Blame - llvm/docs/LangRef.html - toolchain/llvm-project

blob: e0945b1c5a4e82df5ce7821c33a453f94131830f [file] [log] [blame]

Misha Brukman	c501f55	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	cb84e43	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	7630785	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	6af02f3	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	546ea7e	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	156	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	157	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	158	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	159	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	160	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	162	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	163	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				164	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	165	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				167	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	168	</ol>
				169	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	170	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				171	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				174	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	177	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				178	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				182	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				183	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				184	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				185	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	186	</ol>
				187	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	188	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				189	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	190	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	195	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	198	</ol>
				199	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	200	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	201	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	202	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	203	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				205	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	206	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	208	</ol>
				209	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	210	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	211	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	212	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	213	<ol>
				214	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	215	</ol>
				216	</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	217	<li><a href="#int_atomics">Atomic intrinsics</a>
				218	<ol>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	219	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	220	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	222	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				223	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				224	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				225	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				226	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				227	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				228	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				229	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				230	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				231	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	232	</ol>
				233	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	234	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	235	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	236	<li><a href="#int_var_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	237	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	238	<li><a href="#int_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	239	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	240	<li><a href="#int_trap">
				241	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	242	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	243	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	244	</ol>
				245	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	246	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	247
				248	<div class="doc_author">
				249	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				250	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	251	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	252
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	253	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	254	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				255	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	256
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	257	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	258	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	259	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	260	type safety, low-level operations, flexibility, and the capability of
				261	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	262	representation used throughout all phases of the LLVM compilation
				263	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	264	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	265
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	266	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	267	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				268	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	269
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	270	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	273	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	274	representation (suitable for fast loading by a Just-In-Time compiler),
				275	and as a human readable assembly language representation. This allows
				276	LLVM to provide a powerful intermediate representation for efficient
				277	compiler transformations and analysis, while providing a natural means
				278	to debug and visualize the transformations. The three different forms
				279	of LLVM are all equivalent. This document describes the human readable
				280	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	281
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	282	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	283	while being expressive, typed, and extensible at the same time. It
				284	aims to be a "universal IR" of sorts, by being at a low enough level
				285	that high-level ideas may be cleanly mapped to it (similar to how
				286	microprocessors are "universal IR's", allowing many source languages to
				287	be mapped to them). By providing type information, LLVM can be used as
				288	the target of optimizations: for example, through pointer analysis, it
				289	can be proven that a C automatic variable is never accessed outside of
				290	the current function... allowing it to be promoted to a simple SSA
				291	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	292
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	293	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	295	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	296	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	297
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	298	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	299
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	300	<p>It is important to note that this document describes 'well formed'
				301	LLVM assembly language. There is a difference between what the parser
				302	accepts and what is considered 'well formed'. For example, the
				303	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	304
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	305	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	306	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	307	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	308	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	309	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<p>...because the definition of <tt>%x</tt> does not dominate all of
				312	its uses. The LLVM infrastructure provides a verification pass that may
				313	be used to verify that an LLVM module is well formed. This pass is
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	314	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	315	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	316	by the verifier pass indicate bugs in transformation passes or input to
				317	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	318	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	320	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	321
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	322	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	323	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	324	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	326	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	327
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	328	<p>LLVM identifiers come in two basic types: global and local. Global
				329	identifiers (functions, global variables) begin with the @ character. Local
				330	identifiers (register names, types) begin with the % character. Additionally,
				331	there are three different formats for identifiers, for different purposes:
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	332
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	333	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	334	<li>Named values are represented as a string of characters with their prefix.
				335	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				336	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	337	Identifiers which require other characters in their names can be surrounded
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	338	with quotes. In this way, anything except a <tt>"</tt> character can
				339	be used in a named value.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	340
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	341	<li>Unnamed values are represented as an unsigned numeric value with their
				342	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	343
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	344	<li>Constants, which are described in a <a href="#constants">section about
				345	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	346	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	347
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	349	don't need to worry about name clashes with reserved words, and the set of
				350	reserved words may be expanded in the future without penalty. Additionally,
				351	unnamed identifiers allow a compiler to quickly come up with a temporary
				352	variable without having to avoid symbol table conflicts.</p>
				353
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	354	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	355	languages. There are keywords for different opcodes
				356	('<tt><a href="#i_add">add</a></tt>',
				357	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				358	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	359	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	360	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	361	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	362
				363	<p>Here is an example of LLVM code to multiply the integer variable
				364	'<tt>%X</tt>' by 8:</p>
				365
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	366	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	368	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	369	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	370	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	371	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	372	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	374	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	375
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	377	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	378	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	379	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	380	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	381
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	386	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				387	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				388	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	389	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	390	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	392	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				393	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	395	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	396
				397	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				398	line.</li>
				399
				400	<li>Unnamed temporaries are created when the result of a computation is not
				401	assigned to a named value.</li>
				402
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	403	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	404
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	405	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	406
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	407	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	408	demonstrating instructions, we will follow an instruction with a comment that
				409	defines the type and name of value produced. Comments are shown in italic
				410	text.</p>
				411
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	412	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	413
				414	<!-- *********************************************************************** -->
				415	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				416	<!-- *********************************************************************** -->
				417
				418	<!-- ======================================================================= -->
				419	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				420	</div>
				421
				422	<div class="doc_text">
				423
				424	<p>LLVM programs are composed of "Module"s, each of which is a
				425	translation unit of the input programs. Each module consists of
				426	functions, global variables, and symbol table entries. Modules may be
				427	combined together with the LLVM linker, which merges function (and
				428	global variable) definitions, resolves forward declarations, and merges
				429	symbol table entries. Here is an example of the "hello world" module:</p>
				430
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	431	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	432	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	433	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				434	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	435
				436	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	437	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	438
				439	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	440	define i32 @main() { <i>; i32()* </i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	441	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	442	%cast210 = <a
Chris Lattner	2150cde	2007-06-12 17:01:15 +0000	[diff] [blame]	443	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	444
				445	<i>; Call puts function to write out the string to stdout...</i>
				446	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	447	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	449	href="#i_ret">ret</a> i32 0<br>}<br>
				450	</pre>
				451	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	452
				453	<p>This example is made up of a <a href="#globalvars">global variable</a>
				454	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				455	function, and a <a href="#functionstructure">function definition</a>
				456	for "<tt>main</tt>".</p>
				457
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	458	<p>In general, a module is made up of a list of global values,
				459	where both functions and global variables are global values. Global values are
				460	represented by a pointer to a memory location (in this case, a pointer to an
				461	array of char, and a pointer to a function), and have one of the following <a
				462	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	463
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	464	</div>
				465
				466	<!-- ======================================================================= -->
				467	<div class="doc_subsection">
				468	<a name="linkage">Linkage Types</a>
				469	</div>
				470
				471	<div class="doc_text">
				472
				473	<p>
				474	All Global Variables and Functions have one of the following types of linkage:
				475	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	476
				477	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	480
				481	<dd>Global values with internal linkage are only directly accessible by
				482	objects in the current module. In particular, linking code into a module with
				483	an internal global value may cause the internal to be renamed as necessary to
				484	avoid collisions. Because the symbol is internal to the module, all
				485	references can be updated. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	486	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	487	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	488
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	489	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	490
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	491	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				492	the same name when linkage occurs. This is typically used to implement
				493	inline functions, templates, or other code which must be generated in each
				494	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				495	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				499
				500	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				501	linkage, except that unreferenced <tt>common</tt> globals may not be
				502	discarded. This is used for globals that may be emitted in multiple
				503	translation units, but that are not guaranteed to be emitted into every
				504	translation unit that uses them. One example of this is tentative
				505	definitions in C, such as "<tt>int X;</tt>" at global scope.
				506	</dd>
				507
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	508	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	509
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	510	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				511	that some targets may choose to emit different assembly sequences for them
				512	for target-dependent reasons. This is used for globals that are declared
				513	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	516	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	517
				518	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				519	pointer to array type. When two global variables with appending linkage are
				520	linked together, the two global arrays are appended together. This is the
				521	LLVM, typesafe, equivalent of having the system linker append together
				522	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	523	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	525	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	526	<dd>The semantics of this linkage follow the ELF object file model: the
				527	symbol is weak until linked, if not linked, the symbol becomes null instead
				528	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	529	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	530
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	531	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	532
				533	<dd>If none of the above identifiers are used, the global is externally
				534	visible, meaning that it participates in linkage and can be used to resolve
				535	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	537	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	538
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	539	<p>
				540	The next two types of linkage are targeted for Microsoft Windows platform
				541	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	542	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	543	</p>
				544
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	545	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				547
				548	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				549	or variable via a global pointer to a pointer that is set up by the DLL
				550	exporting the symbol. On Microsoft Windows targets, the pointer name is
				551	formed by combining <code>_imp__</code> and the function or variable name.
				552	</dd>
				553
				554	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				555
				556	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				557	pointer to a pointer in a DLL, so that it can be referenced with the
				558	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				559	name is formed by combining <code>_imp__</code> and the function or variable
				560	name.
				561	</dd>
				562
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	563	</dl>
				564
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	565	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	566	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				567	variable and was linked with this one, one of the two would be renamed,
				568	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				569	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	570	outside of the current module.</p>
				571	<p>It is illegal for a function <i>declaration</i>
				572	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	573	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	574	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				575	linkages.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	576	</div>
				577
				578	<!-- ======================================================================= -->
				579	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	580	<a name="callingconv">Calling Conventions</a>
				581	</div>
				582
				583	<div class="doc_text">
				584
				585	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				586	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				587	specified for the call. The calling convention of any pair of dynamic
				588	caller/callee must match, or the behavior of the program is undefined. The
				589	following calling conventions are supported by LLVM, and more may be added in
				590	the future:</p>
				591
				592	<dl>
				593	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				594
				595	<dd>This calling convention (the default if no other calling convention is
				596	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	597	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	598	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	599	</dd>
				600
				601	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				602
				603	<dd>This calling convention attempts to make calls as fast as possible
				604	(e.g. by passing things in registers). This calling convention allows the
				605	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	606	without having to conform to an externally specified ABI (Application Binary
				607	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	608	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				609	supported. This calling convention does not support varargs and requires the
				610	prototype of all callees to exactly match the prototype of the function
				611	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	612	</dd>
				613
				614	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				615
				616	<dd>This calling convention attempts to make code in the caller as efficient
				617	as possible under the assumption that the call is not commonly executed. As
				618	such, these calls often preserve all registers so that the call does not break
				619	any live ranges in the caller side. This calling convention does not support
				620	varargs and requires the prototype of all callees to exactly match the
				621	prototype of the function definition.
				622	</dd>
				623
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	624	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	625
				626	<dd>Any calling convention may be specified by number, allowing
				627	target-specific calling conventions to be used. Target specific calling
				628	conventions start at 64.
				629	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	630	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	631
				632	<p>More calling conventions can be added/defined on an as-needed basis, to
				633	support pascal conventions or any other well-known target-independent
				634	convention.</p>
				635
				636	</div>
				637
				638	<!-- ======================================================================= -->
				639	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	640	<a name="visibility">Visibility Styles</a>
				641	</div>
				642
				643	<div class="doc_text">
				644
				645	<p>
				646	All Global Variables and Functions have one of the following visibility styles:
				647	</p>
				648
				649	<dl>
				650	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				651
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	652	<dd>On targets that use the ELF object file format, default visibility means
				653	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	654	modules and, in shared libraries, means that the declared entity may be
				655	overridden. On Darwin, default visibility means that the declaration is
				656	visible to other modules. Default visibility corresponds to "external
				657	linkage" in the language.
				658	</dd>
				659
				660	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				661
				662	<dd>Two declarations of an object with hidden visibility refer to the same
				663	object if they are in the same shared object. Usually, hidden visibility
				664	indicates that the symbol will not be placed into the dynamic symbol table,
				665	so no other module (executable or shared library) can reference it
				666	directly.
				667	</dd>
				668
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	669	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				670
				671	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				672	the dynamic symbol table, but that references within the defining module will
				673	bind to the local symbol. That is, the symbol cannot be overridden by another
				674	module.
				675	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	676	</dl>
				677
				678	</div>
				679
				680	<!-- ======================================================================= -->
				681	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	682	<a name="globalvars">Global Variables</a>
				683	</div>
				684
				685	<div class="doc_text">
				686
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	687	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	688	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	689	an explicit section to be placed in, and may have an optional explicit alignment
				690	specified. A variable may be defined as "thread_local", which means that it
				691	will not be shared by threads (each thread will have a separated copy of the
				692	variable). A variable may be defined as a global "constant," which indicates
				693	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	694	optimization, allowing the global data to be placed in the read-only section of
				695	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	696	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	697
				698	<p>
				699	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				700	constant, even if the final definition of the global is not. This capability
				701	can be used to enable slightly better optimization of the program, but requires
				702	the language definition to guarantee that optimizations based on the
				703	'constantness' are valid for the translation units that do not include the
				704	definition.
				705	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	706
				707	<p>As SSA values, global variables define pointer values that are in
				708	scope (i.e. they dominate) all basic blocks in the program. Global
				709	variables always define a pointer to their "content" type because they
				710	describe a region of memory, and all memory objects in LLVM are
				711	accessed through pointers.</p>
				712
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	713	<p>A global variable may be declared to reside in a target-specifc numbered
				714	address space. For targets that support them, address spaces may affect how
				715	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	716	the variable. The default address space is zero. The address space qualifier
				717	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	718
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	719	<p>LLVM allows an explicit section to be specified for globals. If the target
				720	supports it, it will emit globals to the section specified.</p>
				721
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	722	<p>An explicit alignment may be specified for a global. If not present, or if
				723	the alignment is set to zero, the alignment of the global is set by the target
				724	to whatever it feels convenient. If an explicit alignment is specified, the
				725	global is forced to have at least that much alignment. All alignments must be
				726	a power of 2.</p>
				727
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	728	<p>For example, the following defines a global in a numbered address space with
				729	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	730
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	731	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	732	<pre>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	733	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	734	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	735	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	736
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	737	</div>
				738
				739
				740	<!-- ======================================================================= -->
				741	<div class="doc_subsection">
				742	<a name="functionstructure">Functions</a>
				743	</div>
				744
				745	<div class="doc_text">
				746
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	747	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				748	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	749	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	750	<a href="#callingconv">calling convention</a>, a return type, an optional
				751	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				752	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	753	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	754	optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	755	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	762	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	dc5cafb	2007-12-10 03:30:21 +0000	[diff] [blame]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	787	</div>
				788
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	789
				790	<!-- ======================================================================= -->
				791	<div class="doc_subsection">
				792	<a name="aliasstructure">Aliases</a>
				793	</div>
				794	<div class="doc_text">
				795	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	25b2e82	2008-03-22 08:36:14 +0000	[diff] [blame]	796	function, global variable, another alias or bitcast of global value). Aliases
				797	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	798	optional <a href="#visibility">visibility style</a>.</p>
				799
				800	<h5>Syntax:</h5>
				801
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	802	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	803	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	804	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	805	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	806	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	807
				808	</div>
				809
				810
				811
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	812	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	813	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				814	<div class="doc_text">
				815	<p>The return type and each parameter of a function type may have a set of
				816	<i>parameter attributes</i> associated with them. Parameter attributes are
				817	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	818	a function. Parameter attributes are considered to be part of the function,
				819	not of the function type, so functions with different parameter attributes
				820	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	821
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	822	<p>Parameter attributes are simple keywords that follow the type specified. If
				823	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	824	example:</p>
				825
				826	<div class="doc_code">
				827	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	828	declare i32 @printf(i8* noalias , ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	829	declare i32 @atoi(i8 zeroext)
				830	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	831	</pre>
				832	</div>
				833
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	834	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				835	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	836
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	837	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	838	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	840	<dd>This indicates to the code generator that the parameter or return value
				841	should be zero-extended to a 32-bit value by the caller (for a parameter)
				842	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	843
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	844	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	845	<dd>This indicates to the code generator that the parameter or return value
				846	should be sign-extended to a 32-bit value by the caller (for a parameter)
				847	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	848
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	849	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	850	<dd>This indicates that this parameter or return value should be treated
				851	in a special target-dependent fashion during while emitting code for a
				852	function call or return (usually, by putting it in a register as opposed
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	853	to memory, though some targets use it to distinguish between two different
				854	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	855
				856	<dt><tt>byval</tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	857	<dd>This indicates that the pointer parameter should really be passed by
				858	value to the function. The attribute implies that a hidden copy of the
				859	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	860	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	861	pointer arguments. It is generally used to pass structs and arrays by
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	862	value, but is also valid on pointers to scalars.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	863
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	864	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	865	<dd>This indicates that the pointer parameter specifies the address of a
				866	structure that is the return value of the function in the source program.
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame^]	867	This pointer must be guaranteed by the caller to be valid: loads and stores
				868	to the structure may be assumed by the callee to not to trap. This may only
				869	be applied to the first parameter.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	870
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	871	<dt><tt>noalias</tt></dt>
Owen Anderson	6110128	2008-02-18 04:09:01 +0000	[diff] [blame]	872	<dd>This indicates that the parameter does not alias any global or any other
				873	parameter. The caller is responsible for ensuring that this is the case,
				874	usually by placing the value in a stack allocation.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	875
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	876	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	877	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	878	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	879	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	880
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	881	</div>
				882
				883	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	884	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	885	<a name="gc">Garbage Collector Names</a>
				886	</div>
				887
				888	<div class="doc_text">
				889	<p>Each function may specify a garbage collector name, which is simply a
				890	string.</p>
				891
				892	<div class="doc_code"><pre
				893	>define void @f() gc "name" { ...</pre></div>
				894
				895	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				896	collector which will cause the compiler to alter its output in order to support
				897	the named garbage collection algorithm.</p>
				898	</div>
				899
				900	<!-- ======================================================================= -->
				901	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	902	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	903	</div>
				904
				905	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	906
				907	<p>Function attributes are set to communicate additional information about
				908	a function. Function attributes are considered to be part of the function,
				909	not of the function type, so functions with different parameter attributes
				910	can have the same function type.</p>
				911
				912	<p>Function attributes are simple keywords that follow the type specified. If
				913	multiple attributes are needed, they are space separated. For
				914	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	915
				916	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	917	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	918	define void @f() noinline { ... }
				919	define void @f() alwaysinline { ... }
				920	define void @f() alwaysinline optsize { ... }
				921	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	922	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	923	</div>
				924
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	925	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	926	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	927	<dd>This attribute indicates that the inliner should attempt to inline this
				928	function into callers whenever possible, ignoring any active inlining size
				929	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	930
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	931	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	932	<dd>This attribute indicates that the inliner should never inline this function
				933	in any situation. This attribute may not be used together with
				934	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	935
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	936	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	937	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	938	make choices that keep the code size of this function low, and otherwise do
				939	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	940
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	941	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	942	<dd>This function attribute indicates that the function never returns normally.
				943	This produces undefined behavior at runtime if the function ever does
				944	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	945
				946	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	947	<dd>This function attribute indicates that the function never returns with an
				948	unwind or exceptional control flow. If the function does unwind, its runtime
				949	behavior is undefined.</dd>
				950
				951	<dt><tt>readnone</tt></dt>
				952	<dd>This attribute indicates that the function computes its result (or its
				953	thrown exception) based strictly on its arguments. It does not read any global
				954	mutable state (e.g. memory, control registers, etc) visible to caller functions.
				955	Furthermore, <tt>readnone</tt> functions never change any state visible to their
				956	caller.
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	957
				958	<dt><tt>readonly</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	959	<dd>This function attribute indicates that the function has no side-effects on
				960	the calling function, but that it depends on state (memory state, control
				961	register state, etc) that may be set in the caller. A readonly function always
				962	returns the same value (or throws the same exception) whenever it is called with
				963	a particular set of arguments and global state.</dd>
				964
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	965	</dl>
				966
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	967	</div>
				968
				969	<!-- ======================================================================= -->
				970	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	971	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	972	</div>
				973
				974	<div class="doc_text">
				975	<p>
				976	Modules may contain "module-level inline asm" blocks, which corresponds to the
				977	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				978	LLVM and treated as a single unit, but may be separated in the .ll file if
				979	desired. The syntax is very simple:
				980	</p>
				981
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	982	<div class="doc_code">
				983	<pre>
				984	module asm "inline asm code goes here"
				985	module asm "more can go here"
				986	</pre>
				987	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	988
				989	<p>The strings can contain any character by escaping non-printable characters.
				990	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				991	for the number.
				992	</p>
				993
				994	<p>
				995	The inline asm code is simply printed to the machine code .s file when
				996	assembly code is generated.
				997	</p>
				998	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	999
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1000	<!-- ======================================================================= -->
				1001	<div class="doc_subsection">
				1002	<a name="datalayout">Data Layout</a>
				1003	</div>
				1004
				1005	<div class="doc_text">
				1006	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	1007	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1008	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1009	<p>The <i>layout specification</i> consists of a list of specifications
				1010	separated by the minus sign character ('-'). Each specification starts with a
				1011	letter and may include other information after the letter to define some
				1012	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1013	<dl>
				1014	<dt><tt>E</tt></dt>
				1015	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1016	bits with the most significance have the lowest address location.</dd>
				1017	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1018	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1019	the bits with the least significance have the lowest address location.</dd>
				1020	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1021	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1022	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1023	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1024	too.</dd>
				1025	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1026	<dd>This specifies the alignment for an integer type of a given bit
				1027	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1028	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1029	<dd>This specifies the alignment for a vector type of a given bit
				1030	<i>size</i>.</dd>
				1031	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1032	<dd>This specifies the alignment for a floating point type of a given bit
				1033	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1034	(double).</dd>
				1035	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1036	<dd>This specifies the alignment for an aggregate type of a given bit
				1037	<i>size</i>.</dd>
				1038	</dl>
				1039	<p>When constructing the data layout for a given target, LLVM starts with a
				1040	default set of specifications which are then (possibly) overriden by the
				1041	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1042	are given in this list:</p>
				1043	<ul>
				1044	<li><tt>E</tt> - big endian</li>
				1045	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1046	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1047	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1048	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1049	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1050	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1051	alignment of 64-bits</li>
				1052	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1053	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1054	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1055	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1056	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1057	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1058	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1059	following rules:
				1060	<ol>
				1061	<li>If the type sought is an exact match for one of the specifications, that
				1062	specification is used.</li>
				1063	<li>If no match is found, and the type sought is an integer type, then the
				1064	smallest integer type that is larger than the bitwidth of the sought type is
				1065	used. If none of the specifications are larger than the bitwidth then the the
				1066	largest integer type is used. For example, given the default specifications
				1067	above, the i7 type will use the alignment of i8 (next largest) while both
				1068	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1069	<li>If no match is found, and the type sought is a vector type, then the
				1070	largest vector type that is smaller than the sought vector type will be used
				1071	as a fall back. This happens because <128 x double> can be implemented in
				1072	terms of 64 <2 x double>, for example.</li>
				1073	</ol>
				1074	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1075
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1076	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1077	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1078	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1079
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1080	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1081
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1082	<p>The LLVM type system is one of the most important features of the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1083	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1084	optimizations to be performed on the intermediate representation directly,
				1085	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1086	extra analyses on the side before the transformation. A strong type
				1087	system makes it easier to read the generated code and enables novel
				1088	analyses and transformations that are not feasible to perform on normal
				1089	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1090
				1091	</div>
				1092
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1093	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1094	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1095	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1096	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1097	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1098	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1099
				1100	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1101	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1102	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1103	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1104	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1105	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1106	</tr>
				1107	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1108	<td><a href="#t_floating">floating point</a></td>
				1109	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1110	</tr>
				1111	<tr>
				1112	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1113	<td><a href="#t_integer">integer</a>,
				1114	<a href="#t_floating">floating point</a>,
				1115	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1116	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1117	<a href="#t_struct">structure</a>,
				1118	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1119	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1120	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1121	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1122	<tr>
				1123	<td><a href="#t_primitive">primitive</a></td>
				1124	<td><a href="#t_label">label</a>,
				1125	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1126	<a href="#t_floating">floating point</a>.</td>
				1127	</tr>
				1128	<tr>
				1129	<td><a href="#t_derived">derived</a></td>
				1130	<td><a href="#t_integer">integer</a>,
				1131	<a href="#t_array">array</a>,
				1132	<a href="#t_function">function</a>,
				1133	<a href="#t_pointer">pointer</a>,
				1134	<a href="#t_struct">structure</a>,
				1135	<a href="#t_pstruct">packed structure</a>,
				1136	<a href="#t_vector">vector</a>,
				1137	<a href="#t_opaque">opaque</a>.
				1138	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1139	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1140	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1141
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1142	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1143	most important. Values of these types are the only ones which can be
				1144	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1145	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1146	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1147
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1148	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1149	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1150
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1151	<div class="doc_text">
				1152	<p>The primitive types are the fundamental building blocks of the LLVM
				1153	system.</p>
				1154
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1155	</div>
				1156
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1157	<!-- _______________________________________________________________________ -->
				1158	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1159
				1160	<div class="doc_text">
				1161	<table>
				1162	<tbody>
				1163	<tr><th>Type</th><th>Description</th></tr>
				1164	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1165	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1166	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1167	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1168	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1169	</tbody>
				1170	</table>
				1171	</div>
				1172
				1173	<!-- _______________________________________________________________________ -->
				1174	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1175
				1176	<div class="doc_text">
				1177	<h5>Overview:</h5>
				1178	<p>The void type does not represent any value and has no size.</p>
				1179
				1180	<h5>Syntax:</h5>
				1181
				1182	<pre>
				1183	void
				1184	</pre>
				1185	</div>
				1186
				1187	<!-- _______________________________________________________________________ -->
				1188	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1189
				1190	<div class="doc_text">
				1191	<h5>Overview:</h5>
				1192	<p>The label type represents code labels.</p>
				1193
				1194	<h5>Syntax:</h5>
				1195
				1196	<pre>
				1197	label
				1198	</pre>
				1199	</div>
				1200
				1201
				1202	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1203	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1204
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1205	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1206
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1207	<p>The real power in LLVM comes from the derived types in the system.
				1208	This is what allows a programmer to represent arrays, functions,
				1209	pointers, and other useful types. Note that these derived types may be
				1210	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1211
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1212	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1213
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1214	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1215	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1216
				1217	<div class="doc_text">
				1218
				1219	<h5>Overview:</h5>
				1220	<p>The integer type is a very simple derived type that simply specifies an
				1221	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1222	2^23-1 (about 8 million) can be specified.</p>
				1223
				1224	<h5>Syntax:</h5>
				1225
				1226	<pre>
				1227	iN
				1228	</pre>
				1229
				1230	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1231	value.</p>
				1232
				1233	<h5>Examples:</h5>
				1234	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1235	<tbody>
				1236	<tr>
				1237	<td><tt>i1</tt></td>
				1238	<td>a single-bit integer.</td>
				1239	</tr><tr>
				1240	<td><tt>i32</tt></td>
				1241	<td>a 32-bit integer.</td>
				1242	</tr><tr>
				1243	<td><tt>i1942652</tt></td>
				1244	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1245	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1246	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1247	</table>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1248	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1249
				1250	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1251	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1252
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1253	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1254
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1255	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1256
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1257	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1258	sequentially in memory. The array type requires a size (number of
				1259	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1260
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1261	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1262
				1263	<pre>
				1264	[<# elements> x <elementtype>]
				1265	</pre>
				1266
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1267	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1268	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1269
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1270	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1271	<table class="layout">
				1272	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1273	<td class="left"><tt>[40 x i32]</tt></td>
				1274	<td class="left">Array of 40 32-bit integer values.</td>
				1275	</tr>
				1276	<tr class="layout">
				1277	<td class="left"><tt>[41 x i32]</tt></td>
				1278	<td class="left">Array of 41 32-bit integer values.</td>
				1279	</tr>
				1280	<tr class="layout">
				1281	<td class="left"><tt>[4 x i8]</tt></td>
				1282	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1283	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1284	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1285	<p>Here are some examples of multidimensional arrays:</p>
				1286	<table class="layout">
				1287	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1288	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1289	<td class="left">3x4 array of 32-bit integer values.</td>
				1290	</tr>
				1291	<tr class="layout">
				1292	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1293	<td class="left">12x10 array of single precision floating point values.</td>
				1294	</tr>
				1295	<tr class="layout">
				1296	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1297	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1298	</tr>
				1299	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1300
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1301	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1302	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1303	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1304	As a special case, however, zero length arrays are recognized to be variable
				1305	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1306	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1307
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1308	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1309
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1310	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1311	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1312	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1313
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1314	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1315
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1316	<p>The function type can be thought of as a function signature. It
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1317	consists of a return type and a list of formal parameter types. The
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1318	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	9c1f8b1	2008-03-24 20:52:42 +0000	[diff] [blame]	1319	If the return type is a struct type then all struct elements must be of first
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1320	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1321
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1322	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1323
				1324	<pre>
				1325	<returntype list> (<parameter list>)
				1326	</pre>
				1327
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1328	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	20f9a62	2004-08-12 20:16:08 +0000	[diff] [blame]	1329	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1330	which indicates that the function takes a variable number of arguments.
				1331	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1332	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1333	'<tt><returntype list></tt>' is a comma-separated list of
				1334	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1335
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1336	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1337	<table class="layout">
				1338	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1339	<td class="left"><tt>i32 (i32)</tt></td>
				1340	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1341	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1342	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1343	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1344	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1345	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1346	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1347	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1348	<tt>float</tt>.
				1349	</td>
				1350	</tr><tr class="layout">
				1351	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1352	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1353	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1354	which returns an integer. This is the signature for <tt>printf</tt> in
				1355	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1356	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1357	</tr><tr class="layout">
				1358	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	8dec6c2	2008-03-24 18:10:52 +0000	[diff] [blame]	1359	<td class="left">A function taking an <tt>i32></tt>, returning two
				1360	<tt> i32 </tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1361	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1362	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1363	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1364
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1365	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1366	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1367	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1368	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1369	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1370	<p>The structure type is used to represent a collection of data members
				1371	together in memory. The packing of the field types is defined to match
				1372	the ABI of the underlying processor. The elements of a structure may
				1373	be any type that has a size.</p>
				1374	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1375	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1376	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1377	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1378	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1379	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1380	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1381	<table class="layout">
				1382	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1383	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1384	<td class="left">A triple of three <tt>i32</tt> values</td>
				1385	</tr><tr class="layout">
				1386	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1387	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1388	second element is a <a href="#t_pointer">pointer</a> to a
				1389	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1390	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1391	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1392	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1393	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1394
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1395	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1396	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1397	</div>
				1398	<div class="doc_text">
				1399	<h5>Overview:</h5>
				1400	<p>The packed structure type is used to represent a collection of data members
				1401	together in memory. There is no padding between fields. Further, the alignment
				1402	of a packed structure is 1 byte. The elements of a packed structure may
				1403	be any type that has a size.</p>
				1404	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1405	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1406	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1407	instruction.</p>
				1408	<h5>Syntax:</h5>
				1409	<pre> < { <type list> } > <br></pre>
				1410	<h5>Examples:</h5>
				1411	<table class="layout">
				1412	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1413	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1414	<td class="left">A triple of three <tt>i32</tt> values</td>
				1415	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1416	<td class="left">
				1417	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1418	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1419	second element is a <a href="#t_pointer">pointer</a> to a
				1420	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1421	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1422	</tr>
				1423	</table>
				1424	</div>
				1425
				1426	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1427	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1428	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1429	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1430	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1431	reference to another object, which must live in memory. Pointer types may have
				1432	an optional address space attribute defining the target-specific numbered
				1433	address space where the pointed-to object resides. The default address space is
				1434	zero.</p>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1435	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1436	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1437	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1438	<table class="layout">
				1439	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1440	<td class="left"><tt>[4x i32]*</tt></td>
				1441	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1442	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1443	</tr>
				1444	<tr class="layout">
				1445	<td class="left"><tt>i32 (i32 ) </tt></td>
				1446	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1447	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1448	<tt>i32</tt>.</td>
				1449	</tr>
				1450	<tr class="layout">
				1451	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1452	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1453	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1454	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1455	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1456	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1457
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1458	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1459	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1461
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1462	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1463
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1464	<p>A vector type is a simple derived type that represents a vector
				1465	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1466	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1467	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1468	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1469	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1470	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1471
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1472	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1473
				1474	<pre>
				1475	< <# elements> x <elementtype> >
				1476	</pre>
				1477
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1478	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1479	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1480
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1481	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1482
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1483	<table class="layout">
				1484	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1485	<td class="left"><tt><4 x i32></tt></td>
				1486	<td class="left">Vector of 4 32-bit integer values.</td>
				1487	</tr>
				1488	<tr class="layout">
				1489	<td class="left"><tt><8 x float></tt></td>
				1490	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1491	</tr>
				1492	<tr class="layout">
				1493	<td class="left"><tt><2 x i64></tt></td>
				1494	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1495	</tr>
				1496	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1497	</div>
				1498
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1499	<!-- _______________________________________________________________________ -->
				1500	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1501	<div class="doc_text">
				1502
				1503	<h5>Overview:</h5>
				1504
				1505	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	a699c4d	2007-10-14 00:34:53 +0000	[diff] [blame]	1506	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1507	In LLVM, opaque types can eventually be resolved to any type (not just a
				1508	structure type).</p>
				1509
				1510	<h5>Syntax:</h5>
				1511
				1512	<pre>
				1513	opaque
				1514	</pre>
				1515
				1516	<h5>Examples:</h5>
				1517
				1518	<table class="layout">
				1519	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1520	<td class="left"><tt>opaque</tt></td>
				1521	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1522	</tr>
				1523	</table>
				1524	</div>
				1525
				1526
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1527	<!-- *********************************************************************** -->
				1528	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1529	<!-- *********************************************************************** -->
				1530
				1531	<div class="doc_text">
				1532
				1533	<p>LLVM has several different basic types of constants. This section describes
				1534	them all and their syntax.</p>
				1535
				1536	</div>
				1537
				1538	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1539	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1540
				1541	<div class="doc_text">
				1542
				1543	<dl>
				1544	<dt><b>Boolean constants</b></dt>
				1545
				1546	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1547	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1548	</dd>
				1549
				1550	<dt><b>Integer constants</b></dt>
				1551
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1552	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1553	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1554	integer types.
				1555	</dd>
				1556
				1557	<dt><b>Floating point constants</b></dt>
				1558
				1559	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1560	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1561	notation (see below). The assembler requires the exact decimal value of
				1562	a floating-point constant. For example, the assembler accepts 1.25 but
				1563	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1564	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1565
				1566	<dt><b>Null pointer constants</b></dt>
				1567
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1568	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1569	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1570
				1571	</dl>
				1572
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1573	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1574	of floating point constants. For example, the form '<tt>double
				1575	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1576	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1577	(and the only time that they are generated by the disassembler) is when a
				1578	floating point constant must be emitted but it cannot be represented as a
				1579	decimal floating point number. For example, NaN's, infinities, and other
				1580	special values are represented in their IEEE hexadecimal format so that
				1581	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1582
				1583	</div>
				1584
				1585	<!-- ======================================================================= -->
				1586	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1587	</div>
				1588
				1589	<div class="doc_text">
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1590	<p>Aggregate constants arise from aggregation of simple constants
				1591	and smaller aggregate constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1592
				1593	<dl>
				1594	<dt><b>Structure constants</b></dt>
				1595
				1596	<dd>Structure constants are represented with notation similar to structure
				1597	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1598	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1599	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1600	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1601	types of elements must match those specified by the type.
				1602	</dd>
				1603
				1604	<dt><b>Array constants</b></dt>
				1605
				1606	<dd>Array constants are represented with notation similar to array type
				1607	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1608	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1609	constants must have <a href="#t_array">array type</a>, and the number and
				1610	types of elements must match those specified by the type.
				1611	</dd>
				1612
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1613	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1614
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1615	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1616	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1617	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1618	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1619	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1620	match those specified by the type.
				1621	</dd>
				1622
				1623	<dt><b>Zero initialization</b></dt>
				1624
				1625	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1626	value to zero of <em>any</em> type, including scalar and aggregate types.
				1627	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1628	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1629	initializers.
				1630	</dd>
				1631	</dl>
				1632
				1633	</div>
				1634
				1635	<!-- ======================================================================= -->
				1636	<div class="doc_subsection">
				1637	<a name="globalconstants">Global Variable and Function Addresses</a>
				1638	</div>
				1639
				1640	<div class="doc_text">
				1641
				1642	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1643	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1644	constants. These constants are explicitly referenced when the <a
				1645	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1646	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1647	file:</p>
				1648
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1649	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1650	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1651	@X = global i32 17
				1652	@Y = global i32 42
				1653	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1654	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1655	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1656
				1657	</div>
				1658
				1659	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1660	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1661	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1662	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1663	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1664	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1665
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1666	<p>Undefined values indicate to the compiler that the program is well defined
				1667	no matter what value is used, giving the compiler more freedom to optimize.
				1668	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1669	</div>
				1670
				1671	<!-- ======================================================================= -->
				1672	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1673	</div>
				1674
				1675	<div class="doc_text">
				1676
				1677	<p>Constant expressions are used to allow expressions involving other constants
				1678	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1679	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1680	that does not have side effects (e.g. load and call are not supported). The
				1681	following is the syntax for constant expressions:</p>
				1682
				1683	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1684	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1685	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1686	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1687
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1688	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1689	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1690	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1691
				1692	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1693	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1694	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1695
				1696	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1697	<dd>Truncate a floating point constant to another floating point type. The
				1698	size of CST must be larger than the size of TYPE. Both types must be
				1699	floating point.</dd>
				1700
				1701	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1702	<dd>Floating point extend a constant to another type. The size of CST must be
				1703	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1704
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1705	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1706	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1707	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1708	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1709	of the same number of elements. If the value won't fit in the integer type,
				1710	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1711
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1712	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1713	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1714	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1715	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1716	of the same number of elements. If the value won't fit in the integer type,
				1717	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1718
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1719	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1720	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1721	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1722	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1723	of the same number of elements. If the value won't fit in the floating point
				1724	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1725
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1726	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1727	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1728	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1729	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1730	of the same number of elements. If the value won't fit in the floating point
				1731	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1732
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1733	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1734	<dd>Convert a pointer typed constant to the corresponding integer constant
				1735	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1736	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1737
				1738	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1739	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1740	pointer type. CST must be of integer type. The CST value is zero extended,
				1741	truncated, or unchanged to make it fit in a pointer size. This one is
				1742	<i>really</i> dangerous!</dd>
				1743
				1744	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1745	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1746	identical (same number of bits). The conversion is done as if the CST value
				1747	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1748	with this operator, just the type. This can be used for conversion of
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1749	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	1750	pointers it is only valid to cast to another pointer type. It is not valid
				1751	to bitcast to or from an aggregate type.
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1752	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1753
				1754	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1755
				1756	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1757	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1758	instruction, the index list may have zero or more indexes, which are required
				1759	to make sense for the type of "CSTPTR".</dd>
				1760
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1761	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1762
				1763	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1764	constants.</dd>
				1765
				1766	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1767	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1768
				1769	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1770	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1771
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	1772	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1773	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1774
				1775	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1776	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1777
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1778	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1779
				1780	<dd>Perform the <a href="#i_extractelement">extractelement
				1781	operation</a> on constants.
				1782
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1783	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1784
				1785	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1786	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1787
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1788
				1789	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1790
				1791	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1792	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1793
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1794	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1795
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1796	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1797	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1798	binary</a> operations. The constraints on operands are the same as those for
				1799	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1800	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1801	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1802	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	1803
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1804	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1805	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1806	<!-- *********************************************************************** -->
				1807
				1808	<!-- ======================================================================= -->
				1809	<div class="doc_subsection">
				1810	<a name="inlineasm">Inline Assembler Expressions</a>
				1811	</div>
				1812
				1813	<div class="doc_text">
				1814
				1815	<p>
				1816	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1817	Module-Level Inline Assembly</a>) through the use of a special value. This
				1818	value represents the inline assembler as a string (containing the instructions
				1819	to emit), a list of operand constraints (stored as a string), and a flag that
				1820	indicates whether or not the inline asm expression has side effects. An example
				1821	inline assembler expression is:
				1822	</p>
				1823
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1824	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1825	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1826	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1827	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1828	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1829
				1830	<p>
				1831	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1832	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1833	</p>
				1834
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1835	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1836	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1837	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1838	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1839	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1840
				1841	<p>
				1842	Inline asms with side effects not visible in the constraint list must be marked
				1843	as having side effects. This is done through the use of the
				1844	'<tt>sideeffect</tt>' keyword, like so:
				1845	</p>
				1846
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1847	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1848	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1849	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1850	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1851	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1852
				1853	<p>TODO: The format of the asm and constraints string still need to be
				1854	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1855	need to be documented).
				1856	</p>
				1857
				1858	</div>
				1859
				1860	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1861	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1862	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1863
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1864	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1865
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1866	<p>The LLVM instruction set consists of several different
				1867	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1868	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1869	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1870	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1871	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1872
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1873	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1874
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1875	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1876	<div class="doc_subsection"> <a name="terminators">Terminator
				1877	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1878
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1879	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1880
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1881	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1882	basic block in a program ends with a "Terminator" instruction, which
				1883	indicates which block should be executed after the current block is
				1884	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1885	value: they produce control flow, not values (the one exception being
				1886	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1887	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1888	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1889	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	1890	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1891	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1892	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1893
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1894	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1895
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1896	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1897	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1898	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1899	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1900	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1901	<pre> ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1902	ret void <i>; Return from void function</i>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1903	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1904	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1905
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1906	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1907
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1908	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1909	value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	1910	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1911	returns value(s) and then causes control flow, and one that just causes
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1912	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1913
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1914	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1915
				1916	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1917	The type of each return value must be a '<a href="#t_firstclass">first
				1918	class</a>' type. Note that a function is not <a href="#wellformed">well
				1919	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1920	function that returns values that do not match the return type of the
				1921	function.</p>
				1922
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1923	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1924
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1925	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1926	returns back to the calling function's context. If the caller is a "<a
John Criswell	40db33f	2004-06-25 15:16:57 +0000	[diff] [blame]	1927	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1928	the instruction after the call. If the caller was an "<a
				1929	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1930	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1931	returns a value, that value shall set the call or invoke instruction's
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1932	return value. If the instruction returns multiple values then these
Devang Patel	d0f4764	2008-03-11 05:51:59 +0000	[diff] [blame]	1933	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1934	</a>' instruction.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1935
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1936	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1937
				1938	<pre>
				1939	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1940	ret void <i>; Return from a void function</i>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1941	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1942	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1943	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1944	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1945	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1946	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1947	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1948	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1949	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1950	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1951	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1952	transfer to a different basic block in the current function. There are
				1953	two forms of this instruction, corresponding to a conditional branch
				1954	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1955	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1956	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1957	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1958	unconditional form of the '<tt>br</tt>' instruction takes a single
				1959	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1960	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1961	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1962	argument is evaluated. If the value is <tt>true</tt>, control flows
				1963	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1964	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1965	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1966	<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	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1967	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1968	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1969	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1970	<div class="doc_subsubsection">
				1971	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1972	</div>
				1973
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1974	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1975	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1976
				1977	<pre>
				1978	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1979	</pre>
				1980
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1981	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1982
				1983	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1984	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1985	instruction, allowing a branch to occur to one of many possible
				1986	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1987
				1988
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1989	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1990
				1991	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1992	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1993	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1994	table is not allowed to contain duplicate constant entries.</p>
				1995
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1996	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1997
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1998	<p>The <tt>switch</tt> instruction specifies a table of values and
				1999	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2000	table is searched for the given value. If the value is found, control flow is
				2001	transfered to the corresponding destination; otherwise, control flow is
				2002	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2003
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2004	<h5>Implementation:</h5>
				2005
				2006	<p>Depending on properties of the target machine and the particular
				2007	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2008	ways. For example, it could be generated as a series of chained conditional
				2009	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2010
				2011	<h5>Example:</h5>
				2012
				2013	<pre>
				2014	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2015	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2016	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2017
				2018	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2019	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2020
				2021	<i>; Implement a jump table:</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2022	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2023	i32 1, label %onone
				2024	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2025	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2026	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2027
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2028	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2029	<div class="doc_subsubsection">
				2030	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2031	</div>
				2032
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2033	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2034
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2035	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2036
				2037	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2038	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2039	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2040	</pre>
				2041
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2042	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2043
				2044	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2045	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2046	'<tt>normal</tt>' label or the
				2047	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2048	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2049	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2050	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	2051	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	d0f4764	2008-03-11 05:51:59 +0000	[diff] [blame]	2052	returns multiple values then individual return values are only accessible through
				2053	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2054
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2055	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2056
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2057	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2058
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2059	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2060	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2061	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2062	convention</a> the call should use. If none is specified, the call defaults
				2063	to using C calling conventions.
				2064	</li>
				2065	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2066	function value being invoked. In most cases, this is a direct function
				2067	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2068	an arbitrary pointer to function value.
				2069	</li>
				2070
				2071	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2072	function to be invoked. </li>
				2073
				2074	<li>'<tt>function args</tt>': argument list whose types match the function
				2075	signature argument types. If the function signature indicates the function
				2076	accepts a variable number of arguments, the extra arguments can be
				2077	specified. </li>
				2078
				2079	<li>'<tt>normal label</tt>': the label reached when the called function
				2080	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2081
				2082	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2083	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2084
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2085	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2086
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2087	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2088
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2089	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2090	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2091	difference is that it establishes an association with a label, which is used by
				2092	the runtime library to unwind the stack.</p>
				2093
				2094	<p>This instruction is used in languages with destructors to ensure that proper
				2095	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2096	exception. Additionally, this is important for implementation of
				2097	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2098
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2099	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2100	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2101	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2102	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2103	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2104	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2105	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2106	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2107
				2108
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2109	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2110
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2111	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2112	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2113
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2114	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2115
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2116	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2117	<pre>
				2118	unwind
				2119	</pre>
				2120
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2121	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2122
				2123	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2124	at the first callee in the dynamic call stack which used an <a
				2125	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2126	primarily used to implement exception handling.</p>
				2127
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2128	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2129
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2130	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2131	immediately halt. The dynamic call stack is then searched for the first <a
				2132	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2133	execution continues at the "exceptional" destination block specified by the
				2134	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2135	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2136	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2137
				2138	<!-- _______________________________________________________________________ -->
				2139
				2140	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2141	Instruction</a> </div>
				2142
				2143	<div class="doc_text">
				2144
				2145	<h5>Syntax:</h5>
				2146	<pre>
				2147	unreachable
				2148	</pre>
				2149
				2150	<h5>Overview:</h5>
				2151
				2152	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2153	instruction is used to inform the optimizer that a particular portion of the
				2154	code is not reachable. This can be used to indicate that the code after a
				2155	no-return function cannot be reached, and other facts.</p>
				2156
				2157	<h5>Semantics:</h5>
				2158
				2159	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2160	</div>
				2161
				2162
				2163
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2164	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2165	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2166	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	<p>Binary operators are used to do most of the computation in a
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2168	program. They require two operands of the same type, execute an operation on them, and
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2169	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2170	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2171	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2172	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2173	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2174	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2175	<div class="doc_subsubsection">
				2176	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2177	</div>
				2178
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2179	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2180
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2181	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2182
				2183	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2184	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2185	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2186
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2187	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2188
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2189	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2190
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2191	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2192
				2193	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2194	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2195	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2196	types.</p>
				2197
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2198	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2199
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2200	<p>The value produced is the integer or floating point sum of the two
				2201	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2202
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2203	<p>If an integer sum has unsigned overflow, the result returned is the
				2204	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2205	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2206
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2207	<p>Because LLVM integers use a two's complement representation, this
				2208	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2209
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2210	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2211
				2212	<pre>
				2213	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2214	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2215	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2216	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2217	<div class="doc_subsubsection">
				2218	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2219	</div>
				2220
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2221	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2222
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2223	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2224
				2225	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2226	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2228
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2230
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2231	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2232	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2233
				2234	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2235	'<tt>neg</tt>' instruction present in most other intermediate
				2236	representations.</p>
				2237
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2238	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2239
				2240	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2241	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2242	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2243	types.</p>
				2244
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2245	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2246
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2247	<p>The value produced is the integer or floating point difference of
				2248	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2249
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2250	<p>If an integer difference has unsigned overflow, the result returned is the
				2251	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2252	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2253
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2254	<p>Because LLVM integers use a two's complement representation, this
				2255	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2256
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2257	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2258	<pre>
				2259	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2260	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2262	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2263
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2265	<div class="doc_subsubsection">
				2266	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2267	</div>
				2268
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2269	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2270
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2271	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2272	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2273	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2274	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2275	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2276	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2277
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2278	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2279
				2280	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2281	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2282	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2283	types.</p>
				2284
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2285	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2286
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2287	<p>The value produced is the integer or floating point product of the
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2288	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2289
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2290	<p>If the result of an integer multiplication has unsigned overflow,
				2291	the result returned is the mathematical result modulo
				2292	2<sup>n</sup>, where n is the bit width of the result.</p>
				2293	<p>Because LLVM integers use a two's complement representation, and the
				2294	result is the same width as the operands, this instruction returns the
				2295	correct result for both signed and unsigned integers. If a full product
				2296	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2297	should be sign-extended or zero-extended as appropriate to the
				2298	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2299	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2300	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2301	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2302	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2303
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2304	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2305	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2306	</a></div>
				2307	<div class="doc_text">
				2308	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2309	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2310	</pre>
				2311	<h5>Overview:</h5>
				2312	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2313	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2314
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2315	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2316
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2317	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2318	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2319	values. Both arguments must have identical types.</p>
				2320
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2321	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2322
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2323	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2324	<p>Note that unsigned integer division and signed integer division are distinct
				2325	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2326	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2327	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2328	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2329	</pre>
				2330	</div>
				2331	<!-- _______________________________________________________________________ -->
				2332	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2333	</a> </div>
				2334	<div class="doc_text">
				2335	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2336	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2337	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2338	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2339
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2340	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2341
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2342	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2343	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2344
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2345	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2346
				2347	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2348	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2349	values. Both arguments must have identical types.</p>
				2350
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2351	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2352	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2353	<p>Note that signed integer division and unsigned integer division are distinct
				2354	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2355	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2356	undefined behavior; this is a rare case, but can occur, for example,
				2357	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2358	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2359	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2360	</pre>
				2361	</div>
				2362	<!-- _______________________________________________________________________ -->
				2363	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2364	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2365	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2366	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2367	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2368	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2369	</pre>
				2370	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2371
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2372	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2373	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2374
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2375	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2376
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2377	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2378	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2379	of floating point values. Both arguments must have identical types.</p>
				2380
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2381	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2382
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2383	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2384
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2385	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2386
				2387	<pre>
				2388	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2389	</pre>
				2390	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2391
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2392	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2393	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2394	</div>
				2395	<div class="doc_text">
				2396	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2397	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2398	</pre>
				2399	<h5>Overview:</h5>
				2400	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2401	unsigned division of its two arguments.</p>
				2402	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2403	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2404	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2405	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2406	<h5>Semantics:</h5>
				2407	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2408	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2409	<p>Note that unsigned integer remainder and signed integer remainder are
				2410	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2411	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2412	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2413	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2414	</pre>
				2415
				2416	</div>
				2417	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2418	<div class="doc_subsubsection">
				2419	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2420	</div>
				2421
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2422	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2423
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2424	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2425
				2426	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2427	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2428	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2429
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2430	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2431
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2432	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2433	signed division of its two operands. This instruction can also take
				2434	<a href="#t_vector">vector</a> versions of the values in which case
				2435	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2436
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2437	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2438
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2439	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2440	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2441	values. Both arguments must have identical types.</p>
				2442
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2443	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2444
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2445	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2446	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2447	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2448	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2449	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2450	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	db3b93b	2007-03-24 22:40:44 +0000	[diff] [blame]	2451	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2452	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2453	<p>Note that signed integer remainder and unsigned integer remainder are
				2454	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2455	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2456	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2457	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2458	(The remainder doesn't actually overflow, but this rule lets srem be
				2459	implemented using instructions that return both the result of the division
				2460	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2461	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2462	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2463	</pre>
				2464
				2465	</div>
				2466	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2467	<div class="doc_subsubsection">
				2468	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2469
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2470	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2471
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2472	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2473	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2474	</pre>
				2475	<h5>Overview:</h5>
				2476	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2477	division of its two operands.</p>
				2478	<h5>Arguments:</h5>
				2479	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2480	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2481	of floating point values. Both arguments must have identical types.</p>
				2482
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2483	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2484
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2485	<p>This instruction returns the <i>remainder</i> of a division.
				2486	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2487
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2488	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2489
				2490	<pre>
				2491	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2492	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2493	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2494
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2495	<!-- ======================================================================= -->
				2496	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2497	Operations</a> </div>
				2498	<div class="doc_text">
				2499	<p>Bitwise binary operators are used to do various forms of
				2500	bit-twiddling in a program. They are generally very efficient
				2501	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2502	instructions. They require two operands of the same type, execute an operation on them,
				2503	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2504	</div>
				2505
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2506	<!-- _______________________________________________________________________ -->
				2507	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2508	Instruction</a> </div>
				2509	<div class="doc_text">
				2510	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2511	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2512	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2513
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2514	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2515
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2516	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2517	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2518
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2519	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2520
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2521	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2522	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2523	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2524
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2525	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2526
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2527	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2528	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2529	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2530
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2531	<h5>Example:</h5><pre>
				2532	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2533	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2534	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2535	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2536	</pre>
				2537	</div>
				2538	<!-- _______________________________________________________________________ -->
				2539	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2540	Instruction</a> </div>
				2541	<div class="doc_text">
				2542	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2543	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2544	</pre>
				2545
				2546	<h5>Overview:</h5>
				2547	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2548	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2549
				2550	<h5>Arguments:</h5>
				2551	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2552	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2553	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2554
				2555	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2556
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2557	<p>This instruction always performs a logical shift right operation. The most
				2558	significant bits of the result will be filled with zero bits after the
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2559	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2560	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2561
				2562	<h5>Example:</h5>
				2563	<pre>
				2564	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2565	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2566	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2567	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2568	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2569	</pre>
				2570	</div>
				2571
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2572	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2573	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2574	Instruction</a> </div>
				2575	<div class="doc_text">
				2576
				2577	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2578	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2579	</pre>
				2580
				2581	<h5>Overview:</h5>
				2582	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2583	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2584
				2585	<h5>Arguments:</h5>
				2586	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2587	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2588	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2589
				2590	<h5>Semantics:</h5>
				2591	<p>This instruction always performs an arithmetic shift right operation,
				2592	The most significant bits of the result will be filled with the sign bit
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2593	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2594	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2595	</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2596
				2597	<h5>Example:</h5>
				2598	<pre>
				2599	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2600	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2601	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2602	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2603	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2604	</pre>
				2605	</div>
				2606
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2607	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2608	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2609	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2611	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2612
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
				2615	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2616	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2617	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2618
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2619	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2620
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2621	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2622	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2623
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2624	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2625
				2626	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2627	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2628	values. Both arguments must have identical types.</p>
				2629
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2630	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2631	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2632	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2633	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2634	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2635	<tbody>
				2636	<tr>
				2637	<td>In0</td>
				2638	<td>In1</td>
				2639	<td>Out</td>
				2640	</tr>
				2641	<tr>
				2642	<td>0</td>
				2643	<td>0</td>
				2644	<td>0</td>
				2645	</tr>
				2646	<tr>
				2647	<td>0</td>
				2648	<td>1</td>
				2649	<td>0</td>
				2650	</tr>
				2651	<tr>
				2652	<td>1</td>
				2653	<td>0</td>
				2654	<td>0</td>
				2655	</tr>
				2656	<tr>
				2657	<td>1</td>
				2658	<td>1</td>
				2659	<td>1</td>
				2660	</tr>
				2661	</tbody>
				2662	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2663	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2664	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2665	<pre>
				2666	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2667	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2668	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2669	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2670	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2673	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2674	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2675	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2676	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2677	<h5>Overview:</h5>
				2678	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2679	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2680	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2681
				2682	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2683	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2684	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2685	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2686	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2687	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2688	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2689	<table border="1" cellspacing="0" cellpadding="4">
				2690	<tbody>
				2691	<tr>
				2692	<td>In0</td>
				2693	<td>In1</td>
				2694	<td>Out</td>
				2695	</tr>
				2696	<tr>
				2697	<td>0</td>
				2698	<td>0</td>
				2699	<td>0</td>
				2700	</tr>
				2701	<tr>
				2702	<td>0</td>
				2703	<td>1</td>
				2704	<td>1</td>
				2705	</tr>
				2706	<tr>
				2707	<td>1</td>
				2708	<td>0</td>
				2709	<td>1</td>
				2710	</tr>
				2711	<tr>
				2712	<td>1</td>
				2713	<td>1</td>
				2714	<td>1</td>
				2715	</tr>
				2716	</tbody>
				2717	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2718	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2719	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2720	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2721	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2722	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2723	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2724	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2725	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2726	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2727	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2728	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2729	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2730	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2731	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2732	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2733	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2734	or of its two operands. The <tt>xor</tt> is used to implement the
				2735	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2736	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2737	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2738	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2739	values. Both arguments must have identical types.</p>
				2740
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2741	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2742
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2743	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2744	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2745	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2746	<table border="1" cellspacing="0" cellpadding="4">
				2747	<tbody>
				2748	<tr>
				2749	<td>In0</td>
				2750	<td>In1</td>
				2751	<td>Out</td>
				2752	</tr>
				2753	<tr>
				2754	<td>0</td>
				2755	<td>0</td>
				2756	<td>0</td>
				2757	</tr>
				2758	<tr>
				2759	<td>0</td>
				2760	<td>1</td>
				2761	<td>1</td>
				2762	</tr>
				2763	<tr>
				2764	<td>1</td>
				2765	<td>0</td>
				2766	<td>1</td>
				2767	</tr>
				2768	<tr>
				2769	<td>1</td>
				2770	<td>1</td>
				2771	<td>0</td>
				2772	</tr>
				2773	</tbody>
				2774	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2775	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2776	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2777	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2778	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2779	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2780	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2781	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2782	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2783	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2784
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2785	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2786	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2787	<a name="vectorops">Vector Operations</a>
				2788	</div>
				2789
				2790	<div class="doc_text">
				2791
				2792	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2793	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2794	vector-specific operations needed to process vectors effectively. While LLVM
				2795	does directly support these vector operations, many sophisticated algorithms
				2796	will want to use target-specific intrinsics to take full advantage of a specific
				2797	target.</p>
				2798
				2799	</div>
				2800
				2801	<!-- _______________________________________________________________________ -->
				2802	<div class="doc_subsubsection">
				2803	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2804	</div>
				2805
				2806	<div class="doc_text">
				2807
				2808	<h5>Syntax:</h5>
				2809
				2810	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2811	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2812	</pre>
				2813
				2814	<h5>Overview:</h5>
				2815
				2816	<p>
				2817	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2818	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2819	</p>
				2820
				2821
				2822	<h5>Arguments:</h5>
				2823
				2824	<p>
				2825	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2826	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2827	an index indicating the position from which to extract the element.
				2828	The index may be a variable.</p>
				2829
				2830	<h5>Semantics:</h5>
				2831
				2832	<p>
				2833	The result is a scalar of the same type as the element type of
				2834	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2835	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2836	results are undefined.
				2837	</p>
				2838
				2839	<h5>Example:</h5>
				2840
				2841	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2842	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2843	</pre>
				2844	</div>
				2845
				2846
				2847	<!-- _______________________________________________________________________ -->
				2848	<div class="doc_subsubsection">
				2849	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2850	</div>
				2851
				2852	<div class="doc_text">
				2853
				2854	<h5>Syntax:</h5>
				2855
				2856	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	2857	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2858	</pre>
				2859
				2860	<h5>Overview:</h5>
				2861
				2862	<p>
				2863	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2864	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2865	</p>
				2866
				2867
				2868	<h5>Arguments:</h5>
				2869
				2870	<p>
				2871	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2872	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2873	scalar value whose type must equal the element type of the first
				2874	operand. The third operand is an index indicating the position at
				2875	which to insert the value. The index may be a variable.</p>
				2876
				2877	<h5>Semantics:</h5>
				2878
				2879	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2880	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2881	element values are those of <tt>val</tt> except at position
				2882	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2883	exceeds the length of <tt>val</tt>, the results are undefined.
				2884	</p>
				2885
				2886	<h5>Example:</h5>
				2887
				2888	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2889	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2890	</pre>
				2891	</div>
				2892
				2893	<!-- _______________________________________________________________________ -->
				2894	<div class="doc_subsubsection">
				2895	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2896	</div>
				2897
				2898	<div class="doc_text">
				2899
				2900	<h5>Syntax:</h5>
				2901
				2902	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2903	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2904	</pre>
				2905
				2906	<h5>Overview:</h5>
				2907
				2908	<p>
				2909	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2910	from two input vectors, returning a vector of the same type.
				2911	</p>
				2912
				2913	<h5>Arguments:</h5>
				2914
				2915	<p>
				2916	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2917	with types that match each other and types that match the result of the
				2918	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2919	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2920	</p>
				2921
				2922	<p>
				2923	The shuffle mask operand is required to be a constant vector with either
				2924	constant integer or undef values.
				2925	</p>
				2926
				2927	<h5>Semantics:</h5>
				2928
				2929	<p>
				2930	The elements of the two input vectors are numbered from left to right across
				2931	both of the vectors. The shuffle mask operand specifies, for each element of
				2932	the result vector, which element of the two input registers the result element
				2933	gets. The element selector may be undef (meaning "don't care") and the second
				2934	operand may be undef if performing a shuffle from only one vector.
				2935	</p>
				2936
				2937	<h5>Example:</h5>
				2938
				2939	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2940	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2941	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2942	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2943	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2944	</pre>
				2945	</div>
				2946
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	2947
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2948	<!-- ======================================================================= -->
				2949	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2950	<a name="aggregateops">Aggregate Operations</a>
				2951	</div>
				2952
				2953	<div class="doc_text">
				2954
				2955	<p>LLVM supports several instructions for working with aggregate values.
				2956	</p>
				2957
				2958	</div>
				2959
				2960	<!-- _______________________________________________________________________ -->
				2961	<div class="doc_subsubsection">
				2962	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2963	</div>
				2964
				2965	<div class="doc_text">
				2966
				2967	<h5>Syntax:</h5>
				2968
				2969	<pre>
				2970	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2971	</pre>
				2972
				2973	<h5>Overview:</h5>
				2974
				2975	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	2976	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2977	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2978	</p>
				2979
				2980
				2981	<h5>Arguments:</h5>
				2982
				2983	<p>
				2984	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2985	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	2986	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	2987	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2988	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2989	</p>
				2990
				2991	<h5>Semantics:</h5>
				2992
				2993	<p>
				2994	The result is the value at the position in the aggregate specified by
				2995	the index operands.
				2996	</p>
				2997
				2998	<h5>Example:</h5>
				2999
				3000	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3001	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3002	</pre>
				3003	</div>
				3004
				3005
				3006	<!-- _______________________________________________________________________ -->
				3007	<div class="doc_subsubsection">
				3008	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3009	</div>
				3010
				3011	<div class="doc_text">
				3012
				3013	<h5>Syntax:</h5>
				3014
				3015	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3016	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3017	</pre>
				3018
				3019	<h5>Overview:</h5>
				3020
				3021	<p>
				3022	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3023	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3024	</p>
				3025
				3026
				3027	<h5>Arguments:</h5>
				3028
				3029	<p>
				3030	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3031	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3032	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3033	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3034	indicating the position at which to insert the value in a similar manner as
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3035	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3036	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3037	The value to insert must have the same type as the value identified
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3038	by the indices.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3039
				3040	<h5>Semantics:</h5>
				3041
				3042	<p>
				3043	The result is an aggregate of the same type as <tt>val</tt>. Its
				3044	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3045	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3046	</p>
				3047
				3048	<h5>Example:</h5>
				3049
				3050	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3051	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3052	</pre>
				3053	</div>
				3054
				3055
				3056	<!-- ======================================================================= -->
				3057	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3058	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3059	</div>
				3060
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3061	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3062
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3063	<p>A key design point of an SSA-based representation is how it
				3064	represents memory. In LLVM, no memory locations are in SSA form, which
				3065	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3066	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3067
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3068	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3069
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3070	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3071	<div class="doc_subsubsection">
				3072	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3073	</div>
				3074
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3075	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3076
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3077	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3078
				3079	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3080	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3081	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3082
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3083	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3084
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3085	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3086	heap and returns a pointer to it. The object is always allocated in the generic
				3087	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3088
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3089	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3090
				3091	<p>The '<tt>malloc</tt>' instruction allocates
				3092	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3093	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3094	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3095	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3096	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3097	be aligned to at least that boundary. If not specified, or if zero, the target can
				3098	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3099
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3100	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3101
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3102	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3103
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3104	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3105	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3106	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3107
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3108	<h5>Example:</h5>
				3109
				3110	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3111	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3112
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3113	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3114	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3115	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3116	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3117	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3118	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3119	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3120
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3121	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3122	<div class="doc_subsubsection">
				3123	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3124	</div>
				3125
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3126	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3127
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3128	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3129
				3130	<pre>
				3131	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3132	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3133
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3134	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3135
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3136	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3137	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3138
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3139	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3140
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3141	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3142	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3143	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3144
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3145	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3146
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3147	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	0f103e1	2008-04-19 22:41:32 +0000	[diff] [blame]	3148	after this instruction executes. If the pointer is null, the operation
				3149	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3150
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3152
				3153	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3154	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3155	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3156	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3157	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3158
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3159	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3160	<div class="doc_subsubsection">
				3161	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3162	</div>
				3163
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3164	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3165
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3166	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3167
				3168	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3169	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3170	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3171
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3172	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3173
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3174	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3175	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3176	returns to its caller. The object is always allocated in the generic address
				3177	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3178
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3179	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3180
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3181	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3182	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3183	appropriate type to the program. If "NumElements" is specified, it is the
				3184	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3185	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3186	to be aligned to at least that boundary. If not specified, or if zero, the target
				3187	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3188
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3189	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3190
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3191	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3192
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3193	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3194	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3195	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3196	instruction is commonly used to represent automatic variables that must
				3197	have an address available. When the function returns (either with the <tt><a
John Criswell	c932bef	2005-05-12 16:55:34 +0000	[diff] [blame]	3198	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3199	instructions), the memory is reclaimed. Allocating zero bytes
				3200	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3201
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3202	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3203
				3204	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3205	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3206	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3207	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3208	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3210	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3211
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3212	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3213	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3214	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3215	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3216	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3217	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3218	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3219	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3220	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3221	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3222	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3223	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3224	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3225	the number or order of execution of this <tt>load</tt> with other
				3226	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3227	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3228	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3229	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3230	(that is, the alignment of the memory address). A value of 0 or an
				3231	omitted "align" argument means that the operation has the preferential
				3232	alignment for the target. It is the responsibility of the code emitter
				3233	to ensure that the alignment information is correct. Overestimating
				3234	the alignment results in an undefined behavior. Underestimating the
				3235	alignment may produce less efficient code. An alignment of 1 is always
				3236	safe.
				3237	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3238	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3239	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3240	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3241	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3242	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3243	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3244	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3245	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3246	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3247	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3248	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3249	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3250	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3251	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3252	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3253	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3254	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3255	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3256	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3257	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3258	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3259	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3260	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3261	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3262	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3263	optimizer is not allowed to modify the number or order of execution of
				3264	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3265	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3266	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3267	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3268	(that is, the alignment of the memory address). A value of 0 or an
				3269	omitted "align" argument means that the operation has the preferential
				3270	alignment for the target. It is the responsibility of the code emitter
				3271	to ensure that the alignment information is correct. Overestimating
				3272	the alignment results in an undefined behavior. Underestimating the
				3273	alignment may produce less efficient code. An alignment of 1 is always
				3274	safe.
				3275	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3276	<h5>Semantics:</h5>
				3277	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3278	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3279	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3280	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8830ffe	2007-10-22 05:10:05 +0000	[diff] [blame]	3281	store i32 3, i32* %ptr <i>; yields {void}</i>
				3282	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3283	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3284	</div>
				3285
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3286	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3287	<div class="doc_subsubsection">
				3288	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3289	</div>
				3290
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3291	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3292	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3293	<pre>
				3294	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3295	</pre>
				3296
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3297	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3298
				3299	<p>
				3300	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3301	subelement of an aggregate data structure.</p>
				3302
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3303	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3304
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3305	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3306	elements of the aggregate object to index to. The actual types of the arguments
				3307	provided depend on the type of the first pointer argument. The
				3308	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	3309	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3310	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3311	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3312	values will be sign extended to 64-bits if required.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3313
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3314	<p>For example, let's consider a C code fragment and how it gets
				3315	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3316
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3317	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3318	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3319	struct RT {
				3320	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3321	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3322	char C;
				3323	};
				3324	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3325	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3326	double Y;
				3327	struct RT Z;
				3328	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3329
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3330	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3331	return &s[1].Z.B[5][13];
				3332	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3333	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3334	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3335
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3336	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3337
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3338	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3339	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3340	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3341	%ST = type { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3342
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3343	define i32* %foo(%ST* %s) {
				3344	entry:
				3345	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3346	ret i32* %reg
				3347	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3348	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3349	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3350
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3351	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3352
				3353	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3354	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3355	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	c031269	2006-12-03 16:53:48 +0000	[diff] [blame]	3356	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3357	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3358	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3359
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3360	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3361	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3362	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3363	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3364	i8 }</tt>' type, another structure. The third index indexes into the second
				3365	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3366	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3367	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3368	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3369
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3370	<p>Note that it is perfectly legal to index partially through a
				3371	structure, returning a pointer to an inner element. Because of this,
				3372	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3373
				3374	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3375	define i32* %foo(%ST* %s) {
				3376	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3377	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3378	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3379	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3380	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3381	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3382	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3383	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3384
				3385	<p>Note that it is undefined to access an array out of bounds: array and
				3386	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3387	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3388	defined to be accessible as variable length arrays, which requires access
				3389	beyond the zero'th element.</p>
				3390
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3391	<p>The getelementptr instruction is often confusing. For some more insight
				3392	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3393	FAQ</a>.</p>
				3394
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3395	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3396
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3397	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3398	<i>; yields [12 x i8]*:aptr</i>
				3399	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3400	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3401	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3402
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3403	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3404	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3405	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3406	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3407	<p>The instructions in this category are the conversion instructions (casting)
				3408	which all take a single operand and a type. They perform various bit conversions
				3409	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3410	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3411
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3412	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3413	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3414	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3415	</div>
				3416	<div class="doc_text">
				3417
				3418	<h5>Syntax:</h5>
				3419	<pre>
				3420	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3421	</pre>
				3422
				3423	<h5>Overview:</h5>
				3424	<p>
				3425	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3426	</p>
				3427
				3428	<h5>Arguments:</h5>
				3429	<p>
				3430	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3431	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3432	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3433	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3434	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3435
				3436	<h5>Semantics:</h5>
				3437	<p>
				3438	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3439	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3440	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3441	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3442
				3443	<h5>Example:</h5>
				3444	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3445	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3446	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3447	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3448	</pre>
				3449	</div>
				3450
				3451	<!-- _______________________________________________________________________ -->
				3452	<div class="doc_subsubsection">
				3453	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3454	</div>
				3455	<div class="doc_text">
				3456
				3457	<h5>Syntax:</h5>
				3458	<pre>
				3459	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3460	</pre>
				3461
				3462	<h5>Overview:</h5>
				3463	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3464	<tt>ty2</tt>.</p>
				3465
				3466
				3467	<h5>Arguments:</h5>
				3468	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3469	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3470	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3471	<tt>value</tt> must be smaller than the bit size of the destination type,
				3472	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3473
				3474	<h5>Semantics:</h5>
				3475	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3476	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3477
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3478	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3479
				3480	<h5>Example:</h5>
				3481	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3482	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3483	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3484	</pre>
				3485	</div>
				3486
				3487	<!-- _______________________________________________________________________ -->
				3488	<div class="doc_subsubsection">
				3489	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3490	</div>
				3491	<div class="doc_text">
				3492
				3493	<h5>Syntax:</h5>
				3494	<pre>
				3495	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3496	</pre>
				3497
				3498	<h5>Overview:</h5>
				3499	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3500
				3501	<h5>Arguments:</h5>
				3502	<p>
				3503	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3504	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3505	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3506	<tt>value</tt> must be smaller than the bit size of the destination type,
				3507	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3508
				3509	<h5>Semantics:</h5>
				3510	<p>
				3511	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3512	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3513	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3514
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3515	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3516
				3517	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3518	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3519	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3520	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3521	</pre>
				3522	</div>
				3523
				3524	<!-- _______________________________________________________________________ -->
				3525	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3526	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3527	</div>
				3528
				3529	<div class="doc_text">
				3530
				3531	<h5>Syntax:</h5>
				3532
				3533	<pre>
				3534	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3535	</pre>
				3536
				3537	<h5>Overview:</h5>
				3538	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3539	<tt>ty2</tt>.</p>
				3540
				3541
				3542	<h5>Arguments:</h5>
				3543	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3544	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3545	cast it to. The size of <tt>value</tt> must be larger than the size of
				3546	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3547	<i>no-op cast</i>.</p>
				3548
				3549	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3550	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3551	<a href="#t_floating">floating point</a> type to a smaller
				3552	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3553	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3554
				3555	<h5>Example:</h5>
				3556	<pre>
				3557	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3558	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3559	</pre>
				3560	</div>
				3561
				3562	<!-- _______________________________________________________________________ -->
				3563	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3564	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3565	</div>
				3566	<div class="doc_text">
				3567
				3568	<h5>Syntax:</h5>
				3569	<pre>
				3570	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3571	</pre>
				3572
				3573	<h5>Overview:</h5>
				3574	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3575	floating point value.</p>
				3576
				3577	<h5>Arguments:</h5>
				3578	<p>The '<tt>fpext</tt>' instruction takes a
				3579	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3580	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3581	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3582
				3583	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3584	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3585	<a href="#t_floating">floating point</a> type to a larger
				3586	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3587	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3588	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3589
				3590	<h5>Example:</h5>
				3591	<pre>
				3592	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3593	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3594	</pre>
				3595	</div>
				3596
				3597	<!-- _______________________________________________________________________ -->
				3598	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3599	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3600	</div>
				3601	<div class="doc_text">
				3602
				3603	<h5>Syntax:</h5>
				3604	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3605	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3606	</pre>
				3607
				3608	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3609	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3610	unsigned integer equivalent of type <tt>ty2</tt>.
				3611	</p>
				3612
				3613	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3614	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3615	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3616	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3617	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3618	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3619
				3620	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3621	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3622	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3623	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3624	the results are undefined.</p>
				3625
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3626	<h5>Example:</h5>
				3627	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3628	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3629	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3630	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3631	</pre>
				3632	</div>
				3633
				3634	<!-- _______________________________________________________________________ -->
				3635	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3636	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3637	</div>
				3638	<div class="doc_text">
				3639
				3640	<h5>Syntax:</h5>
				3641	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3642	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3643	</pre>
				3644
				3645	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3646	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3647	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3648	</p>
				3649
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3650	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3651	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3652	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3653	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3654	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3655	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3656
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3657	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3658	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3659	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3660	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3661	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3662
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3663	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3664	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3665	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3666	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3667	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3668	</pre>
				3669	</div>
				3670
				3671	<!-- _______________________________________________________________________ -->
				3672	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3673	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3674	</div>
				3675	<div class="doc_text">
				3676
				3677	<h5>Syntax:</h5>
				3678	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3679	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3680	</pre>
				3681
				3682	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3683	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3684	integer and converts that value to the <tt>ty2</tt> type.</p>
				3685
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3686	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3687	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3688	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3689	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3690	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3691	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3692
				3693	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3694	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3695	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3696	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3697
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3698	<h5>Example:</h5>
				3699	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3700	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3701	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3702	</pre>
				3703	</div>
				3704
				3705	<!-- _______________________________________________________________________ -->
				3706	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3707	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3708	</div>
				3709	<div class="doc_text">
				3710
				3711	<h5>Syntax:</h5>
				3712	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3713	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3714	</pre>
				3715
				3716	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3717	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3718	integer and converts that value to the <tt>ty2</tt> type.</p>
				3719
				3720	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3721	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3722	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3723	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3724	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3725	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3726
				3727	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3728	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3729	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3730	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3731
				3732	<h5>Example:</h5>
				3733	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3734	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3735	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3736	</pre>
				3737	</div>
				3738
				3739	<!-- _______________________________________________________________________ -->
				3740	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3741	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3742	</div>
				3743	<div class="doc_text">
				3744
				3745	<h5>Syntax:</h5>
				3746	<pre>
				3747	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3748	</pre>
				3749
				3750	<h5>Overview:</h5>
				3751	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3752	the integer type <tt>ty2</tt>.</p>
				3753
				3754	<h5>Arguments:</h5>
				3755	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3756	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3757	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3758
				3759	<h5>Semantics:</h5>
				3760	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3761	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3762	truncating or zero extending that value to the size of the integer type. If
				3763	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3764	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3765	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3766	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3767
				3768	<h5>Example:</h5>
				3769	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3770	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3771	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3772	</pre>
				3773	</div>
				3774
				3775	<!-- _______________________________________________________________________ -->
				3776	<div class="doc_subsubsection">
				3777	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3778	</div>
				3779	<div class="doc_text">
				3780
				3781	<h5>Syntax:</h5>
				3782	<pre>
				3783	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3784	</pre>
				3785
				3786	<h5>Overview:</h5>
				3787	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3788	a pointer type, <tt>ty2</tt>.</p>
				3789
				3790	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3791	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3792	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	3793	<a href="#t_pointer">pointer</a> type.
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3794
				3795	<h5>Semantics:</h5>
				3796	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3797	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3798	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3799	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3800	the size of a pointer then a zero extension is done. If they are the same size,
				3801	nothing is done (<i>no-op cast</i>).</p>
				3802
				3803	<h5>Example:</h5>
				3804	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3805	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3806	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3807	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3808	</pre>
				3809	</div>
				3810
				3811	<!-- _______________________________________________________________________ -->
				3812	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3813	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3814	</div>
				3815	<div class="doc_text">
				3816
				3817	<h5>Syntax:</h5>
				3818	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3819	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3820	</pre>
				3821
				3822	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3823
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3824	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3825	<tt>ty2</tt> without changing any bits.</p>
				3826
				3827	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3828
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3829	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	3830	a non-aggregate first class value, and a type to cast it to, which must also be
				3831	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3832	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	3833	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3834	type is a pointer, the destination type must also be a pointer. This
				3835	instruction supports bitwise conversion of vectors to integers and to vectors
				3836	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3837
				3838	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3839	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3840	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3841	this conversion. The conversion is done as if the <tt>value</tt> had been
				3842	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3843	converted to other pointer types with this instruction. To convert pointers to
				3844	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3845	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3846
				3847	<h5>Example:</h5>
				3848	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3849	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3850	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3851	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3852	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3853	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3854
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3855	<!-- ======================================================================= -->
				3856	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3857	<div class="doc_text">
				3858	<p>The instructions in this category are the "miscellaneous"
				3859	instructions, which defy better classification.</p>
				3860	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3861
				3862	<!-- _______________________________________________________________________ -->
				3863	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3864	</div>
				3865	<div class="doc_text">
				3866	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3867	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3868	</pre>
				3869	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3870	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3871	a vector of boolean values based on comparison
				3872	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3873	<h5>Arguments:</h5>
				3874	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3875	the condition code indicating the kind of comparison to perform. It is not
				3876	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3877	<ol>
				3878	<li><tt>eq</tt>: equal</li>
				3879	<li><tt>ne</tt>: not equal </li>
				3880	<li><tt>ugt</tt>: unsigned greater than</li>
				3881	<li><tt>uge</tt>: unsigned greater or equal</li>
				3882	<li><tt>ult</tt>: unsigned less than</li>
				3883	<li><tt>ule</tt>: unsigned less or equal</li>
				3884	<li><tt>sgt</tt>: signed greater than</li>
				3885	<li><tt>sge</tt>: signed greater or equal</li>
				3886	<li><tt>slt</tt>: signed less than</li>
				3887	<li><tt>sle</tt>: signed less or equal</li>
				3888	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3889	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3890	<a href="#t_pointer">pointer</a>
				3891	or integer <a href="#t_vector">vector</a> typed.
				3892	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3893	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3894	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3895	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3896	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3897	<ol>
				3898	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3899	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3900	</li>
				3901	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3902	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3903	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3904	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3905	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3906	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3907	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3908	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3909	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3910	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3911	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3912	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3913	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3914	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3915	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3916	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3917	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3918	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3919	</ol>
				3920	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3921	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3922	<p>If the operands are integer vectors, then they are compared
				3923	element by element. The result is an <tt>i1</tt> vector with
				3924	the same number of elements as the values being compared.
				3925	Otherwise, the result is an <tt>i1</tt>.
				3926	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3927
				3928	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3929	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3930	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3931	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3932	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3933	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3934	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3935	</pre>
				3936	</div>
				3937
				3938	<!-- _______________________________________________________________________ -->
				3939	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3940	</div>
				3941	<div class="doc_text">
				3942	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3943	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3944	</pre>
				3945	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3946	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3947	or vector of boolean values based on comparison
				3948	of its operands.
				3949	<p>
				3950	If the operands are floating point scalars, then the result
				3951	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3952	</p>
				3953	<p>If the operands are floating point vectors, then the result type
				3954	is a vector of boolean with the same number of elements as the
				3955	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3956	<h5>Arguments:</h5>
				3957	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3958	the condition code indicating the kind of comparison to perform. It is not
				3959	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3960	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3961	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3962	<li><tt>oeq</tt>: ordered and equal</li>
				3963	<li><tt>ogt</tt>: ordered and greater than </li>
				3964	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3965	<li><tt>olt</tt>: ordered and less than </li>
				3966	<li><tt>ole</tt>: ordered and less than or equal</li>
				3967	<li><tt>one</tt>: ordered and not equal</li>
				3968	<li><tt>ord</tt>: ordered (no nans)</li>
				3969	<li><tt>ueq</tt>: unordered or equal</li>
				3970	<li><tt>ugt</tt>: unordered or greater than </li>
				3971	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3972	<li><tt>ult</tt>: unordered or less than </li>
				3973	<li><tt>ule</tt>: unordered or less than or equal</li>
				3974	<li><tt>une</tt>: unordered or not equal</li>
				3975	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3976	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3977	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3978	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	3979	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3980	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3981	either a <a href="#t_floating">floating point</a> type
				3982	or a <a href="#t_vector">vector</a> of floating point type.
				3983	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3984	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3985	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3986	according to the condition code given as <tt>cond</tt>.
				3987	If the operands are vectors, then the vectors are compared
				3988	element by element.
				3989	Each comparison performed
				3990	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3991	<ol>
				3992	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3993	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3994	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3995	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3996	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3997	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3998	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3999	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4000	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4001	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4002	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4003	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4004	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4005	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4006	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4007	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4008	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4009	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4010	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4011	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4012	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4013	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4014	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4015	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4016	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4017	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4018	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4019	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4020	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4021
				4022	<h5>Example:</h5>
				4023	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4024	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4025	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4026	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4027	</pre>
				4028	</div>
				4029
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4030	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4031	<div class="doc_subsubsection">
				4032	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4033	</div>
				4034	<div class="doc_text">
				4035	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4036	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4037	</pre>
				4038	<h5>Overview:</h5>
				4039	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4040	element-wise comparison of its two integer vector operands.</p>
				4041	<h5>Arguments:</h5>
				4042	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4043	the condition code indicating the kind of comparison to perform. It is not
				4044	a value, just a keyword. The possible condition code are:
				4045	<ol>
				4046	<li><tt>eq</tt>: equal</li>
				4047	<li><tt>ne</tt>: not equal </li>
				4048	<li><tt>ugt</tt>: unsigned greater than</li>
				4049	<li><tt>uge</tt>: unsigned greater or equal</li>
				4050	<li><tt>ult</tt>: unsigned less than</li>
				4051	<li><tt>ule</tt>: unsigned less or equal</li>
				4052	<li><tt>sgt</tt>: signed greater than</li>
				4053	<li><tt>sge</tt>: signed greater or equal</li>
				4054	<li><tt>slt</tt>: signed less than</li>
				4055	<li><tt>sle</tt>: signed less or equal</li>
				4056	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4057	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4058	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4059	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4060	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4061	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4062	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4063	identical type as the values being compared. The most significant bit in each
				4064	element is 1 if the element-wise comparison evaluates to true, and is 0
				4065	otherwise. All other bits of the result are undefined. The condition codes
				4066	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4067	instruction</a>.
				4068
				4069	<h5>Example:</h5>
				4070	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4071	<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>
				4072	<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	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4073	</pre>
				4074	</div>
				4075
				4076	<!-- _______________________________________________________________________ -->
				4077	<div class="doc_subsubsection">
				4078	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4079	</div>
				4080	<div class="doc_text">
				4081	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4082	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4083	<h5>Overview:</h5>
				4084	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4085	element-wise comparison of its two floating point vector operands. The output
				4086	elements have the same width as the input elements.</p>
				4087	<h5>Arguments:</h5>
				4088	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4089	the condition code indicating the kind of comparison to perform. It is not
				4090	a value, just a keyword. The possible condition code are:
				4091	<ol>
				4092	<li><tt>false</tt>: no comparison, always returns false</li>
				4093	<li><tt>oeq</tt>: ordered and equal</li>
				4094	<li><tt>ogt</tt>: ordered and greater than </li>
				4095	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4096	<li><tt>olt</tt>: ordered and less than </li>
				4097	<li><tt>ole</tt>: ordered and less than or equal</li>
				4098	<li><tt>one</tt>: ordered and not equal</li>
				4099	<li><tt>ord</tt>: ordered (no nans)</li>
				4100	<li><tt>ueq</tt>: unordered or equal</li>
				4101	<li><tt>ugt</tt>: unordered or greater than </li>
				4102	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4103	<li><tt>ult</tt>: unordered or less than </li>
				4104	<li><tt>ule</tt>: unordered or less than or equal</li>
				4105	<li><tt>une</tt>: unordered or not equal</li>
				4106	<li><tt>uno</tt>: unordered (either nans)</li>
				4107	<li><tt>true</tt>: no comparison, always returns true</li>
				4108	</ol>
				4109	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4110	<a href="#t_floating">floating point</a> typed. They must also be identical
				4111	types.</p>
				4112	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4113	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4114	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4115	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4116	an identical number of elements as the values being compared, and each element
				4117	having identical with to the width of the floating point elements. The most
				4118	significant bit in each element is 1 if the element-wise comparison evaluates to
				4119	true, and is 0 otherwise. All other bits of the result are undefined. The
				4120	condition codes are evaluated identically to the
				4121	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4122
				4123	<h5>Example:</h5>
				4124	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4125	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4126	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4127	</pre>
				4128	</div>
				4129
				4130	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4131	<div class="doc_subsubsection">
				4132	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4133	</div>
				4134
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4135	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4136
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4137	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4138
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4139	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4140	<h5>Overview:</h5>
				4141	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4142	the SSA graph representing the function.</p>
				4143	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4144
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4145	<p>The type of the incoming values is specified with the first type
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4146	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4147	as arguments, with one pair for each predecessor basic block of the
				4148	current block. Only values of <a href="#t_firstclass">first class</a>
				4149	type may be used as the value arguments to the PHI node. Only labels
				4150	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4151
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4152	<p>There must be no non-phi instructions between the start of a basic
				4153	block and the PHI instructions: i.e. PHI instructions must be first in
				4154	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4155
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4156	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4157
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4158	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4159	specified by the pair corresponding to the predecessor basic block that executed
				4160	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4161
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4162	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4163	<pre>
				4164	Loop: ; Infinite loop that counts from 0 on up...
				4165	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4166	%nextindvar = add i32 %indvar, 1
				4167	br label %Loop
				4168	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4169	</div>
				4170
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4171	<!-- _______________________________________________________________________ -->
				4172	<div class="doc_subsubsection">
				4173	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4174	</div>
				4175
				4176	<div class="doc_text">
				4177
				4178	<h5>Syntax:</h5>
				4179
				4180	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4181	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4182
				4183	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4184	</pre>
				4185
				4186	<h5>Overview:</h5>
				4187
				4188	<p>
				4189	The '<tt>select</tt>' instruction is used to choose one value based on a
				4190	condition, without branching.
				4191	</p>
				4192
				4193
				4194	<h5>Arguments:</h5>
				4195
				4196	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4197	The '<tt>select</tt>' instruction requires an 'i1' value or
				4198	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4199	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4200	type. If the val1/val2 are vectors and
				4201	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4202	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4203	</p>
				4204
				4205	<h5>Semantics:</h5>
				4206
				4207	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4208	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4209	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4210	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4211	<p>
				4212	If the condition is a vector of i1, then the value arguments must
				4213	be vectors of the same size, and the selection is done element
				4214	by element.
				4215	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4216
				4217	<h5>Example:</h5>
				4218
				4219	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4220	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4221	</pre>
				4222	</div>
				4223
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4224
				4225	<!-- _______________________________________________________________________ -->
				4226	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4227	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4228	</div>
				4229
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4230	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4231
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4232	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4233	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4234	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4235	</pre>
				4236
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4237	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4238
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4239	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4240
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4241	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4242
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4243	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4244
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4245	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4246	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4247	<p>The optional "tail" marker indicates whether the callee function accesses
				4248	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4249	function call is eligible for tail call optimization. Note that calls may
				4250	be marked "tail" even if they do not occur before a <a
				4251	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4252	</li>
				4253	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4254	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4255	convention</a> the call should use. If none is specified, the call defaults
				4256	to using C calling conventions.
				4257	</li>
				4258	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4259	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4260	the type of the return value. Functions that return no value are marked
				4261	<tt><a href="#t_void">void</a></tt>.</p>
				4262	</li>
				4263	<li>
				4264	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4265	value being invoked. The argument types must match the types implied by
				4266	this signature. This type can be omitted if the function is not varargs
				4267	and if the function type does not return a pointer to a function.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4268	</li>
				4269	<li>
				4270	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4271	be invoked. In most cases, this is a direct function invocation, but
				4272	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4273	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4274	</li>
				4275	<li>
				4276	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4277	function signature argument types. All arguments must be of
				4278	<a href="#t_firstclass">first class</a> type. If the function signature
				4279	indicates the function accepts a variable number of arguments, the extra
				4280	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4281	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4282	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4283
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4284	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4285
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4286	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4287	transfer to a specified function, with its incoming arguments bound to
				4288	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4289	instruction in the called function, control flow continues with the
				4290	instruction after the function call, and the return value of the
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4291	function is bound to the result argument. If the callee returns multiple
				4292	values then the return values of the function are only accessible through
				4293	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4294
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4295	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4296
				4297	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4298	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4299	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4300	%X = tail call i32 @foo() <i>; yields i32</i>
				4301	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4302	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4303
				4304	%struct.A = type { i32, i8 }
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4305	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4306	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4307	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4308	</pre>
				4309
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4310	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4311
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4312	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4313	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4314	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4315	</div>
				4316
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4317	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4318
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4319	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4320
				4321	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4322	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4323	</pre>
				4324
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4325	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4326
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4327	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4328	the "variable argument" area of a function call. It is used to implement the
				4329	<tt>va_arg</tt> macro in C.</p>
				4330
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4331	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4332
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4333	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4334	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4335	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4336	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4337
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4338	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4339
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4340	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4341	type from the specified <tt>va_list</tt> and causes the
				4342	<tt>va_list</tt> to point to the next argument. For more information,
				4343	see the variable argument handling <a href="#int_varargs">Intrinsic
				4344	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4345
				4346	<p>It is legal for this instruction to be called in a function which does not
				4347	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4348	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4349
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4350	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4351	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4352	argument.</p>
				4353
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4354	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4355
				4356	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4357
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4358	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4359
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4360	<!-- _______________________________________________________________________ -->
				4361	<div class="doc_subsubsection">
				4362	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4363	</div>
				4364
				4365	<div class="doc_text">
				4366
				4367	<h5>Syntax:</h5>
				4368	<pre>
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4369	<resultval> = getresult <type> <retval>, <index>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4370	</pre>
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4371
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4372	<h5>Overview:</h5>
				4373
				4374	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4375	from a '<tt><a href="#i_call">call</a></tt>'
				4376	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4377	results.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4378
				4379	<h5>Arguments:</h5>
				4380
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4381	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	1a640a6	2008-04-23 04:06:52 +0000	[diff] [blame]	4382	first argument, or an undef value. The value must have <a
				4383	href="#t_struct">structure type</a>. The second argument is a constant
				4384	unsigned index value which must be in range for the number of values returned
				4385	by the call.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4386
				4387	<h5>Semantics:</h5>
				4388
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4389	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4390	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4391
				4392	<h5>Example:</h5>
				4393
				4394	<pre>
				4395	%struct.A = type { i32, i8 }
				4396
				4397	%r = call %struct.A @foo()
Chris Lattner	141b613	2008-03-21 17:20:51 +0000	[diff] [blame]	4398	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4399	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4400	add i32 %gr, 42
				4401	add i8 %gr1, 41
				4402	</pre>
				4403
				4404	</div>
				4405
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4406	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4407	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4408	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4409
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4410	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4411
				4412	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4413	well known names and semantics and are required to follow certain restrictions.
				4414	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4415	language that does not require changing all of the transformations in LLVM when
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	4416	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4417
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4418	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4419	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4420	begin with this prefix. Intrinsic functions must always be external functions:
				4421	you cannot define the body of intrinsic functions. Intrinsic functions may
				4422	only be used in call or invoke instructions: it is illegal to take the address
				4423	of an intrinsic function. Additionally, because intrinsic functions are part
				4424	of the LLVM language, it is required if any are added that they be documented
				4425	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4426
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4427	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4428	a family of functions that perform the same operation but on different data
				4429	types. Because LLVM can represent over 8 million different integer types,
				4430	overloading is used commonly to allow an intrinsic function to operate on any
				4431	integer type. One or more of the argument types or the result type can be
				4432	overloaded to accept any integer type. Argument types may also be defined as
				4433	exactly matching a previous argument's type or the result type. This allows an
				4434	intrinsic function which accepts multiple arguments, but needs all of them to
				4435	be of the same type, to only be overloaded with respect to a single argument or
				4436	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4437
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4438	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4439	encoded into its function name, each preceded by a period. Only those types
				4440	which are overloaded result in a name suffix. Arguments whose type is matched
				4441	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4442	take an integer of any width and returns an integer of exactly the same integer
				4443	width. This leads to a family of functions such as
				4444	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4445	Only one type, the return type, is overloaded, and only one type suffix is
				4446	required. Because the argument's type is matched against the return type, it
				4447	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4448
				4449	<p>To learn how to add an intrinsic function, please see the
				4450	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4451	</p>
				4452
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4453	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4454
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4455	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4456	<div class="doc_subsection">
				4457	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4458	</div>
				4459
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4460	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4461
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4462	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4463	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4464	intrinsic functions. These functions are related to the similarly
				4465	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4466
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4467	<p>All of these functions operate on arguments that use a
				4468	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4469	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4470	transformations should be prepared to handle these functions regardless of
				4471	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4472
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4473	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4474	instruction and the variable argument handling intrinsic functions are
				4475	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4476
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4477	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4478	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4479	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4480	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4481	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4482	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4483	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4484
				4485	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4486	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4487
				4488	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4489	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4490	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4491	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4492	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4493
				4494	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4495	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4496	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4497	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4498
				4499	declare void @llvm.va_start(i8*)
				4500	declare void @llvm.va_copy(i8, i8)
				4501	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4502	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4503	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4504
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4505	</div>
				4506
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4507	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4508	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4509	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4510	</div>
				4511
				4512
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4513	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4514	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4515	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4516	<h5>Overview:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4517	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4518	<tt>*<arglist></tt> for subsequent use by <tt><a
				4519	href="#i_va_arg">va_arg</a></tt>.</p>
				4520
				4521	<h5>Arguments:</h5>
				4522
				4523	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4524
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4525	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4526
				4527	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4528	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4529	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4530	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4531	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4532	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4533
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4534	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4535
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4536	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4537	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4538	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4539	</div>
				4540
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4541	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4542	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4543	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4544	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4545
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4546	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4547	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4548	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4549
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4550	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4551
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4552	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4553
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4554	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4555
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4556	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4557	macro available in C. In a target-dependent way, it destroys the
				4558	<tt>va_list</tt> element to which the argument points. Calls to <a
				4559	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4560	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4561	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4562
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4563	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4564
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4565	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4566	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4567	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4568	</div>
				4569
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4570	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4571
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4572	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4573
				4574	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4575	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4576	</pre>
				4577
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4578	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4579
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4580	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4581	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4582
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4583	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4584
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4585	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	5305ea5	2005-06-22 20:38:11 +0000	[diff] [blame]	4586	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4587
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4588
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4589	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4590
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4591	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4592	macro available in C. In a target-dependent way, it copies the source
				4593	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4594	intrinsic is necessary because the <tt><a href="#int_va_start">
				4595	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4596	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4597
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4598	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4599
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4600	<!-- ======================================================================= -->
				4601	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4602	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4603	</div>
				4604
				4605	<div class="doc_text">
				4606
				4607	<p>
				4608	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4609	Collection</a> (GC) requires the implementation and generation of these
				4610	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4611	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4612	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4613	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4614	Front-ends for type-safe garbage collected languages should generate these
				4615	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4616	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4617	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4618
				4619	<p>The garbage collection intrinsics only operate on objects in the generic
				4620	address space (address space zero).</p>
				4621
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4622	</div>
				4623
				4624	<!-- _______________________________________________________________________ -->
				4625	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4626	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4627	</div>
				4628
				4629	<div class="doc_text">
				4630
				4631	<h5>Syntax:</h5>
				4632
				4633	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4634	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4635	</pre>
				4636
				4637	<h5>Overview:</h5>
				4638
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4639	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4640	the code generator, and allows some metadata to be associated with it.</p>
				4641
				4642	<h5>Arguments:</h5>
				4643
				4644	<p>The first argument specifies the address of a stack object that contains the
				4645	root pointer. The second pointer (which must be either a constant or a global
				4646	value address) contains the meta-data to be associated with the root.</p>
				4647
				4648	<h5>Semantics:</h5>
				4649
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4650	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4651	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4652	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4653	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4654	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4655
				4656	</div>
				4657
				4658
				4659	<!-- _______________________________________________________________________ -->
				4660	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4661	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4662	</div>
				4663
				4664	<div class="doc_text">
				4665
				4666	<h5>Syntax:</h5>
				4667
				4668	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4669	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4670	</pre>
				4671
				4672	<h5>Overview:</h5>
				4673
				4674	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4675	locations, allowing garbage collector implementations that require read
				4676	barriers.</p>
				4677
				4678	<h5>Arguments:</h5>
				4679
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4680	<p>The second argument is the address to read from, which should be an address
				4681	allocated from the garbage collector. The first object is a pointer to the
				4682	start of the referenced object, if needed by the language runtime (otherwise
				4683	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4684
				4685	<h5>Semantics:</h5>
				4686
				4687	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4688	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4689	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4690	may only be used in a function which <a href="#gc">specifies a GC
				4691	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4692
				4693	</div>
				4694
				4695
				4696	<!-- _______________________________________________________________________ -->
				4697	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4698	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4699	</div>
				4700
				4701	<div class="doc_text">
				4702
				4703	<h5>Syntax:</h5>
				4704
				4705	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4706	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4707	</pre>
				4708
				4709	<h5>Overview:</h5>
				4710
				4711	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4712	locations, allowing garbage collector implementations that require write
				4713	barriers (such as generational or reference counting collectors).</p>
				4714
				4715	<h5>Arguments:</h5>
				4716
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4717	<p>The first argument is the reference to store, the second is the start of the
				4718	object to store it to, and the third is the address of the field of Obj to
				4719	store to. If the runtime does not require a pointer to the object, Obj may be
				4720	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4721
				4722	<h5>Semantics:</h5>
				4723
				4724	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4725	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4726	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4727	may only be used in a function which <a href="#gc">specifies a GC
				4728	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4729
				4730	</div>
				4731
				4732
				4733
				4734	<!-- ======================================================================= -->
				4735	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4736	<a name="int_codegen">Code Generator Intrinsics</a>
				4737	</div>
				4738
				4739	<div class="doc_text">
				4740	<p>
				4741	These intrinsics are provided by LLVM to expose special features that may only
				4742	be implemented with code generator support.
				4743	</p>
				4744
				4745	</div>
				4746
				4747	<!-- _______________________________________________________________________ -->
				4748	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4749	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4750	</div>
				4751
				4752	<div class="doc_text">
				4753
				4754	<h5>Syntax:</h5>
				4755	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4756	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4757	</pre>
				4758
				4759	<h5>Overview:</h5>
				4760
				4761	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4762	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4763	target-specific value indicating the return address of the current function
				4764	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4765	</p>
				4766
				4767	<h5>Arguments:</h5>
				4768
				4769	<p>
				4770	The argument to this intrinsic indicates which function to return the address
				4771	for. Zero indicates the calling function, one indicates its caller, etc. The
				4772	argument is <b>required</b> to be a constant integer value.
				4773	</p>
				4774
				4775	<h5>Semantics:</h5>
				4776
				4777	<p>
				4778	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4779	the return address of the specified call frame, or zero if it cannot be
				4780	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4781	for arguments other than zero, so it should only be used for debugging purposes.
				4782	</p>
				4783
				4784	<p>
				4785	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4786	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4787	source-language caller.
				4788	</p>
				4789	</div>
				4790
				4791
				4792	<!-- _______________________________________________________________________ -->
				4793	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4794	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4795	</div>
				4796
				4797	<div class="doc_text">
				4798
				4799	<h5>Syntax:</h5>
				4800	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4801	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4802	</pre>
				4803
				4804	<h5>Overview:</h5>
				4805
				4806	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4807	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4808	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4809	</p>
				4810
				4811	<h5>Arguments:</h5>
				4812
				4813	<p>
				4814	The argument to this intrinsic indicates which function to return the frame
				4815	pointer for. Zero indicates the calling function, one indicates its caller,
				4816	etc. The argument is <b>required</b> to be a constant integer value.
				4817	</p>
				4818
				4819	<h5>Semantics:</h5>
				4820
				4821	<p>
				4822	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4823	the frame address of the specified call frame, or zero if it cannot be
				4824	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4825	for arguments other than zero, so it should only be used for debugging purposes.
				4826	</p>
				4827
				4828	<p>
				4829	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4830	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4831	source-language caller.
				4832	</p>
				4833	</div>
				4834
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4835	<!-- _______________________________________________________________________ -->
				4836	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4837	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4838	</div>
				4839
				4840	<div class="doc_text">
				4841
				4842	<h5>Syntax:</h5>
				4843	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4844	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4845	</pre>
				4846
				4847	<h5>Overview:</h5>
				4848
				4849	<p>
				4850	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4851	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4852	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4853	features like scoped automatic variable sized arrays in C99.
				4854	</p>
				4855
				4856	<h5>Semantics:</h5>
				4857
				4858	<p>
				4859	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4860	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4861	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4862	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4863	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4864	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4865	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4866	</p>
				4867
				4868	</div>
				4869
				4870	<!-- _______________________________________________________________________ -->
				4871	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4872	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4873	</div>
				4874
				4875	<div class="doc_text">
				4876
				4877	<h5>Syntax:</h5>
				4878	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4879	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4880	</pre>
				4881
				4882	<h5>Overview:</h5>
				4883
				4884	<p>
				4885	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4886	the function stack to the state it was in when the corresponding <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4887	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4888	useful for implementing language features like scoped automatic variable sized
				4889	arrays in C99.
				4890	</p>
				4891
				4892	<h5>Semantics:</h5>
				4893
				4894	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4895	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4896	</p>
				4897
				4898	</div>
				4899
				4900
				4901	<!-- _______________________________________________________________________ -->
				4902	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4903	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4904	</div>
				4905
				4906	<div class="doc_text">
				4907
				4908	<h5>Syntax:</h5>
				4909	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4910	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4911	</pre>
				4912
				4913	<h5>Overview:</h5>
				4914
				4915
				4916	<p>
				4917	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4918	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4919	no
				4920	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	4921	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4922	</p>
				4923
				4924	<h5>Arguments:</h5>
				4925
				4926	<p>
				4927	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4928	determining if the fetch should be for a read (0) or write (1), and
				4929	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	4930	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4931	<tt>locality</tt> arguments must be constant integers.
				4932	</p>
				4933
				4934	<h5>Semantics:</h5>
				4935
				4936	<p>
				4937	This intrinsic does not modify the behavior of the program. In particular,
				4938	prefetches cannot trap and do not produce a value. On targets that support this
				4939	intrinsic, the prefetch can provide hints to the processor cache for better
				4940	performance.
				4941	</p>
				4942
				4943	</div>
				4944
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4945	<!-- _______________________________________________________________________ -->
				4946	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4947	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4948	</div>
				4949
				4950	<div class="doc_text">
				4951
				4952	<h5>Syntax:</h5>
				4953	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4954	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4955	</pre>
				4956
				4957	<h5>Overview:</h5>
				4958
				4959
				4960	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4961	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4962	(PC) in a region of
				4963	code to simulators and other tools. The method is target specific, but it is
				4964	expected that the marker will use exported symbols to transmit the PC of the
				4965	marker.
				4966	The marker makes no guarantees that it will remain with any specific instruction
				4967	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b40261e	2006-03-24 07:16:10 +0000	[diff] [blame]	4968	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4969	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4970	</p>
				4971
				4972	<h5>Arguments:</h5>
				4973
				4974	<p>
				4975	<tt>id</tt> is a numerical id identifying the marker.
				4976	</p>
				4977
				4978	<h5>Semantics:</h5>
				4979
				4980	<p>
				4981	This intrinsic does not modify the behavior of the program. Backends that do not
				4982	support this intrinisic may ignore it.
				4983	</p>
				4984
				4985	</div>
				4986
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4987	<!-- _______________________________________________________________________ -->
				4988	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4989	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4990	</div>
				4991
				4992	<div class="doc_text">
				4993
				4994	<h5>Syntax:</h5>
				4995	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4996	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4997	</pre>
				4998
				4999	<h5>Overview:</h5>
				5000
				5001
				5002	<p>
				5003	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5004	counter register (or similar low latency, high accuracy clocks) on those targets
				5005	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5006	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5007	should only be used for small timings.
				5008	</p>
				5009
				5010	<h5>Semantics:</h5>
				5011
				5012	<p>
				5013	When directly supported, reading the cycle counter should not modify any memory.
				5014	Implementations are allowed to either return a application specific value or a
				5015	system wide value. On backends without support, this is lowered to a constant 0.
				5016	</p>
				5017
				5018	</div>
				5019
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5020	<!-- ======================================================================= -->
				5021	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5022	<a name="int_libc">Standard C Library Intrinsics</a>
				5023	</div>
				5024
				5025	<div class="doc_text">
				5026	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5027	LLVM provides intrinsics for a few important standard C library functions.
				5028	These intrinsics allow source-language front-ends to pass information about the
				5029	alignment of the pointer arguments to the code generator, providing opportunity
				5030	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5031	</p>
				5032
				5033	</div>
				5034
				5035	<!-- _______________________________________________________________________ -->
				5036	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5037	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5038	</div>
				5039
				5040	<div class="doc_text">
				5041
				5042	<h5>Syntax:</h5>
				5043	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5044	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5045	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5046	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5047	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5048	</pre>
				5049
				5050	<h5>Overview:</h5>
				5051
				5052	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5053	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5054	location to the destination location.
				5055	</p>
				5056
				5057	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5058	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5059	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5060	</p>
				5061
				5062	<h5>Arguments:</h5>
				5063
				5064	<p>
				5065	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5066	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5067	specifying the number of bytes to copy, and the fourth argument is the alignment
				5068	of the source and destination locations.
				5069	</p>
				5070
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5071	<p>
				5072	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5073	the caller guarantees that both the source and destination pointers are aligned
				5074	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5075	</p>
				5076
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5077	<h5>Semantics:</h5>
				5078
				5079	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5080	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5081	location to the destination location, which are not allowed to overlap. It
				5082	copies "len" bytes of memory over. If the argument is known to be aligned to
				5083	some boundary, this can be specified as the fourth argument, otherwise it should
				5084	be set to 0 or 1.
				5085	</p>
				5086	</div>
				5087
				5088
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5089	<!-- _______________________________________________________________________ -->
				5090	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5091	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5092	</div>
				5093
				5094	<div class="doc_text">
				5095
				5096	<h5>Syntax:</h5>
				5097	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5098	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5099	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5100	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5101	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5102	</pre>
				5103
				5104	<h5>Overview:</h5>
				5105
				5106	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5107	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5108	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5109	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5110	</p>
				5111
				5112	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5113	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5114	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5115	</p>
				5116
				5117	<h5>Arguments:</h5>
				5118
				5119	<p>
				5120	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5121	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5122	specifying the number of bytes to copy, and the fourth argument is the alignment
				5123	of the source and destination locations.
				5124	</p>
				5125
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5126	<p>
				5127	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5128	the caller guarantees that the source and destination pointers are aligned to
				5129	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5130	</p>
				5131
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5132	<h5>Semantics:</h5>
				5133
				5134	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5135	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5136	location to the destination location, which may overlap. It
				5137	copies "len" bytes of memory over. If the argument is known to be aligned to
				5138	some boundary, this can be specified as the fourth argument, otherwise it should
				5139	be set to 0 or 1.
				5140	</p>
				5141	</div>
				5142
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5143
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5144	<!-- _______________________________________________________________________ -->
				5145	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5146	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5147	</div>
				5148
				5149	<div class="doc_text">
				5150
				5151	<h5>Syntax:</h5>
				5152	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5153	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5154	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5155	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5156	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5157	</pre>
				5158
				5159	<h5>Overview:</h5>
				5160
				5161	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5162	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5163	byte value.
				5164	</p>
				5165
				5166	<p>
				5167	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5168	does not return a value, and takes an extra alignment argument.
				5169	</p>
				5170
				5171	<h5>Arguments:</h5>
				5172
				5173	<p>
				5174	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5175	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5176	argument specifying the number of bytes to fill, and the fourth argument is the
				5177	known alignment of destination location.
				5178	</p>
				5179
				5180	<p>
				5181	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5182	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5183	</p>
				5184
				5185	<h5>Semantics:</h5>
				5186
				5187	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5188	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5189	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5190	destination location. If the argument is known to be aligned to some boundary,
				5191	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5192	1.
				5193	</p>
				5194	</div>
				5195
				5196
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5197	<!-- _______________________________________________________________________ -->
				5198	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5199	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5200	</div>
				5201
				5202	<div class="doc_text">
				5203
				5204	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5205	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5206	floating point or vector of floating point type. Not all targets support all
				5207	types however.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5208	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5209	declare float @llvm.sqrt.f32(float %Val)
				5210	declare double @llvm.sqrt.f64(double %Val)
				5211	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5212	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5213	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5214	</pre>
				5215
				5216	<h5>Overview:</h5>
				5217
				5218	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5219	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5220	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5221	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	00d7cb9	2008-01-29 07:00:44 +0000	[diff] [blame]	5222	negative numbers other than -0.0 (which allows for better optimization, because
				5223	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5224	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5225	</p>
				5226
				5227	<h5>Arguments:</h5>
				5228
				5229	<p>
				5230	The argument and return value are floating point numbers of the same type.
				5231	</p>
				5232
				5233	<h5>Semantics:</h5>
				5234
				5235	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5236	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5237	floating point number.
				5238	</p>
				5239	</div>
				5240
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5241	<!-- _______________________________________________________________________ -->
				5242	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5243	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5244	</div>
				5245
				5246	<div class="doc_text">
				5247
				5248	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5249	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5250	floating point or vector of floating point type. Not all targets support all
				5251	types however.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5252	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5253	declare float @llvm.powi.f32(float %Val, i32 %power)
				5254	declare double @llvm.powi.f64(double %Val, i32 %power)
				5255	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5256	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5257	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5258	</pre>
				5259
				5260	<h5>Overview:</h5>
				5261
				5262	<p>
				5263	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5264	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5265	multiplications is not defined. When a vector of floating point type is
				5266	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5267	</p>
				5268
				5269	<h5>Arguments:</h5>
				5270
				5271	<p>
				5272	The second argument is an integer power, and the first is a value to raise to
				5273	that power.
				5274	</p>
				5275
				5276	<h5>Semantics:</h5>
				5277
				5278	<p>
				5279	This function returns the first value raised to the second power with an
				5280	unspecified sequence of rounding operations.</p>
				5281	</div>
				5282
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5283	<!-- _______________________________________________________________________ -->
				5284	<div class="doc_subsubsection">
				5285	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5286	</div>
				5287
				5288	<div class="doc_text">
				5289
				5290	<h5>Syntax:</h5>
				5291	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5292	floating point or vector of floating point type. Not all targets support all
				5293	types however.
				5294	<pre>
				5295	declare float @llvm.sin.f32(float %Val)
				5296	declare double @llvm.sin.f64(double %Val)
				5297	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5298	declare fp128 @llvm.sin.f128(fp128 %Val)
				5299	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5300	</pre>
				5301
				5302	<h5>Overview:</h5>
				5303
				5304	<p>
				5305	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5306	</p>
				5307
				5308	<h5>Arguments:</h5>
				5309
				5310	<p>
				5311	The argument and return value are floating point numbers of the same type.
				5312	</p>
				5313
				5314	<h5>Semantics:</h5>
				5315
				5316	<p>
				5317	This function returns the sine of the specified operand, returning the
				5318	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5319	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5320	</div>
				5321
				5322	<!-- _______________________________________________________________________ -->
				5323	<div class="doc_subsubsection">
				5324	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5325	</div>
				5326
				5327	<div class="doc_text">
				5328
				5329	<h5>Syntax:</h5>
				5330	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5331	floating point or vector of floating point type. Not all targets support all
				5332	types however.
				5333	<pre>
				5334	declare float @llvm.cos.f32(float %Val)
				5335	declare double @llvm.cos.f64(double %Val)
				5336	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5337	declare fp128 @llvm.cos.f128(fp128 %Val)
				5338	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5339	</pre>
				5340
				5341	<h5>Overview:</h5>
				5342
				5343	<p>
				5344	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5345	</p>
				5346
				5347	<h5>Arguments:</h5>
				5348
				5349	<p>
				5350	The argument and return value are floating point numbers of the same type.
				5351	</p>
				5352
				5353	<h5>Semantics:</h5>
				5354
				5355	<p>
				5356	This function returns the cosine of the specified operand, returning the
				5357	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5358	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5359	</div>
				5360
				5361	<!-- _______________________________________________________________________ -->
				5362	<div class="doc_subsubsection">
				5363	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5364	</div>
				5365
				5366	<div class="doc_text">
				5367
				5368	<h5>Syntax:</h5>
				5369	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5370	floating point or vector of floating point type. Not all targets support all
				5371	types however.
				5372	<pre>
				5373	declare float @llvm.pow.f32(float %Val, float %Power)
				5374	declare double @llvm.pow.f64(double %Val, double %Power)
				5375	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5376	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5377	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5378	</pre>
				5379
				5380	<h5>Overview:</h5>
				5381
				5382	<p>
				5383	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5384	specified (positive or negative) power.
				5385	</p>
				5386
				5387	<h5>Arguments:</h5>
				5388
				5389	<p>
				5390	The second argument is a floating point power, and the first is a value to
				5391	raise to that power.
				5392	</p>
				5393
				5394	<h5>Semantics:</h5>
				5395
				5396	<p>
				5397	This function returns the first value raised to the second power,
				5398	returning the
				5399	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5400	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5401	</div>
				5402
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5403
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5404	<!-- ======================================================================= -->
				5405	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5406	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5407	</div>
				5408
				5409	<div class="doc_text">
				5410	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5411	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5412	These allow efficient code generation for some algorithms.
				5413	</p>
				5414
				5415	</div>
				5416
				5417	<!-- _______________________________________________________________________ -->
				5418	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5419	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5420	</div>
				5421
				5422	<div class="doc_text">
				5423
				5424	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5425	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5426	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5427	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5428	declare i16 @llvm.bswap.i16(i16 <id>)
				5429	declare i32 @llvm.bswap.i32(i32 <id>)
				5430	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5431	</pre>
				5432
				5433	<h5>Overview:</h5>
				5434
				5435	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5436	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5437	values with an even number of bytes (positive multiple of 16 bits). These are
				5438	useful for performing operations on data that is not in the target's native
				5439	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5440	</p>
				5441
				5442	<h5>Semantics:</h5>
				5443
				5444	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5445	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5446	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5447	intrinsic returns an i32 value that has the four bytes of the input i32
				5448	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5449	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5450	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5451	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5452	</p>
				5453
				5454	</div>
				5455
				5456	<!-- _______________________________________________________________________ -->
				5457	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5458	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5459	</div>
				5460
				5461	<div class="doc_text">
				5462
				5463	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5464	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5465	width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5466	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5467	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5468	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5469	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5470	declare i64 @llvm.ctpop.i64(i64 <src>)
				5471	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5472	</pre>
				5473
				5474	<h5>Overview:</h5>
				5475
				5476	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5477	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5478	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5479	</p>
				5480
				5481	<h5>Arguments:</h5>
				5482
				5483	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5484	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5485	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5486	</p>
				5487
				5488	<h5>Semantics:</h5>
				5489
				5490	<p>
				5491	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5492	</p>
				5493	</div>
				5494
				5495	<!-- _______________________________________________________________________ -->
				5496	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5497	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5498	</div>
				5499
				5500	<div class="doc_text">
				5501
				5502	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5503	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5504	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5505	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5506	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5507	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5508	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5509	declare i64 @llvm.ctlz.i64(i64 <src>)
				5510	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5511	</pre>
				5512
				5513	<h5>Overview:</h5>
				5514
				5515	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5516	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5517	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5518	</p>
				5519
				5520	<h5>Arguments:</h5>
				5521
				5522	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5523	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5524	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5525	</p>
				5526
				5527	<h5>Semantics:</h5>
				5528
				5529	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5530	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5531	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5532	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5533	</p>
				5534	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5535
				5536
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5537
				5538	<!-- _______________________________________________________________________ -->
				5539	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5540	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5541	</div>
				5542
				5543	<div class="doc_text">
				5544
				5545	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5546	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5547	integer bit width. Not all targets support all bit widths however.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5548	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5549	declare i8 @llvm.cttz.i8 (i8 <src>)
				5550	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5551	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5552	declare i64 @llvm.cttz.i64(i64 <src>)
				5553	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5554	</pre>
				5555
				5556	<h5>Overview:</h5>
				5557
				5558	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5559	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5560	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5561	</p>
				5562
				5563	<h5>Arguments:</h5>
				5564
				5565	<p>
				5566	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5567	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5568	</p>
				5569
				5570	<h5>Semantics:</h5>
				5571
				5572	<p>
				5573	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5574	in a variable. If the src == 0 then the result is the size in bits of the type
				5575	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5576	</p>
				5577	</div>
				5578
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5579	<!-- _______________________________________________________________________ -->
				5580	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5581	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5582	</div>
				5583
				5584	<div class="doc_text">
				5585
				5586	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5587	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5588	on any integer bit width.
				5589	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5590	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5591	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5592	</pre>
				5593
				5594	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5595	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5596	range of bits from an integer value and returns them in the same bit width as
				5597	the original value.</p>
				5598
				5599	<h5>Arguments:</h5>
				5600	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5601	any bit width but they must have the same bit width. The second and third
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5602	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5603
				5604	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5605	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5606	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5607	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5608	operates in forward mode.</p>
				5609	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5610	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5611	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5612	<ol>
				5613	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5614	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5615	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5616	to determine the number of bits to retain.</li>
				5617	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5618	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5619	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5620	<p>In reverse mode, a similar computation is made except that the bits are
				5621	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5622	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5623	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5624	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5625	</div>
				5626
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5627	<div class="doc_subsubsection">
				5628	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5629	</div>
				5630
				5631	<div class="doc_text">
				5632
				5633	<h5>Syntax:</h5>
				5634	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5635	on any integer bit width.
				5636	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5637	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5638	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5639	</pre>
				5640
				5641	<h5>Overview:</h5>
				5642	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5643	of bits in an integer value with another integer value. It returns the integer
				5644	with the replaced bits.</p>
				5645
				5646	<h5>Arguments:</h5>
				5647	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5648	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5649	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5650	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5651	type since they specify only a bit index.</p>
				5652
				5653	<h5>Semantics:</h5>
				5654	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5655	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5656	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5657	operates in forward mode.</p>
				5658	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5659	truncating it down to the size of the replacement area or zero extending it
				5660	up to that size.</p>
				5661	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5662	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5663	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5664	to the <tt>%hi</tt>th bit.
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5665	<p>In reverse mode, a similar computation is made except that the bits are
				5666	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5667	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5668	<h5>Examples:</h5>
				5669	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5670	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5671	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5672	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5673	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5674	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	5675	</pre>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5676	</div>
				5677
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5678	<!-- ======================================================================= -->
				5679	<div class="doc_subsection">
				5680	<a name="int_debugger">Debugger Intrinsics</a>
				5681	</div>
				5682
				5683	<div class="doc_text">
				5684	<p>
				5685	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5686	are described in the <a
				5687	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5688	Debugging</a> document.
				5689	</p>
				5690	</div>
				5691
				5692
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	5693	<!-- ======================================================================= -->
				5694	<div class="doc_subsection">
				5695	<a name="int_eh">Exception Handling Intrinsics</a>
				5696	</div>
				5697
				5698	<div class="doc_text">
				5699	<p> The LLVM exception handling intrinsics (which all start with
				5700	<tt>llvm.eh.</tt> prefix), are described in the <a
				5701	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5702	Handling</a> document. </p>
				5703	</div>
				5704
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	5705	<!-- ======================================================================= -->
				5706	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5707	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5708	</div>
				5709
				5710	<div class="doc_text">
				5711	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5712	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5713	the <tt>nest</tt> attribute, from a function. The result is a callable
				5714	function pointer lacking the nest parameter - the caller does not need
				5715	to provide a value for it. Instead, the value to use is stored in
				5716	advance in a "trampoline", a block of memory usually allocated
				5717	on the stack, which also contains code to splice the nest value into the
				5718	argument list. This is used to implement the GCC nested function address
				5719	extension.
				5720	</p>
				5721	<p>
				5722	For example, if the function is
				5723	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5724	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5725	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5726	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5727	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5728	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5729	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5730	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5731	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5732	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5733	</div>
				5734
				5735	<!-- _______________________________________________________________________ -->
				5736	<div class="doc_subsubsection">
				5737	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5738	</div>
				5739	<div class="doc_text">
				5740	<h5>Syntax:</h5>
				5741	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5742	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5743	</pre>
				5744	<h5>Overview:</h5>
				5745	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5746	This fills the memory pointed to by <tt>tramp</tt> with code
				5747	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5748	</p>
				5749	<h5>Arguments:</h5>
				5750	<p>
				5751	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5752	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5753	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	f2bcd37	2007-08-22 23:39:54 +0000	[diff] [blame]	5754	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5755	currently provides no portable way of determining them, so a front-end that
				5756	generates this intrinsic needs to have some target-specific knowledge.
				5757	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5758	</p>
				5759	<h5>Semantics:</h5>
				5760	<p>
				5761	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5762	dependent code, turning it into a function. A pointer to this function is
				5763	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5764	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5765	before being called. The new function's signature is the same as that of
				5766	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5767	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5768	of pointer type. Calling the new function is equivalent to calling
				5769	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5770	missing <tt>nest</tt> argument. If, after calling
				5771	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5772	modified, then the effect of any later call to the returned function pointer is
				5773	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5774	</p>
				5775	</div>
				5776
				5777	<!-- ======================================================================= -->
				5778	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5779	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5780	</div>
				5781
				5782	<div class="doc_text">
				5783	<p>
				5784	These intrinsic functions expand the "universal IR" of LLVM to represent
				5785	hardware constructs for atomic operations and memory synchronization. This
				5786	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5787	is aimed at a low enough level to allow any programming models or APIs
				5788	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5789	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5790	hardware behavior. Just as hardware provides a "universal IR" for source
				5791	languages, it also provides a starting point for developing a "universal"
				5792	atomic operation and synchronization IR.
				5793	</p>
				5794	<p>
				5795	These do <em>not</em> form an API such as high-level threading libraries,
				5796	software transaction memory systems, atomic primitives, and intrinsic
				5797	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5798	application libraries. The hardware interface provided by LLVM should allow
				5799	a clean implementation of all of these APIs and parallel programming models.
				5800	No one model or paradigm should be selected above others unless the hardware
				5801	itself ubiquitously does so.
				5802
				5803	</p>
				5804	</div>
				5805
				5806	<!-- _______________________________________________________________________ -->
				5807	<div class="doc_subsubsection">
				5808	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5809	</div>
				5810	<div class="doc_text">
				5811	<h5>Syntax:</h5>
				5812	<pre>
				5813	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5814	i1 <device> )
				5815
				5816	</pre>
				5817	<h5>Overview:</h5>
				5818	<p>
				5819	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5820	specific pairs of memory access types.
				5821	</p>
				5822	<h5>Arguments:</h5>
				5823	<p>
				5824	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5825	The first four arguments enables a specific barrier as listed below. The fith
				5826	argument specifies that the barrier applies to io or device or uncached memory.
				5827
				5828	</p>
				5829	<ul>
				5830	<li><tt>ll</tt>: load-load barrier</li>
				5831	<li><tt>ls</tt>: load-store barrier</li>
				5832	<li><tt>sl</tt>: store-load barrier</li>
				5833	<li><tt>ss</tt>: store-store barrier</li>
				5834	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5835	</ul>
				5836	<h5>Semantics:</h5>
				5837	<p>
				5838	This intrinsic causes the system to enforce some ordering constraints upon
				5839	the loads and stores of the program. This barrier does not indicate
				5840	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5841	which they occur. For any of the specified pairs of load and store operations
				5842	(f.ex. load-load, or store-load), all of the first operations preceding the
				5843	barrier will complete before any of the second operations succeeding the
				5844	barrier begin. Specifically the semantics for each pairing is as follows:
				5845	</p>
				5846	<ul>
				5847	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5848	after the barrier begins.</li>
				5849
				5850	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5851	store after the barrier begins.</li>
				5852	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5853	store after the barrier begins.</li>
				5854	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5855	load after the barrier begins.</li>
				5856	</ul>
				5857	<p>
				5858	These semantics are applied with a logical "and" behavior when more than one
				5859	is enabled in a single memory barrier intrinsic.
				5860	</p>
				5861	<p>
				5862	Backends may implement stronger barriers than those requested when they do not
				5863	support as fine grained a barrier as requested. Some architectures do not
				5864	need all types of barriers and on such architectures, these become noops.
				5865	</p>
				5866	<h5>Example:</h5>
				5867	<pre>
				5868	%ptr = malloc i32
				5869	store i32 4, %ptr
				5870
				5871	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5872	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5873	<i>; guarantee the above finishes</i>
				5874	store i32 8, %ptr <i>; before this begins</i>
				5875	</pre>
				5876	</div>
				5877
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5878	<!-- _______________________________________________________________________ -->
				5879	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5880	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5881	</div>
				5882	<div class="doc_text">
				5883	<h5>Syntax:</h5>
				5884	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5885	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5886	any integer bit width and for different address spaces. Not all targets
				5887	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5888
				5889	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5890	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5891	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5892	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5893	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5894
				5895	</pre>
				5896	<h5>Overview:</h5>
				5897	<p>
				5898	This loads a value in memory and compares it to a given value. If they are
				5899	equal, it stores a new value into the memory.
				5900	</p>
				5901	<h5>Arguments:</h5>
				5902	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5903	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5904	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5905	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5906	this integer type. While any bit width integer may be used, targets may only
				5907	lower representations they support in hardware.
				5908
				5909	</p>
				5910	<h5>Semantics:</h5>
				5911	<p>
				5912	This entire intrinsic must be executed atomically. It first loads the value
				5913	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5914	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5915	loaded value is yielded in all cases. This provides the equivalent of an
				5916	atomic compare-and-swap operation within the SSA framework.
				5917	</p>
				5918	<h5>Examples:</h5>
				5919
				5920	<pre>
				5921	%ptr = malloc i32
				5922	store i32 4, %ptr
				5923
				5924	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5925	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5926	<i>; yields {i32}:result1 = 4</i>
				5927	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5928	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5929
				5930	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5931	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5932	<i>; yields {i32}:result2 = 8</i>
				5933	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5934
				5935	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5936	</pre>
				5937	</div>
				5938
				5939	<!-- _______________________________________________________________________ -->
				5940	<div class="doc_subsubsection">
				5941	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5942	</div>
				5943	<div class="doc_text">
				5944	<h5>Syntax:</h5>
				5945
				5946	<p>
				5947	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5948	integer bit width. Not all targets support all bit widths however.</p>
				5949	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5950	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5951	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5952	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5953	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5954
				5955	</pre>
				5956	<h5>Overview:</h5>
				5957	<p>
				5958	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5959	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5960	at <tt>ptr</tt>.
				5961	</p>
				5962	<h5>Arguments:</h5>
				5963
				5964	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5965	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5966	<tt>val</tt> argument and the result must be integers of the same bit width.
				5967	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5968	integer type. The targets may only lower integer representations they
				5969	support.
				5970	</p>
				5971	<h5>Semantics:</h5>
				5972	<p>
				5973	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5974	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5975	equivalent of an atomic swap operation within the SSA framework.
				5976
				5977	</p>
				5978	<h5>Examples:</h5>
				5979	<pre>
				5980	%ptr = malloc i32
				5981	store i32 4, %ptr
				5982
				5983	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5984	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5985	<i>; yields {i32}:result1 = 4</i>
				5986	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5987	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5988
				5989	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5990	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5991	<i>; yields {i32}:result2 = 8</i>
				5992
				5993	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5994	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5995	</pre>
				5996	</div>
				5997
				5998	<!-- _______________________________________________________________________ -->
				5999	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6000	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6001
				6002	</div>
				6003	<div class="doc_text">
				6004	<h5>Syntax:</h5>
				6005	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6006	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6007	integer bit width. Not all targets support all bit widths however.</p>
				6008	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6009	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6010	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6011	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6012	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6013
				6014	</pre>
				6015	<h5>Overview:</h5>
				6016	<p>
				6017	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6018	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6019	</p>
				6020	<h5>Arguments:</h5>
				6021	<p>
				6022
				6023	The intrinsic takes two arguments, the first a pointer to an integer value
				6024	and the second an integer value. The result is also an integer value. These
				6025	integer types can have any bit width, but they must all have the same bit
				6026	width. The targets may only lower integer representations they support.
				6027	</p>
				6028	<h5>Semantics:</h5>
				6029	<p>
				6030	This intrinsic does a series of operations atomically. It first loads the
				6031	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6032	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6033	</p>
				6034
				6035	<h5>Examples:</h5>
				6036	<pre>
				6037	%ptr = malloc i32
				6038	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6039	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6040	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6041	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6042	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6043	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6044	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6045	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6046	</pre>
				6047	</div>
				6048
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6049	<!-- _______________________________________________________________________ -->
				6050	<div class="doc_subsubsection">
				6051	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6052
				6053	</div>
				6054	<div class="doc_text">
				6055	<h5>Syntax:</h5>
				6056	<p>
				6057	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6058	any integer bit width and for different address spaces. Not all targets
				6059	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6060	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6061	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6062	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6063	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6064	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6065
				6066	</pre>
				6067	<h5>Overview:</h5>
				6068	<p>
				6069	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6070	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6071	</p>
				6072	<h5>Arguments:</h5>
				6073	<p>
				6074
				6075	The intrinsic takes two arguments, the first a pointer to an integer value
				6076	and the second an integer value. The result is also an integer value. These
				6077	integer types can have any bit width, but they must all have the same bit
				6078	width. The targets may only lower integer representations they support.
				6079	</p>
				6080	<h5>Semantics:</h5>
				6081	<p>
				6082	This intrinsic does a series of operations atomically. It first loads the
				6083	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6084	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6085	</p>
				6086
				6087	<h5>Examples:</h5>
				6088	<pre>
				6089	%ptr = malloc i32
				6090	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6091	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6092	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6093	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6094	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6095	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6096	<i>; yields {i32}:result3 = 2</i>
				6097	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6098	</pre>
				6099	</div>
				6100
				6101	<!-- _______________________________________________________________________ -->
				6102	<div class="doc_subsubsection">
				6103	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6104	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6105	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6106	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6107
				6108	</div>
				6109	<div class="doc_text">
				6110	<h5>Syntax:</h5>
				6111	<p>
				6112	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6113	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6114	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6115	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6116	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6117	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6118	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6119	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6120	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6121
				6122	</pre>
				6123
				6124	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6125	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6126	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6127	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6128	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6129
				6130	</pre>
				6131
				6132	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6133	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6134	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6135	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6136	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6137
				6138	</pre>
				6139
				6140	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6141	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6142	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6143	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6144	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6145
				6146	</pre>
				6147	<h5>Overview:</h5>
				6148	<p>
				6149	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6150	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6151	at <tt>ptr</tt>.
				6152	</p>
				6153	<h5>Arguments:</h5>
				6154	<p>
				6155
				6156	These intrinsics take two arguments, the first a pointer to an integer value
				6157	and the second an integer value. The result is also an integer value. These
				6158	integer types can have any bit width, but they must all have the same bit
				6159	width. The targets may only lower integer representations they support.
				6160	</p>
				6161	<h5>Semantics:</h5>
				6162	<p>
				6163	These intrinsics does a series of operations atomically. They first load the
				6164	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6165	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6166	value stored at <tt>ptr</tt>.
				6167	</p>
				6168
				6169	<h5>Examples:</h5>
				6170	<pre>
				6171	%ptr = malloc i32
				6172	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6173	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6174	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6175	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6176	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6177	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6178	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6179	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6180	<i>; yields {i32}:result3 = FF</i>
				6181	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6182	</pre>
				6183	</div>
				6184
				6185
				6186	<!-- _______________________________________________________________________ -->
				6187	<div class="doc_subsubsection">
				6188	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6189	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6190	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6191	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6192
				6193	</div>
				6194	<div class="doc_text">
				6195	<h5>Syntax:</h5>
				6196	<p>
				6197	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6198	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6199	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6200	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6201	support all bit widths however.</p>
				6202	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6203	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6204	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6205	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6206	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6207
				6208	</pre>
				6209
				6210	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6211	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6212	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6213	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6214	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6215
				6216	</pre>
				6217
				6218	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6219	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6220	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6221	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6222	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6223
				6224	</pre>
				6225
				6226	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6227	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6228	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6229	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6230	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6231
				6232	</pre>
				6233	<h5>Overview:</h5>
				6234	<p>
				6235	These intrinsics takes the signed or unsigned minimum or maximum of
				6236	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6237	original value at <tt>ptr</tt>.
				6238	</p>
				6239	<h5>Arguments:</h5>
				6240	<p>
				6241
				6242	These intrinsics take two arguments, the first a pointer to an integer value
				6243	and the second an integer value. The result is also an integer value. These
				6244	integer types can have any bit width, but they must all have the same bit
				6245	width. The targets may only lower integer representations they support.
				6246	</p>
				6247	<h5>Semantics:</h5>
				6248	<p>
				6249	These intrinsics does a series of operations atomically. They first load the
				6250	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6251	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6252	the original value stored at <tt>ptr</tt>.
				6253	</p>
				6254
				6255	<h5>Examples:</h5>
				6256	<pre>
				6257	%ptr = malloc i32
				6258	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6259	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6260	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6261	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6262	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6263	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6264	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6265	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6266	<i>; yields {i32}:result3 = 8</i>
				6267	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6268	</pre>
				6269	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6270
				6271	<!-- ======================================================================= -->
				6272	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6273	<a name="int_general">General Intrinsics</a>
				6274	</div>
				6275
				6276	<div class="doc_text">
				6277	<p> This class of intrinsics is designed to be generic and has
				6278	no specific purpose. </p>
				6279	</div>
				6280
				6281	<!-- _______________________________________________________________________ -->
				6282	<div class="doc_subsubsection">
				6283	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6284	</div>
				6285
				6286	<div class="doc_text">
				6287
				6288	<h5>Syntax:</h5>
				6289	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6290	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6291	</pre>
				6292
				6293	<h5>Overview:</h5>
				6294
				6295	<p>
				6296	The '<tt>llvm.var.annotation</tt>' intrinsic
				6297	</p>
				6298
				6299	<h5>Arguments:</h5>
				6300
				6301	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6302	The first argument is a pointer to a value, the second is a pointer to a
				6303	global string, the third is a pointer to a global string which is the source
				6304	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6305	</p>
				6306
				6307	<h5>Semantics:</h5>
				6308
				6309	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6310	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6311	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6312	annotations. These have no other defined use, they are ignored by code
				6313	generation and optimization.
				6314	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6315	</div>
				6316
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6317	<!-- _______________________________________________________________________ -->
				6318	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6319	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6320	</div>
				6321
				6322	<div class="doc_text">
				6323
				6324	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6325	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6326	any integer bit width.
				6327	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6328	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6329	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6330	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6331	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6332	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6333	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6334	</pre>
				6335
				6336	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6337
				6338	<p>
				6339	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6340	</p>
				6341
				6342	<h5>Arguments:</h5>
				6343
				6344	<p>
				6345	The first argument is an integer value (result of some expression),
				6346	the second is a pointer to a global string, the third is a pointer to a global
				6347	string which is the source file name, and the last argument is the line number.
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6348	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6349	</p>
				6350
				6351	<h5>Semantics:</h5>
				6352
				6353	<p>
				6354	This intrinsic allows annotations to be put on arbitrary expressions
				6355	with arbitrary strings. This can be useful for special purpose optimizations
				6356	that want to look for these annotations. These have no other defined use, they
				6357	are ignored by code generation and optimization.
				6358	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6359
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6360	<!-- _______________________________________________________________________ -->
				6361	<div class="doc_subsubsection">
				6362	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6363	</div>
				6364
				6365	<div class="doc_text">
				6366
				6367	<h5>Syntax:</h5>
				6368	<pre>
				6369	declare void @llvm.trap()
				6370	</pre>
				6371
				6372	<h5>Overview:</h5>
				6373
				6374	<p>
				6375	The '<tt>llvm.trap</tt>' intrinsic
				6376	</p>
				6377
				6378	<h5>Arguments:</h5>
				6379
				6380	<p>
				6381	None
				6382	</p>
				6383
				6384	<h5>Semantics:</h5>
				6385
				6386	<p>
				6387	This intrinsics is lowered to the target dependent trap instruction. If the
				6388	target does not have a trap instruction, this intrinsic will be lowered to the
				6389	call of the abort() function.
				6390	</p>
				6391	</div>
				6392
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6393	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6394	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6395	<address>
				6396	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6397	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6398	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6399	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6400
				6401	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	6402	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6403	Last modified: $Date$
				6404	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6405
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	6406	</body>
				6407	</html>