | |
| 4890 | <h5>Arguments:</h5> |
| 4891 | |
| 4892 | <p> |
| 4893 | The argument to this intrinsic indicates which function to return the address |
| 4894 | for. Zero indicates the calling function, one indicates its caller, etc. The |
| 4895 | argument is <b>required</b> to be a constant integer value. |
| 4896 | </p> |
| 4897 | |
| 4898 | <h5>Semantics:</h5> |
| 4899 | |
| 4900 | <p> |
| 4901 | The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating |
| 4902 | the return address of the specified call frame, or zero if it cannot be |
| 4903 | identified. The value returned by this intrinsic is likely to be incorrect or 0 |
| 4904 | for arguments other than zero, so it should only be used for debugging purposes. |
| 4905 | </p> |
| 4906 | |
| 4907 | <p> |
| 4908 | Note that calling this intrinsic does not prevent function inlining or other |
Chris Lattner | b40bb38 | 2005-03-07 20:30:51 +0000 | [diff] [blame] | 4909 | aggressive transformations, so the value returned may not be that of the obvious |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4910 | source-language caller. |
| 4911 | </p> |
| 4912 | </div> |
| 4913 | |
| 4914 | |
| 4915 | <!-- _______________________________________________________________________ --> |
| 4916 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4917 | <a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4918 | </div> |
| 4919 | |
| 4920 | <div class="doc_text"> |
| 4921 | |
| 4922 | <h5>Syntax:</h5> |
| 4923 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 4924 | declare i8 *@llvm.frameaddress(i32 <level>) |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4925 | </pre> |
| 4926 | |
| 4927 | <h5>Overview:</h5> |
| 4928 | |
| 4929 | <p> |
Chris Lattner | 32b5d71 | 2006-10-15 20:05:59 +0000 | [diff] [blame] | 4930 | The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the |
| 4931 | target-specific frame pointer value for the specified stack frame. |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4932 | </p> |
| 4933 | |
| 4934 | <h5>Arguments:</h5> |
| 4935 | |
| 4936 | <p> |
| 4937 | The argument to this intrinsic indicates which function to return the frame |
| 4938 | pointer for. Zero indicates the calling function, one indicates its caller, |
| 4939 | etc. The argument is <b>required</b> to be a constant integer value. |
| 4940 | </p> |
| 4941 | |
| 4942 | <h5>Semantics:</h5> |
| 4943 | |
| 4944 | <p> |
| 4945 | The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating |
| 4946 | the frame address of the specified call frame, or zero if it cannot be |
| 4947 | identified. The value returned by this intrinsic is likely to be incorrect or 0 |
| 4948 | for arguments other than zero, so it should only be used for debugging purposes. |
| 4949 | </p> |
| 4950 | |
| 4951 | <p> |
| 4952 | Note that calling this intrinsic does not prevent function inlining or other |
Chris Lattner | b40bb38 | 2005-03-07 20:30:51 +0000 | [diff] [blame] | 4953 | aggressive transformations, so the value returned may not be that of the obvious |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 4954 | source-language caller. |
| 4955 | </p> |
| 4956 | </div> |
| 4957 | |
Chris Lattner | 9a9d7ac | 2005-02-28 19:24:19 +0000 | [diff] [blame] | 4958 | <!-- _______________________________________________________________________ --> |
| 4959 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4960 | <a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a> |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 4961 | </div> |
| 4962 | |
| 4963 | <div class="doc_text"> |
| 4964 | |
| 4965 | <h5>Syntax:</h5> |
| 4966 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 4967 | declare i8 *@llvm.stacksave() |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 4968 | </pre> |
| 4969 | |
| 4970 | <h5>Overview:</h5> |
| 4971 | |
| 4972 | <p> |
| 4973 | The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4974 | the function stack, for use with <a href="#int_stackrestore"> |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 4975 | <tt>llvm.stackrestore</tt></a>. This is useful for implementing language |
| 4976 | features like scoped automatic variable sized arrays in C99. |
| 4977 | </p> |
| 4978 | |
| 4979 | <h5>Semantics:</h5> |
| 4980 | |
| 4981 | <p> |
| 4982 | This intrinsic returns a opaque pointer value that can be passed to <a |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4983 | href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 4984 | <tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from |
| 4985 | <tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the |
| 4986 | state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In |
| 4987 | practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack |
| 4988 | that were allocated after the <tt>llvm.stacksave</tt> was executed. |
| 4989 | </p> |
| 4990 | |
| 4991 | </div> |
| 4992 | |
| 4993 | <!-- _______________________________________________________________________ --> |
| 4994 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 4995 | <a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a> |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 4996 | </div> |
| 4997 | |
| 4998 | <div class="doc_text"> |
| 4999 | |
| 5000 | <h5>Syntax:</h5> |
| 5001 | <pre> |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5002 | declare void @llvm.stackrestore(i8 * %ptr) |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 5003 | </pre> |
| 5004 | |
| 5005 | <h5>Overview:</h5> |
| 5006 | |
| 5007 | <p> |
| 5008 | The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of |
| 5009 | the function stack to the state it was in when the corresponding <a |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5010 | href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 5011 | useful for implementing language features like scoped automatic variable sized |
| 5012 | arrays in C99. |
| 5013 | </p> |
| 5014 | |
| 5015 | <h5>Semantics:</h5> |
| 5016 | |
| 5017 | <p> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5018 | See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>. |
Chris Lattner | 57e1f39 | 2006-01-13 02:03:13 +0000 | [diff] [blame] | 5019 | </p> |
| 5020 | |
| 5021 | </div> |
| 5022 | |
| 5023 | |
| 5024 | <!-- _______________________________________________________________________ --> |
| 5025 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5026 | <a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a> |
Chris Lattner | 9a9d7ac | 2005-02-28 19:24:19 +0000 | [diff] [blame] | 5027 | </div> |
| 5028 | |
| 5029 | <div class="doc_text"> |
| 5030 | |
| 5031 | <h5>Syntax:</h5> |
| 5032 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 5033 | declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>) |
Chris Lattner | 9a9d7ac | 2005-02-28 19:24:19 +0000 | [diff] [blame] | 5034 | </pre> |
| 5035 | |
| 5036 | <h5>Overview:</h5> |
| 5037 | |
| 5038 | |
| 5039 | <p> |
| 5040 | The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 5041 | a prefetch instruction if supported; otherwise, it is a noop. Prefetches have |
| 5042 | no |
| 5043 | effect on the behavior of the program but can change its performance |
Chris Lattner | 2a61536 | 2005-02-28 19:47:14 +0000 | [diff] [blame] | 5044 | characteristics. |
Chris Lattner | 9a9d7ac | 2005-02-28 19:24:19 +0000 | [diff] [blame] | 5045 | </p> |
| 5046 | |
| 5047 | <h5>Arguments:</h5> |
| 5048 | |
| 5049 | <p> |
| 5050 | <tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier |
| 5051 | determining if the fetch should be for a read (0) or write (1), and |
| 5052 | <tt>locality</tt> is a temporal locality specifier ranging from (0) - no |
Chris Lattner | aeffb4a | 2005-03-07 20:31:38 +0000 | [diff] [blame] | 5053 | locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and |
Chris Lattner | 9a9d7ac | 2005-02-28 19:24:19 +0000 | [diff] [blame] | 5054 | <tt>locality</tt> arguments must be constant integers. |
| 5055 | </p> |
| 5056 | |
| 5057 | <h5>Semantics:</h5> |
| 5058 | |
| 5059 | <p> |
| 5060 | This intrinsic does not modify the behavior of the program. In particular, |
| 5061 | prefetches cannot trap and do not produce a value. On targets that support this |
| 5062 | intrinsic, the prefetch can provide hints to the processor cache for better |
| 5063 | performance. |
| 5064 | </p> |
| 5065 | |
| 5066 | </div> |
| 5067 | |
Andrew Lenharth | 7f4ec3b | 2005-03-28 20:05:49 +0000 | [diff] [blame] | 5068 | <!-- _______________________________________________________________________ --> |
| 5069 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5070 | <a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a> |
Andrew Lenharth | 7f4ec3b | 2005-03-28 20:05:49 +0000 | [diff] [blame] | 5071 | </div> |
| 5072 | |
| 5073 | <div class="doc_text"> |
| 5074 | |
| 5075 | <h5>Syntax:</h5> |
| 5076 | <pre> |
Chris Lattner | 1df4f75 | 2007-09-21 17:30:40 +0000 | [diff] [blame] | 5077 | declare void @llvm.pcmarker(i32 <id>) |
Andrew Lenharth | 7f4ec3b | 2005-03-28 20:05:49 +0000 | [diff] [blame] | 5078 | </pre> |
| 5079 | |
| 5080 | <h5>Overview:</h5> |
| 5081 | |
| 5082 | |
| 5083 | <p> |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 5084 | The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 5085 | (PC) in a region of |
| 5086 | code to simulators and other tools. The method is target specific, but it is |
| 5087 | expected that the marker will use exported symbols to transmit the PC of the |
| 5088 | marker. |
| 5089 | The marker makes no guarantees that it will remain with any specific instruction |
| 5090 | after optimizations. It is possible that the presence of a marker will inhibit |
Chris Lattner | b3e7afd | 2006-03-24 07:16:10 +0000 | [diff] [blame] | 5091 | optimizations. The intended use is to be inserted after optimizations to allow |
John Criswell | fc6b895 | 2005-05-16 16:17:45 +0000 | [diff] [blame] | 5092 | correlations of simulation runs. |
Andrew Lenharth | 7f4ec3b | 2005-03-28 20:05:49 +0000 | [diff] [blame] | 5093 | </p> |
| 5094 | |
| 5095 | <h5>Arguments:</h5> |
| 5096 | |
| 5097 | <p> |
| 5098 | <tt>id</tt> is a numerical id identifying the marker. |
| 5099 | </p> |
| 5100 | |
| 5101 | <h5>Semantics:</h5> |
| 5102 | |
| 5103 | <p> |
| 5104 | This intrinsic does not modify the behavior of the program. Backends that do not |
| 5105 | support this intrinisic may ignore it. |
| 5106 | </p> |
| 5107 | |
| 5108 | </div> |
| 5109 | |
Andrew Lenharth | 51b8d54 | 2005-11-11 16:47:30 +0000 | [diff] [blame] | 5110 | <!-- _______________________________________________________________________ --> |
| 5111 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5112 | <a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a> |
Andrew Lenharth | 51b8d54 | 2005-11-11 16:47:30 +0000 | [diff] [blame] | 5113 | </div> |
| 5114 | |
| 5115 | <div class="doc_text"> |
| 5116 | |
| 5117 | <h5>Syntax:</h5> |
| 5118 | <pre> |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5119 | declare i64 @llvm.readcyclecounter( ) |
Andrew Lenharth | 51b8d54 | 2005-11-11 16:47:30 +0000 | [diff] [blame] | 5120 | </pre> |
| 5121 | |
| 5122 | <h5>Overview:</h5> |
| 5123 | |
| 5124 | |
| 5125 | <p> |
| 5126 | The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle |
| 5127 | counter register (or similar low latency, high accuracy clocks) on those targets |
| 5128 | that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC. |
| 5129 | As the backing counters overflow quickly (on the order of 9 seconds on alpha), this |
| 5130 | should only be used for small timings. |
| 5131 | </p> |
| 5132 | |
| 5133 | <h5>Semantics:</h5> |
| 5134 | |
| 5135 | <p> |
| 5136 | When directly supported, reading the cycle counter should not modify any memory. |
| 5137 | Implementations are allowed to either return a application specific value or a |
| 5138 | system wide value. On backends without support, this is lowered to a constant 0. |
| 5139 | </p> |
| 5140 | |
| 5141 | </div> |
| 5142 | |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5143 | <!-- ======================================================================= --> |
| 5144 | <div class="doc_subsection"> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5145 | <a name="int_libc">Standard C Library Intrinsics</a> |
| 5146 | </div> |
| 5147 | |
| 5148 | <div class="doc_text"> |
| 5149 | <p> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5150 | LLVM provides intrinsics for a few important standard C library functions. |
| 5151 | These intrinsics allow source-language front-ends to pass information about the |
| 5152 | alignment of the pointer arguments to the code generator, providing opportunity |
| 5153 | for more efficient code generation. |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5154 | </p> |
| 5155 | |
| 5156 | </div> |
| 5157 | |
| 5158 | <!-- _______________________________________________________________________ --> |
| 5159 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5160 | <a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5161 | </div> |
| 5162 | |
| 5163 | <div class="doc_text"> |
| 5164 | |
| 5165 | <h5>Syntax:</h5> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5166 | <p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit |
| 5167 | width. Not all targets support all bit widths however.</p> |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5168 | <pre> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5169 | declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>, |
| 5170 | i8 <len>, i32 <align>) |
| 5171 | declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>, |
| 5172 | i16 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5173 | declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5174 | i32 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5175 | declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5176 | i64 <len>, i32 <align>) |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5177 | </pre> |
| 5178 | |
| 5179 | <h5>Overview:</h5> |
| 5180 | |
| 5181 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5182 | The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5183 | location to the destination location. |
| 5184 | </p> |
| 5185 | |
| 5186 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5187 | Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt> |
| 5188 | intrinsics do not return a value, and takes an extra alignment argument. |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5189 | </p> |
| 5190 | |
| 5191 | <h5>Arguments:</h5> |
| 5192 | |
| 5193 | <p> |
| 5194 | The first argument is a pointer to the destination, the second is a pointer to |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5195 | the source. The third argument is an integer argument |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5196 | specifying the number of bytes to copy, and the fourth argument is the alignment |
| 5197 | of the source and destination locations. |
| 5198 | </p> |
| 5199 | |
Chris Lattner | 3301ced | 2004-02-12 21:18:15 +0000 | [diff] [blame] | 5200 | <p> |
| 5201 | If the call to this intrinisic has an alignment value that is not 0 or 1, then |
Chris Lattner | f0afc2c | 2006-03-04 00:02:10 +0000 | [diff] [blame] | 5202 | the caller guarantees that both the source and destination pointers are aligned |
| 5203 | to that boundary. |
Chris Lattner | 3301ced | 2004-02-12 21:18:15 +0000 | [diff] [blame] | 5204 | </p> |
| 5205 | |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5206 | <h5>Semantics:</h5> |
| 5207 | |
| 5208 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5209 | The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source |
Chris Lattner | 33aec9e | 2004-02-12 17:01:32 +0000 | [diff] [blame] | 5210 | location to the destination location, which are not allowed to overlap. It |
| 5211 | copies "len" bytes of memory over. If the argument is known to be aligned to |
| 5212 | some boundary, this can be specified as the fourth argument, otherwise it should |
| 5213 | be set to 0 or 1. |
| 5214 | </p> |
| 5215 | </div> |
| 5216 | |
| 5217 | |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5218 | <!-- _______________________________________________________________________ --> |
| 5219 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5220 | <a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a> |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5221 | </div> |
| 5222 | |
| 5223 | <div class="doc_text"> |
| 5224 | |
| 5225 | <h5>Syntax:</h5> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5226 | <p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit |
| 5227 | width. Not all targets support all bit widths however.</p> |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5228 | <pre> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5229 | declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>, |
| 5230 | i8 <len>, i32 <align>) |
| 5231 | declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>, |
| 5232 | i16 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5233 | declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5234 | i32 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5235 | declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5236 | i64 <len>, i32 <align>) |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5237 | </pre> |
| 5238 | |
| 5239 | <h5>Overview:</h5> |
| 5240 | |
| 5241 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5242 | The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source |
| 5243 | location to the destination location. It is similar to the |
Chris Lattner | 4b2cbcf | 2008-01-06 19:51:52 +0000 | [diff] [blame] | 5244 | '<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap. |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5245 | </p> |
| 5246 | |
| 5247 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5248 | Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt> |
| 5249 | intrinsics do not return a value, and takes an extra alignment argument. |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5250 | </p> |
| 5251 | |
| 5252 | <h5>Arguments:</h5> |
| 5253 | |
| 5254 | <p> |
| 5255 | The first argument is a pointer to the destination, the second is a pointer to |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5256 | the source. The third argument is an integer argument |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5257 | specifying the number of bytes to copy, and the fourth argument is the alignment |
| 5258 | of the source and destination locations. |
| 5259 | </p> |
| 5260 | |
Chris Lattner | 3301ced | 2004-02-12 21:18:15 +0000 | [diff] [blame] | 5261 | <p> |
| 5262 | If the call to this intrinisic has an alignment value that is not 0 or 1, then |
Chris Lattner | f0afc2c | 2006-03-04 00:02:10 +0000 | [diff] [blame] | 5263 | the caller guarantees that the source and destination pointers are aligned to |
| 5264 | that boundary. |
Chris Lattner | 3301ced | 2004-02-12 21:18:15 +0000 | [diff] [blame] | 5265 | </p> |
| 5266 | |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5267 | <h5>Semantics:</h5> |
| 5268 | |
| 5269 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5270 | The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source |
Chris Lattner | 0eb51b4 | 2004-02-12 18:10:10 +0000 | [diff] [blame] | 5271 | location to the destination location, which may overlap. It |
| 5272 | copies "len" bytes of memory over. If the argument is known to be aligned to |
| 5273 | some boundary, this can be specified as the fourth argument, otherwise it should |
| 5274 | be set to 0 or 1. |
| 5275 | </p> |
| 5276 | </div> |
| 5277 | |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 5278 | |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5279 | <!-- _______________________________________________________________________ --> |
| 5280 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5281 | <a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5282 | </div> |
| 5283 | |
| 5284 | <div class="doc_text"> |
| 5285 | |
| 5286 | <h5>Syntax:</h5> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5287 | <p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit |
| 5288 | width. Not all targets support all bit widths however.</p> |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5289 | <pre> |
Chris Lattner | 824b958 | 2008-11-21 16:42:48 +0000 | [diff] [blame] | 5290 | declare void @llvm.memset.i8(i8 * <dest>, i8 <val>, |
| 5291 | i8 <len>, i32 <align>) |
| 5292 | declare void @llvm.memset.i16(i8 * <dest>, i8 <val>, |
| 5293 | i16 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5294 | declare void @llvm.memset.i32(i8 * <dest>, i8 <val>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5295 | i32 <len>, i32 <align>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5296 | declare void @llvm.memset.i64(i8 * <dest>, i8 <val>, |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5297 | i64 <len>, i32 <align>) |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5298 | </pre> |
| 5299 | |
| 5300 | <h5>Overview:</h5> |
| 5301 | |
| 5302 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5303 | The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5304 | byte value. |
| 5305 | </p> |
| 5306 | |
| 5307 | <p> |
| 5308 | Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic |
| 5309 | does not return a value, and takes an extra alignment argument. |
| 5310 | </p> |
| 5311 | |
| 5312 | <h5>Arguments:</h5> |
| 5313 | |
| 5314 | <p> |
| 5315 | The first argument is a pointer to the destination to fill, the second is the |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5316 | byte value to fill it with, the third argument is an integer |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5317 | argument specifying the number of bytes to fill, and the fourth argument is the |
| 5318 | known alignment of destination location. |
| 5319 | </p> |
| 5320 | |
| 5321 | <p> |
| 5322 | If the call to this intrinisic has an alignment value that is not 0 or 1, then |
Chris Lattner | f0afc2c | 2006-03-04 00:02:10 +0000 | [diff] [blame] | 5323 | the caller guarantees that the destination pointer is aligned to that boundary. |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5324 | </p> |
| 5325 | |
| 5326 | <h5>Semantics:</h5> |
| 5327 | |
| 5328 | <p> |
Chris Lattner | 5b310c3 | 2006-03-03 00:07:20 +0000 | [diff] [blame] | 5329 | The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at |
| 5330 | the |
Chris Lattner | 1061064 | 2004-02-14 04:08:35 +0000 | [diff] [blame] | 5331 | destination location. If the argument is known to be aligned to some boundary, |
| 5332 | this can be specified as the fourth argument, otherwise it should be set to 0 or |
| 5333 | 1. |
| 5334 | </p> |
| 5335 | </div> |
| 5336 | |
| 5337 | |
Chris Lattner | 3200628 | 2004-06-11 02:28:03 +0000 | [diff] [blame] | 5338 | <!-- _______________________________________________________________________ --> |
| 5339 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5340 | <a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a> |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5341 | </div> |
| 5342 | |
| 5343 | <div class="doc_text"> |
| 5344 | |
| 5345 | <h5>Syntax:</h5> |
Dale Johannesen | 408f9c1 | 2007-10-02 17:47:38 +0000 | [diff] [blame] | 5346 | <p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5347 | floating point or vector of floating point type. Not all targets support all |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5348 | types however.</p> |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5349 | <pre> |
Dale Johannesen | 408f9c1 | 2007-10-02 17:47:38 +0000 | [diff] [blame] | 5350 | declare float @llvm.sqrt.f32(float %Val) |
| 5351 | declare double @llvm.sqrt.f64(double %Val) |
| 5352 | declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val) |
| 5353 | declare fp128 @llvm.sqrt.f128(fp128 %Val) |
| 5354 | declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val) |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5355 | </pre> |
| 5356 | |
| 5357 | <h5>Overview:</h5> |
| 5358 | |
| 5359 | <p> |
Reid Spencer | 0b11820 | 2006-01-16 21:12:35 +0000 | [diff] [blame] | 5360 | The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand, |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5361 | returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5362 | <tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for |
Chris Lattner | 103e2d7 | 2008-01-29 07:00:44 +0000 | [diff] [blame] | 5363 | negative numbers other than -0.0 (which allows for better optimization, because |
| 5364 | there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is |
| 5365 | defined to return -0.0 like IEEE sqrt. |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5366 | </p> |
| 5367 | |
| 5368 | <h5>Arguments:</h5> |
| 5369 | |
| 5370 | <p> |
| 5371 | The argument and return value are floating point numbers of the same type. |
| 5372 | </p> |
| 5373 | |
| 5374 | <h5>Semantics:</h5> |
| 5375 | |
| 5376 | <p> |
Dan Gohman | d6257fe | 2007-07-16 14:37:41 +0000 | [diff] [blame] | 5377 | This function returns the sqrt of the specified operand if it is a nonnegative |
Chris Lattner | a4d7414 | 2005-07-21 01:29:16 +0000 | [diff] [blame] | 5378 | floating point number. |
| 5379 | </p> |
| 5380 | </div> |
| 5381 | |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5382 | <!-- _______________________________________________________________________ --> |
| 5383 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5384 | <a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a> |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5385 | </div> |
| 5386 | |
| 5387 | <div class="doc_text"> |
| 5388 | |
| 5389 | <h5>Syntax:</h5> |
Dale Johannesen | 408f9c1 | 2007-10-02 17:47:38 +0000 | [diff] [blame] | 5390 | <p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5391 | floating point or vector of floating point type. Not all targets support all |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5392 | types however.</p> |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5393 | <pre> |
Dale Johannesen | 408f9c1 | 2007-10-02 17:47:38 +0000 | [diff] [blame] | 5394 | declare float @llvm.powi.f32(float %Val, i32 %power) |
| 5395 | declare double @llvm.powi.f64(double %Val, i32 %power) |
| 5396 | declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power) |
| 5397 | declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power) |
| 5398 | declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power) |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5399 | </pre> |
| 5400 | |
| 5401 | <h5>Overview:</h5> |
| 5402 | |
| 5403 | <p> |
| 5404 | The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the |
| 5405 | specified (positive or negative) power. The order of evaluation of |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5406 | multiplications is not defined. When a vector of floating point type is |
| 5407 | used, the second argument remains a scalar integer value. |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5408 | </p> |
| 5409 | |
| 5410 | <h5>Arguments:</h5> |
| 5411 | |
| 5412 | <p> |
| 5413 | The second argument is an integer power, and the first is a value to raise to |
| 5414 | that power. |
| 5415 | </p> |
| 5416 | |
| 5417 | <h5>Semantics:</h5> |
| 5418 | |
| 5419 | <p> |
| 5420 | This function returns the first value raised to the second power with an |
| 5421 | unspecified sequence of rounding operations.</p> |
| 5422 | </div> |
| 5423 | |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5424 | <!-- _______________________________________________________________________ --> |
| 5425 | <div class="doc_subsubsection"> |
| 5426 | <a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a> |
| 5427 | </div> |
| 5428 | |
| 5429 | <div class="doc_text"> |
| 5430 | |
| 5431 | <h5>Syntax:</h5> |
| 5432 | <p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any |
| 5433 | floating point or vector of floating point type. Not all targets support all |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5434 | types however.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5435 | <pre> |
| 5436 | declare float @llvm.sin.f32(float %Val) |
| 5437 | declare double @llvm.sin.f64(double %Val) |
| 5438 | declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val) |
| 5439 | declare fp128 @llvm.sin.f128(fp128 %Val) |
| 5440 | declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val) |
| 5441 | </pre> |
| 5442 | |
| 5443 | <h5>Overview:</h5> |
| 5444 | |
| 5445 | <p> |
| 5446 | The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand. |
| 5447 | </p> |
| 5448 | |
| 5449 | <h5>Arguments:</h5> |
| 5450 | |
| 5451 | <p> |
| 5452 | The argument and return value are floating point numbers of the same type. |
| 5453 | </p> |
| 5454 | |
| 5455 | <h5>Semantics:</h5> |
| 5456 | |
| 5457 | <p> |
| 5458 | This function returns the sine of the specified operand, returning the |
| 5459 | same values as the libm <tt>sin</tt> functions would, and handles error |
Dan Gohman | ba83b7e | 2007-10-17 18:05:13 +0000 | [diff] [blame] | 5460 | conditions in the same way.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5461 | </div> |
| 5462 | |
| 5463 | <!-- _______________________________________________________________________ --> |
| 5464 | <div class="doc_subsubsection"> |
| 5465 | <a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a> |
| 5466 | </div> |
| 5467 | |
| 5468 | <div class="doc_text"> |
| 5469 | |
| 5470 | <h5>Syntax:</h5> |
| 5471 | <p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any |
| 5472 | floating point or vector of floating point type. Not all targets support all |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5473 | types however.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5474 | <pre> |
| 5475 | declare float @llvm.cos.f32(float %Val) |
| 5476 | declare double @llvm.cos.f64(double %Val) |
| 5477 | declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val) |
| 5478 | declare fp128 @llvm.cos.f128(fp128 %Val) |
| 5479 | declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val) |
| 5480 | </pre> |
| 5481 | |
| 5482 | <h5>Overview:</h5> |
| 5483 | |
| 5484 | <p> |
| 5485 | The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand. |
| 5486 | </p> |
| 5487 | |
| 5488 | <h5>Arguments:</h5> |
| 5489 | |
| 5490 | <p> |
| 5491 | The argument and return value are floating point numbers of the same type. |
| 5492 | </p> |
| 5493 | |
| 5494 | <h5>Semantics:</h5> |
| 5495 | |
| 5496 | <p> |
| 5497 | This function returns the cosine of the specified operand, returning the |
| 5498 | same values as the libm <tt>cos</tt> functions would, and handles error |
Dan Gohman | ba83b7e | 2007-10-17 18:05:13 +0000 | [diff] [blame] | 5499 | conditions in the same way.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5500 | </div> |
| 5501 | |
| 5502 | <!-- _______________________________________________________________________ --> |
| 5503 | <div class="doc_subsubsection"> |
| 5504 | <a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a> |
| 5505 | </div> |
| 5506 | |
| 5507 | <div class="doc_text"> |
| 5508 | |
| 5509 | <h5>Syntax:</h5> |
| 5510 | <p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any |
| 5511 | floating point or vector of floating point type. Not all targets support all |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5512 | types however.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5513 | <pre> |
| 5514 | declare float @llvm.pow.f32(float %Val, float %Power) |
| 5515 | declare double @llvm.pow.f64(double %Val, double %Power) |
| 5516 | declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power) |
| 5517 | declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power) |
| 5518 | declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power) |
| 5519 | </pre> |
| 5520 | |
| 5521 | <h5>Overview:</h5> |
| 5522 | |
| 5523 | <p> |
| 5524 | The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the |
| 5525 | specified (positive or negative) power. |
| 5526 | </p> |
| 5527 | |
| 5528 | <h5>Arguments:</h5> |
| 5529 | |
| 5530 | <p> |
| 5531 | The second argument is a floating point power, and the first is a value to |
| 5532 | raise to that power. |
| 5533 | </p> |
| 5534 | |
| 5535 | <h5>Semantics:</h5> |
| 5536 | |
| 5537 | <p> |
| 5538 | This function returns the first value raised to the second power, |
| 5539 | returning the |
| 5540 | same values as the libm <tt>pow</tt> functions would, and handles error |
Dan Gohman | ba83b7e | 2007-10-17 18:05:13 +0000 | [diff] [blame] | 5541 | conditions in the same way.</p> |
Dan Gohman | 91c284c | 2007-10-15 20:30:11 +0000 | [diff] [blame] | 5542 | </div> |
| 5543 | |
Chris Lattner | f4d252d | 2006-09-08 06:34:02 +0000 | [diff] [blame] | 5544 | |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5545 | <!-- ======================================================================= --> |
| 5546 | <div class="doc_subsection"> |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5547 | <a name="int_manip">Bit Manipulation Intrinsics</a> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5548 | </div> |
| 5549 | |
| 5550 | <div class="doc_text"> |
| 5551 | <p> |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5552 | LLVM provides intrinsics for a few important bit manipulation operations. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5553 | These allow efficient code generation for some algorithms. |
| 5554 | </p> |
| 5555 | |
| 5556 | </div> |
| 5557 | |
| 5558 | <!-- _______________________________________________________________________ --> |
| 5559 | <div class="doc_subsubsection"> |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5560 | <a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a> |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5561 | </div> |
| 5562 | |
| 5563 | <div class="doc_text"> |
| 5564 | |
| 5565 | <h5>Syntax:</h5> |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5566 | <p>This is an overloaded intrinsic function. You can use bswap on any integer |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5567 | type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p> |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5568 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5569 | declare i16 @llvm.bswap.i16(i16 <id>) |
| 5570 | declare i32 @llvm.bswap.i32(i32 <id>) |
| 5571 | declare i64 @llvm.bswap.i64(i64 <id>) |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5572 | </pre> |
| 5573 | |
| 5574 | <h5>Overview:</h5> |
| 5575 | |
| 5576 | <p> |
Reid Spencer | 338ea09 | 2007-04-02 02:25:19 +0000 | [diff] [blame] | 5577 | The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5578 | values with an even number of bytes (positive multiple of 16 bits). These are |
| 5579 | useful for performing operations on data that is not in the target's native |
| 5580 | byte order. |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5581 | </p> |
| 5582 | |
| 5583 | <h5>Semantics:</h5> |
| 5584 | |
| 5585 | <p> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5586 | The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5587 | and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt> |
| 5588 | intrinsic returns an i32 value that has the four bytes of the input i32 |
| 5589 | swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5590 | i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>, |
| 5591 | <tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5592 | additional even-byte lengths (6 bytes, 8 bytes and more, respectively). |
Nate Begeman | 7e36c47 | 2006-01-13 23:26:38 +0000 | [diff] [blame] | 5593 | </p> |
| 5594 | |
| 5595 | </div> |
| 5596 | |
| 5597 | <!-- _______________________________________________________________________ --> |
| 5598 | <div class="doc_subsubsection"> |
Reid Spencer | 0b11820 | 2006-01-16 21:12:35 +0000 | [diff] [blame] | 5599 | <a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5600 | </div> |
| 5601 | |
| 5602 | <div class="doc_text"> |
| 5603 | |
| 5604 | <h5>Syntax:</h5> |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5605 | <p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5606 | width. Not all targets support all bit widths however.</p> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5607 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5608 | declare i8 @llvm.ctpop.i8 (i8 <src>) |
| 5609 | declare i16 @llvm.ctpop.i16(i16 <src>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5610 | declare i32 @llvm.ctpop.i32(i32 <src>) |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5611 | declare i64 @llvm.ctpop.i64(i64 <src>) |
| 5612 | declare i256 @llvm.ctpop.i256(i256 <src>) |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5613 | </pre> |
| 5614 | |
| 5615 | <h5>Overview:</h5> |
| 5616 | |
| 5617 | <p> |
Chris Lattner | ec6cb61 | 2006-01-16 22:38:59 +0000 | [diff] [blame] | 5618 | The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a |
| 5619 | value. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5620 | </p> |
| 5621 | |
| 5622 | <h5>Arguments:</h5> |
| 5623 | |
| 5624 | <p> |
Chris Lattner | cfe6b37 | 2005-05-07 01:46:40 +0000 | [diff] [blame] | 5625 | The only argument is the value to be counted. The argument may be of any |
Reid Spencer | a517338 | 2007-01-04 16:43:23 +0000 | [diff] [blame] | 5626 | integer type. The return type must match the argument type. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5627 | </p> |
| 5628 | |
| 5629 | <h5>Semantics:</h5> |
| 5630 | |
| 5631 | <p> |
| 5632 | The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable. |
| 5633 | </p> |
| 5634 | </div> |
| 5635 | |
| 5636 | <!-- _______________________________________________________________________ --> |
| 5637 | <div class="doc_subsubsection"> |
Chris Lattner | 8a886be | 2006-01-16 22:34:14 +0000 | [diff] [blame] | 5638 | <a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5639 | </div> |
| 5640 | |
| 5641 | <div class="doc_text"> |
| 5642 | |
| 5643 | <h5>Syntax:</h5> |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5644 | <p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5645 | integer bit width. Not all targets support all bit widths however.</p> |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5646 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5647 | declare i8 @llvm.ctlz.i8 (i8 <src>) |
| 5648 | declare i16 @llvm.ctlz.i16(i16 <src>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5649 | declare i32 @llvm.ctlz.i32(i32 <src>) |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5650 | declare i64 @llvm.ctlz.i64(i64 <src>) |
| 5651 | declare i256 @llvm.ctlz.i256(i256 <src>) |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5652 | </pre> |
| 5653 | |
| 5654 | <h5>Overview:</h5> |
| 5655 | |
| 5656 | <p> |
Reid Spencer | 0b11820 | 2006-01-16 21:12:35 +0000 | [diff] [blame] | 5657 | The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of |
| 5658 | leading zeros in a variable. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5659 | </p> |
| 5660 | |
| 5661 | <h5>Arguments:</h5> |
| 5662 | |
| 5663 | <p> |
Chris Lattner | cfe6b37 | 2005-05-07 01:46:40 +0000 | [diff] [blame] | 5664 | The only argument is the value to be counted. The argument may be of any |
Reid Spencer | a517338 | 2007-01-04 16:43:23 +0000 | [diff] [blame] | 5665 | integer type. The return type must match the argument type. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5666 | </p> |
| 5667 | |
| 5668 | <h5>Semantics:</h5> |
| 5669 | |
| 5670 | <p> |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5671 | The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros |
| 5672 | in a variable. If the src == 0 then the result is the size in bits of the type |
Reid Spencer | ca86e16 | 2006-12-31 07:07:53 +0000 | [diff] [blame] | 5673 | of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>. |
Andrew Lenharth | ec370fd | 2005-05-03 18:01:48 +0000 | [diff] [blame] | 5674 | </p> |
| 5675 | </div> |
Chris Lattner | 3200628 | 2004-06-11 02:28:03 +0000 | [diff] [blame] | 5676 | |
| 5677 | |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5678 | |
| 5679 | <!-- _______________________________________________________________________ --> |
| 5680 | <div class="doc_subsubsection"> |
Chris Lattner | 8a886be | 2006-01-16 22:34:14 +0000 | [diff] [blame] | 5681 | <a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a> |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5682 | </div> |
| 5683 | |
| 5684 | <div class="doc_text"> |
| 5685 | |
| 5686 | <h5>Syntax:</h5> |
Reid Spencer | 409e28f | 2007-04-01 08:04:23 +0000 | [diff] [blame] | 5687 | <p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5688 | integer bit width. Not all targets support all bit widths however.</p> |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5689 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5690 | declare i8 @llvm.cttz.i8 (i8 <src>) |
| 5691 | declare i16 @llvm.cttz.i16(i16 <src>) |
Anton Korobeynikov | ec43a06 | 2007-03-22 00:02:17 +0000 | [diff] [blame] | 5692 | declare i32 @llvm.cttz.i32(i32 <src>) |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5693 | declare i64 @llvm.cttz.i64(i64 <src>) |
| 5694 | declare i256 @llvm.cttz.i256(i256 <src>) |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5695 | </pre> |
| 5696 | |
| 5697 | <h5>Overview:</h5> |
| 5698 | |
| 5699 | <p> |
Reid Spencer | 0b11820 | 2006-01-16 21:12:35 +0000 | [diff] [blame] | 5700 | The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of |
| 5701 | trailing zeros. |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5702 | </p> |
| 5703 | |
| 5704 | <h5>Arguments:</h5> |
| 5705 | |
| 5706 | <p> |
| 5707 | The only argument is the value to be counted. The argument may be of any |
Reid Spencer | a517338 | 2007-01-04 16:43:23 +0000 | [diff] [blame] | 5708 | integer type. The return type must match the argument type. |
Chris Lattner | eff29ab | 2005-05-15 19:39:26 +0000 | [diff] [blame] | 5709 | </p> |
| 5710 | |
| 5711 | <h5>Semantics:</h5> |
| 5712 | |
| 5713 | <p> |
| 5714 | The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros |
| 5715 | in a variable. If the src == 0 then the result is the size in bits of the type |
| 5716 | of src. For example, <tt>llvm.cttz(2) = 1</tt>. |
| 5717 | </p> |
| 5718 | </div> |
| 5719 | |
Reid Spencer | 497d93e | 2007-04-01 08:27:01 +0000 | [diff] [blame] | 5720 | <!-- _______________________________________________________________________ --> |
| 5721 | <div class="doc_subsubsection"> |
Reid Spencer | beacf66 | 2007-04-10 02:51:31 +0000 | [diff] [blame] | 5722 | <a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a> |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5723 | </div> |
| 5724 | |
| 5725 | <div class="doc_text"> |
| 5726 | |
| 5727 | <h5>Syntax:</h5> |
Reid Spencer | beacf66 | 2007-04-10 02:51:31 +0000 | [diff] [blame] | 5728 | <p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5729 | on any integer bit width.</p> |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5730 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5731 | declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit) |
| 5732 | declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit) |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5733 | </pre> |
| 5734 | |
| 5735 | <h5>Overview:</h5> |
Reid Spencer | beacf66 | 2007-04-10 02:51:31 +0000 | [diff] [blame] | 5736 | <p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5737 | range of bits from an integer value and returns them in the same bit width as |
| 5738 | the original value.</p> |
| 5739 | |
| 5740 | <h5>Arguments:</h5> |
| 5741 | <p>The first argument, <tt>%val</tt> and the result may be integer types of |
| 5742 | any bit width but they must have the same bit width. The second and third |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5743 | arguments must be <tt>i32</tt> type since they specify only a bit index.</p> |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5744 | |
| 5745 | <h5>Semantics:</h5> |
Reid Spencer | beacf66 | 2007-04-10 02:51:31 +0000 | [diff] [blame] | 5746 | <p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes |
Reid Spencer | a3e435f | 2007-04-04 02:42:35 +0000 | [diff] [blame] | 5747 | of operation: forwards and reverse. If <tt>%loBit</tt> is greater than |
| 5748 | <tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it |
| 5749 | operates in forward mode.</p> |
| 5750 | <p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt> |
| 5751 | right by <tt>%loBit</tt> bits and then ANDing it with a mask with |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5752 | only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p> |
| 5753 | <ol> |
| 5754 | <li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified |
| 5755 | by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li> |
| 5756 | <li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value |
| 5757 | to determine the number of bits to retain.</li> |
| 5758 | <li>A mask of the retained bits is created by shifting a -1 value.</li> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5759 | <li>The mask is ANDed with <tt>%val</tt> to produce the result.</li> |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5760 | </ol> |
Reid Spencer | d6a85b5 | 2007-05-14 16:14:57 +0000 | [diff] [blame] | 5761 | <p>In reverse mode, a similar computation is made except that the bits are |
| 5762 | returned in the reverse order. So, for example, if <tt>X</tt> has the value |
| 5763 | <tt>i16 0x0ACF (101011001111)</tt> and we apply |
| 5764 | <tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value |
| 5765 | <tt>i16 0x0026 (000000100110)</tt>.</p> |
Reid Spencer | a13ba7d | 2007-04-01 19:00:37 +0000 | [diff] [blame] | 5766 | </div> |
| 5767 | |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 5768 | <div class="doc_subsubsection"> |
| 5769 | <a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a> |
| 5770 | </div> |
| 5771 | |
| 5772 | <div class="doc_text"> |
| 5773 | |
| 5774 | <h5>Syntax:</h5> |
| 5775 | <p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5776 | on any integer bit width.</p> |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 5777 | <pre> |
Chandler Carruth | 6994040 | 2007-08-04 01:51:18 +0000 | [diff] [blame] | 5778 | declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi) |
| 5779 | declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi) |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 5780 | </pre> |
| 5781 | |
| 5782 | <h5>Overview:</h5> |
| 5783 | <p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range |
| 5784 | of bits in an integer value with another integer value. It returns the integer |
| 5785 | with the replaced bits.</p> |
| 5786 | |
| 5787 | <h5>Arguments:</h5> |
| 5788 | <p>The first argument, <tt>%val</tt> and the result may be integer types of |
| 5789 | any bit width but they must have the same bit width. <tt>%val</tt> is the value |
| 5790 | whose bits will be replaced. The second argument, <tt>%repl</tt> may be an |
| 5791 | integer of any bit width. The third and fourth arguments must be <tt>i32</tt> |
| 5792 | type since they specify only a bit index.</p> |
| 5793 | |
| 5794 | <h5>Semantics:</h5> |
| 5795 | <p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes |
| 5796 | of operation: forwards and reverse. If <tt>%lo</tt> is greater than |
| 5797 | <tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it |
| 5798 | operates in forward mode.</p> |
| 5799 | <p>For both modes, the <tt>%repl</tt> value is prepared for use by either |
| 5800 | truncating it down to the size of the replacement area or zero extending it |
| 5801 | up to that size.</p> |
| 5802 | <p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive) |
| 5803 | are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit |
| 5804 | in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5805 | to the <tt>%hi</tt>th bit.</p> |
Reid Spencer | c6749c4 | 2007-05-14 16:50:20 +0000 | [diff] [blame] | 5806 | <p>In reverse mode, a similar computation is made except that the bits are |
| 5807 | reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5808 | <tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p> |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 5809 | <h5>Examples:</h5> |
| 5810 | <pre> |
Reid Spencer | f0dbf64 | 2007-04-12 01:03:03 +0000 | [diff] [blame] | 5811 | llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F |
Reid Spencer | c6749c4 | 2007-05-14 16:50:20 +0000 | [diff] [blame] | 5812 | llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F |
| 5813 | llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F |
| 5814 | llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7 |
Reid Spencer | f0dbf64 | 2007-04-12 01:03:03 +0000 | [diff] [blame] | 5815 | llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07 |
Reid Spencer | c891084 | 2007-04-11 23:49:50 +0000 | [diff] [blame] | 5816 | </pre> |
Reid Spencer | f86037f | 2007-04-11 23:23:49 +0000 | [diff] [blame] | 5817 | </div> |
| 5818 | |
Chris Lattner | 8ff7590 | 2004-01-06 05:31:32 +0000 | [diff] [blame] | 5819 | <!-- ======================================================================= --> |
| 5820 | <div class="doc_subsection"> |
| 5821 | <a name="int_debugger">Debugger Intrinsics</a> |
| 5822 | </div> |
| 5823 | |
| 5824 | <div class="doc_text"> |
| 5825 | <p> |
| 5826 | The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix), |
| 5827 | are described in the <a |
| 5828 | href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level |
| 5829 | Debugging</a> document. |
| 5830 | </p> |
| 5831 | </div> |
| 5832 | |
| 5833 | |
Jim Laskey | dd4ef1b | 2007-03-14 19:31:19 +0000 | [diff] [blame] | 5834 | <!-- ======================================================================= --> |
| 5835 | <div class="doc_subsection"> |
| 5836 | <a name="int_eh">Exception Handling Intrinsics</a> |
| 5837 | </div> |
| 5838 | |
| 5839 | <div class="doc_text"> |
| 5840 | <p> The LLVM exception handling intrinsics (which all start with |
| 5841 | <tt>llvm.eh.</tt> prefix), are described in the <a |
| 5842 | href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception |
| 5843 | Handling</a> document. </p> |
| 5844 | </div> |
| 5845 | |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 5846 | <!-- ======================================================================= --> |
| 5847 | <div class="doc_subsection"> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5848 | <a name="int_trampoline">Trampoline Intrinsic</a> |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5849 | </div> |
| 5850 | |
| 5851 | <div class="doc_text"> |
| 5852 | <p> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5853 | This intrinsic makes it possible to excise one parameter, marked with |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5854 | the <tt>nest</tt> attribute, from a function. The result is a callable |
| 5855 | function pointer lacking the nest parameter - the caller does not need |
| 5856 | to provide a value for it. Instead, the value to use is stored in |
| 5857 | advance in a "trampoline", a block of memory usually allocated |
| 5858 | on the stack, which also contains code to splice the nest value into the |
| 5859 | argument list. This is used to implement the GCC nested function address |
| 5860 | extension. |
| 5861 | </p> |
| 5862 | <p> |
| 5863 | For example, if the function is |
| 5864 | <tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function |
Bill Wendling | 03295ca | 2007-09-22 09:23:55 +0000 | [diff] [blame] | 5865 | pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p> |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5866 | <pre> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5867 | %tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86 |
| 5868 | %tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0 |
| 5869 | %p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8*), i8* %nval ) |
| 5870 | %fp = bitcast i8* %p to i32 (i32, i32)* |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5871 | </pre> |
Bill Wendling | 03295ca | 2007-09-22 09:23:55 +0000 | [diff] [blame] | 5872 | <p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent |
| 5873 | to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p> |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5874 | </div> |
| 5875 | |
| 5876 | <!-- _______________________________________________________________________ --> |
| 5877 | <div class="doc_subsubsection"> |
| 5878 | <a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a> |
| 5879 | </div> |
| 5880 | <div class="doc_text"> |
| 5881 | <h5>Syntax:</h5> |
| 5882 | <pre> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5883 | declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>) |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5884 | </pre> |
| 5885 | <h5>Overview:</h5> |
| 5886 | <p> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5887 | This fills the memory pointed to by <tt>tramp</tt> with code |
| 5888 | and returns a function pointer suitable for executing it. |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5889 | </p> |
| 5890 | <h5>Arguments:</h5> |
| 5891 | <p> |
| 5892 | The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all |
| 5893 | pointers. The <tt>tramp</tt> argument must point to a sufficiently large |
| 5894 | and sufficiently aligned block of memory; this memory is written to by the |
Duncan Sands | c00c2ba | 2007-08-22 23:39:54 +0000 | [diff] [blame] | 5895 | intrinsic. Note that the size and the alignment are target-specific - LLVM |
| 5896 | currently provides no portable way of determining them, so a front-end that |
| 5897 | generates this intrinsic needs to have some target-specific knowledge. |
| 5898 | The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>. |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5899 | </p> |
| 5900 | <h5>Semantics:</h5> |
| 5901 | <p> |
| 5902 | The block of memory pointed to by <tt>tramp</tt> is filled with target |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5903 | dependent code, turning it into a function. A pointer to this function is |
| 5904 | returned, but needs to be bitcast to an |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5905 | <a href="#int_trampoline">appropriate function pointer type</a> |
Duncan Sands | f7331b3 | 2007-09-11 14:10:23 +0000 | [diff] [blame] | 5906 | before being called. The new function's signature is the same as that of |
| 5907 | <tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute |
| 5908 | removed. At most one such <tt>nest</tt> argument is allowed, and it must be |
| 5909 | of pointer type. Calling the new function is equivalent to calling |
| 5910 | <tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the |
| 5911 | missing <tt>nest</tt> argument. If, after calling |
| 5912 | <tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is |
| 5913 | modified, then the effect of any later call to the returned function pointer is |
| 5914 | undefined. |
Duncan Sands | 36397f5 | 2007-07-27 12:58:54 +0000 | [diff] [blame] | 5915 | </p> |
| 5916 | </div> |
| 5917 | |
| 5918 | <!-- ======================================================================= --> |
| 5919 | <div class="doc_subsection"> |
Andrew Lenharth | 22c5c1b | 2008-02-16 01:24:58 +0000 | [diff] [blame] | 5920 | <a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a> |
| 5921 | </div> |
| 5922 | |
| 5923 | <div class="doc_text"> |
| 5924 | <p> |
| 5925 | These intrinsic functions expand the "universal IR" of LLVM to represent |
| 5926 | hardware constructs for atomic operations and memory synchronization. This |
| 5927 | provides an interface to the hardware, not an interface to the programmer. It |
Chris Lattner | d3eda89 | 2008-08-05 18:29:16 +0000 | [diff] [blame] | 5928 | is aimed at a low enough level to allow any programming models or APIs |
| 5929 | (Application Programming Interfaces) which |
Andrew Lenharth | 22c5c1b | 2008-02-16 01:24:58 +0000 | [diff] [blame] | 5930 | need atomic behaviors to map cleanly onto it. It is also modeled primarily on |
| 5931 | hardware behavior. Just as hardware provides a "universal IR" for source |
| 5932 | languages, it also provides a starting point for developing a "universal" |
| 5933 | atomic operation and synchronization IR. |
| 5934 | </p> |
| 5935 | <p> |
| 5936 | These do <em>not</em> form an API such as high-level threading libraries, |
| 5937 | software transaction memory systems, atomic primitives, and intrinsic |
| 5938 | functions as found in BSD, GNU libc, atomic_ops, APR, and other system and |
| 5939 | application libraries. The hardware interface provided by LLVM should allow |
| 5940 | a clean implementation of all of these APIs and parallel programming models. |
| 5941 | No one model or paradigm should be selected above others unless the hardware |
| 5942 | itself ubiquitously does so. |
| 5943 | |
| 5944 | </p> |
| 5945 | </div> |
| 5946 | |
| 5947 | <!-- _______________________________________________________________________ --> |
| 5948 | <div class="doc_subsubsection"> |
| 5949 | <a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a> |
| 5950 | </div> |
| 5951 | <div class="doc_text"> |
| 5952 | <h5>Syntax:</h5> |
| 5953 | <pre> |
| 5954 | declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>, |
| 5955 | i1 <device> ) |
| 5956 | |
| 5957 | </pre> |
| 5958 | <h5>Overview:</h5> |
| 5959 | <p> |
| 5960 | The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between |
| 5961 | specific pairs of memory access types. |
| 5962 | </p> |
| 5963 | <h5>Arguments:</h5> |
| 5964 | <p> |
| 5965 | The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments. |
| 5966 | The first four arguments enables a specific barrier as listed below. The fith |
| 5967 | argument specifies that the barrier applies to io or device or uncached memory. |
| 5968 | |
| 5969 | </p> |
| 5970 | <ul> |
| 5971 | <li><tt>ll</tt>: load-load barrier</li> |
| 5972 | <li><tt>ls</tt>: load-store barrier</li> |
| 5973 | <li><tt>sl</tt>: store-load barrier</li> |
| 5974 | <li><tt>ss</tt>: store-store barrier</li> |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 5975 | <li><tt>device</tt>: barrier applies to device and uncached memory also.</li> |
Andrew Lenharth | 22c5c1b | 2008-02-16 01:24:58 +0000 | [diff] [blame] | 5976 | </ul> |
| 5977 | <h5>Semantics:</h5> |
| 5978 | <p> |
| 5979 | This intrinsic causes the system to enforce some ordering constraints upon |
| 5980 | the loads and stores of the program. This barrier does not indicate |
| 5981 | <em>when</em> any events will occur, it only enforces an <em>order</em> in |
| 5982 | which they occur. For any of the specified pairs of load and store operations |
| 5983 | (f.ex. load-load, or store-load), all of the first operations preceding the |
| 5984 | barrier will complete before any of the second operations succeeding the |
| 5985 | barrier begin. Specifically the semantics for each pairing is as follows: |
| 5986 | </p> |
| 5987 | <ul> |
| 5988 | <li><tt>ll</tt>: All loads before the barrier must complete before any load |
| 5989 | after the barrier begins.</li> |
| 5990 | |
| 5991 | <li><tt>ls</tt>: All loads before the barrier must complete before any |
| 5992 | store after the barrier begins.</li> |
| 5993 | <li><tt>ss</tt>: All stores before the barrier must complete before any |
| 5994 | store after the barrier begins.</li> |
| 5995 | <li><tt>sl</tt>: All stores before the barrier must complete before any |
| 5996 | load after the barrier begins.</li> |
| 5997 | </ul> |
| 5998 | <p> |
| 5999 | These semantics are applied with a logical "and" behavior when more than one |
| 6000 | is enabled in a single memory barrier intrinsic. |
| 6001 | </p> |
| 6002 | <p> |
| 6003 | Backends may implement stronger barriers than those requested when they do not |
| 6004 | support as fine grained a barrier as requested. Some architectures do not |
| 6005 | need all types of barriers and on such architectures, these become noops. |
| 6006 | </p> |
| 6007 | <h5>Example:</h5> |
| 6008 | <pre> |
| 6009 | %ptr = malloc i32 |
| 6010 | store i32 4, %ptr |
| 6011 | |
| 6012 | %result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i> |
| 6013 | call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false ) |
| 6014 | <i>; guarantee the above finishes</i> |
| 6015 | store i32 8, %ptr <i>; before this begins</i> |
| 6016 | </pre> |
| 6017 | </div> |
| 6018 | |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6019 | <!-- _______________________________________________________________________ --> |
| 6020 | <div class="doc_subsubsection"> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6021 | <a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a> |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6022 | </div> |
| 6023 | <div class="doc_text"> |
| 6024 | <h5>Syntax:</h5> |
| 6025 | <p> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6026 | This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on |
| 6027 | any integer bit width and for different address spaces. Not all targets |
| 6028 | support all bit widths however.</p> |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6029 | |
| 6030 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6031 | declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> ) |
| 6032 | declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> ) |
| 6033 | declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> ) |
| 6034 | declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6035 | |
| 6036 | </pre> |
| 6037 | <h5>Overview:</h5> |
| 6038 | <p> |
| 6039 | This loads a value in memory and compares it to a given value. If they are |
| 6040 | equal, it stores a new value into the memory. |
| 6041 | </p> |
| 6042 | <h5>Arguments:</h5> |
| 6043 | <p> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6044 | The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6045 | well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the |
| 6046 | same bit width. The <tt>ptr</tt> argument must be a pointer to a value of |
| 6047 | this integer type. While any bit width integer may be used, targets may only |
| 6048 | lower representations they support in hardware. |
| 6049 | |
| 6050 | </p> |
| 6051 | <h5>Semantics:</h5> |
| 6052 | <p> |
| 6053 | This entire intrinsic must be executed atomically. It first loads the value |
| 6054 | in memory pointed to by <tt>ptr</tt> and compares it with the value |
| 6055 | <tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The |
| 6056 | loaded value is yielded in all cases. This provides the equivalent of an |
| 6057 | atomic compare-and-swap operation within the SSA framework. |
| 6058 | </p> |
| 6059 | <h5>Examples:</h5> |
| 6060 | |
| 6061 | <pre> |
| 6062 | %ptr = malloc i32 |
| 6063 | store i32 4, %ptr |
| 6064 | |
| 6065 | %val1 = add i32 4, 4 |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6066 | %result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6067 | <i>; yields {i32}:result1 = 4</i> |
| 6068 | %stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i> |
| 6069 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i> |
| 6070 | |
| 6071 | %val2 = add i32 1, 1 |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6072 | %result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6073 | <i>; yields {i32}:result2 = 8</i> |
| 6074 | %stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i> |
| 6075 | |
| 6076 | %memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i> |
| 6077 | </pre> |
| 6078 | </div> |
| 6079 | |
| 6080 | <!-- _______________________________________________________________________ --> |
| 6081 | <div class="doc_subsubsection"> |
| 6082 | <a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a> |
| 6083 | </div> |
| 6084 | <div class="doc_text"> |
| 6085 | <h5>Syntax:</h5> |
| 6086 | |
| 6087 | <p> |
| 6088 | This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any |
| 6089 | integer bit width. Not all targets support all bit widths however.</p> |
| 6090 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6091 | declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> ) |
| 6092 | declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> ) |
| 6093 | declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> ) |
| 6094 | declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6095 | |
| 6096 | </pre> |
| 6097 | <h5>Overview:</h5> |
| 6098 | <p> |
| 6099 | This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields |
| 6100 | the value from memory. It then stores the value in <tt>val</tt> in the memory |
| 6101 | at <tt>ptr</tt>. |
| 6102 | </p> |
| 6103 | <h5>Arguments:</h5> |
| 6104 | |
| 6105 | <p> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6106 | The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6107 | <tt>val</tt> argument and the result must be integers of the same bit width. |
| 6108 | The first argument, <tt>ptr</tt>, must be a pointer to a value of this |
| 6109 | integer type. The targets may only lower integer representations they |
| 6110 | support. |
| 6111 | </p> |
| 6112 | <h5>Semantics:</h5> |
| 6113 | <p> |
| 6114 | This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and |
| 6115 | stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the |
| 6116 | equivalent of an atomic swap operation within the SSA framework. |
| 6117 | |
| 6118 | </p> |
| 6119 | <h5>Examples:</h5> |
| 6120 | <pre> |
| 6121 | %ptr = malloc i32 |
| 6122 | store i32 4, %ptr |
| 6123 | |
| 6124 | %val1 = add i32 4, 4 |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6125 | %result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6126 | <i>; yields {i32}:result1 = 4</i> |
| 6127 | %stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i> |
| 6128 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i> |
| 6129 | |
| 6130 | %val2 = add i32 1, 1 |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6131 | %result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6132 | <i>; yields {i32}:result2 = 8</i> |
| 6133 | |
| 6134 | %stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i> |
| 6135 | %memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i> |
| 6136 | </pre> |
| 6137 | </div> |
| 6138 | |
| 6139 | <!-- _______________________________________________________________________ --> |
| 6140 | <div class="doc_subsubsection"> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6141 | <a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a> |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6142 | |
| 6143 | </div> |
| 6144 | <div class="doc_text"> |
| 6145 | <h5>Syntax:</h5> |
| 6146 | <p> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6147 | This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6148 | integer bit width. Not all targets support all bit widths however.</p> |
| 6149 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6150 | declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> ) |
| 6151 | declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> ) |
| 6152 | declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> ) |
| 6153 | declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6154 | |
| 6155 | </pre> |
| 6156 | <h5>Overview:</h5> |
| 6157 | <p> |
| 6158 | This intrinsic adds <tt>delta</tt> to the value stored in memory at |
| 6159 | <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>. |
| 6160 | </p> |
| 6161 | <h5>Arguments:</h5> |
| 6162 | <p> |
| 6163 | |
| 6164 | The intrinsic takes two arguments, the first a pointer to an integer value |
| 6165 | and the second an integer value. The result is also an integer value. These |
| 6166 | integer types can have any bit width, but they must all have the same bit |
| 6167 | width. The targets may only lower integer representations they support. |
| 6168 | </p> |
| 6169 | <h5>Semantics:</h5> |
| 6170 | <p> |
| 6171 | This intrinsic does a series of operations atomically. It first loads the |
| 6172 | value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result |
| 6173 | to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>. |
| 6174 | </p> |
| 6175 | |
| 6176 | <h5>Examples:</h5> |
| 6177 | <pre> |
| 6178 | %ptr = malloc i32 |
| 6179 | store i32 4, %ptr |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6180 | %result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6181 | <i>; yields {i32}:result1 = 4</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6182 | %result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6183 | <i>; yields {i32}:result2 = 8</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6184 | %result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 ) |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6185 | <i>; yields {i32}:result3 = 10</i> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6186 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i> |
Andrew Lenharth | ab0b949 | 2008-02-21 06:45:13 +0000 | [diff] [blame] | 6187 | </pre> |
| 6188 | </div> |
| 6189 | |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6190 | <!-- _______________________________________________________________________ --> |
| 6191 | <div class="doc_subsubsection"> |
| 6192 | <a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a> |
| 6193 | |
| 6194 | </div> |
| 6195 | <div class="doc_text"> |
| 6196 | <h5>Syntax:</h5> |
| 6197 | <p> |
| 6198 | This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6199 | any integer bit width and for different address spaces. Not all targets |
| 6200 | support all bit widths however.</p> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6201 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6202 | declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> ) |
| 6203 | declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> ) |
| 6204 | declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6205 | declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6206 | |
| 6207 | </pre> |
| 6208 | <h5>Overview:</h5> |
| 6209 | <p> |
| 6210 | This intrinsic subtracts <tt>delta</tt> to the value stored in memory at |
| 6211 | <tt>ptr</tt>. It yields the original value at <tt>ptr</tt>. |
| 6212 | </p> |
| 6213 | <h5>Arguments:</h5> |
| 6214 | <p> |
| 6215 | |
| 6216 | The intrinsic takes two arguments, the first a pointer to an integer value |
| 6217 | and the second an integer value. The result is also an integer value. These |
| 6218 | integer types can have any bit width, but they must all have the same bit |
| 6219 | width. The targets may only lower integer representations they support. |
| 6220 | </p> |
| 6221 | <h5>Semantics:</h5> |
| 6222 | <p> |
| 6223 | This intrinsic does a series of operations atomically. It first loads the |
| 6224 | value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the |
| 6225 | result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>. |
| 6226 | </p> |
| 6227 | |
| 6228 | <h5>Examples:</h5> |
| 6229 | <pre> |
| 6230 | %ptr = malloc i32 |
| 6231 | store i32 8, %ptr |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6232 | %result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6233 | <i>; yields {i32}:result1 = 8</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6234 | %result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6235 | <i>; yields {i32}:result2 = 4</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6236 | %result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6237 | <i>; yields {i32}:result3 = 2</i> |
| 6238 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i> |
| 6239 | </pre> |
| 6240 | </div> |
| 6241 | |
| 6242 | <!-- _______________________________________________________________________ --> |
| 6243 | <div class="doc_subsubsection"> |
| 6244 | <a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br> |
| 6245 | <a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br> |
| 6246 | <a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br> |
| 6247 | <a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br> |
| 6248 | |
| 6249 | </div> |
| 6250 | <div class="doc_text"> |
| 6251 | <h5>Syntax:</h5> |
| 6252 | <p> |
| 6253 | These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>, |
| 6254 | <tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6255 | <tt>llvm.atomic.load_xor</tt> on any integer bit width and for different |
| 6256 | address spaces. Not all targets support all bit widths however.</p> |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6257 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6258 | declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> ) |
| 6259 | declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6260 | declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6261 | declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6262 | |
| 6263 | </pre> |
| 6264 | |
| 6265 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6266 | declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> ) |
| 6267 | declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6268 | declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6269 | declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6270 | |
| 6271 | </pre> |
| 6272 | |
| 6273 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6274 | declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> ) |
| 6275 | declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> ) |
| 6276 | declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6277 | declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6278 | |
| 6279 | </pre> |
| 6280 | |
| 6281 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6282 | declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> ) |
| 6283 | declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> ) |
| 6284 | declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6285 | declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6286 | |
| 6287 | </pre> |
| 6288 | <h5>Overview:</h5> |
| 6289 | <p> |
| 6290 | These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to |
| 6291 | the value stored in memory at <tt>ptr</tt>. It yields the original value |
| 6292 | at <tt>ptr</tt>. |
| 6293 | </p> |
| 6294 | <h5>Arguments:</h5> |
| 6295 | <p> |
| 6296 | |
| 6297 | These intrinsics take two arguments, the first a pointer to an integer value |
| 6298 | and the second an integer value. The result is also an integer value. These |
| 6299 | integer types can have any bit width, but they must all have the same bit |
| 6300 | width. The targets may only lower integer representations they support. |
| 6301 | </p> |
| 6302 | <h5>Semantics:</h5> |
| 6303 | <p> |
| 6304 | These intrinsics does a series of operations atomically. They first load the |
| 6305 | value stored at <tt>ptr</tt>. They then do the bitwise operation |
| 6306 | <tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original |
| 6307 | value stored at <tt>ptr</tt>. |
| 6308 | </p> |
| 6309 | |
| 6310 | <h5>Examples:</h5> |
| 6311 | <pre> |
| 6312 | %ptr = malloc i32 |
| 6313 | store i32 0x0F0F, %ptr |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6314 | %result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6315 | <i>; yields {i32}:result0 = 0x0F0F</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6316 | %result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6317 | <i>; yields {i32}:result1 = 0xFFFFFFF0</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6318 | %result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6319 | <i>; yields {i32}:result2 = 0xF0</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6320 | %result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6321 | <i>; yields {i32}:result3 = FF</i> |
| 6322 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i> |
| 6323 | </pre> |
| 6324 | </div> |
| 6325 | |
| 6326 | |
| 6327 | <!-- _______________________________________________________________________ --> |
| 6328 | <div class="doc_subsubsection"> |
| 6329 | <a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br> |
| 6330 | <a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br> |
| 6331 | <a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br> |
| 6332 | <a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br> |
| 6333 | |
| 6334 | </div> |
| 6335 | <div class="doc_text"> |
| 6336 | <h5>Syntax:</h5> |
| 6337 | <p> |
| 6338 | These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>, |
| 6339 | <tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6340 | <tt>llvm.atomic.load_umin</tt> on any integer bit width and for different |
| 6341 | address spaces. Not all targets |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6342 | support all bit widths however.</p> |
| 6343 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6344 | declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> ) |
| 6345 | declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6346 | declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6347 | declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6348 | |
| 6349 | </pre> |
| 6350 | |
| 6351 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6352 | declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> ) |
| 6353 | declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6354 | declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> ) |
| 6355 | declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6356 | |
| 6357 | </pre> |
| 6358 | |
| 6359 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6360 | declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> ) |
| 6361 | declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6362 | declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> ) |
| 6363 | declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6364 | |
| 6365 | </pre> |
| 6366 | |
| 6367 | <pre> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6368 | declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> ) |
| 6369 | declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> ) |
| 6370 | declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> ) |
| 6371 | declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6372 | |
| 6373 | </pre> |
| 6374 | <h5>Overview:</h5> |
| 6375 | <p> |
| 6376 | These intrinsics takes the signed or unsigned minimum or maximum of |
| 6377 | <tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the |
| 6378 | original value at <tt>ptr</tt>. |
| 6379 | </p> |
| 6380 | <h5>Arguments:</h5> |
| 6381 | <p> |
| 6382 | |
| 6383 | These intrinsics take two arguments, the first a pointer to an integer value |
| 6384 | and the second an integer value. The result is also an integer value. These |
| 6385 | integer types can have any bit width, but they must all have the same bit |
| 6386 | width. The targets may only lower integer representations they support. |
| 6387 | </p> |
| 6388 | <h5>Semantics:</h5> |
| 6389 | <p> |
| 6390 | These intrinsics does a series of operations atomically. They first load the |
| 6391 | value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max |
| 6392 | <tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield |
| 6393 | the original value stored at <tt>ptr</tt>. |
| 6394 | </p> |
| 6395 | |
| 6396 | <h5>Examples:</h5> |
| 6397 | <pre> |
| 6398 | %ptr = malloc i32 |
| 6399 | store i32 7, %ptr |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6400 | %result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6401 | <i>; yields {i32}:result0 = 7</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6402 | %result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6403 | <i>; yields {i32}:result1 = -2</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6404 | %result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6405 | <i>; yields {i32}:result2 = 8</i> |
Mon P Wang | e3b3a72 | 2008-07-30 04:36:53 +0000 | [diff] [blame] | 6406 | %result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 ) |
Mon P Wang | 2887310 | 2008-06-25 08:15:39 +0000 | [diff] [blame] | 6407 | <i>; yields {i32}:result3 = 8</i> |
| 6408 | %memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i> |
| 6409 | </pre> |
| 6410 | </div> |
Andrew Lenharth | 22c5c1b | 2008-02-16 01:24:58 +0000 | [diff] [blame] | 6411 | |
| 6412 | <!-- ======================================================================= --> |
| 6413 | <div class="doc_subsection"> |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 6414 | <a name="int_general">General Intrinsics</a> |
| 6415 | </div> |
| 6416 | |
| 6417 | <div class="doc_text"> |
| 6418 | <p> This class of intrinsics is designed to be generic and has |
| 6419 | no specific purpose. </p> |
| 6420 | </div> |
| 6421 | |
| 6422 | <!-- _______________________________________________________________________ --> |
| 6423 | <div class="doc_subsubsection"> |
| 6424 | <a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a> |
| 6425 | </div> |
| 6426 | |
| 6427 | <div class="doc_text"> |
| 6428 | |
| 6429 | <h5>Syntax:</h5> |
| 6430 | <pre> |
Tanya Lattner | d2e8442 | 2007-06-18 23:42:37 +0000 | [diff] [blame] | 6431 | declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> ) |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 6432 | </pre> |
| 6433 | |
| 6434 | <h5>Overview:</h5> |
| 6435 | |
| 6436 | <p> |
| 6437 | The '<tt>llvm.var.annotation</tt>' intrinsic |
| 6438 | </p> |
| 6439 | |
| 6440 | <h5>Arguments:</h5> |
| 6441 | |
| 6442 | <p> |
Tanya Lattner | d2e8442 | 2007-06-18 23:42:37 +0000 | [diff] [blame] | 6443 | The first argument is a pointer to a value, the second is a pointer to a |
| 6444 | global string, the third is a pointer to a global string which is the source |
| 6445 | file name, and the last argument is the line number. |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 6446 | </p> |
| 6447 | |
| 6448 | <h5>Semantics:</h5> |
| 6449 | |
| 6450 | <p> |
Anton Korobeynikov | 4cb8618 | 2008-01-15 22:31:34 +0000 | [diff] [blame] | 6451 | This intrinsic allows annotation of local variables with arbitrary strings. |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 6452 | This can be useful for special purpose optimizations that want to look for these |
Anton Korobeynikov | 4cb8618 | 2008-01-15 22:31:34 +0000 | [diff] [blame] | 6453 | annotations. These have no other defined use, they are ignored by code |
| 6454 | generation and optimization. |
| 6455 | </p> |
Tanya Lattner | 6d806e9 | 2007-06-15 20:50:54 +0000 | [diff] [blame] | 6456 | </div> |
| 6457 | |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6458 | <!-- _______________________________________________________________________ --> |
| 6459 | <div class="doc_subsubsection"> |
Tanya Lattner | e1a8da0 | 2007-09-21 23:57:59 +0000 | [diff] [blame] | 6460 | <a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a> |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6461 | </div> |
| 6462 | |
| 6463 | <div class="doc_text"> |
| 6464 | |
| 6465 | <h5>Syntax:</h5> |
Tanya Lattner | 39cfba6 | 2007-09-21 23:56:27 +0000 | [diff] [blame] | 6466 | <p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on |
| 6467 | any integer bit width. |
| 6468 | </p> |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6469 | <pre> |
Tanya Lattner | d3989a8 | 2007-09-22 00:03:01 +0000 | [diff] [blame] | 6470 | declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> ) |
| 6471 | declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> ) |
| 6472 | declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> ) |
| 6473 | declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> ) |
| 6474 | declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> ) |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6475 | </pre> |
| 6476 | |
| 6477 | <h5>Overview:</h5> |
Tanya Lattner | 39cfba6 | 2007-09-21 23:56:27 +0000 | [diff] [blame] | 6478 | |
| 6479 | <p> |
| 6480 | The '<tt>llvm.annotation</tt>' intrinsic. |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6481 | </p> |
| 6482 | |
| 6483 | <h5>Arguments:</h5> |
| 6484 | |
| 6485 | <p> |
| 6486 | The first argument is an integer value (result of some expression), |
| 6487 | the second is a pointer to a global string, the third is a pointer to a global |
| 6488 | string which is the source file name, and the last argument is the line number. |
Tanya Lattner | 39cfba6 | 2007-09-21 23:56:27 +0000 | [diff] [blame] | 6489 | It returns the value of the first argument. |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6490 | </p> |
| 6491 | |
| 6492 | <h5>Semantics:</h5> |
| 6493 | |
| 6494 | <p> |
| 6495 | This intrinsic allows annotations to be put on arbitrary expressions |
| 6496 | with arbitrary strings. This can be useful for special purpose optimizations |
| 6497 | that want to look for these annotations. These have no other defined use, they |
| 6498 | are ignored by code generation and optimization. |
Dan Gohman | 0e451ce | 2008-10-14 16:51:45 +0000 | [diff] [blame] | 6499 | </p> |
Tanya Lattner | b636788 | 2007-09-21 22:59:12 +0000 | [diff] [blame] | 6500 | </div> |
Jim Laskey | dd4ef1b | 2007-03-14 19:31:19 +0000 | [diff] [blame] | 6501 | |
Anton Korobeynikov | 4cb8618 | 2008-01-15 22:31:34 +0000 | [diff] [blame] | 6502 | <!-- _______________________________________________________________________ --> |
| 6503 | <div class="doc_subsubsection"> |
| 6504 | <a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a> |
| 6505 | </div> |
| 6506 | |
| 6507 | <div class="doc_text"> |
| 6508 | |
| 6509 | <h5>Syntax:</h5> |
| 6510 | <pre> |
| 6511 | declare void @llvm.trap() |
| 6512 | </pre> |
| 6513 | |
| 6514 | <h5>Overview:</h5> |
| 6515 | |
| 6516 | <p> |
| 6517 | The '<tt>llvm.trap</tt>' intrinsic |
| 6518 | </p> |
| 6519 | |
| 6520 | <h5>Arguments:</h5> |
| 6521 | |
| 6522 | <p> |
| 6523 | None |
| 6524 | </p> |
| 6525 | |
| 6526 | <h5>Semantics:</h5> |
| 6527 | |
| 6528 | <p> |
| 6529 | This intrinsics is lowered to the target dependent trap instruction. If the |
| 6530 | target does not have a trap instruction, this intrinsic will be lowered to the |
| 6531 | call of the abort() function. |
| 6532 | </p> |
| 6533 | </div> |
| 6534 | |
Bill Wendling | 69e4adb | 2008-11-19 05:56:17 +0000 | [diff] [blame] | 6535 | <!-- _______________________________________________________________________ --> |
| 6536 | <div class="doc_subsubsection"> |
Misha Brukman | dccb025 | 2008-11-22 23:55:29 +0000 | [diff] [blame] | 6537 | <a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a> |
Bill Wendling | 69e4adb | 2008-11-19 05:56:17 +0000 | [diff] [blame] | 6538 | </div> |
| 6539 | <div class="doc_text"> |
| 6540 | <h5>Syntax:</h5> |
| 6541 | <pre> |
| 6542 | declare void @llvm.stackprotector( i8* <guard>, i8** <slot> ) |
| 6543 | |
| 6544 | </pre> |
| 6545 | <h5>Overview:</h5> |
| 6546 | <p> |
| 6547 | The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores |
| 6548 | it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that |
| 6549 | it is placed on the stack before local variables. |
| 6550 | </p> |
| 6551 | <h5>Arguments:</h5> |
| 6552 | <p> |
| 6553 | The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The |
| 6554 | first argument is the value loaded from the stack guard |
| 6555 | <tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that |
| 6556 | has enough space to hold the value of the guard. |
| 6557 | </p> |
| 6558 | <h5>Semantics:</h5> |
| 6559 | <p> |
| 6560 | This intrinsic causes the prologue/epilogue inserter to force the position of |
| 6561 | the <tt>AllocaInst</tt> stack slot to be before local variables on the |
| 6562 | stack. This is to ensure that if a local variable on the stack is overwritten, |
| 6563 | it will destroy the value of the guard. When the function exits, the guard on |
| 6564 | the stack is checked against the original guard. If they're different, then |
| 6565 | the program aborts by calling the <tt>__stack_chk_fail()</tt> function. |
| 6566 | </p> |
| 6567 | </div> |
| 6568 | |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 6569 | <!-- *********************************************************************** --> |
Chris Lattner | 0095054 | 2001-06-06 20:29:01 +0000 | [diff] [blame] | 6570 | <hr> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 6571 | <address> |
| 6572 | <a href="http://jigsaw.w3.org/css-validator/check/referer"><img |
Misha Brukman | 4440870 | 2008-12-11 17:34:48 +0000 | [diff] [blame] | 6573 | src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 6574 | <a href="http://validator.w3.org/check/referer"><img |
Misha Brukman | 4440870 | 2008-12-11 17:34:48 +0000 | [diff] [blame] | 6575 | src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 6576 | |
| 6577 | <a href="mailto:sabre@nondot.org">Chris Lattner</a><br> |
Reid Spencer | 05fe4b0 | 2006-03-14 05:39:39 +0000 | [diff] [blame] | 6578 | <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br> |
Misha Brukman | daa4cb0 | 2004-03-01 17:47:27 +0000 | [diff] [blame] | 6579 | Last modified: $Date$ |
| 6580 | </address> |
Chris Lattner | c7d3ab3 | 2008-01-04 04:33:49 +0000 | [diff] [blame] | 6581 | |
Misha Brukman | 9d0919f | 2003-11-08 01:05:38 +0000 | [diff] [blame] | 6582 | </body> |
| 6583 | </html> |