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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	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	44	</ol>
				45	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	46	<li><a href="#t_derived">Derived Types</a>
				47	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	48	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	49	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	50	<li><a href="#t_function">Function Type</a></li>
				51	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	52	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	53	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	54	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	55	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	56	</ol>
				57	</li>
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	58	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	59	</ol>
				60	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	61	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	62	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	63	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	64	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	65	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				66	<li><a href="#undefvalues">Undefined Values</a></li>
				67	<li><a href="#constantexprs">Constant Expressions</a></li>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	68	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	69	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	70	<li><a href="#othervalues">Other Values</a>
				71	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	72	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	73	</ol>
				74	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	75	<li><a href="#instref">Instruction Reference</a>
				76	<ol>
				77	<li><a href="#terminators">Terminator Instructions</a>
				78	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	79	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				80	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	81	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				82	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	83	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	84	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	85	</ol>
				86	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	87	<li><a href="#binaryops">Binary Operations</a>
				88	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	89	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				90	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				91	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	92	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				93	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				94	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	95	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				96	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				97	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	98	</ol>
				99	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	100	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				101	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	102	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				103	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				104	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	106	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	107	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	108	</ol>
				109	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	110	<li><a href="#vectorops">Vector Operations</a>
				111	<ol>
				112	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				113	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				114	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	115	</ol>
				116	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	117	<li><a href="#aggregateops">Aggregate Operations</a>
				118	<ol>
				119	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				120	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				121	</ol>
				122	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	123	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	124	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	125	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				126	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				127	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	128	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				129	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				130	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	131	</ol>
				132	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	133	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	134	<ol>
				135	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	140	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	144	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				145	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	146	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	147	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	148	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	149	<li><a href="#otherops">Other Operations</a>
				150	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	151	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				152	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	153	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				154	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	155	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	156	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	157	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	158	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></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	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	161	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	163	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	164	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	165	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				166	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	167	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				168	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				169	<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]	170	</ol>
				171	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	172	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				173	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	174	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				175	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				176	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	177	</ol>
				178	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	179	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				180	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	181	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				182	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				183	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				184	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				185	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				186	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				187	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	188	</ol>
				189	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	190	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				191	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	192	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	197	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	200	</ol>
				201	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	202	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	203	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	204	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	205	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				206	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	208	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				209	<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]	210	</ol>
				211	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	212	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				213	<ol>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	214	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				215	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	219	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	220	</ol>
				221	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	222	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	223	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	224	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	225	<ol>
				226	<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]	227	</ol>
				228	</li>
Bill Wendling	f85850f	2008-11-18 22:10:53 +0000	[diff] [blame]	229	<li><a href="#int_atomics">Atomic intrinsics</a>
				230	<ol>
				231	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				232	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				233	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				234	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				235	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				236	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				237	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				238	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				239	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				240	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				241	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				242	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				243	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				244	</ol>
				245	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	246	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	247	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	248	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	249	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	250	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	251	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	252	<li><a href="#int_trap">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	253	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				254	<li><a href="#int_stackprotector">
				255	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	256	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	257	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	258	</ol>
				259	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	260	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	261
				262	<div class="doc_author">
				263	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				264	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	265	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	266
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	267	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	268	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				269	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	271	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	273	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	274	type safety, low-level operations, flexibility, and the capability of
				275	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	276	representation used throughout all phases of the LLVM compilation
				277	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	278	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	279
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	280	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	281	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				282	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	283
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	284	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	285
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	287	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]	288	representation (suitable for fast loading by a Just-In-Time compiler),
				289	and as a human readable assembly language representation. This allows
				290	LLVM to provide a powerful intermediate representation for efficient
				291	compiler transformations and analysis, while providing a natural means
				292	to debug and visualize the transformations. The three different forms
				293	of LLVM are all equivalent. This document describes the human readable
				294	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	295
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	296	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	297	while being expressive, typed, and extensible at the same time. It
				298	aims to be a "universal IR" of sorts, by being at a low enough level
				299	that high-level ideas may be cleanly mapped to it (similar to how
				300	microprocessors are "universal IR's", allowing many source languages to
				301	be mapped to them). By providing type information, LLVM can be used as
				302	the target of optimizations: for example, through pointer analysis, it
				303	can be proven that a C automatic variable is never accessed outside of
				304	the current function... allowing it to be promoted to a simple SSA
				305	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	306
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	307	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	308
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	309	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	312	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	314	<p>It is important to note that this document describes 'well formed'
				315	LLVM assembly language. There is a difference between what the parser
				316	accepts and what is considered 'well formed'. For example, the
				317	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	319	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	320	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	321	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	322	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	323	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	325	<p>...because the definition of <tt>%x</tt> does not dominate all of
				326	its uses. The LLVM infrastructure provides a verification pass that may
				327	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]	328	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	329	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	330	by the verifier pass indicate bugs in transformation passes or input to
				331	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	332	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	333
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	334	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	335
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	336	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	337	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	338	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	339
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	340	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	341
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	342	<p>LLVM identifiers come in two basic types: global and local. Global
				343	identifiers (functions, global variables) begin with the @ character. Local
				344	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	345	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	347	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<li>Named values are represented as a string of characters with their prefix.
				349	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				350	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]	351	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	2008-10-14 23:51:43 +0000	[diff] [blame]	352	with quotes. Special characters may be escaped using "\xx" where xx is the
				353	ASCII code for the character in hexadecimal. In this way, any character can
				354	be used in a name value, even quotes themselves.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	355
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	356	<li>Unnamed values are represented as an unsigned numeric value with their
				357	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	358
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	359	<li>Constants, which are described in a <a href="#constants">section about
				360	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	361	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	362
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	363	<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]	364	don't need to worry about name clashes with reserved words, and the set of
				365	reserved words may be expanded in the future without penalty. Additionally,
				366	unnamed identifiers allow a compiler to quickly come up with a temporary
				367	variable without having to avoid symbol table conflicts.</p>
				368
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	369	<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]	370	languages. There are keywords for different opcodes
				371	('<tt><a href="#i_add">add</a></tt>',
				372	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				373	'<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]	374	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]	375	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	376	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	377
				378	<p>Here is an example of LLVM code to multiply the integer variable
				379	'<tt>%X</tt>' by 8:</p>
				380
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	382
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	383	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	384	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	385	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	386	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	387	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	388
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	389	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	391	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	392	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	393	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	394	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	395	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	396
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	397	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	398
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	399	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	400	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	401	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				402	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				403	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	404	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	405	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	406
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	407	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				408	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	409
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	410	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	411
				412	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				413	line.</li>
				414
				415	<li>Unnamed temporaries are created when the result of a computation is not
				416	assigned to a named value.</li>
				417
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	418	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	419
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	420	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	421
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	422	<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]	423	demonstrating instructions, we will follow an instruction with a comment that
				424	defines the type and name of value produced. Comments are shown in italic
				425	text.</p>
				426
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	427	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	428
				429	<!-- *********************************************************************** -->
				430	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				431	<!-- *********************************************************************** -->
				432
				433	<!-- ======================================================================= -->
				434	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				435	</div>
				436
				437	<div class="doc_text">
				438
				439	<p>LLVM programs are composed of "Module"s, each of which is a
				440	translation unit of the input programs. Each module consists of
				441	functions, global variables, and symbol table entries. Modules may be
				442	combined together with the LLVM linker, which merges function (and
				443	global variable) definitions, resolves forward declarations, and merges
				444	symbol table entries. Here is an example of the "hello world" module:</p>
				445
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	446	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	448	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				449	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]	450
				451	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	452	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	453
				454	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	455	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	456	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	457	%cast210 = <a
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	458	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]	459
				460	<i>; Call puts function to write out the string to stdout...</i>
				461	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	462	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	463	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	464	href="#i_ret">ret</a> i32 0<br>}<br>
				465	</pre>
				466	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	467
				468	<p>This example is made up of a <a href="#globalvars">global variable</a>
				469	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				470	function, and a <a href="#functionstructure">function definition</a>
				471	for "<tt>main</tt>".</p>
				472
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	473	<p>In general, a module is made up of a list of global values,
				474	where both functions and global variables are global values. Global values are
				475	represented by a pointer to a memory location (in this case, a pointer to an
				476	array of char, and a pointer to a function), and have one of the following <a
				477	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	478
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	479	</div>
				480
				481	<!-- ======================================================================= -->
				482	<div class="doc_subsection">
				483	<a name="linkage">Linkage Types</a>
				484	</div>
				485
				486	<div class="doc_text">
				487
				488	<p>
				489	All Global Variables and Functions have one of the following types of linkage:
				490	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	491
				492	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	493
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	494	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				495
				496	<dd>Global values with private linkage are only directly accessible by
				497	objects in the current module. In particular, linking code into a module with
				498	an private global value may cause the private to be renamed as necessary to
				499	avoid collisions. Because the symbol is private to the module, all
				500	references can be updated. This doesn't show up in any symbol table in the
				501	object file.
				502	</dd>
				503
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	504	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	505
Duncan Sands	35e43c1	2009-01-16 09:29:46 +0000	[diff] [blame]	506	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	507	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	508	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	509	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	511	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	512
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	513	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				514	the same name when linkage occurs. This is typically used to implement
				515	inline functions, templates, or other code which must be generated in each
				516	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				517	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	518	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	519
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	520	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				521
				522	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				523	linkage, except that unreferenced <tt>common</tt> globals may not be
				524	discarded. This is used for globals that may be emitted in multiple
				525	translation units, but that are not guaranteed to be emitted into every
				526	translation unit that uses them. One example of this is tentative
				527	definitions in C, such as "<tt>int X;</tt>" at global scope.
				528	</dd>
				529
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	532	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				533	that some targets may choose to emit different assembly sequences for them
				534	for target-dependent reasons. This is used for globals that are declared
				535	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	537
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	538	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	539
				540	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				541	pointer to array type. When two global variables with appending linkage are
				542	linked together, the two global arrays are appended together. This is the
				543	LLVM, typesafe, equivalent of having the system linker append together
				544	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	545	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	546
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	547	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	548
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	549	<dd>The semantics of this linkage follow the ELF object file model: the
				550	symbol is weak until linked, if not linked, the symbol becomes null instead
				551	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	552	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	553
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
				555	<dt><tt><b><a name="linkage_common">common_odr</a></b></tt>: </dt>
				556	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
				557	<dt><tt><b><a name="linkage_externweak">extern_weak_odr</a></b></tt>: </dt>
				558	<dd>Some languages allow inequivalent globals to be merged, such as two
				559	functions with different semantics. Other languages, such as <tt>C++</tt>,
				560	ensure that only equivalent globals are ever merged (the "one definition
				561	rule" - <tt>odr</tt>). Such languages can use the <tt>linkonce_odr</tt>,
				562	<tt>common_odr</tt>, <tt>weak_odr</tt> and <tt>extern_weak_odr</tt> linkage
				563	types to indicate that the global will only be merged with equivalent
				564	globals. These linkage types are otherwise the same as their
				565	non-<tt>odr</tt> versions.
				566	</dd>
				567
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	568	<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]	569
				570	<dd>If none of the above identifiers are used, the global is externally
				571	visible, meaning that it participates in linkage and can be used to resolve
				572	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	573	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	574	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	575
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	576	<p>
				577	The next two types of linkage are targeted for Microsoft Windows platform
				578	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	579	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	580	</p>
				581
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	582	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	583	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				584
				585	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				586	or variable via a global pointer to a pointer that is set up by the DLL
				587	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	588	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	589	</dd>
				590
				591	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				592
				593	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				594	pointer to a pointer in a DLL, so that it can be referenced with the
				595	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	596	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	597	name.
				598	</dd>
				599
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	600	</dl>
				601
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	602	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	603	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				604	variable and was linked with this one, one of the two would be renamed,
				605	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				606	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	607	outside of the current module.</p>
				608	<p>It is illegal for a function <i>declaration</i>
				609	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	610	<tt>extern_weak</tt> or <tt>extern_weak_odr</tt>.</p>
				611	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				612	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	613	</div>
				614
				615	<!-- ======================================================================= -->
				616	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	617	<a name="callingconv">Calling Conventions</a>
				618	</div>
				619
				620	<div class="doc_text">
				621
				622	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				623	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				624	specified for the call. The calling convention of any pair of dynamic
				625	caller/callee must match, or the behavior of the program is undefined. The
				626	following calling conventions are supported by LLVM, and more may be added in
				627	the future:</p>
				628
				629	<dl>
				630	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				631
				632	<dd>This calling convention (the default if no other calling convention is
				633	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	634	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	635	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	636	</dd>
				637
				638	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				639
				640	<dd>This calling convention attempts to make calls as fast as possible
				641	(e.g. by passing things in registers). This calling convention allows the
				642	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]	643	without having to conform to an externally specified ABI (Application Binary
				644	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	645	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				646	supported. This calling convention does not support varargs and requires the
				647	prototype of all callees to exactly match the prototype of the function
				648	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	649	</dd>
				650
				651	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				652
				653	<dd>This calling convention attempts to make code in the caller as efficient
				654	as possible under the assumption that the call is not commonly executed. As
				655	such, these calls often preserve all registers so that the call does not break
				656	any live ranges in the caller side. This calling convention does not support
				657	varargs and requires the prototype of all callees to exactly match the
				658	prototype of the function definition.
				659	</dd>
				660
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	661	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	662
				663	<dd>Any calling convention may be specified by number, allowing
				664	target-specific calling conventions to be used. Target specific calling
				665	conventions start at 64.
				666	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	667	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	668
				669	<p>More calling conventions can be added/defined on an as-needed basis, to
				670	support pascal conventions or any other well-known target-independent
				671	convention.</p>
				672
				673	</div>
				674
				675	<!-- ======================================================================= -->
				676	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	677	<a name="visibility">Visibility Styles</a>
				678	</div>
				679
				680	<div class="doc_text">
				681
				682	<p>
				683	All Global Variables and Functions have one of the following visibility styles:
				684	</p>
				685
				686	<dl>
				687	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				688
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	689	<dd>On targets that use the ELF object file format, default visibility means
				690	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	691	modules and, in shared libraries, means that the declared entity may be
				692	overridden. On Darwin, default visibility means that the declaration is
				693	visible to other modules. Default visibility corresponds to "external
				694	linkage" in the language.
				695	</dd>
				696
				697	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				698
				699	<dd>Two declarations of an object with hidden visibility refer to the same
				700	object if they are in the same shared object. Usually, hidden visibility
				701	indicates that the symbol will not be placed into the dynamic symbol table,
				702	so no other module (executable or shared library) can reference it
				703	directly.
				704	</dd>
				705
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	706	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				707
				708	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				709	the dynamic symbol table, but that references within the defining module will
				710	bind to the local symbol. That is, the symbol cannot be overridden by another
				711	module.
				712	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	713	</dl>
				714
				715	</div>
				716
				717	<!-- ======================================================================= -->
				718	<div class="doc_subsection">
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	719	<a name="namedtypes">Named Types</a>
				720	</div>
				721
				722	<div class="doc_text">
				723
				724	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				725	it easier to read the IR and make the IR more condensed (particularly when
				726	recursive types are involved). An example of a name specification is:
				727	</p>
				728
				729	<div class="doc_code">
				730	<pre>
				731	%mytype = type { %mytype*, i32 }
				732	</pre>
				733	</div>
				734
				735	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				736	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				737	expected with the syntax "%mytype".</p>
				738
				739	<p>Note that type names are aliases for the structural type that they indicate,
				740	and that you can therefore specify multiple names for the same type. This often
				741	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				742	structural typing, the name is not part of the type. When printing out LLVM IR,
				743	the printer will pick <em>one name</em> to render all types of a particular
				744	shape. This means that if you have code where two different source types end up
				745	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				746	unexpected type. This is an important design point and isn't going to
				747	change.</p>
				748
				749	</div>
				750
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	751	<!-- ======================================================================= -->
				752	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	753	<a name="globalvars">Global Variables</a>
				754	</div>
				755
				756	<div class="doc_text">
				757
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	758	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	759	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	760	an explicit section to be placed in, and may have an optional explicit alignment
				761	specified. A variable may be defined as "thread_local", which means that it
				762	will not be shared by threads (each thread will have a separated copy of the
				763	variable). A variable may be defined as a global "constant," which indicates
				764	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]	765	optimization, allowing the global data to be placed in the read-only section of
				766	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	767	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]	768
				769	<p>
				770	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				771	constant, even if the final definition of the global is not. This capability
				772	can be used to enable slightly better optimization of the program, but requires
				773	the language definition to guarantee that optimizations based on the
				774	'constantness' are valid for the translation units that do not include the
				775	definition.
				776	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	777
				778	<p>As SSA values, global variables define pointer values that are in
				779	scope (i.e. they dominate) all basic blocks in the program. Global
				780	variables always define a pointer to their "content" type because they
				781	describe a region of memory, and all memory objects in LLVM are
				782	accessed through pointers.</p>
				783
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	784	<p>A global variable may be declared to reside in a target-specifc numbered
				785	address space. For targets that support them, address spaces may affect how
				786	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	787	the variable. The default address space is zero. The address space qualifier
				788	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	789
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	790	<p>LLVM allows an explicit section to be specified for globals. If the target
				791	supports it, it will emit globals to the section specified.</p>
				792
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	793	<p>An explicit alignment may be specified for a global. If not present, or if
				794	the alignment is set to zero, the alignment of the global is set by the target
				795	to whatever it feels convenient. If an explicit alignment is specified, the
				796	global is forced to have at least that much alignment. All alignments must be
				797	a power of 2.</p>
				798
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	799	<p>For example, the following defines a global in a numbered address space with
				800	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	801
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	802	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	803	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	804	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	805	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	806	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	807
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	808	</div>
				809
				810
				811	<!-- ======================================================================= -->
				812	<div class="doc_subsection">
				813	<a name="functionstructure">Functions</a>
				814	</div>
				815
				816	<div class="doc_text">
				817
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	818	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				819	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	820	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	821	<a href="#callingconv">calling convention</a>, a return type, an optional
				822	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				823	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	824	<a href="#paramattrs">parameter attributes</a>), optional
				825	<a href="#fnattrs">function attributes</a>, an optional section,
				826	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	827	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]	828
				829	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				830	optional <a href="#linkage">linkage type</a>, an optional
				831	<a href="#visibility">visibility style</a>, an optional
				832	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	833	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	834	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]	835	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	836
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	837	<p>A function definition contains a list of basic blocks, forming the CFG
				838	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	839	the function. Each basic block may optionally start with a label (giving the
				840	basic block a symbol table entry), contains a list of instructions, and ends
				841	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				842	function return).</p>
				843
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	844	<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]	845	executed on entrance to the function, and it is not allowed to have predecessor
				846	basic blocks (i.e. there can not be any branches to the entry block of a
				847	function). Because the block can have no predecessors, it also cannot have any
				848	<a href="#i_phi">PHI nodes</a>.</p>
				849
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	850	<p>LLVM allows an explicit section to be specified for functions. If the target
				851	supports it, it will emit functions to the section specified.</p>
				852
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	853	<p>An explicit alignment may be specified for a function. If not present, or if
				854	the alignment is set to zero, the alignment of the function is set by the target
				855	to whatever it feels convenient. If an explicit alignment is specified, the
				856	function is forced to have at least that much alignment. All alignments must be
				857	a power of 2.</p>
				858
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	859	<h5>Syntax:</h5>
				860
				861	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	862	<tt>
				863	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				864	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				865	<ResultType> @<FunctionName> ([argument list])
				866	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				867	[<a href="#gc">gc</a>] { ... }
				868	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	869	</div>
				870
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	871	</div>
				872
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	873
				874	<!-- ======================================================================= -->
				875	<div class="doc_subsection">
				876	<a name="aliasstructure">Aliases</a>
				877	</div>
				878	<div class="doc_text">
				879	<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]	880	function, global variable, another alias or bitcast of global value). Aliases
				881	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	882	optional <a href="#visibility">visibility style</a>.</p>
				883
				884	<h5>Syntax:</h5>
				885
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	886	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	887	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	888	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	889	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	890	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	891
				892	</div>
				893
				894
				895
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	896	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	897	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				898	<div class="doc_text">
				899	<p>The return type and each parameter of a function type may have a set of
				900	<i>parameter attributes</i> associated with them. Parameter attributes are
				901	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	902	a function. Parameter attributes are considered to be part of the function,
				903	not of the function type, so functions with different parameter attributes
				904	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	905
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	906	<p>Parameter attributes are simple keywords that follow the type specified. If
				907	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	908	example:</p>
				909
				910	<div class="doc_code">
				911	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	912	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	913	declare i32 @atoi(i8 zeroext)
				914	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	915	</pre>
				916	</div>
				917
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	918	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				919	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	920
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	921	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	922	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	923	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	924	<dd>This indicates to the code generator that the parameter or return value
				925	should be zero-extended to a 32-bit value by the caller (for a parameter)
				926	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	927
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	928	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	929	<dd>This indicates to the code generator that the parameter or return value
				930	should be sign-extended to a 32-bit value by the caller (for a parameter)
				931	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	932
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	933	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	934	<dd>This indicates that this parameter or return value should be treated
				935	in a special target-dependent fashion during while emitting code for a
				936	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]	937	to memory, though some targets use it to distinguish between two different
				938	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	939
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	940	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	941	<dd>This indicates that the pointer parameter should really be passed by
				942	value to the function. The attribute implies that a hidden copy of the
				943	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]	944	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]	945	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	946	value, but is also valid on pointers to scalars. The copy is considered to
				947	belong to the caller not the callee (for example,
				948	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	949	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	2009-02-05 05:42:28 +0000	[diff] [blame]	950	values. The byval attribute also supports specifying an alignment with the
				951	align attribute. This has a target-specific effect on the code generator
				952	that usually indicates a desired alignment for the synthesized stack
				953	slot.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	954
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	955	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	956	<dd>This indicates that the pointer parameter specifies the address of a
				957	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]	958	This pointer must be guaranteed by the caller to be valid: loads and stores
				959	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	960	be applied to the first parameter. This is not a valid attribute for
				961	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	962
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	963	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	964	<dd>This indicates that the pointer does not alias any global or any other
				965	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	d59572c	2008-11-24 05:00:44 +0000	[diff] [blame]	966	case. On a function return value, <tt>noalias</tt> additionally indicates
				967	that the pointer does not alias any other pointers visible to the
Nick Lewycky	2abb108	2008-12-19 06:39:12 +0000	[diff] [blame]	968	caller. For further details, please see the discussion of the NoAlias
				969	response in
				970	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				971	analysis</a>.</dd>
				972
				973	<dt><tt>nocapture</tt></dt>
				974	<dd>This indicates that the callee does not make any copies of the pointer
				975	that outlive the callee itself. This is not a valid attribute for return
				976	values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	977
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	978	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	979	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	980	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				981	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	982	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	983
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	984	</div>
				985
				986	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	987	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	988	<a name="gc">Garbage Collector Names</a>
				989	</div>
				990
				991	<div class="doc_text">
				992	<p>Each function may specify a garbage collector name, which is simply a
				993	string.</p>
				994
				995	<div class="doc_code"><pre
				996	>define void @f() gc "name" { ...</pre></div>
				997
				998	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				999	collector which will cause the compiler to alter its output in order to support
				1000	the named garbage collection algorithm.</p>
				1001	</div>
				1002
				1003	<!-- ======================================================================= -->
				1004	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1005	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1006	</div>
				1007
				1008	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1009
				1010	<p>Function attributes are set to communicate additional information about
				1011	a function. Function attributes are considered to be part of the function,
				1012	not of the function type, so functions with different parameter attributes
				1013	can have the same function type.</p>
				1014
				1015	<p>Function attributes are simple keywords that follow the type specified. If
				1016	multiple attributes are needed, they are space separated. For
				1017	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1018
				1019	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1020	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1021	define void @f() noinline { ... }
				1022	define void @f() alwaysinline { ... }
				1023	define void @f() alwaysinline optsize { ... }
				1024	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1025	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1026	</div>
				1027
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1028	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1029	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1030	<dd>This attribute indicates that the inliner should attempt to inline this
				1031	function into callers whenever possible, ignoring any active inlining size
				1032	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1033
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1034	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1035	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1036	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1037	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1038
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1039	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1040	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1041	make choices that keep the code size of this function low, and otherwise do
				1042	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1043
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1044	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1045	<dd>This function attribute indicates that the function never returns normally.
				1046	This produces undefined behavior at runtime if the function ever does
				1047	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1048
				1049	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	<dd>This function attribute indicates that the function never returns with an
				1051	unwind or exceptional control flow. If the function does unwind, its runtime
				1052	behavior is undefined.</dd>
				1053
				1054	<dt><tt>readnone</tt></dt>
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1055	<dd>This attribute indicates that the function computes its result (or the
				1056	exception it throws) based strictly on its arguments, without dereferencing any
				1057	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1058	registers, etc) visible to caller functions. It does not write through any
				1059	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				1060	never changes any state visible to callers.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1061
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1062	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1063	<dd>This attribute indicates that the function does not write through any
				1064	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1065	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1066	caller functions. It may dereference pointer arguments and read state that may
				1067	be set in the caller. A readonly function always returns the same value (or
				1068	throws the same exception) when called with the same set of arguments and global
				1069	state.</dd>
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1070
				1071	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1072	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1073	protector. It is in the form of a "canary"—a random value placed on the
				1074	stack before the local variables that's checked upon return from the function to
				1075	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1076	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1077
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1078	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1079	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1080	have an <tt>ssp</tt> attribute.</p></dd>
				1081
				1082	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1083	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1084	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1085	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1086
				1087	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1088	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1089	an <tt>ssp</tt> attribute, then the resulting function will have
				1090	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1091	</dl>
				1092
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1093	</div>
				1094
				1095	<!-- ======================================================================= -->
				1096	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1097	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1098	</div>
				1099
				1100	<div class="doc_text">
				1101	<p>
				1102	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1103	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1104	LLVM and treated as a single unit, but may be separated in the .ll file if
				1105	desired. The syntax is very simple:
				1106	</p>
				1107
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1108	<div class="doc_code">
				1109	<pre>
				1110	module asm "inline asm code goes here"
				1111	module asm "more can go here"
				1112	</pre>
				1113	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1114
				1115	<p>The strings can contain any character by escaping non-printable characters.
				1116	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1117	for the number.
				1118	</p>
				1119
				1120	<p>
				1121	The inline asm code is simply printed to the machine code .s file when
				1122	assembly code is generated.
				1123	</p>
				1124	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1125
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1126	<!-- ======================================================================= -->
				1127	<div class="doc_subsection">
				1128	<a name="datalayout">Data Layout</a>
				1129	</div>
				1130
				1131	<div class="doc_text">
				1132	<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]	1133	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1134	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1135	<p>The <i>layout specification</i> consists of a list of specifications
				1136	separated by the minus sign character ('-'). Each specification starts with a
				1137	letter and may include other information after the letter to define some
				1138	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1139	<dl>
				1140	<dt><tt>E</tt></dt>
				1141	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1142	bits with the most significance have the lowest address location.</dd>
				1143	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1144	<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]	1145	the bits with the least significance have the lowest address location.</dd>
				1146	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1147	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1148	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1149	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1150	too.</dd>
				1151	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1152	<dd>This specifies the alignment for an integer type of a given bit
				1153	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1154	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1155	<dd>This specifies the alignment for a vector type of a given bit
				1156	<i>size</i>.</dd>
				1157	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1158	<dd>This specifies the alignment for a floating point type of a given bit
				1159	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1160	(double).</dd>
				1161	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1162	<dd>This specifies the alignment for an aggregate type of a given bit
				1163	<i>size</i>.</dd>
				1164	</dl>
				1165	<p>When constructing the data layout for a given target, LLVM starts with a
				1166	default set of specifications which are then (possibly) overriden by the
				1167	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1168	are given in this list:</p>
				1169	<ul>
				1170	<li><tt>E</tt> - big endian</li>
				1171	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1172	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1173	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1174	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1175	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1176	<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]	1177	alignment of 64-bits</li>
				1178	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1179	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1180	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1181	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1182	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1183	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1184	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1185	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1186	<ol>
				1187	<li>If the type sought is an exact match for one of the specifications, that
				1188	specification is used.</li>
				1189	<li>If no match is found, and the type sought is an integer type, then the
				1190	smallest integer type that is larger than the bitwidth of the sought type is
				1191	used. If none of the specifications are larger than the bitwidth then the the
				1192	largest integer type is used. For example, given the default specifications
				1193	above, the i7 type will use the alignment of i8 (next largest) while both
				1194	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1195	<li>If no match is found, and the type sought is a vector type, then the
				1196	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1197	as a fall back. This happens because <128 x double> can be implemented
				1198	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1199	</ol>
				1200	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1201
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1202	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1203	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1204	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1205
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1206	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1207
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1208	<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]	1209	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1210	optimizations to be performed on the intermediate representation directly,
				1211	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1212	extra analyses on the side before the transformation. A strong type
				1213	system makes it easier to read the generated code and enables novel
				1214	analyses and transformations that are not feasible to perform on normal
				1215	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1216
				1217	</div>
				1218
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1219	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1220	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1221	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1222	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1223	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1224	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1225
				1226	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1227	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1228	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1229	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1230	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1231	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1232	</tr>
				1233	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1234	<td><a href="#t_floating">floating point</a></td>
				1235	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1236	</tr>
				1237	<tr>
				1238	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1239	<td><a href="#t_integer">integer</a>,
				1240	<a href="#t_floating">floating point</a>,
				1241	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1242	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1243	<a href="#t_struct">structure</a>,
				1244	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1245	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1246	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1247	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1248	<tr>
				1249	<td><a href="#t_primitive">primitive</a></td>
				1250	<td><a href="#t_label">label</a>,
				1251	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1252	<a href="#t_floating">floating point</a>.</td>
				1253	</tr>
				1254	<tr>
				1255	<td><a href="#t_derived">derived</a></td>
				1256	<td><a href="#t_integer">integer</a>,
				1257	<a href="#t_array">array</a>,
				1258	<a href="#t_function">function</a>,
				1259	<a href="#t_pointer">pointer</a>,
				1260	<a href="#t_struct">structure</a>,
				1261	<a href="#t_pstruct">packed structure</a>,
				1262	<a href="#t_vector">vector</a>,
				1263	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1264	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1265	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1266	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1267	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1268
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1269	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1270	most important. Values of these types are the only ones which can be
				1271	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1272	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1273	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1274
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1275	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1276	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1277
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1278	<div class="doc_text">
				1279	<p>The primitive types are the fundamental building blocks of the LLVM
				1280	system.</p>
				1281
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1282	</div>
				1283
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1284	<!-- _______________________________________________________________________ -->
				1285	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1286
				1287	<div class="doc_text">
				1288	<table>
				1289	<tbody>
				1290	<tr><th>Type</th><th>Description</th></tr>
				1291	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1292	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1293	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1294	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1295	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1296	</tbody>
				1297	</table>
				1298	</div>
				1299
				1300	<!-- _______________________________________________________________________ -->
				1301	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1302
				1303	<div class="doc_text">
				1304	<h5>Overview:</h5>
				1305	<p>The void type does not represent any value and has no size.</p>
				1306
				1307	<h5>Syntax:</h5>
				1308
				1309	<pre>
				1310	void
				1311	</pre>
				1312	</div>
				1313
				1314	<!-- _______________________________________________________________________ -->
				1315	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1316
				1317	<div class="doc_text">
				1318	<h5>Overview:</h5>
				1319	<p>The label type represents code labels.</p>
				1320
				1321	<h5>Syntax:</h5>
				1322
				1323	<pre>
				1324	label
				1325	</pre>
				1326	</div>
				1327
				1328
				1329	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1330	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1331
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1332	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1333
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1334	<p>The real power in LLVM comes from the derived types in the system.
				1335	This is what allows a programmer to represent arrays, functions,
				1336	pointers, and other useful types. Note that these derived types may be
				1337	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]	1338
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1339	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1340
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1341	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1342	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1343
				1344	<div class="doc_text">
				1345
				1346	<h5>Overview:</h5>
				1347	<p>The integer type is a very simple derived type that simply specifies an
				1348	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1349	2^23-1 (about 8 million) can be specified.</p>
				1350
				1351	<h5>Syntax:</h5>
				1352
				1353	<pre>
				1354	iN
				1355	</pre>
				1356
				1357	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1358	value.</p>
				1359
				1360	<h5>Examples:</h5>
				1361	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1362	<tbody>
				1363	<tr>
				1364	<td><tt>i1</tt></td>
				1365	<td>a single-bit integer.</td>
				1366	</tr><tr>
				1367	<td><tt>i32</tt></td>
				1368	<td>a 32-bit integer.</td>
				1369	</tr><tr>
				1370	<td><tt>i1942652</tt></td>
				1371	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1372	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1373	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1374	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1375
				1376	<p>Note that the code generator does not yet support large integer types
				1377	to be used as function return types. The specific limit on how large a
				1378	return type the code generator can currently handle is target-dependent;
				1379	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1380	targets.</p>
				1381
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1382	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1383
				1384	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1385	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1386
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1387	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1388
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1389	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1390
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1391	<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]	1392	sequentially in memory. The array type requires a size (number of
				1393	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1394
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1395	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1396
				1397	<pre>
				1398	[<# elements> x <elementtype>]
				1399	</pre>
				1400
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1401	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1402	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1403
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1404	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1405	<table class="layout">
				1406	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1407	<td class="left"><tt>[40 x i32]</tt></td>
				1408	<td class="left">Array of 40 32-bit integer values.</td>
				1409	</tr>
				1410	<tr class="layout">
				1411	<td class="left"><tt>[41 x i32]</tt></td>
				1412	<td class="left">Array of 41 32-bit integer values.</td>
				1413	</tr>
				1414	<tr class="layout">
				1415	<td class="left"><tt>[4 x i8]</tt></td>
				1416	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1417	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1418	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1419	<p>Here are some examples of multidimensional arrays:</p>
				1420	<table class="layout">
				1421	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1422	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1423	<td class="left">3x4 array of 32-bit integer values.</td>
				1424	</tr>
				1425	<tr class="layout">
				1426	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1427	<td class="left">12x10 array of single precision floating point values.</td>
				1428	</tr>
				1429	<tr class="layout">
				1430	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1431	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1432	</tr>
				1433	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1434
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1435	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1436	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]	1437	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1438	As a special case, however, zero length arrays are recognized to be variable
				1439	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1440	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1441
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1442	<p>Note that the code generator does not yet support large aggregate types
				1443	to be used as function return types. The specific limit on how large an
				1444	aggregate return type the code generator can currently handle is
				1445	target-dependent, and also dependent on the aggregate element types.</p>
				1446
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1447	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1448
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1449	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1450	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1451	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1452
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1453	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1454
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1455	<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]	1456	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]	1457	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]	1458	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]	1459	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1460
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1461	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1462
				1463	<pre>
				1464	<returntype list> (<parameter list>)
				1465	</pre>
				1466
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1467	<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]	1468	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1469	which indicates that the function takes a variable number of arguments.
				1470	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1471	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1472	'<tt><returntype list></tt>' is a comma-separated list of
				1473	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1474
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1475	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1476	<table class="layout">
				1477	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1478	<td class="left"><tt>i32 (i32)</tt></td>
				1479	<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]	1480	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1481	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1482	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1483	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1484	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1485	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1486	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1487	<tt>float</tt>.
				1488	</td>
				1489	</tr><tr class="layout">
				1490	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1491	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1492	<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]	1493	which returns an integer. This is the signature for <tt>printf</tt> in
				1494	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1495	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1496	</tr><tr class="layout">
				1497	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1498	<td class="left">A function taking an <tt>i32</tt>, returning two
				1499	<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]	1500	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1501	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1502	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1503
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1504	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1505	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1506	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1507	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1508	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1509	<p>The structure type is used to represent a collection of data members
				1510	together in memory. The packing of the field types is defined to match
				1511	the ABI of the underlying processor. The elements of a structure may
				1512	be any type that has a size.</p>
				1513	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1514	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1515	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1516	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1517	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1518	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1519	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1520	<table class="layout">
				1521	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1522	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1523	<td class="left">A triple of three <tt>i32</tt> values</td>
				1524	</tr><tr class="layout">
				1525	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1526	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1527	second element is a <a href="#t_pointer">pointer</a> to a
				1528	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1529	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1530	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1531	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1532
				1533	<p>Note that the code generator does not yet support large aggregate types
				1534	to be used as function return types. The specific limit on how large an
				1535	aggregate return type the code generator can currently handle is
				1536	target-dependent, and also dependent on the aggregate element types.</p>
				1537
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1538	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1539
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1540	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1541	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1542	</div>
				1543	<div class="doc_text">
				1544	<h5>Overview:</h5>
				1545	<p>The packed structure type is used to represent a collection of data members
				1546	together in memory. There is no padding between fields. Further, the alignment
				1547	of a packed structure is 1 byte. The elements of a packed structure may
				1548	be any type that has a size.</p>
				1549	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1550	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1551	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1552	instruction.</p>
				1553	<h5>Syntax:</h5>
				1554	<pre> < { <type list> } > <br></pre>
				1555	<h5>Examples:</h5>
				1556	<table class="layout">
				1557	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1558	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1559	<td class="left">A triple of three <tt>i32</tt> values</td>
				1560	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1561	<td class="left">
				1562	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1563	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1564	second element is a <a href="#t_pointer">pointer</a> to a
				1565	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1566	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1567	</tr>
				1568	</table>
				1569	</div>
				1570
				1571	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1572	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1573	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1574	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1575	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1576	reference to another object, which must live in memory. Pointer types may have
				1577	an optional address space attribute defining the target-specific numbered
				1578	address space where the pointed-to object resides. The default address space is
				1579	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1580
				1581	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	d1d4cff	2009-02-08 22:21:28 +0000	[diff] [blame]	1582	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1583
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1584	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1585	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1586	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1587	<table class="layout">
				1588	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1589	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1590	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1591	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1592	</tr>
				1593	<tr class="layout">
				1594	<td class="left"><tt>i32 (i32 ) </tt></td>
				1595	<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]	1596	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]	1597	<tt>i32</tt>.</td>
				1598	</tr>
				1599	<tr class="layout">
				1600	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1601	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1602	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1603	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1604	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1605	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1606
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1607	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1608	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1609	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1610
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1611	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1612
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1613	<p>A vector type is a simple derived type that represents a vector
				1614	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1615	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1616	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1617	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1618	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1619	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1620
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1621	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1622
				1623	<pre>
				1624	< <# elements> x <elementtype> >
				1625	</pre>
				1626
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1627	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1628	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1629
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1630	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1631
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1632	<table class="layout">
				1633	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1634	<td class="left"><tt><4 x i32></tt></td>
				1635	<td class="left">Vector of 4 32-bit integer values.</td>
				1636	</tr>
				1637	<tr class="layout">
				1638	<td class="left"><tt><8 x float></tt></td>
				1639	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1640	</tr>
				1641	<tr class="layout">
				1642	<td class="left"><tt><2 x i64></tt></td>
				1643	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1644	</tr>
				1645	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1646
				1647	<p>Note that the code generator does not yet support large vector types
				1648	to be used as function return types. The specific limit on how large a
				1649	vector return type codegen can currently handle is target-dependent;
				1650	currently it's often a few times longer than a hardware vector register.</p>
				1651
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1652	</div>
				1653
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1654	<!-- _______________________________________________________________________ -->
				1655	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1656	<div class="doc_text">
				1657
				1658	<h5>Overview:</h5>
				1659
				1660	<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]	1661	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]	1662	In LLVM, opaque types can eventually be resolved to any type (not just a
				1663	structure type).</p>
				1664
				1665	<h5>Syntax:</h5>
				1666
				1667	<pre>
				1668	opaque
				1669	</pre>
				1670
				1671	<h5>Examples:</h5>
				1672
				1673	<table class="layout">
				1674	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1675	<td class="left"><tt>opaque</tt></td>
				1676	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1677	</tr>
				1678	</table>
				1679	</div>
				1680
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1681	<!-- ======================================================================= -->
				1682	<div class="doc_subsection">
				1683	<a name="t_uprefs">Type Up-references</a>
				1684	</div>
				1685
				1686	<div class="doc_text">
				1687	<h5>Overview:</h5>
				1688	<p>
				1689	An "up reference" allows you to refer to a lexically enclosing type without
				1690	requiring it to have a name. For instance, a structure declaration may contain a
				1691	pointer to any of the types it is lexically a member of. Example of up
				1692	references (with their equivalent as named type declarations) include:</p>
				1693
				1694	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1695	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1696	{ \2 }* %y = type { %y }*
				1697	\1* %z = type %z*
				1698	</pre>
				1699
				1700	<p>
				1701	An up reference is needed by the asmprinter for printing out cyclic types when
				1702	there is no declared name for a type in the cycle. Because the asmprinter does
				1703	not want to print out an infinite type string, it needs a syntax to handle
				1704	recursive types that have no names (all names are optional in llvm IR).
				1705	</p>
				1706
				1707	<h5>Syntax:</h5>
				1708	<pre>
				1709	\<level>
				1710	</pre>
				1711
				1712	<p>
				1713	The level is the count of the lexical type that is being referred to.
				1714	</p>
				1715
				1716	<h5>Examples:</h5>
				1717
				1718	<table class="layout">
				1719	<tr class="layout">
				1720	<td class="left"><tt>\1*</tt></td>
				1721	<td class="left">Self-referential pointer.</td>
				1722	</tr>
				1723	<tr class="layout">
				1724	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1725	<td class="left">Recursive structure where the upref refers to the out-most
				1726	structure.</td>
				1727	</tr>
				1728	</table>
				1729	</div>
				1730
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1731
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1732	<!-- *********************************************************************** -->
				1733	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1734	<!-- *********************************************************************** -->
				1735
				1736	<div class="doc_text">
				1737
				1738	<p>LLVM has several different basic types of constants. This section describes
				1739	them all and their syntax.</p>
				1740
				1741	</div>
				1742
				1743	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1744	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1745
				1746	<div class="doc_text">
				1747
				1748	<dl>
				1749	<dt><b>Boolean constants</b></dt>
				1750
				1751	<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]	1752	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1753	</dd>
				1754
				1755	<dt><b>Integer constants</b></dt>
				1756
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1757	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1758	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1759	integer types.
				1760	</dd>
				1761
				1762	<dt><b>Floating point constants</b></dt>
				1763
				1764	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1765	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1766	notation (see below). The assembler requires the exact decimal value of
				1767	a floating-point constant. For example, the assembler accepts 1.25 but
				1768	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1769	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]	1770
				1771	<dt><b>Null pointer constants</b></dt>
				1772
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1773	<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]	1774	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1775
				1776	</dl>
				1777
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1778	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1779	of floating point constants. For example, the form '<tt>double
				1780	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1781	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]	1782	(and the only time that they are generated by the disassembler) is when a
				1783	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1784	decimal floating point number in a reasonable number of digits. For example,
				1785	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1786	special values are represented in their IEEE hexadecimal format so that
				1787	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1788	<p>When using the hexadecimal form, constants of types float and double are
				1789	represented using the 16-digit form shown above (which matches the IEEE754
				1790	representation for double); float values must, however, be exactly representable
				1791	as IEE754 single precision.
				1792	Hexadecimal format is always used for long
				1793	double, and there are three forms of long double. The 80-bit
				1794	format used by x86 is represented as <tt>0xK</tt>
				1795	followed by 20 hexadecimal digits.
				1796	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1797	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1798	format is represented
				1799	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1800	target uses this format. Long doubles will only work if they match
				1801	the long double format on your target. All hexadecimal formats are big-endian
				1802	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1803	</div>
				1804
				1805	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1806	<div class="doc_subsection">
				1807	<a name="aggregateconstants"> <!-- old anchor -->
				1808	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1809	</div>
				1810
				1811	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1812	<p>Complex constants are a (potentially recursive) combination of simple
				1813	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1814
				1815	<dl>
				1816	<dt><b>Structure constants</b></dt>
				1817
				1818	<dd>Structure constants are represented with notation similar to structure
				1819	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1820	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1821	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]	1822	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]	1823	types of elements must match those specified by the type.
				1824	</dd>
				1825
				1826	<dt><b>Array constants</b></dt>
				1827
				1828	<dd>Array constants are represented with notation similar to array type
				1829	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1830	(<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]	1831	constants must have <a href="#t_array">array type</a>, and the number and
				1832	types of elements must match those specified by the type.
				1833	</dd>
				1834
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1835	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1836
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1837	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1838	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1839	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1840	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1841	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]	1842	match those specified by the type.
				1843	</dd>
				1844
				1845	<dt><b>Zero initialization</b></dt>
				1846
				1847	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1848	value to zero of <em>any</em> type, including scalar and aggregate types.
				1849	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]	1850	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1851	initializers.
				1852	</dd>
				1853	</dl>
				1854
				1855	</div>
				1856
				1857	<!-- ======================================================================= -->
				1858	<div class="doc_subsection">
				1859	<a name="globalconstants">Global Variable and Function Addresses</a>
				1860	</div>
				1861
				1862	<div class="doc_text">
				1863
				1864	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1865	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1866	constants. These constants are explicitly referenced when the <a
				1867	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]	1868	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1869	file:</p>
				1870
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1871	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1872	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1873	@X = global i32 17
				1874	@Y = global i32 42
				1875	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1876	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1877	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1878
				1879	</div>
				1880
				1881	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1882	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1883	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1884	<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]	1885	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]	1886	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1887
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1888	<p>Undefined values indicate to the compiler that the program is well defined
				1889	no matter what value is used, giving the compiler more freedom to optimize.
				1890	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1891	</div>
				1892
				1893	<!-- ======================================================================= -->
				1894	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1895	</div>
				1896
				1897	<div class="doc_text">
				1898
				1899	<p>Constant expressions are used to allow expressions involving other constants
				1900	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1901	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]	1902	that does not have side effects (e.g. load and call are not supported). The
				1903	following is the syntax for constant expressions:</p>
				1904
				1905	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1906	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1907	<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]	1908	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1909
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1910	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1911	<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]	1912	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]	1913
				1914	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1915	<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]	1916	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]	1917
				1918	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1919	<dd>Truncate a floating point constant to another floating point type. The
				1920	size of CST must be larger than the size of TYPE. Both types must be
				1921	floating point.</dd>
				1922
				1923	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1924	<dd>Floating point extend a constant to another type. The size of CST must be
				1925	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1926
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1927	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1928	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1929	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1930	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1931	of the same number of elements. If the value won't fit in the integer type,
				1932	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1933
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1934	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1935	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1936	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1937	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1938	of the same number of elements. If the value won't fit in the integer type,
				1939	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1940
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1941	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1942	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1943	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1944	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1945	of the same number of elements. If the value won't fit in the floating point
				1946	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1947
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1948	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1949	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1950	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1951	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1952	of the same number of elements. If the value won't fit in the floating point
				1953	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1954
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1955	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1956	<dd>Convert a pointer typed constant to the corresponding integer constant
				1957	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1958	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1959
				1960	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1961	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1962	pointer type. CST must be of integer type. The CST value is zero extended,
				1963	truncated, or unchanged to make it fit in a pointer size. This one is
				1964	<i>really</i> dangerous!</dd>
				1965
				1966	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	1967	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				1968	are the same as those for the <a href="#i_bitcast">bitcast
				1969	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1970
				1971	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1972
				1973	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1974	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1975	instruction, the index list may have zero or more indexes, which are required
				1976	to make sense for the type of "CSTPTR".</dd>
				1977
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1978	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1979
				1980	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1981	constants.</dd>
				1982
				1983	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1984	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1985
				1986	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1987	<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]	1988
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	1989	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1990	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1991
				1992	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1993	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1994
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1995	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1996
				1997	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1998	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1999
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2000	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2001
				2002	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2003	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2004
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2005
				2006	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2007
				2008	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2009	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2010
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2011	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2012
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2013	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2014	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]	2015	binary</a> operations. The constraints on operands are the same as those for
				2016	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2017	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2018	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2019	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2020
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2021	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2022	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2023	<!-- *********************************************************************** -->
				2024
				2025	<!-- ======================================================================= -->
				2026	<div class="doc_subsection">
				2027	<a name="inlineasm">Inline Assembler Expressions</a>
				2028	</div>
				2029
				2030	<div class="doc_text">
				2031
				2032	<p>
				2033	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2034	Module-Level Inline Assembly</a>) through the use of a special value. This
				2035	value represents the inline assembler as a string (containing the instructions
				2036	to emit), a list of operand constraints (stored as a string), and a flag that
				2037	indicates whether or not the inline asm expression has side effects. An example
				2038	inline assembler expression is:
				2039	</p>
				2040
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2041	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2042	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2043	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2044	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2045	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2046
				2047	<p>
				2048	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2049	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2050	</p>
				2051
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2052	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2053	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2054	%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]	2055	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2056	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2057
				2058	<p>
				2059	Inline asms with side effects not visible in the constraint list must be marked
				2060	as having side effects. This is done through the use of the
				2061	'<tt>sideeffect</tt>' keyword, like so:
				2062	</p>
				2063
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2064	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2065	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2066	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2067	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2068	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2069
				2070	<p>TODO: The format of the asm and constraints string still need to be
				2071	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	d552826	2008-10-04 18:36:02 +0000	[diff] [blame]	2072	need to be documented). This is probably best done by reference to another
				2073	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2074	</p>
				2075
				2076	</div>
				2077
				2078	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2079	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2080	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2081
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2082	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2083
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2084	<p>The LLVM instruction set consists of several different
				2085	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2086	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2087	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2088	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2089	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2090
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2091	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2092
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2093	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2094	<div class="doc_subsection"> <a name="terminators">Terminator
				2095	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2096
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2097	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2098
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2099	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2100	basic block in a program ends with a "Terminator" instruction, which
				2101	indicates which block should be executed after the current block is
				2102	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2103	value: they produce control flow, not values (the one exception being
				2104	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2105	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2106	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2107	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2108	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2109	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2110	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2111
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2112	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2113
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2114	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2115	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2116	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2117	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2118	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2119	<pre>
				2120	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]	2121	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2122	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2123
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2124	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2125
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2126	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2127	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2128	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2129	returns a value and then causes control flow, and one that just causes
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2130	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2131
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2132	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2133
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2134	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2135	the return value. The type of the return value must be a
				2136	'<a href="#t_firstclass">first class</a>' type.</p>
				2137
				2138	<p>A function is not <a href="#wellformed">well formed</a> if
				2139	it it has a non-void return type and contains a '<tt>ret</tt>'
				2140	instruction with no return value or a return value with a type that
				2141	does not match its type, or if it has a void return type and contains
				2142	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2143
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2144	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2145
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2146	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2147	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]	2148	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2149	the instruction after the call. If the caller was an "<a
				2150	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2151	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2152	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2153	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2154
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2155	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2156
				2157	<pre>
				2158	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2159	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2160	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2161	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2162
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2163	<p>Note that the code generator does not yet fully support large
				2164	return values. The specific sizes that are currently supported are
				2165	dependent on the target. For integers, on 32-bit targets the limit
				2166	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2167	For aggregate types, the current limits are dependent on the element
				2168	types; for example targets are often limited to 2 total integer
				2169	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2170
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2171	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2172	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2173	<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]	2174	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2175	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2176	<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]	2177	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2179	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2180	transfer to a different basic block in the current function. There are
				2181	two forms of this instruction, corresponding to a conditional branch
				2182	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2183	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2184	<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]	2185	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2186	unconditional form of the '<tt>br</tt>' instruction takes a single
				2187	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2188	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2189	<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]	2190	argument is evaluated. If the value is <tt>true</tt>, control flows
				2191	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2192	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2193	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2194	<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]	2195	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]	2196	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2198	<div class="doc_subsubsection">
				2199	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2200	</div>
				2201
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2202	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2204
				2205	<pre>
				2206	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2207	</pre>
				2208
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2209	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2210
				2211	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2212	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2213	instruction, allowing a branch to occur to one of many possible
				2214	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2215
				2216
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2218
				2219	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2220	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2221	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2222	table is not allowed to contain duplicate constant entries.</p>
				2223
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2225
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2226	<p>The <tt>switch</tt> instruction specifies a table of values and
				2227	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2228	table is searched for the given value. If the value is found, control flow is
				2229	transfered to the corresponding destination; otherwise, control flow is
				2230	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2231
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2232	<h5>Implementation:</h5>
				2233
				2234	<p>Depending on properties of the target machine and the particular
				2235	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2236	ways. For example, it could be generated as a series of chained conditional
				2237	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2238
				2239	<h5>Example:</h5>
				2240
				2241	<pre>
				2242	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2243	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2244	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2245
				2246	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2247	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2248
				2249	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2250	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2251	i32 1, label %onone
				2252	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2253	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2254	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2255
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2257	<div class="doc_subsubsection">
				2258	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2259	</div>
				2260
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2261	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2262
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2264
				2265	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2266	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2267	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2268	</pre>
				2269
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2270	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2271
				2272	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2273	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2274	'<tt>normal</tt>' label or the
				2275	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2276	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2277	"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]	2278	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2279	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2280
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2281	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2282
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2283	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2284
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2285	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2286	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2287	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2288	convention</a> the call should use. If none is specified, the call defaults
				2289	to using C calling conventions.
				2290	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2291
				2292	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2293	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2294	and '<tt>inreg</tt>' attributes are valid here.</li>
				2295
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2296	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2297	function value being invoked. In most cases, this is a direct function
				2298	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2299	an arbitrary pointer to function value.
				2300	</li>
				2301
				2302	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2303	function to be invoked. </li>
				2304
				2305	<li>'<tt>function args</tt>': argument list whose types match the function
				2306	signature argument types. If the function signature indicates the function
				2307	accepts a variable number of arguments, the extra arguments can be
				2308	specified. </li>
				2309
				2310	<li>'<tt>normal label</tt>': the label reached when the called function
				2311	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2312
				2313	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2314	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2315
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2316	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2317	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2318	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2319	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2320
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2321	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2322
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2323	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2324	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2325	difference is that it establishes an association with a label, which is used by
				2326	the runtime library to unwind the stack.</p>
				2327
				2328	<p>This instruction is used in languages with destructors to ensure that proper
				2329	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2330	exception. Additionally, this is important for implementation of
				2331	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2332
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2333	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2334	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2335	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2336	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2337	%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]	2338	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2339	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2340	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2341
				2342
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2343	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2344
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2345	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2346	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2347
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2348	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2349
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2350	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2351	<pre>
				2352	unwind
				2353	</pre>
				2354
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2355	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2356
				2357	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2358	at the first callee in the dynamic call stack which used an <a
				2359	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2360	primarily used to implement exception handling.</p>
				2361
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2362	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2363
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2364	<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]	2365	immediately halt. The dynamic call stack is then searched for the first <a
				2366	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2367	execution continues at the "exceptional" destination block specified by the
				2368	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2369	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2370	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2371
				2372	<!-- _______________________________________________________________________ -->
				2373
				2374	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2375	Instruction</a> </div>
				2376
				2377	<div class="doc_text">
				2378
				2379	<h5>Syntax:</h5>
				2380	<pre>
				2381	unreachable
				2382	</pre>
				2383
				2384	<h5>Overview:</h5>
				2385
				2386	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2387	instruction is used to inform the optimizer that a particular portion of the
				2388	code is not reachable. This can be used to indicate that the code after a
				2389	no-return function cannot be reached, and other facts.</p>
				2390
				2391	<h5>Semantics:</h5>
				2392
				2393	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2394	</div>
				2395
				2396
				2397
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2398	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2399	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2400	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2401	<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]	2402	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]	2403	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2404	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]	2405	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2406	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2407	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2408	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2409	<div class="doc_subsubsection">
				2410	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2411	</div>
				2412
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2413	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2414
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2415	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2416
				2417	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2418	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2419	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2420
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2421	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2422
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2423	<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]	2424
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2425	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2426
				2427	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2428	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2429	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2430	types.</p>
				2431
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2432	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2433
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2434	<p>The value produced is the integer or floating point sum of the two
				2435	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2436
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2437	<p>If an integer sum has unsigned overflow, the result returned is the
				2438	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2439	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2440
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2441	<p>Because LLVM integers use a two's complement representation, this
				2442	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2443
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2444	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2445
				2446	<pre>
				2447	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2448	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2449	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2450	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2451	<div class="doc_subsubsection">
				2452	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2453	</div>
				2454
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2455	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2456
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2457	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2458
				2459	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2460	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2461	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2462
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2463	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2464
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2465	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2466	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2467
				2468	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2469	'<tt>neg</tt>' instruction present in most other intermediate
				2470	representations.</p>
				2471
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2472	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2473
				2474	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2475	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2476	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2477	types.</p>
				2478
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2479	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2480
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2481	<p>The value produced is the integer or floating point difference of
				2482	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2483
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2484	<p>If an integer difference has unsigned overflow, the result returned is the
				2485	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2486	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2487
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2488	<p>Because LLVM integers use a two's complement representation, this
				2489	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2490
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2491	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2492	<pre>
				2493	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2494	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2495	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2496	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2497
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2498	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2499	<div class="doc_subsubsection">
				2500	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2501	</div>
				2502
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2503	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2505	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2506	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2508	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2509	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2510	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2511
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2512	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
				2514	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2515	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2516	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2517	types.</p>
				2518
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2519	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2521	<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]	2522	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2523
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2524	<p>If the result of an integer multiplication has unsigned overflow,
				2525	the result returned is the mathematical result modulo
				2526	2<sup>n</sup>, where n is the bit width of the result.</p>
				2527	<p>Because LLVM integers use a two's complement representation, and the
				2528	result is the same width as the operands, this instruction returns the
				2529	correct result for both signed and unsigned integers. If a full product
				2530	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2531	should be sign-extended or zero-extended as appropriate to the
				2532	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2533	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2534	<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]	2535	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2536	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2537
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2538	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2539	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2540	</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> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2544	</pre>
				2545	<h5>Overview:</h5>
				2546	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2547	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2548
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2549	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2550
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2551	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2552	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2553	values. Both arguments must have identical types.</p>
				2554
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2555	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2556
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2557	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2558	<p>Note that unsigned integer division and signed integer division are distinct
				2559	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2560	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2561	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2562	<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]	2563	</pre>
				2564	</div>
				2565	<!-- _______________________________________________________________________ -->
				2566	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2567	</a> </div>
				2568	<div class="doc_text">
				2569	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2570	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2571	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2572	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2573
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2574	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2575
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2576	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2577	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2578
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2579	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2580
				2581	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2582	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2583	values. Both arguments must have identical types.</p>
				2584
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2585	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2586	<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]	2587	<p>Note that signed integer division and unsigned integer division are distinct
				2588	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2589	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2590	undefined behavior; this is a rare case, but can occur, for example,
				2591	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2592	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2593	<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]	2594	</pre>
				2595	</div>
				2596	<!-- _______________________________________________________________________ -->
				2597	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2598	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2599	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2600	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2601	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2602	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2603	</pre>
				2604	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2606	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2607	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2608
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2609	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2611	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2612	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2613	of floating point values. Both arguments must have identical types.</p>
				2614
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2615	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2616
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2617	<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]	2618
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2619	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2620
				2621	<pre>
				2622	<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]	2623	</pre>
				2624	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2625
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2626	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2627	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2628	</div>
				2629	<div class="doc_text">
				2630	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2631	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2632	</pre>
				2633	<h5>Overview:</h5>
				2634	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2635	unsigned division of its two arguments.</p>
				2636	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2637	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2638	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2639	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2640	<h5>Semantics:</h5>
				2641	<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]	2642	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2643	<p>Note that unsigned integer remainder and signed integer remainder are
				2644	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2645	<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]	2646	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2647	<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]	2648	</pre>
				2649
				2650	</div>
				2651	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2652	<div class="doc_subsubsection">
				2653	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2654	</div>
				2655
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2656	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2657
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2658	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2659
				2660	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2661	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2662	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2663
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2664	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2665
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2666	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2667	signed division of its two operands. This instruction can also take
				2668	<a href="#t_vector">vector</a> versions of the values in which case
				2669	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2670
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2671	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2672
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2673	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2674	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2675	values. Both arguments must have identical types.</p>
				2676
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2677	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2678
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2679	<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]	2680	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2681	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]	2682	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2683	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]	2684	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]	2685	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2686	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2687	<p>Note that signed integer remainder and unsigned integer remainder are
				2688	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2689	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2690	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2691	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2692	(The remainder doesn't actually overflow, but this rule lets srem be
				2693	implemented using instructions that return both the result of the division
				2694	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2695	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2696	<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]	2697	</pre>
				2698
				2699	</div>
				2700	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2701	<div class="doc_subsubsection">
				2702	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2703
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2704	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2705
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2706	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2707	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2708	</pre>
				2709	<h5>Overview:</h5>
				2710	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2711	division of its two operands.</p>
				2712	<h5>Arguments:</h5>
				2713	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2714	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2715	of floating point values. Both arguments must have identical types.</p>
				2716
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2717	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2718
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2719	<p>This instruction returns the <i>remainder</i> of a division.
				2720	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2721
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2722	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2723
				2724	<pre>
				2725	<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]	2726	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2727	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2728
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2729	<!-- ======================================================================= -->
				2730	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2731	Operations</a> </div>
				2732	<div class="doc_text">
				2733	<p>Bitwise binary operators are used to do various forms of
				2734	bit-twiddling in a program. They are generally very efficient
				2735	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2736	instructions. They require two operands of the same type, execute an operation on them,
				2737	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]	2738	</div>
				2739
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2740	<!-- _______________________________________________________________________ -->
				2741	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2742	Instruction</a> </div>
				2743	<div class="doc_text">
				2744	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2745	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2746	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2747
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2748	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2749
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2750	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2751	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2752
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2753	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2754
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2755	<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]	2756	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]	2757	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2758
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2759	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2760
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2761	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2762	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2763	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2764	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2765	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2766
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2767	<h5>Example:</h5><pre>
				2768	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2769	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2770	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2771	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2772	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2773	</pre>
				2774	</div>
				2775	<!-- _______________________________________________________________________ -->
				2776	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2777	Instruction</a> </div>
				2778	<div class="doc_text">
				2779	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2780	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2781	</pre>
				2782
				2783	<h5>Overview:</h5>
				2784	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2785	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]	2786
				2787	<h5>Arguments:</h5>
				2788	<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]	2789	<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]	2790	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2791
				2792	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2793
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2794	<p>This instruction always performs a logical shift right operation. The most
				2795	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]	2796	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2797	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2798	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2799	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2800
				2801	<h5>Example:</h5>
				2802	<pre>
				2803	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2804	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2805	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2806	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2807	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2808	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2809	</pre>
				2810	</div>
				2811
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2812	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2813	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2814	Instruction</a> </div>
				2815	<div class="doc_text">
				2816
				2817	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2818	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2819	</pre>
				2820
				2821	<h5>Overview:</h5>
				2822	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2823	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]	2824
				2825	<h5>Arguments:</h5>
				2826	<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]	2827	<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]	2828	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2829
				2830	<h5>Semantics:</h5>
				2831	<p>This instruction always performs an arithmetic shift right operation,
				2832	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]	2833	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2834	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2835	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2836	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2837
				2838	<h5>Example:</h5>
				2839	<pre>
				2840	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2841	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2842	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2843	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2844	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2845	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2846	</pre>
				2847	</div>
				2848
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2849	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2850	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2851	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2852
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2853	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2854
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2855	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2856
				2857	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2858	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2859	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2860
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2861	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2862
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2863	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2864	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2865
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2866	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2867
				2868	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2869	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2870	values. Both arguments must have identical types.</p>
				2871
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2872	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2873	<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]	2874	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2875	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2876	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2877	<tbody>
				2878	<tr>
				2879	<td>In0</td>
				2880	<td>In1</td>
				2881	<td>Out</td>
				2882	</tr>
				2883	<tr>
				2884	<td>0</td>
				2885	<td>0</td>
				2886	<td>0</td>
				2887	</tr>
				2888	<tr>
				2889	<td>0</td>
				2890	<td>1</td>
				2891	<td>0</td>
				2892	</tr>
				2893	<tr>
				2894	<td>1</td>
				2895	<td>0</td>
				2896	<td>0</td>
				2897	</tr>
				2898	<tr>
				2899	<td>1</td>
				2900	<td>1</td>
				2901	<td>1</td>
				2902	</tr>
				2903	</tbody>
				2904	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2905	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2906	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2907	<pre>
				2908	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2909	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2910	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2911	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2912	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2913	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2914	<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]	2915	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2916	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2917	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2918	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2919	<h5>Overview:</h5>
				2920	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2921	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2922	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2923
				2924	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2925	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2926	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2927	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2928	<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]	2929	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2930	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2931	<table border="1" cellspacing="0" cellpadding="4">
				2932	<tbody>
				2933	<tr>
				2934	<td>In0</td>
				2935	<td>In1</td>
				2936	<td>Out</td>
				2937	</tr>
				2938	<tr>
				2939	<td>0</td>
				2940	<td>0</td>
				2941	<td>0</td>
				2942	</tr>
				2943	<tr>
				2944	<td>0</td>
				2945	<td>1</td>
				2946	<td>1</td>
				2947	</tr>
				2948	<tr>
				2949	<td>1</td>
				2950	<td>0</td>
				2951	<td>1</td>
				2952	</tr>
				2953	<tr>
				2954	<td>1</td>
				2955	<td>1</td>
				2956	<td>1</td>
				2957	</tr>
				2958	</tbody>
				2959	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2960	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2961	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2962	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2963	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2964	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2965	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2966	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2967	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2968	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2969	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2970	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2971	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2972	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2973	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2974	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2975	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2976	or of its two operands. The <tt>xor</tt> is used to implement the
				2977	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2978	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2979	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2980	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2981	values. Both arguments must have identical types.</p>
				2982
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2983	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2984
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2985	<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]	2986	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2987	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2988	<table border="1" cellspacing="0" cellpadding="4">
				2989	<tbody>
				2990	<tr>
				2991	<td>In0</td>
				2992	<td>In1</td>
				2993	<td>Out</td>
				2994	</tr>
				2995	<tr>
				2996	<td>0</td>
				2997	<td>0</td>
				2998	<td>0</td>
				2999	</tr>
				3000	<tr>
				3001	<td>0</td>
				3002	<td>1</td>
				3003	<td>1</td>
				3004	</tr>
				3005	<tr>
				3006	<td>1</td>
				3007	<td>0</td>
				3008	<td>1</td>
				3009	</tr>
				3010	<tr>
				3011	<td>1</td>
				3012	<td>1</td>
				3013	<td>0</td>
				3014	</tr>
				3015	</tbody>
				3016	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3017	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3018	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3019	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3020	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3021	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3022	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3023	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3024	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3025	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3026
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3027	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3028	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3029	<a name="vectorops">Vector Operations</a>
				3030	</div>
				3031
				3032	<div class="doc_text">
				3033
				3034	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3035	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3036	vector-specific operations needed to process vectors effectively. While LLVM
				3037	does directly support these vector operations, many sophisticated algorithms
				3038	will want to use target-specific intrinsics to take full advantage of a specific
				3039	target.</p>
				3040
				3041	</div>
				3042
				3043	<!-- _______________________________________________________________________ -->
				3044	<div class="doc_subsubsection">
				3045	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3046	</div>
				3047
				3048	<div class="doc_text">
				3049
				3050	<h5>Syntax:</h5>
				3051
				3052	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3053	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3054	</pre>
				3055
				3056	<h5>Overview:</h5>
				3057
				3058	<p>
				3059	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3060	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3061	</p>
				3062
				3063
				3064	<h5>Arguments:</h5>
				3065
				3066	<p>
				3067	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3068	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]	3069	an index indicating the position from which to extract the element.
				3070	The index may be a variable.</p>
				3071
				3072	<h5>Semantics:</h5>
				3073
				3074	<p>
				3075	The result is a scalar of the same type as the element type of
				3076	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3077	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3078	results are undefined.
				3079	</p>
				3080
				3081	<h5>Example:</h5>
				3082
				3083	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3084	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3085	</pre>
				3086	</div>
				3087
				3088
				3089	<!-- _______________________________________________________________________ -->
				3090	<div class="doc_subsubsection">
				3091	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3092	</div>
				3093
				3094	<div class="doc_text">
				3095
				3096	<h5>Syntax:</h5>
				3097
				3098	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3099	<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]	3100	</pre>
				3101
				3102	<h5>Overview:</h5>
				3103
				3104	<p>
				3105	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3106	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3107	</p>
				3108
				3109
				3110	<h5>Arguments:</h5>
				3111
				3112	<p>
				3113	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3114	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]	3115	scalar value whose type must equal the element type of the first
				3116	operand. The third operand is an index indicating the position at
				3117	which to insert the value. The index may be a variable.</p>
				3118
				3119	<h5>Semantics:</h5>
				3120
				3121	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3122	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]	3123	element values are those of <tt>val</tt> except at position
				3124	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3125	exceeds the length of <tt>val</tt>, the results are undefined.
				3126	</p>
				3127
				3128	<h5>Example:</h5>
				3129
				3130	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3131	%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]	3132	</pre>
				3133	</div>
				3134
				3135	<!-- _______________________________________________________________________ -->
				3136	<div class="doc_subsubsection">
				3137	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3138	</div>
				3139
				3140	<div class="doc_text">
				3141
				3142	<h5>Syntax:</h5>
				3143
				3144	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3145	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3146	</pre>
				3147
				3148	<h5>Overview:</h5>
				3149
				3150	<p>
				3151	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3152	from two input vectors, returning a vector with the same element type as
				3153	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3154	</p>
				3155
				3156	<h5>Arguments:</h5>
				3157
				3158	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3159	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3160	with types that match each other. The third argument is a shuffle mask whose
				3161	element type is always 'i32'. The result of the instruction is a vector whose
				3162	length is the same as the shuffle mask and whose element type is the same as
				3163	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3164	</p>
				3165
				3166	<p>
				3167	The shuffle mask operand is required to be a constant vector with either
				3168	constant integer or undef values.
				3169	</p>
				3170
				3171	<h5>Semantics:</h5>
				3172
				3173	<p>
				3174	The elements of the two input vectors are numbered from left to right across
				3175	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3176	the result vector, which element of the two input vectors the result element
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3177	gets. The element selector may be undef (meaning "don't care") and the second
				3178	operand may be undef if performing a shuffle from only one vector.
				3179	</p>
				3180
				3181	<h5>Example:</h5>
				3182
				3183	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3184	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3185	<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]	3186	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3187	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3188	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3189	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3190	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3191	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3192	</pre>
				3193	</div>
				3194
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3195
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3196	<!-- ======================================================================= -->
				3197	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3198	<a name="aggregateops">Aggregate Operations</a>
				3199	</div>
				3200
				3201	<div class="doc_text">
				3202
				3203	<p>LLVM supports several instructions for working with aggregate values.
				3204	</p>
				3205
				3206	</div>
				3207
				3208	<!-- _______________________________________________________________________ -->
				3209	<div class="doc_subsubsection">
				3210	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3211	</div>
				3212
				3213	<div class="doc_text">
				3214
				3215	<h5>Syntax:</h5>
				3216
				3217	<pre>
				3218	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3219	</pre>
				3220
				3221	<h5>Overview:</h5>
				3222
				3223	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3224	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3225	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3226	</p>
				3227
				3228
				3229	<h5>Arguments:</h5>
				3230
				3231	<p>
				3232	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3233	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]	3234	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3235	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3236	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3237	</p>
				3238
				3239	<h5>Semantics:</h5>
				3240
				3241	<p>
				3242	The result is the value at the position in the aggregate specified by
				3243	the index operands.
				3244	</p>
				3245
				3246	<h5>Example:</h5>
				3247
				3248	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3249	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3250	</pre>
				3251	</div>
				3252
				3253
				3254	<!-- _______________________________________________________________________ -->
				3255	<div class="doc_subsubsection">
				3256	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3257	</div>
				3258
				3259	<div class="doc_text">
				3260
				3261	<h5>Syntax:</h5>
				3262
				3263	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3264	<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]	3265	</pre>
				3266
				3267	<h5>Overview:</h5>
				3268
				3269	<p>
				3270	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3271	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3272	</p>
				3273
				3274
				3275	<h5>Arguments:</h5>
				3276
				3277	<p>
				3278	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3279	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3280	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3281	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3282	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]	3283	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3284	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3285	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]	3286	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3287	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3288
				3289	<h5>Semantics:</h5>
				3290
				3291	<p>
				3292	The result is an aggregate of the same type as <tt>val</tt>. Its
				3293	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]	3294	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3295	</p>
				3296
				3297	<h5>Example:</h5>
				3298
				3299	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3300	%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]	3301	</pre>
				3302	</div>
				3303
				3304
				3305	<!-- ======================================================================= -->
				3306	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3307	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3308	</div>
				3309
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3310	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3311
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3312	<p>A key design point of an SSA-based representation is how it
				3313	represents memory. In LLVM, no memory locations are in SSA form, which
				3314	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3315	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3316
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3317	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3318
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3319	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3320	<div class="doc_subsubsection">
				3321	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3322	</div>
				3323
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3324	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3325
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3326	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3327
				3328	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3329	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3330	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3331
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3332	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3333
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3334	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3335	heap and returns a pointer to it. The object is always allocated in the generic
				3336	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3337
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3338	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3339
				3340	<p>The '<tt>malloc</tt>' instruction allocates
				3341	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3342	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]	3343	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3344	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3345	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]	3346	be aligned to at least that boundary. If not specified, or if zero, the target can
				3347	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3348
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3349	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3350
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3351	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3352
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3353	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3354	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3355	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3356
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3357	<h5>Example:</h5>
				3358
				3359	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3360	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3361
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3362	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3363	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3364	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3365	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3366	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3367	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3368
				3369	<p>Note that the code generator does not yet respect the
				3370	alignment value.</p>
				3371
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3372	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3373
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3374	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3375	<div class="doc_subsubsection">
				3376	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3377	</div>
				3378
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3379	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3380
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3381	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3382
				3383	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3384	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3385	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3386
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3387	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3388
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3389	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3390	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3391
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3392	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3393
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3394	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3395	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3396	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3397
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3398	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3399
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3400	<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]	3401	after this instruction executes. If the pointer is null, the operation
				3402	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3403
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3404	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3405
				3406	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3407	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3408	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3409	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3410	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3411
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3412	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3413	<div class="doc_subsubsection">
				3414	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3415	</div>
				3416
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3417	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3418
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3419	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3420
				3421	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3422	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3423	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3424
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3425	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3427	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3428	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3429	returns to its caller. The object is always allocated in the generic address
				3430	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3431
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3432	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3433
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3434	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3435	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3436	appropriate type to the program. If "NumElements" is specified, it is the
				3437	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3438	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]	3439	to be aligned to at least that boundary. If not specified, or if zero, the target
				3440	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3441
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3442	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3443
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3444	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3445
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3446	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3447	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3448	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3449	instruction is commonly used to represent automatic variables that must
				3450	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]	3451	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]	3452	instructions), the memory is reclaimed. Allocating zero bytes
				3453	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3454
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3455	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3456
				3457	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3458	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3459	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3460	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3461	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3462	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3463	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3464
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3465	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3466	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3467	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3468	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3469	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3470	<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]	3471	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3472	<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]	3473	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3474	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3475	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3476	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]	3477	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]	3478	the number or order of execution of this <tt>load</tt> with other
				3479	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3480	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3481	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3482	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3483	(that is, the alignment of the memory address). A value of 0 or an
				3484	omitted "align" argument means that the operation has the preferential
				3485	alignment for the target. It is the responsibility of the code emitter
				3486	to ensure that the alignment information is correct. Overestimating
				3487	the alignment results in an undefined behavior. Underestimating the
				3488	alignment may produce less efficient code. An alignment of 1 is always
				3489	safe.
				3490	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3491	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3492	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3493	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3494	<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]	3495	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3496	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3497	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3498	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3499	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3500	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3501	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3502	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3503	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3504	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3505	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3506	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3507	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3508	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3509	<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]	3510	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3511	<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]	3512	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]	3513	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3514	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3515	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]	3516	optimizer is not allowed to modify the number or order of execution of
				3517	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3518	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3519	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3520	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3521	(that is, the alignment of the memory address). A value of 0 or an
				3522	omitted "align" argument means that the operation has the preferential
				3523	alignment for the target. It is the responsibility of the code emitter
				3524	to ensure that the alignment information is correct. Overestimating
				3525	the alignment results in an undefined behavior. Underestimating the
				3526	alignment may produce less efficient code. An alignment of 1 is always
				3527	safe.
				3528	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3529	<h5>Semantics:</h5>
				3530	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3531	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3532	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3533	<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]	3534	store i32 3, i32* %ptr <i>; yields {void}</i>
				3535	%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]	3536	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3537	</div>
				3538
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3539	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3540	<div class="doc_subsubsection">
				3541	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3542	</div>
				3543
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3544	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3545	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3546	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3547	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3548	</pre>
				3549
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3550	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3551
				3552	<p>
				3553	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3554	subelement of an aggregate data structure. It performs address calculation only
				3555	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3556
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3557	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3558
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3559	<p>The first argument is always a pointer, and forms the basis of the
				3560	calculation. The remaining arguments are indices, that indicate which of the
				3561	elements of the aggregate object are indexed. The interpretation of each index
				3562	is dependent on the type being indexed into. The first index always indexes the
				3563	pointer value given as the first argument, the second index indexes a value of
				3564	the type pointed to (not necessarily the value directly pointed to, since the
				3565	first index can be non-zero), etc. The first type indexed into must be a pointer
				3566	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3567	types being indexed into can never be pointers, since that would require loading
				3568	the pointer before continuing calculation.</p>
				3569
				3570	<p>The type of each index argument depends on the type it is indexing into.
				3571	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3572	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
				3573	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3574	will be sign extended to 64-bits if required.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3575
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3576	<p>For example, let's consider a C code fragment and how it gets
				3577	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3578
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3579	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3580	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3581	struct RT {
				3582	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3583	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3584	char C;
				3585	};
				3586	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3587	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3588	double Y;
				3589	struct RT Z;
				3590	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3591
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3592	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3593	return &s[1].Z.B[5][13];
				3594	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3595	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3596	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3597
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3598	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3599
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3600	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3601	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3602	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3603	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3604
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3605	define i32* %foo(%ST* %s) {
				3606	entry:
				3607	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3608	ret i32* %reg
				3609	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3610	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3611	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3612
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3613	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3614
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3615	<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]	3616	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]	3617	}</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]	3618	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3619	i8 }</tt>' type, another structure. The third index indexes into the second
				3620	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]	3621	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3622	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3623	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]	3624
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3625	<p>Note that it is perfectly legal to index partially through a
				3626	structure, returning a pointer to an inner element. Because of this,
				3627	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3628
				3629	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3630	define i32* %foo(%ST* %s) {
				3631	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3632	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3633	%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]	3634	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3635	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3636	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3637	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3638	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3639
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3640	<p>Note that it is undefined to access an array out of bounds: array
				3641	and pointer indexes must always be within the defined bounds of the
				3642	array type when accessed with an instruction that dereferences the
				3643	pointer (e.g. a load or store instruction). The one exception for
				3644	this rule is zero length arrays. These arrays are defined to be
				3645	accessible as variable length arrays, which requires access beyond the
				3646	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3647
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3648	<p>The getelementptr instruction is often confusing. For some more insight
				3649	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3650	FAQ</a>.</p>
				3651
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3652	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3653
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3654	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3655	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3656	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3657	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3658	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3659	<i>; yields i8*:eptr</i>
				3660	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3661	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3662	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3663
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3664	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3665	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3666	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3667	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3668	<p>The instructions in this category are the conversion instructions (casting)
				3669	which all take a single operand and a type. They perform various bit conversions
				3670	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3671	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3672
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3673	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3674	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3675	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3676	</div>
				3677	<div class="doc_text">
				3678
				3679	<h5>Syntax:</h5>
				3680	<pre>
				3681	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3682	</pre>
				3683
				3684	<h5>Overview:</h5>
				3685	<p>
				3686	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3687	</p>
				3688
				3689	<h5>Arguments:</h5>
				3690	<p>
				3691	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3692	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]	3693	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]	3694	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3695	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3696
				3697	<h5>Semantics:</h5>
				3698	<p>
				3699	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]	3700	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3701	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3702	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3703
				3704	<h5>Example:</h5>
				3705	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3706	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3707	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3708	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3709	</pre>
				3710	</div>
				3711
				3712	<!-- _______________________________________________________________________ -->
				3713	<div class="doc_subsubsection">
				3714	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3715	</div>
				3716	<div class="doc_text">
				3717
				3718	<h5>Syntax:</h5>
				3719	<pre>
				3720	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3721	</pre>
				3722
				3723	<h5>Overview:</h5>
				3724	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3725	<tt>ty2</tt>.</p>
				3726
				3727
				3728	<h5>Arguments:</h5>
				3729	<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]	3730	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3731	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]	3732	<tt>value</tt> must be smaller than the bit size of the destination type,
				3733	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3734
				3735	<h5>Semantics:</h5>
				3736	<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]	3737	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]	3738
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3739	<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]	3740
				3741	<h5>Example:</h5>
				3742	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3743	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3744	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3745	</pre>
				3746	</div>
				3747
				3748	<!-- _______________________________________________________________________ -->
				3749	<div class="doc_subsubsection">
				3750	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3751	</div>
				3752	<div class="doc_text">
				3753
				3754	<h5>Syntax:</h5>
				3755	<pre>
				3756	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3757	</pre>
				3758
				3759	<h5>Overview:</h5>
				3760	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3761
				3762	<h5>Arguments:</h5>
				3763	<p>
				3764	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]	3765	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3766	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]	3767	<tt>value</tt> must be smaller than the bit size of the destination type,
				3768	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3769
				3770	<h5>Semantics:</h5>
				3771	<p>
				3772	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3773	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]	3774	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3775
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3776	<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]	3777
				3778	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3779	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3780	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3781	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3782	</pre>
				3783	</div>
				3784
				3785	<!-- _______________________________________________________________________ -->
				3786	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3787	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3788	</div>
				3789
				3790	<div class="doc_text">
				3791
				3792	<h5>Syntax:</h5>
				3793
				3794	<pre>
				3795	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3796	</pre>
				3797
				3798	<h5>Overview:</h5>
				3799	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3800	<tt>ty2</tt>.</p>
				3801
				3802
				3803	<h5>Arguments:</h5>
				3804	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3805	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3806	cast it to. The size of <tt>value</tt> must be larger than the size of
				3807	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3808	<i>no-op cast</i>.</p>
				3809
				3810	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3811	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3812	<a href="#t_floating">floating point</a> type to a smaller
				3813	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3814	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3815
				3816	<h5>Example:</h5>
				3817	<pre>
				3818	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3819	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3820	</pre>
				3821	</div>
				3822
				3823	<!-- _______________________________________________________________________ -->
				3824	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3825	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3826	</div>
				3827	<div class="doc_text">
				3828
				3829	<h5>Syntax:</h5>
				3830	<pre>
				3831	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3832	</pre>
				3833
				3834	<h5>Overview:</h5>
				3835	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3836	floating point value.</p>
				3837
				3838	<h5>Arguments:</h5>
				3839	<p>The '<tt>fpext</tt>' instruction takes a
				3840	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3841	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3842	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3843
				3844	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3845	<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]	3846	<a href="#t_floating">floating point</a> type to a larger
				3847	<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]	3848	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]	3849	<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]	3850
				3851	<h5>Example:</h5>
				3852	<pre>
				3853	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3854	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3855	</pre>
				3856	</div>
				3857
				3858	<!-- _______________________________________________________________________ -->
				3859	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3860	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3861	</div>
				3862	<div class="doc_text">
				3863
				3864	<h5>Syntax:</h5>
				3865	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3866	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3867	</pre>
				3868
				3869	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3870	<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]	3871	unsigned integer equivalent of type <tt>ty2</tt>.
				3872	</p>
				3873
				3874	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3875	<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]	3876	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3877	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3878	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3879	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]	3880
				3881	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3882	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3883	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3884	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3885	the results are undefined.</p>
				3886
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3887	<h5>Example:</h5>
				3888	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3889	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3890	%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]	3891	%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]	3892	</pre>
				3893	</div>
				3894
				3895	<!-- _______________________________________________________________________ -->
				3896	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3897	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3898	</div>
				3899	<div class="doc_text">
				3900
				3901	<h5>Syntax:</h5>
				3902	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3903	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3904	</pre>
				3905
				3906	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3907	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3908	<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]	3909	</p>
				3910
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3911	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3912	<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]	3913	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3914	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3915	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3916	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]	3917
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3918	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3919	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3920	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3921	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3922	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3923
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3924	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3925	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3926	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3927	%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]	3928	%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]	3929	</pre>
				3930	</div>
				3931
				3932	<!-- _______________________________________________________________________ -->
				3933	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3934	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3935	</div>
				3936	<div class="doc_text">
				3937
				3938	<h5>Syntax:</h5>
				3939	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3940	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3941	</pre>
				3942
				3943	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3944	<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]	3945	integer and converts that value to the <tt>ty2</tt> type.</p>
				3946
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3947	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3948	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3949	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3950	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3951	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3952	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]	3953
				3954	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3955	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3956	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3957	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]	3958
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3959	<h5>Example:</h5>
				3960	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3961	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3962	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3963	</pre>
				3964	</div>
				3965
				3966	<!-- _______________________________________________________________________ -->
				3967	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3968	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3969	</div>
				3970	<div class="doc_text">
				3971
				3972	<h5>Syntax:</h5>
				3973	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3974	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3975	</pre>
				3976
				3977	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3978	<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]	3979	integer and converts that value to the <tt>ty2</tt> type.</p>
				3980
				3981	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3982	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3983	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3984	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3985	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3986	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]	3987
				3988	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3989	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3990	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3991	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]	3992
				3993	<h5>Example:</h5>
				3994	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3995	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3996	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3997	</pre>
				3998	</div>
				3999
				4000	<!-- _______________________________________________________________________ -->
				4001	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4002	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4003	</div>
				4004	<div class="doc_text">
				4005
				4006	<h5>Syntax:</h5>
				4007	<pre>
				4008	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4009	</pre>
				4010
				4011	<h5>Overview:</h5>
				4012	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4013	the integer type <tt>ty2</tt>.</p>
				4014
				4015	<h5>Arguments:</h5>
				4016	<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]	4017	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4018	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4019
				4020	<h5>Semantics:</h5>
				4021	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4022	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4023	truncating or zero extending that value to the size of the integer type. If
				4024	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4025	<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]	4026	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4027	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4028
				4029	<h5>Example:</h5>
				4030	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4031	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4032	%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]	4033	</pre>
				4034	</div>
				4035
				4036	<!-- _______________________________________________________________________ -->
				4037	<div class="doc_subsubsection">
				4038	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4039	</div>
				4040	<div class="doc_text">
				4041
				4042	<h5>Syntax:</h5>
				4043	<pre>
				4044	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4045	</pre>
				4046
				4047	<h5>Overview:</h5>
				4048	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4049	a pointer type, <tt>ty2</tt>.</p>
				4050
				4051	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4052	<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]	4053	value to cast, and a type to cast it to, which must be a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4054	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4055
				4056	<h5>Semantics:</h5>
				4057	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4058	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4059	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4060	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4061	the size of a pointer then a zero extension is done. If they are the same size,
				4062	nothing is done (<i>no-op cast</i>).</p>
				4063
				4064	<h5>Example:</h5>
				4065	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4066	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4067	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4068	%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]	4069	</pre>
				4070	</div>
				4071
				4072	<!-- _______________________________________________________________________ -->
				4073	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4074	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4075	</div>
				4076	<div class="doc_text">
				4077
				4078	<h5>Syntax:</h5>
				4079	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4080	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4081	</pre>
				4082
				4083	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4084
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4085	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4086	<tt>ty2</tt> without changing any bits.</p>
				4087
				4088	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4089
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4090	<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]	4091	a non-aggregate first class value, and a type to cast it to, which must also be
				4092	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4093	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4094	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]	4095	type is a pointer, the destination type must also be a pointer. This
				4096	instruction supports bitwise conversion of vectors to integers and to vectors
				4097	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4098
				4099	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4100	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4101	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4102	this conversion. The conversion is done as if the <tt>value</tt> had been
				4103	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4104	converted to other pointer types with this instruction. To convert pointers to
				4105	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4106	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4107
				4108	<h5>Example:</h5>
				4109	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4110	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4111	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4112	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4113	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4114	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4115
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4116	<!-- ======================================================================= -->
				4117	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4118	<div class="doc_text">
				4119	<p>The instructions in this category are the "miscellaneous"
				4120	instructions, which defy better classification.</p>
				4121	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4122
				4123	<!-- _______________________________________________________________________ -->
				4124	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4125	</div>
				4126	<div class="doc_text">
				4127	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4128	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4129	</pre>
				4130	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4131	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4132	a vector of boolean values based on comparison
				4133	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4134	<h5>Arguments:</h5>
				4135	<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]	4136	the condition code indicating the kind of comparison to perform. It is not
				4137	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4138	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4139	<ol>
				4140	<li><tt>eq</tt>: equal</li>
				4141	<li><tt>ne</tt>: not equal </li>
				4142	<li><tt>ugt</tt>: unsigned greater than</li>
				4143	<li><tt>uge</tt>: unsigned greater or equal</li>
				4144	<li><tt>ult</tt>: unsigned less than</li>
				4145	<li><tt>ule</tt>: unsigned less or equal</li>
				4146	<li><tt>sgt</tt>: signed greater than</li>
				4147	<li><tt>sge</tt>: signed greater or equal</li>
				4148	<li><tt>slt</tt>: signed less than</li>
				4149	<li><tt>sle</tt>: signed less or equal</li>
				4150	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4151	<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]	4152	<a href="#t_pointer">pointer</a>
				4153	or integer <a href="#t_vector">vector</a> typed.
				4154	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4155	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4156	<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]	4157	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4158	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4159	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4160	<ol>
				4161	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4162	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4163	</li>
				4164	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4165	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4166	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4167	<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]	4168	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4169	<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]	4170	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4171	<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]	4172	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4173	<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]	4174	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4175	<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]	4176	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4177	<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]	4178	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4179	<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]	4180	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4181	<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]	4182	</ol>
				4183	<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]	4184	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4185	<p>If the operands are integer vectors, then they are compared
				4186	element by element. The result is an <tt>i1</tt> vector with
				4187	the same number of elements as the values being compared.
				4188	Otherwise, the result is an <tt>i1</tt>.
				4189	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4190
				4191	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4192	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4193	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4194	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4195	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4196	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4197	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4198	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4199
				4200	<p>Note that the code generator does not yet support vector types with
				4201	the <tt>icmp</tt> instruction.</p>
				4202
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4203	</div>
				4204
				4205	<!-- _______________________________________________________________________ -->
				4206	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4207	</div>
				4208	<div class="doc_text">
				4209	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4210	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4211	</pre>
				4212	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4213	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4214	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4215	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4216	<p>
				4217	If the operands are floating point scalars, then the result
				4218	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4219	</p>
				4220	<p>If the operands are floating point vectors, then the result type
				4221	is a vector of boolean with the same number of elements as the
				4222	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4223	<h5>Arguments:</h5>
				4224	<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]	4225	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4226	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4227	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4228	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4229	<li><tt>oeq</tt>: ordered and equal</li>
				4230	<li><tt>ogt</tt>: ordered and greater than </li>
				4231	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4232	<li><tt>olt</tt>: ordered and less than </li>
				4233	<li><tt>ole</tt>: ordered and less than or equal</li>
				4234	<li><tt>one</tt>: ordered and not equal</li>
				4235	<li><tt>ord</tt>: ordered (no nans)</li>
				4236	<li><tt>ueq</tt>: unordered or equal</li>
				4237	<li><tt>ugt</tt>: unordered or greater than </li>
				4238	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4239	<li><tt>ult</tt>: unordered or less than </li>
				4240	<li><tt>ule</tt>: unordered or less than or equal</li>
				4241	<li><tt>une</tt>: unordered or not equal</li>
				4242	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4243	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4244	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4245	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4246	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4247	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4248	either a <a href="#t_floating">floating point</a> type
				4249	or a <a href="#t_vector">vector</a> of floating point type.
				4250	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4251	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4252	<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]	4253	according to the condition code given as <tt>cond</tt>.
				4254	If the operands are vectors, then the vectors are compared
				4255	element by element.
				4256	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4257	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4258	<ol>
				4259	<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]	4260	<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]	4261	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4262	<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]	4263	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4264	<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]	4265	<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]	4266	<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]	4267	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4268	<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]	4269	<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]	4270	<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]	4271	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4272	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4273	<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]	4274	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4275	<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]	4276	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4277	<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]	4278	<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]	4279	<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]	4280	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4281	<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]	4282	<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]	4283	<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]	4284	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4285	<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]	4286	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4287	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4288
				4289	<h5>Example:</h5>
				4290	<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]	4291	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4292	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4293	<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]	4294	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4295
				4296	<p>Note that the code generator does not yet support vector types with
				4297	the <tt>fcmp</tt> instruction.</p>
				4298
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4299	</div>
				4300
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4301	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4302	<div class="doc_subsubsection">
				4303	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4304	</div>
				4305	<div class="doc_text">
				4306	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4307	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4308	</pre>
				4309	<h5>Overview:</h5>
				4310	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4311	element-wise comparison of its two integer vector operands.</p>
				4312	<h5>Arguments:</h5>
				4313	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4314	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4315	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4316	<ol>
				4317	<li><tt>eq</tt>: equal</li>
				4318	<li><tt>ne</tt>: not equal </li>
				4319	<li><tt>ugt</tt>: unsigned greater than</li>
				4320	<li><tt>uge</tt>: unsigned greater or equal</li>
				4321	<li><tt>ult</tt>: unsigned less than</li>
				4322	<li><tt>ule</tt>: unsigned less or equal</li>
				4323	<li><tt>sgt</tt>: signed greater than</li>
				4324	<li><tt>sge</tt>: signed greater or equal</li>
				4325	<li><tt>slt</tt>: signed less than</li>
				4326	<li><tt>sle</tt>: signed less or equal</li>
				4327	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4328	<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]	4329	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4330	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4331	<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]	4332	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4333	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4334	identical type as the values being compared. The most significant bit in each
				4335	element is 1 if the element-wise comparison evaluates to true, and is 0
				4336	otherwise. All other bits of the result are undefined. The condition codes
				4337	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4338	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4339
				4340	<h5>Example:</h5>
				4341	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4342	<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>
				4343	<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]	4344	</pre>
				4345	</div>
				4346
				4347	<!-- _______________________________________________________________________ -->
				4348	<div class="doc_subsubsection">
				4349	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4350	</div>
				4351	<div class="doc_text">
				4352	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4353	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4354	<h5>Overview:</h5>
				4355	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4356	element-wise comparison of its two floating point vector operands. The output
				4357	elements have the same width as the input elements.</p>
				4358	<h5>Arguments:</h5>
				4359	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4360	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4361	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4362	<ol>
				4363	<li><tt>false</tt>: no comparison, always returns false</li>
				4364	<li><tt>oeq</tt>: ordered and equal</li>
				4365	<li><tt>ogt</tt>: ordered and greater than </li>
				4366	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4367	<li><tt>olt</tt>: ordered and less than </li>
				4368	<li><tt>ole</tt>: ordered and less than or equal</li>
				4369	<li><tt>one</tt>: ordered and not equal</li>
				4370	<li><tt>ord</tt>: ordered (no nans)</li>
				4371	<li><tt>ueq</tt>: unordered or equal</li>
				4372	<li><tt>ugt</tt>: unordered or greater than </li>
				4373	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4374	<li><tt>ult</tt>: unordered or less than </li>
				4375	<li><tt>ule</tt>: unordered or less than or equal</li>
				4376	<li><tt>une</tt>: unordered or not equal</li>
				4377	<li><tt>uno</tt>: unordered (either nans)</li>
				4378	<li><tt>true</tt>: no comparison, always returns true</li>
				4379	</ol>
				4380	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4381	<a href="#t_floating">floating point</a> typed. They must also be identical
				4382	types.</p>
				4383	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4384	<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]	4385	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4386	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4387	an identical number of elements as the values being compared, and each element
				4388	having identical with to the width of the floating point elements. The most
				4389	significant bit in each element is 1 if the element-wise comparison evaluates to
				4390	true, and is 0 otherwise. All other bits of the result are undefined. The
				4391	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4392	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4393
				4394	<h5>Example:</h5>
				4395	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4396	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4397	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4398
				4399	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4400	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4401	</pre>
				4402	</div>
				4403
				4404	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4405	<div class="doc_subsubsection">
				4406	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4407	</div>
				4408
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4409	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4410
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4411	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4412
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4413	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4414	<h5>Overview:</h5>
				4415	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4416	the SSA graph representing the function.</p>
				4417	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4418
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4419	<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]	4420	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4421	as arguments, with one pair for each predecessor basic block of the
				4422	current block. Only values of <a href="#t_firstclass">first class</a>
				4423	type may be used as the value arguments to the PHI node. Only labels
				4424	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4425
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4426	<p>There must be no non-phi instructions between the start of a basic
				4427	block and the PHI instructions: i.e. PHI instructions must be first in
				4428	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4429
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4430	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4431
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4432	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4433	specified by the pair corresponding to the predecessor basic block that executed
				4434	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4435
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4436	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4437	<pre>
				4438	Loop: ; Infinite loop that counts from 0 on up...
				4439	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4440	%nextindvar = add i32 %indvar, 1
				4441	br label %Loop
				4442	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4443	</div>
				4444
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4445	<!-- _______________________________________________________________________ -->
				4446	<div class="doc_subsubsection">
				4447	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4448	</div>
				4449
				4450	<div class="doc_text">
				4451
				4452	<h5>Syntax:</h5>
				4453
				4454	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4455	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4456
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4457	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4458	</pre>
				4459
				4460	<h5>Overview:</h5>
				4461
				4462	<p>
				4463	The '<tt>select</tt>' instruction is used to choose one value based on a
				4464	condition, without branching.
				4465	</p>
				4466
				4467
				4468	<h5>Arguments:</h5>
				4469
				4470	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4471	The '<tt>select</tt>' instruction requires an 'i1' value or
				4472	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4473	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]	4474	type. If the val1/val2 are vectors and
				4475	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4476	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4477	</p>
				4478
				4479	<h5>Semantics:</h5>
				4480
				4481	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4482	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]	4483	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4484	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4485	<p>
				4486	If the condition is a vector of i1, then the value arguments must
				4487	be vectors of the same size, and the selection is done element
				4488	by element.
				4489	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4490
				4491	<h5>Example:</h5>
				4492
				4493	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4494	%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]	4495	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4496
				4497	<p>Note that the code generator does not yet support conditions
				4498	with vector type.</p>
				4499
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4500	</div>
				4501
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4502
				4503	<!-- _______________________________________________________________________ -->
				4504	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4505	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4506	</div>
				4507
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4508	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4509
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4510	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4511	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4512	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4513	</pre>
				4514
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4515	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4516
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4517	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4518
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4519	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4520
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4521	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4522
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4523	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4524	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4525	<p>The optional "tail" marker indicates whether the callee function accesses
				4526	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]	4527	function call is eligible for tail call optimization. Note that calls may
				4528	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4529	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4530	</li>
				4531	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4532	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4533	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4534	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4535	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4536
				4537	<li>
				4538	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4539	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4540	and '<tt>inreg</tt>' attributes are valid here.</p>
				4541	</li>
				4542
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4543	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4544	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4545	the type of the return value. Functions that return no value are marked
				4546	<tt><a href="#t_void">void</a></tt>.</p>
				4547	</li>
				4548	<li>
				4549	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4550	value being invoked. The argument types must match the types implied by
				4551	this signature. This type can be omitted if the function is not varargs
				4552	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]	4553	</li>
				4554	<li>
				4555	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4556	be invoked. In most cases, this is a direct function invocation, but
				4557	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]	4558	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4559	</li>
				4560	<li>
				4561	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4562	function signature argument types. All arguments must be of
				4563	<a href="#t_firstclass">first class</a> type. If the function signature
				4564	indicates the function accepts a variable number of arguments, the extra
				4565	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4566	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4567	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4568	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4569	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4570	'<tt>readnone</tt>' attributes are valid here.</p>
				4571	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4572	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4573
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4574	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4575
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4576	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4577	transfer to a specified function, with its incoming arguments bound to
				4578	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4579	instruction in the called function, control flow continues with the
				4580	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4581	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4582
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4583	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4584
				4585	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4586	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4587	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4588	%X = tail call i32 @foo() <i>; yields i32</i>
				4589	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4590	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4591
				4592	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4593	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4594	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4595	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4596	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	eefa7df	2008-10-07 10:03:45 +0000	[diff] [blame]	4597	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4598	</pre>
				4599
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4600	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4601
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4602	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4603	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4604	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4605	</div>
				4606
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4607	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4608
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4609	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4610
				4611	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4612	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4613	</pre>
				4614
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4615	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4616
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4617	<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]	4618	the "variable argument" area of a function call. It is used to implement the
				4619	<tt>va_arg</tt> macro in C.</p>
				4620
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4621	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4622
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4623	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4624	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4625	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]	4626	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4627
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4628	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4629
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4630	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4631	type from the specified <tt>va_list</tt> and causes the
				4632	<tt>va_list</tt> to point to the next argument. For more information,
				4633	see the variable argument handling <a href="#int_varargs">Intrinsic
				4634	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4635
				4636	<p>It is legal for this instruction to be called in a function which does not
				4637	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4638	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4639
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4640	<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]	4641	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4642	argument.</p>
				4643
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4644	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4645
				4646	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4647
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4648	<p>Note that the code generator does not yet fully support va_arg
				4649	on many targets. Also, it does not currently support va_arg with
				4650	aggregate types on any target.</p>
				4651
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4652	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4653
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4654	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4655	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4656	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4657
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4658	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4659
				4660	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4661	well known names and semantics and are required to follow certain restrictions.
				4662	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4663	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]	4664	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]	4665
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4666	<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]	4667	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4668	begin with this prefix. Intrinsic functions must always be external functions:
				4669	you cannot define the body of intrinsic functions. Intrinsic functions may
				4670	only be used in call or invoke instructions: it is illegal to take the address
				4671	of an intrinsic function. Additionally, because intrinsic functions are part
				4672	of the LLVM language, it is required if any are added that they be documented
				4673	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4674
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4675	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4676	a family of functions that perform the same operation but on different data
				4677	types. Because LLVM can represent over 8 million different integer types,
				4678	overloading is used commonly to allow an intrinsic function to operate on any
				4679	integer type. One or more of the argument types or the result type can be
				4680	overloaded to accept any integer type. Argument types may also be defined as
				4681	exactly matching a previous argument's type or the result type. This allows an
				4682	intrinsic function which accepts multiple arguments, but needs all of them to
				4683	be of the same type, to only be overloaded with respect to a single argument or
				4684	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4685
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4686	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4687	encoded into its function name, each preceded by a period. Only those types
				4688	which are overloaded result in a name suffix. Arguments whose type is matched
				4689	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4690	take an integer of any width and returns an integer of exactly the same integer
				4691	width. This leads to a family of functions such as
				4692	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4693	Only one type, the return type, is overloaded, and only one type suffix is
				4694	required. Because the argument's type is matched against the return type, it
				4695	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4696
				4697	<p>To learn how to add an intrinsic function, please see the
				4698	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4699	</p>
				4700
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4701	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4702
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4703	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4704	<div class="doc_subsection">
				4705	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4706	</div>
				4707
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4708	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4709
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4710	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4711	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]	4712	intrinsic functions. These functions are related to the similarly
				4713	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4714
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4715	<p>All of these functions operate on arguments that use a
				4716	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4717	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4718	transformations should be prepared to handle these functions regardless of
				4719	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4720
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4721	<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]	4722	instruction and the variable argument handling intrinsic functions are
				4723	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4724
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4725	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4726	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4727	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4728	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4729	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4730	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4731	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4732
				4733	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4734	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4735
				4736	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4737	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4738	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4739	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4740	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4741
				4742	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4743	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4744	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4745	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4746
				4747	declare void @llvm.va_start(i8*)
				4748	declare void @llvm.va_copy(i8, i8)
				4749	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4750	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4751	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4752
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4753	</div>
				4754
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4755	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4756	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4757	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4758	</div>
				4759
				4760
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4761	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4762	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4763	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4764	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4765	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4766	<tt>*<arglist></tt> for subsequent use by <tt><a
				4767	href="#i_va_arg">va_arg</a></tt>.</p>
				4768
				4769	<h5>Arguments:</h5>
				4770
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4771	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4772
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4773	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4774
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4775	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4776	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4777	<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]	4778	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4779	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]	4780	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]	4781
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4782	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4783
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4784	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4785	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4786	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4787	</div>
				4788
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4789	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4790	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4791	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4792	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4793
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4794	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4795	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]	4796	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]	4797
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4798	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4799
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4800	<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]	4801
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4802	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4803
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4804	<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]	4805	macro available in C. In a target-dependent way, it destroys the
				4806	<tt>va_list</tt> element to which the argument points. Calls to <a
				4807	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4808	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4809	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4810
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4811	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4812
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4813	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4814	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4815	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4816	</div>
				4817
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4818	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4819
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4820	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4821
				4822	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4823	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4824	</pre>
				4825
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4826	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4827
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4828	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4829	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4830
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4831	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4832
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4833	<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]	4834	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]	4835
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4836
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4837	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4838
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4839	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4840	macro available in C. In a target-dependent way, it copies the source
				4841	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4842	intrinsic is necessary because the <tt><a href="#int_va_start">
				4843	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4844	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4845
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4846	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4847
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4848	<!-- ======================================================================= -->
				4849	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4850	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4851	</div>
				4852
				4853	<div class="doc_text">
				4854
				4855	<p>
				4856	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4857	Collection</a> (GC) requires the implementation and generation of these
				4858	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4859	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]	4860	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4861	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]	4862	Front-ends for type-safe garbage collected languages should generate these
				4863	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4864	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4865	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4866
				4867	<p>The garbage collection intrinsics only operate on objects in the generic
				4868	address space (address space zero).</p>
				4869
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4870	</div>
				4871
				4872	<!-- _______________________________________________________________________ -->
				4873	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4874	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4875	</div>
				4876
				4877	<div class="doc_text">
				4878
				4879	<h5>Syntax:</h5>
				4880
				4881	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4882	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4883	</pre>
				4884
				4885	<h5>Overview:</h5>
				4886
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4887	<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]	4888	the code generator, and allows some metadata to be associated with it.</p>
				4889
				4890	<h5>Arguments:</h5>
				4891
				4892	<p>The first argument specifies the address of a stack object that contains the
				4893	root pointer. The second pointer (which must be either a constant or a global
				4894	value address) contains the meta-data to be associated with the root.</p>
				4895
				4896	<h5>Semantics:</h5>
				4897
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4898	<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]	4899	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4900	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4901	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4902	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4903
				4904	</div>
				4905
				4906
				4907	<!-- _______________________________________________________________________ -->
				4908	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4909	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4910	</div>
				4911
				4912	<div class="doc_text">
				4913
				4914	<h5>Syntax:</h5>
				4915
				4916	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4917	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4918	</pre>
				4919
				4920	<h5>Overview:</h5>
				4921
				4922	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4923	locations, allowing garbage collector implementations that require read
				4924	barriers.</p>
				4925
				4926	<h5>Arguments:</h5>
				4927
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4928	<p>The second argument is the address to read from, which should be an address
				4929	allocated from the garbage collector. The first object is a pointer to the
				4930	start of the referenced object, if needed by the language runtime (otherwise
				4931	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4932
				4933	<h5>Semantics:</h5>
				4934
				4935	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4936	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4937	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4938	may only be used in a function which <a href="#gc">specifies a GC
				4939	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4940
				4941	</div>
				4942
				4943
				4944	<!-- _______________________________________________________________________ -->
				4945	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4946	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4947	</div>
				4948
				4949	<div class="doc_text">
				4950
				4951	<h5>Syntax:</h5>
				4952
				4953	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4954	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4955	</pre>
				4956
				4957	<h5>Overview:</h5>
				4958
				4959	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4960	locations, allowing garbage collector implementations that require write
				4961	barriers (such as generational or reference counting collectors).</p>
				4962
				4963	<h5>Arguments:</h5>
				4964
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4965	<p>The first argument is the reference to store, the second is the start of the
				4966	object to store it to, and the third is the address of the field of Obj to
				4967	store to. If the runtime does not require a pointer to the object, Obj may be
				4968	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4969
				4970	<h5>Semantics:</h5>
				4971
				4972	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4973	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4974	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4975	may only be used in a function which <a href="#gc">specifies a GC
				4976	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4977
				4978	</div>
				4979
				4980
				4981
				4982	<!-- ======================================================================= -->
				4983	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4984	<a name="int_codegen">Code Generator Intrinsics</a>
				4985	</div>
				4986
				4987	<div class="doc_text">
				4988	<p>
				4989	These intrinsics are provided by LLVM to expose special features that may only
				4990	be implemented with code generator support.
				4991	</p>
				4992
				4993	</div>
				4994
				4995	<!-- _______________________________________________________________________ -->
				4996	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4997	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4998	</div>
				4999
				5000	<div class="doc_text">
				5001
				5002	<h5>Syntax:</h5>
				5003	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5004	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5005	</pre>
				5006
				5007	<h5>Overview:</h5>
				5008
				5009	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5010	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5011	target-specific value indicating the return address of the current function
				5012	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5013	</p>
				5014
				5015	<h5>Arguments:</h5>
				5016
				5017	<p>
				5018	The argument to this intrinsic indicates which function to return the address
				5019	for. Zero indicates the calling function, one indicates its caller, etc. The
				5020	argument is <b>required</b> to be a constant integer value.
				5021	</p>
				5022
				5023	<h5>Semantics:</h5>
				5024
				5025	<p>
				5026	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5027	the return address of the specified call frame, or zero if it cannot be
				5028	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5029	for arguments other than zero, so it should only be used for debugging purposes.
				5030	</p>
				5031
				5032	<p>
				5033	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5034	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]	5035	source-language caller.
				5036	</p>
				5037	</div>
				5038
				5039
				5040	<!-- _______________________________________________________________________ -->
				5041	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5042	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5043	</div>
				5044
				5045	<div class="doc_text">
				5046
				5047	<h5>Syntax:</h5>
				5048	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5049	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5050	</pre>
				5051
				5052	<h5>Overview:</h5>
				5053
				5054	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5055	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5056	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5057	</p>
				5058
				5059	<h5>Arguments:</h5>
				5060
				5061	<p>
				5062	The argument to this intrinsic indicates which function to return the frame
				5063	pointer for. Zero indicates the calling function, one indicates its caller,
				5064	etc. The argument is <b>required</b> to be a constant integer value.
				5065	</p>
				5066
				5067	<h5>Semantics:</h5>
				5068
				5069	<p>
				5070	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5071	the frame address of the specified call frame, or zero if it cannot be
				5072	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5073	for arguments other than zero, so it should only be used for debugging purposes.
				5074	</p>
				5075
				5076	<p>
				5077	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5078	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]	5079	source-language caller.
				5080	</p>
				5081	</div>
				5082
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5083	<!-- _______________________________________________________________________ -->
				5084	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5085	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5086	</div>
				5087
				5088	<div class="doc_text">
				5089
				5090	<h5>Syntax:</h5>
				5091	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5092	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5093	</pre>
				5094
				5095	<h5>Overview:</h5>
				5096
				5097	<p>
				5098	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]	5099	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5100	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5101	features like scoped automatic variable sized arrays in C99.
				5102	</p>
				5103
				5104	<h5>Semantics:</h5>
				5105
				5106	<p>
				5107	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]	5108	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5109	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5110	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5111	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5112	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5113	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5114	</p>
				5115
				5116	</div>
				5117
				5118	<!-- _______________________________________________________________________ -->
				5119	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5120	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5121	</div>
				5122
				5123	<div class="doc_text">
				5124
				5125	<h5>Syntax:</h5>
				5126	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5127	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5128	</pre>
				5129
				5130	<h5>Overview:</h5>
				5131
				5132	<p>
				5133	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5134	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]	5135	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5136	useful for implementing language features like scoped automatic variable sized
				5137	arrays in C99.
				5138	</p>
				5139
				5140	<h5>Semantics:</h5>
				5141
				5142	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5143	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]	5144	</p>
				5145
				5146	</div>
				5147
				5148
				5149	<!-- _______________________________________________________________________ -->
				5150	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5151	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5152	</div>
				5153
				5154	<div class="doc_text">
				5155
				5156	<h5>Syntax:</h5>
				5157	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5158	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5159	</pre>
				5160
				5161	<h5>Overview:</h5>
				5162
				5163
				5164	<p>
				5165	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]	5166	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5167	no
				5168	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5169	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5170	</p>
				5171
				5172	<h5>Arguments:</h5>
				5173
				5174	<p>
				5175	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5176	determining if the fetch should be for a read (0) or write (1), and
				5177	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5178	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]	5179	<tt>locality</tt> arguments must be constant integers.
				5180	</p>
				5181
				5182	<h5>Semantics:</h5>
				5183
				5184	<p>
				5185	This intrinsic does not modify the behavior of the program. In particular,
				5186	prefetches cannot trap and do not produce a value. On targets that support this
				5187	intrinsic, the prefetch can provide hints to the processor cache for better
				5188	performance.
				5189	</p>
				5190
				5191	</div>
				5192
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5193	<!-- _______________________________________________________________________ -->
				5194	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5195	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5196	</div>
				5197
				5198	<div class="doc_text">
				5199
				5200	<h5>Syntax:</h5>
				5201	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5202	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5203	</pre>
				5204
				5205	<h5>Overview:</h5>
				5206
				5207
				5208	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5209	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]	5210	(PC) in a region of
				5211	code to simulators and other tools. The method is target specific, but it is
				5212	expected that the marker will use exported symbols to transmit the PC of the
				5213	marker.
				5214	The marker makes no guarantees that it will remain with any specific instruction
				5215	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]	5216	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5217	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5218	</p>
				5219
				5220	<h5>Arguments:</h5>
				5221
				5222	<p>
				5223	<tt>id</tt> is a numerical id identifying the marker.
				5224	</p>
				5225
				5226	<h5>Semantics:</h5>
				5227
				5228	<p>
				5229	This intrinsic does not modify the behavior of the program. Backends that do not
				5230	support this intrinisic may ignore it.
				5231	</p>
				5232
				5233	</div>
				5234
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5235	<!-- _______________________________________________________________________ -->
				5236	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5237	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5238	</div>
				5239
				5240	<div class="doc_text">
				5241
				5242	<h5>Syntax:</h5>
				5243	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5244	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5245	</pre>
				5246
				5247	<h5>Overview:</h5>
				5248
				5249
				5250	<p>
				5251	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5252	counter register (or similar low latency, high accuracy clocks) on those targets
				5253	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5254	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5255	should only be used for small timings.
				5256	</p>
				5257
				5258	<h5>Semantics:</h5>
				5259
				5260	<p>
				5261	When directly supported, reading the cycle counter should not modify any memory.
				5262	Implementations are allowed to either return a application specific value or a
				5263	system wide value. On backends without support, this is lowered to a constant 0.
				5264	</p>
				5265
				5266	</div>
				5267
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5268	<!-- ======================================================================= -->
				5269	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5270	<a name="int_libc">Standard C Library Intrinsics</a>
				5271	</div>
				5272
				5273	<div class="doc_text">
				5274	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5275	LLVM provides intrinsics for a few important standard C library functions.
				5276	These intrinsics allow source-language front-ends to pass information about the
				5277	alignment of the pointer arguments to the code generator, providing opportunity
				5278	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5279	</p>
				5280
				5281	</div>
				5282
				5283	<!-- _______________________________________________________________________ -->
				5284	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5285	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5286	</div>
				5287
				5288	<div class="doc_text">
				5289
				5290	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5291	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5292	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5293	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5294	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5295	i8 <len>, i32 <align>)
				5296	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5297	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5298	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5299	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5300	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5301	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5302	</pre>
				5303
				5304	<h5>Overview:</h5>
				5305
				5306	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5307	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]	5308	location to the destination location.
				5309	</p>
				5310
				5311	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5312	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5313	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5314	</p>
				5315
				5316	<h5>Arguments:</h5>
				5317
				5318	<p>
				5319	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]	5320	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5321	specifying the number of bytes to copy, and the fourth argument is the alignment
				5322	of the source and destination locations.
				5323	</p>
				5324
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5325	<p>
				5326	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]	5327	the caller guarantees that both the source and destination pointers are aligned
				5328	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5329	</p>
				5330
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5331	<h5>Semantics:</h5>
				5332
				5333	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5334	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]	5335	location to the destination location, which are not allowed to overlap. It
				5336	copies "len" bytes of memory over. If the argument is known to be aligned to
				5337	some boundary, this can be specified as the fourth argument, otherwise it should
				5338	be set to 0 or 1.
				5339	</p>
				5340	</div>
				5341
				5342
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5343	<!-- _______________________________________________________________________ -->
				5344	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5345	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5346	</div>
				5347
				5348	<div class="doc_text">
				5349
				5350	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5351	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5352	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5353	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5354	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5355	i8 <len>, i32 <align>)
				5356	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5357	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5358	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5359	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5360	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5361	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5362	</pre>
				5363
				5364	<h5>Overview:</h5>
				5365
				5366	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5367	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5368	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5369	'<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]	5370	</p>
				5371
				5372	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5373	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5374	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5375	</p>
				5376
				5377	<h5>Arguments:</h5>
				5378
				5379	<p>
				5380	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]	5381	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5382	specifying the number of bytes to copy, and the fourth argument is the alignment
				5383	of the source and destination locations.
				5384	</p>
				5385
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5386	<p>
				5387	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]	5388	the caller guarantees that the source and destination pointers are aligned to
				5389	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5390	</p>
				5391
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5392	<h5>Semantics:</h5>
				5393
				5394	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5395	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]	5396	location to the destination location, which may overlap. It
				5397	copies "len" bytes of memory over. If the argument is known to be aligned to
				5398	some boundary, this can be specified as the fourth argument, otherwise it should
				5399	be set to 0 or 1.
				5400	</p>
				5401	</div>
				5402
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5403
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5404	<!-- _______________________________________________________________________ -->
				5405	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5406	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5407	</div>
				5408
				5409	<div class="doc_text">
				5410
				5411	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5412	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5413	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5414	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5415	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5416	i8 <len>, i32 <align>)
				5417	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5418	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5419	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5420	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5421	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5422	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5423	</pre>
				5424
				5425	<h5>Overview:</h5>
				5426
				5427	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5428	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]	5429	byte value.
				5430	</p>
				5431
				5432	<p>
				5433	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5434	does not return a value, and takes an extra alignment argument.
				5435	</p>
				5436
				5437	<h5>Arguments:</h5>
				5438
				5439	<p>
				5440	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]	5441	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5442	argument specifying the number of bytes to fill, and the fourth argument is the
				5443	known alignment of destination location.
				5444	</p>
				5445
				5446	<p>
				5447	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]	5448	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5449	</p>
				5450
				5451	<h5>Semantics:</h5>
				5452
				5453	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5454	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5455	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5456	destination location. If the argument is known to be aligned to some boundary,
				5457	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5458	1.
				5459	</p>
				5460	</div>
				5461
				5462
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5463	<!-- _______________________________________________________________________ -->
				5464	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5465	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5466	</div>
				5467
				5468	<div class="doc_text">
				5469
				5470	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5471	<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]	5472	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5473	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5474	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5475	declare float @llvm.sqrt.f32(float %Val)
				5476	declare double @llvm.sqrt.f64(double %Val)
				5477	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5478	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5479	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5480	</pre>
				5481
				5482	<h5>Overview:</h5>
				5483
				5484	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5485	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]	5486	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]	5487	<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]	5488	negative numbers other than -0.0 (which allows for better optimization, because
				5489	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5490	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5491	</p>
				5492
				5493	<h5>Arguments:</h5>
				5494
				5495	<p>
				5496	The argument and return value are floating point numbers of the same type.
				5497	</p>
				5498
				5499	<h5>Semantics:</h5>
				5500
				5501	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5502	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]	5503	floating point number.
				5504	</p>
				5505	</div>
				5506
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5507	<!-- _______________________________________________________________________ -->
				5508	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5509	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5510	</div>
				5511
				5512	<div class="doc_text">
				5513
				5514	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5515	<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]	5516	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5517	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5518	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5519	declare float @llvm.powi.f32(float %Val, i32 %power)
				5520	declare double @llvm.powi.f64(double %Val, i32 %power)
				5521	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5522	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5523	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5524	</pre>
				5525
				5526	<h5>Overview:</h5>
				5527
				5528	<p>
				5529	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5530	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5531	multiplications is not defined. When a vector of floating point type is
				5532	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5533	</p>
				5534
				5535	<h5>Arguments:</h5>
				5536
				5537	<p>
				5538	The second argument is an integer power, and the first is a value to raise to
				5539	that power.
				5540	</p>
				5541
				5542	<h5>Semantics:</h5>
				5543
				5544	<p>
				5545	This function returns the first value raised to the second power with an
				5546	unspecified sequence of rounding operations.</p>
				5547	</div>
				5548
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5549	<!-- _______________________________________________________________________ -->
				5550	<div class="doc_subsubsection">
				5551	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5552	</div>
				5553
				5554	<div class="doc_text">
				5555
				5556	<h5>Syntax:</h5>
				5557	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5558	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5559	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5560	<pre>
				5561	declare float @llvm.sin.f32(float %Val)
				5562	declare double @llvm.sin.f64(double %Val)
				5563	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5564	declare fp128 @llvm.sin.f128(fp128 %Val)
				5565	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5566	</pre>
				5567
				5568	<h5>Overview:</h5>
				5569
				5570	<p>
				5571	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5572	</p>
				5573
				5574	<h5>Arguments:</h5>
				5575
				5576	<p>
				5577	The argument and return value are floating point numbers of the same type.
				5578	</p>
				5579
				5580	<h5>Semantics:</h5>
				5581
				5582	<p>
				5583	This function returns the sine of the specified operand, returning the
				5584	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]	5585	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5586	</div>
				5587
				5588	<!-- _______________________________________________________________________ -->
				5589	<div class="doc_subsubsection">
				5590	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5591	</div>
				5592
				5593	<div class="doc_text">
				5594
				5595	<h5>Syntax:</h5>
				5596	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5597	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5598	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5599	<pre>
				5600	declare float @llvm.cos.f32(float %Val)
				5601	declare double @llvm.cos.f64(double %Val)
				5602	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5603	declare fp128 @llvm.cos.f128(fp128 %Val)
				5604	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5605	</pre>
				5606
				5607	<h5>Overview:</h5>
				5608
				5609	<p>
				5610	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5611	</p>
				5612
				5613	<h5>Arguments:</h5>
				5614
				5615	<p>
				5616	The argument and return value are floating point numbers of the same type.
				5617	</p>
				5618
				5619	<h5>Semantics:</h5>
				5620
				5621	<p>
				5622	This function returns the cosine of the specified operand, returning the
				5623	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]	5624	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5625	</div>
				5626
				5627	<!-- _______________________________________________________________________ -->
				5628	<div class="doc_subsubsection">
				5629	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5630	</div>
				5631
				5632	<div class="doc_text">
				5633
				5634	<h5>Syntax:</h5>
				5635	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5636	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5637	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5638	<pre>
				5639	declare float @llvm.pow.f32(float %Val, float %Power)
				5640	declare double @llvm.pow.f64(double %Val, double %Power)
				5641	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5642	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5643	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5644	</pre>
				5645
				5646	<h5>Overview:</h5>
				5647
				5648	<p>
				5649	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5650	specified (positive or negative) power.
				5651	</p>
				5652
				5653	<h5>Arguments:</h5>
				5654
				5655	<p>
				5656	The second argument is a floating point power, and the first is a value to
				5657	raise to that power.
				5658	</p>
				5659
				5660	<h5>Semantics:</h5>
				5661
				5662	<p>
				5663	This function returns the first value raised to the second power,
				5664	returning the
				5665	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]	5666	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5667	</div>
				5668
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5669
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5670	<!-- ======================================================================= -->
				5671	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5672	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5673	</div>
				5674
				5675	<div class="doc_text">
				5676	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5677	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5678	These allow efficient code generation for some algorithms.
				5679	</p>
				5680
				5681	</div>
				5682
				5683	<!-- _______________________________________________________________________ -->
				5684	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5685	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5686	</div>
				5687
				5688	<div class="doc_text">
				5689
				5690	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5691	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5692	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5693	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5694	declare i16 @llvm.bswap.i16(i16 <id>)
				5695	declare i32 @llvm.bswap.i32(i32 <id>)
				5696	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5697	</pre>
				5698
				5699	<h5>Overview:</h5>
				5700
				5701	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5702	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]	5703	values with an even number of bytes (positive multiple of 16 bits). These are
				5704	useful for performing operations on data that is not in the target's native
				5705	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5706	</p>
				5707
				5708	<h5>Semantics:</h5>
				5709
				5710	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5711	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]	5712	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5713	intrinsic returns an i32 value that has the four bytes of the input i32
				5714	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]	5715	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5716	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5717	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5718	</p>
				5719
				5720	</div>
				5721
				5722	<!-- _______________________________________________________________________ -->
				5723	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5724	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5725	</div>
				5726
				5727	<div class="doc_text">
				5728
				5729	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5730	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5731	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5732	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5733	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5734	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5735	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5736	declare i64 @llvm.ctpop.i64(i64 <src>)
				5737	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5738	</pre>
				5739
				5740	<h5>Overview:</h5>
				5741
				5742	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5743	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5744	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5745	</p>
				5746
				5747	<h5>Arguments:</h5>
				5748
				5749	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5750	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]	5751	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5752	</p>
				5753
				5754	<h5>Semantics:</h5>
				5755
				5756	<p>
				5757	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5758	</p>
				5759	</div>
				5760
				5761	<!-- _______________________________________________________________________ -->
				5762	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5763	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5764	</div>
				5765
				5766	<div class="doc_text">
				5767
				5768	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5769	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5770	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5771	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5772	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5773	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5774	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5775	declare i64 @llvm.ctlz.i64(i64 <src>)
				5776	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5777	</pre>
				5778
				5779	<h5>Overview:</h5>
				5780
				5781	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5782	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5783	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5784	</p>
				5785
				5786	<h5>Arguments:</h5>
				5787
				5788	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5789	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]	5790	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5791	</p>
				5792
				5793	<h5>Semantics:</h5>
				5794
				5795	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5796	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5797	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]	5798	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5799	</p>
				5800	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5801
				5802
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5803
				5804	<!-- _______________________________________________________________________ -->
				5805	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5806	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5807	</div>
				5808
				5809	<div class="doc_text">
				5810
				5811	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5812	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5813	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5814	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5815	declare i8 @llvm.cttz.i8 (i8 <src>)
				5816	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5817	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5818	declare i64 @llvm.cttz.i64(i64 <src>)
				5819	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5820	</pre>
				5821
				5822	<h5>Overview:</h5>
				5823
				5824	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5825	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5826	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5827	</p>
				5828
				5829	<h5>Arguments:</h5>
				5830
				5831	<p>
				5832	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]	5833	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5834	</p>
				5835
				5836	<h5>Semantics:</h5>
				5837
				5838	<p>
				5839	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5840	in a variable. If the src == 0 then the result is the size in bits of the type
				5841	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5842	</p>
				5843	</div>
				5844
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5845	<!-- _______________________________________________________________________ -->
				5846	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5847	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5848	</div>
				5849
				5850	<div class="doc_text">
				5851
				5852	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5853	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5854	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5855	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5856	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5857	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5858	</pre>
				5859
				5860	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5861	<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]	5862	range of bits from an integer value and returns them in the same bit width as
				5863	the original value.</p>
				5864
				5865	<h5>Arguments:</h5>
				5866	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5867	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]	5868	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]	5869
				5870	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5871	<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]	5872	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5873	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5874	operates in forward mode.</p>
				5875	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5876	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]	5877	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5878	<ol>
				5879	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5880	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5881	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5882	to determine the number of bits to retain.</li>
				5883	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5884	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5885	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5886	<p>In reverse mode, a similar computation is made except that the bits are
				5887	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5888	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5889	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5890	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5891	</div>
				5892
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5893	<div class="doc_subsubsection">
				5894	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5895	</div>
				5896
				5897	<div class="doc_text">
				5898
				5899	<h5>Syntax:</h5>
				5900	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5901	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5902	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5903	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5904	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]	5905	</pre>
				5906
				5907	<h5>Overview:</h5>
				5908	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5909	of bits in an integer value with another integer value. It returns the integer
				5910	with the replaced bits.</p>
				5911
				5912	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5913	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				5914	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5915	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5916	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5917	type since they specify only a bit index.</p>
				5918
				5919	<h5>Semantics:</h5>
				5920	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5921	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5922	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5923	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5924
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5925	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5926	truncating it down to the size of the replacement area or zero extending it
				5927	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5928
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5929	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5930	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5931	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5932	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5933
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5934	<p>In reverse mode, a similar computation is made except that the bits are
				5935	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5936	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5937
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5938	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5939
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5940	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5941	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5942	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5943	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5944	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5945	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	5946	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5947
				5948	</div>
				5949
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	5950	<!-- ======================================================================= -->
				5951	<div class="doc_subsection">
				5952	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5953	</div>
				5954
				5955	<div class="doc_text">
				5956	<p>
				5957	LLVM provides intrinsics for some arithmetic with overflow operations.
				5958	</p>
				5959
				5960	</div>
				5961
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5962	<!-- _______________________________________________________________________ -->
				5963	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	5964	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5965	</div>
				5966
				5967	<div class="doc_text">
				5968
				5969	<h5>Syntax:</h5>
				5970
				5971	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	5972	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5973
				5974	<pre>
				5975	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5976	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5977	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5978	</pre>
				5979
				5980	<h5>Overview:</h5>
				5981
				5982	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5983	a signed addition of the two arguments, and indicate whether an overflow
				5984	occurred during the signed summation.</p>
				5985
				5986	<h5>Arguments:</h5>
				5987
				5988	<p>The arguments (%a and %b) and the first element of the result structure may
				5989	be of integer types of any bit width, but they must have the same bit width. The
				5990	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				5991	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				5992
				5993	<h5>Semantics:</h5>
				5994
				5995	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5996	a signed addition of the two variables. They return a structure — the
				5997	first element of which is the signed summation, and the second element of which
				5998	is a bit specifying if the signed summation resulted in an overflow.</p>
				5999
				6000	<h5>Examples:</h5>
				6001	<pre>
				6002	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6003	%sum = extractvalue {i32, i1} %res, 0
				6004	%obit = extractvalue {i32, i1} %res, 1
				6005	br i1 %obit, label %overflow, label %normal
				6006	</pre>
				6007
				6008	</div>
				6009
				6010	<!-- _______________________________________________________________________ -->
				6011	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6012	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6013	</div>
				6014
				6015	<div class="doc_text">
				6016
				6017	<h5>Syntax:</h5>
				6018
				6019	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6020	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6021
				6022	<pre>
				6023	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6024	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6025	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6026	</pre>
				6027
				6028	<h5>Overview:</h5>
				6029
				6030	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6031	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6032	during the unsigned summation.</p>
				6033
				6034	<h5>Arguments:</h5>
				6035
				6036	<p>The arguments (%a and %b) and the first element of the result structure may
				6037	be of integer types of any bit width, but they must have the same bit width. The
				6038	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6039	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6040
				6041	<h5>Semantics:</h5>
				6042
				6043	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6044	an unsigned addition of the two arguments. They return a structure — the
				6045	first element of which is the sum, and the second element of which is a bit
				6046	specifying if the unsigned summation resulted in a carry.</p>
				6047
				6048	<h5>Examples:</h5>
				6049	<pre>
				6050	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6051	%sum = extractvalue {i32, i1} %res, 0
				6052	%obit = extractvalue {i32, i1} %res, 1
				6053	br i1 %obit, label %carry, label %normal
				6054	</pre>
				6055
				6056	</div>
				6057
				6058	<!-- _______________________________________________________________________ -->
				6059	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6060	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6061	</div>
				6062
				6063	<div class="doc_text">
				6064
				6065	<h5>Syntax:</h5>
				6066
				6067	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6068	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6069
				6070	<pre>
				6071	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6072	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6073	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6074	</pre>
				6075
				6076	<h5>Overview:</h5>
				6077
				6078	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6079	a signed subtraction of the two arguments, and indicate whether an overflow
				6080	occurred during the signed subtraction.</p>
				6081
				6082	<h5>Arguments:</h5>
				6083
				6084	<p>The arguments (%a and %b) and the first element of the result structure may
				6085	be of integer types of any bit width, but they must have the same bit width. The
				6086	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6087	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6088
				6089	<h5>Semantics:</h5>
				6090
				6091	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6092	a signed subtraction of the two arguments. They return a structure — the
				6093	first element of which is the subtraction, and the second element of which is a bit
				6094	specifying if the signed subtraction resulted in an overflow.</p>
				6095
				6096	<h5>Examples:</h5>
				6097	<pre>
				6098	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6099	%sum = extractvalue {i32, i1} %res, 0
				6100	%obit = extractvalue {i32, i1} %res, 1
				6101	br i1 %obit, label %overflow, label %normal
				6102	</pre>
				6103
				6104	</div>
				6105
				6106	<!-- _______________________________________________________________________ -->
				6107	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6108	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6109	</div>
				6110
				6111	<div class="doc_text">
				6112
				6113	<h5>Syntax:</h5>
				6114
				6115	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6116	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6117
				6118	<pre>
				6119	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6120	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6121	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6122	</pre>
				6123
				6124	<h5>Overview:</h5>
				6125
				6126	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6127	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6128	occurred during the unsigned subtraction.</p>
				6129
				6130	<h5>Arguments:</h5>
				6131
				6132	<p>The arguments (%a and %b) and the first element of the result structure may
				6133	be of integer types of any bit width, but they must have the same bit width. The
				6134	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6135	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6136
				6137	<h5>Semantics:</h5>
				6138
				6139	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6140	an unsigned subtraction of the two arguments. They return a structure — the
				6141	first element of which is the subtraction, and the second element of which is a bit
				6142	specifying if the unsigned subtraction resulted in an overflow.</p>
				6143
				6144	<h5>Examples:</h5>
				6145	<pre>
				6146	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6147	%sum = extractvalue {i32, i1} %res, 0
				6148	%obit = extractvalue {i32, i1} %res, 1
				6149	br i1 %obit, label %overflow, label %normal
				6150	</pre>
				6151
				6152	</div>
				6153
				6154	<!-- _______________________________________________________________________ -->
				6155	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6156	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6157	</div>
				6158
				6159	<div class="doc_text">
				6160
				6161	<h5>Syntax:</h5>
				6162
				6163	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6164	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6165
				6166	<pre>
				6167	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6168	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6169	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6170	</pre>
				6171
				6172	<h5>Overview:</h5>
				6173
				6174	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6175	a signed multiplication of the two arguments, and indicate whether an overflow
				6176	occurred during the signed multiplication.</p>
				6177
				6178	<h5>Arguments:</h5>
				6179
				6180	<p>The arguments (%a and %b) and the first element of the result structure may
				6181	be of integer types of any bit width, but they must have the same bit width. The
				6182	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6183	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6184
				6185	<h5>Semantics:</h5>
				6186
				6187	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6188	a signed multiplication of the two arguments. They return a structure —
				6189	the first element of which is the multiplication, and the second element of
				6190	which is a bit specifying if the signed multiplication resulted in an
				6191	overflow.</p>
				6192
				6193	<h5>Examples:</h5>
				6194	<pre>
				6195	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6196	%sum = extractvalue {i32, i1} %res, 0
				6197	%obit = extractvalue {i32, i1} %res, 1
				6198	br i1 %obit, label %overflow, label %normal
				6199	</pre>
				6200
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6201	</div>
				6202
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6203	<!-- _______________________________________________________________________ -->
				6204	<div class="doc_subsubsection">
				6205	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6206	</div>
				6207
				6208	<div class="doc_text">
				6209
				6210	<h5>Syntax:</h5>
				6211
				6212	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6213	on any integer bit width.</p>
				6214
				6215	<pre>
				6216	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6217	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6218	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6219	</pre>
				6220
				6221	<h5>Overview:</h5>
				6222
				6223	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6224	actively being fixed, but it should not currently be used!</i></p>
				6225
				6226	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6227	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6228	occurred during the unsigned multiplication.</p>
				6229
				6230	<h5>Arguments:</h5>
				6231
				6232	<p>The arguments (%a and %b) and the first element of the result structure may
				6233	be of integer types of any bit width, but they must have the same bit width. The
				6234	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6235	and <tt>%b</tt> are the two values that will undergo unsigned
				6236	multiplication.</p>
				6237
				6238	<h5>Semantics:</h5>
				6239
				6240	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6241	an unsigned multiplication of the two arguments. They return a structure —
				6242	the first element of which is the multiplication, and the second element of
				6243	which is a bit specifying if the unsigned multiplication resulted in an
				6244	overflow.</p>
				6245
				6246	<h5>Examples:</h5>
				6247	<pre>
				6248	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6249	%sum = extractvalue {i32, i1} %res, 0
				6250	%obit = extractvalue {i32, i1} %res, 1
				6251	br i1 %obit, label %overflow, label %normal
				6252	</pre>
				6253
				6254	</div>
				6255
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6256	<!-- ======================================================================= -->
				6257	<div class="doc_subsection">
				6258	<a name="int_debugger">Debugger Intrinsics</a>
				6259	</div>
				6260
				6261	<div class="doc_text">
				6262	<p>
				6263	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6264	are described in the <a
				6265	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6266	Debugging</a> document.
				6267	</p>
				6268	</div>
				6269
				6270
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6271	<!-- ======================================================================= -->
				6272	<div class="doc_subsection">
				6273	<a name="int_eh">Exception Handling Intrinsics</a>
				6274	</div>
				6275
				6276	<div class="doc_text">
				6277	<p> The LLVM exception handling intrinsics (which all start with
				6278	<tt>llvm.eh.</tt> prefix), are described in the <a
				6279	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6280	Handling</a> document. </p>
				6281	</div>
				6282
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6283	<!-- ======================================================================= -->
				6284	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6285	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6286	</div>
				6287
				6288	<div class="doc_text">
				6289	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6290	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6291	the <tt>nest</tt> attribute, from a function. The result is a callable
				6292	function pointer lacking the nest parameter - the caller does not need
				6293	to provide a value for it. Instead, the value to use is stored in
				6294	advance in a "trampoline", a block of memory usually allocated
				6295	on the stack, which also contains code to splice the nest value into the
				6296	argument list. This is used to implement the GCC nested function address
				6297	extension.
				6298	</p>
				6299	<p>
				6300	For example, if the function is
				6301	<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]	6302	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]	6303	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6304	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6305	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6306	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6307	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6308	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6309	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6310	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]	6311	</div>
				6312
				6313	<!-- _______________________________________________________________________ -->
				6314	<div class="doc_subsubsection">
				6315	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6316	</div>
				6317	<div class="doc_text">
				6318	<h5>Syntax:</h5>
				6319	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6320	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6321	</pre>
				6322	<h5>Overview:</h5>
				6323	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6324	This fills the memory pointed to by <tt>tramp</tt> with code
				6325	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6326	</p>
				6327	<h5>Arguments:</h5>
				6328	<p>
				6329	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6330	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6331	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]	6332	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6333	currently provides no portable way of determining them, so a front-end that
				6334	generates this intrinsic needs to have some target-specific knowledge.
				6335	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]	6336	</p>
				6337	<h5>Semantics:</h5>
				6338	<p>
				6339	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]	6340	dependent code, turning it into a function. A pointer to this function is
				6341	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6342	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6343	before being called. The new function's signature is the same as that of
				6344	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6345	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6346	of pointer type. Calling the new function is equivalent to calling
				6347	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6348	missing <tt>nest</tt> argument. If, after calling
				6349	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6350	modified, then the effect of any later call to the returned function pointer is
				6351	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6352	</p>
				6353	</div>
				6354
				6355	<!-- ======================================================================= -->
				6356	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6357	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6358	</div>
				6359
				6360	<div class="doc_text">
				6361	<p>
				6362	These intrinsic functions expand the "universal IR" of LLVM to represent
				6363	hardware constructs for atomic operations and memory synchronization. This
				6364	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]	6365	is aimed at a low enough level to allow any programming models or APIs
				6366	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6367	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6368	hardware behavior. Just as hardware provides a "universal IR" for source
				6369	languages, it also provides a starting point for developing a "universal"
				6370	atomic operation and synchronization IR.
				6371	</p>
				6372	<p>
				6373	These do <em>not</em> form an API such as high-level threading libraries,
				6374	software transaction memory systems, atomic primitives, and intrinsic
				6375	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6376	application libraries. The hardware interface provided by LLVM should allow
				6377	a clean implementation of all of these APIs and parallel programming models.
				6378	No one model or paradigm should be selected above others unless the hardware
				6379	itself ubiquitously does so.
				6380
				6381	</p>
				6382	</div>
				6383
				6384	<!-- _______________________________________________________________________ -->
				6385	<div class="doc_subsubsection">
				6386	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6387	</div>
				6388	<div class="doc_text">
				6389	<h5>Syntax:</h5>
				6390	<pre>
				6391	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6392	i1 <device> )
				6393
				6394	</pre>
				6395	<h5>Overview:</h5>
				6396	<p>
				6397	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6398	specific pairs of memory access types.
				6399	</p>
				6400	<h5>Arguments:</h5>
				6401	<p>
				6402	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6403	The first four arguments enables a specific barrier as listed below. The fith
				6404	argument specifies that the barrier applies to io or device or uncached memory.
				6405
				6406	</p>
				6407	<ul>
				6408	<li><tt>ll</tt>: load-load barrier</li>
				6409	<li><tt>ls</tt>: load-store barrier</li>
				6410	<li><tt>sl</tt>: store-load barrier</li>
				6411	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6412	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6413	</ul>
				6414	<h5>Semantics:</h5>
				6415	<p>
				6416	This intrinsic causes the system to enforce some ordering constraints upon
				6417	the loads and stores of the program. This barrier does not indicate
				6418	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6419	which they occur. For any of the specified pairs of load and store operations
				6420	(f.ex. load-load, or store-load), all of the first operations preceding the
				6421	barrier will complete before any of the second operations succeeding the
				6422	barrier begin. Specifically the semantics for each pairing is as follows:
				6423	</p>
				6424	<ul>
				6425	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6426	after the barrier begins.</li>
				6427
				6428	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6429	store after the barrier begins.</li>
				6430	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6431	store after the barrier begins.</li>
				6432	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6433	load after the barrier begins.</li>
				6434	</ul>
				6435	<p>
				6436	These semantics are applied with a logical "and" behavior when more than one
				6437	is enabled in a single memory barrier intrinsic.
				6438	</p>
				6439	<p>
				6440	Backends may implement stronger barriers than those requested when they do not
				6441	support as fine grained a barrier as requested. Some architectures do not
				6442	need all types of barriers and on such architectures, these become noops.
				6443	</p>
				6444	<h5>Example:</h5>
				6445	<pre>
				6446	%ptr = malloc i32
				6447	store i32 4, %ptr
				6448
				6449	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6450	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6451	<i>; guarantee the above finishes</i>
				6452	store i32 8, %ptr <i>; before this begins</i>
				6453	</pre>
				6454	</div>
				6455
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6456	<!-- _______________________________________________________________________ -->
				6457	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6458	<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]	6459	</div>
				6460	<div class="doc_text">
				6461	<h5>Syntax:</h5>
				6462	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6463	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6464	any integer bit width and for different address spaces. Not all targets
				6465	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6466
				6467	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6468	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6469	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6470	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6471	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]	6472
				6473	</pre>
				6474	<h5>Overview:</h5>
				6475	<p>
				6476	This loads a value in memory and compares it to a given value. If they are
				6477	equal, it stores a new value into the memory.
				6478	</p>
				6479	<h5>Arguments:</h5>
				6480	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6481	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]	6482	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6483	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6484	this integer type. While any bit width integer may be used, targets may only
				6485	lower representations they support in hardware.
				6486
				6487	</p>
				6488	<h5>Semantics:</h5>
				6489	<p>
				6490	This entire intrinsic must be executed atomically. It first loads the value
				6491	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6492	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6493	loaded value is yielded in all cases. This provides the equivalent of an
				6494	atomic compare-and-swap operation within the SSA framework.
				6495	</p>
				6496	<h5>Examples:</h5>
				6497
				6498	<pre>
				6499	%ptr = malloc i32
				6500	store i32 4, %ptr
				6501
				6502	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6503	%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]	6504	<i>; yields {i32}:result1 = 4</i>
				6505	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6506	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6507
				6508	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6509	%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]	6510	<i>; yields {i32}:result2 = 8</i>
				6511	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6512
				6513	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6514	</pre>
				6515	</div>
				6516
				6517	<!-- _______________________________________________________________________ -->
				6518	<div class="doc_subsubsection">
				6519	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6520	</div>
				6521	<div class="doc_text">
				6522	<h5>Syntax:</h5>
				6523
				6524	<p>
				6525	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6526	integer bit width. Not all targets support all bit widths however.</p>
				6527	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6528	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6529	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6530	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6531	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6532
				6533	</pre>
				6534	<h5>Overview:</h5>
				6535	<p>
				6536	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6537	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6538	at <tt>ptr</tt>.
				6539	</p>
				6540	<h5>Arguments:</h5>
				6541
				6542	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6543	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6544	<tt>val</tt> argument and the result must be integers of the same bit width.
				6545	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6546	integer type. The targets may only lower integer representations they
				6547	support.
				6548	</p>
				6549	<h5>Semantics:</h5>
				6550	<p>
				6551	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6552	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6553	equivalent of an atomic swap operation within the SSA framework.
				6554
				6555	</p>
				6556	<h5>Examples:</h5>
				6557	<pre>
				6558	%ptr = malloc i32
				6559	store i32 4, %ptr
				6560
				6561	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6562	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6563	<i>; yields {i32}:result1 = 4</i>
				6564	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6565	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6566
				6567	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6568	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6569	<i>; yields {i32}:result2 = 8</i>
				6570
				6571	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6572	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6573	</pre>
				6574	</div>
				6575
				6576	<!-- _______________________________________________________________________ -->
				6577	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6578	<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]	6579
				6580	</div>
				6581	<div class="doc_text">
				6582	<h5>Syntax:</h5>
				6583	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6584	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]	6585	integer bit width. Not all targets support all bit widths however.</p>
				6586	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6587	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6588	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6589	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6590	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6591
				6592	</pre>
				6593	<h5>Overview:</h5>
				6594	<p>
				6595	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6596	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6597	</p>
				6598	<h5>Arguments:</h5>
				6599	<p>
				6600
				6601	The intrinsic takes two arguments, the first a pointer to an integer value
				6602	and the second an integer value. The result is also an integer value. These
				6603	integer types can have any bit width, but they must all have the same bit
				6604	width. The targets may only lower integer representations they support.
				6605	</p>
				6606	<h5>Semantics:</h5>
				6607	<p>
				6608	This intrinsic does a series of operations atomically. It first loads the
				6609	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6610	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6611	</p>
				6612
				6613	<h5>Examples:</h5>
				6614	<pre>
				6615	%ptr = malloc i32
				6616	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6617	%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]	6618	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6619	%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]	6620	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6621	%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]	6622	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6623	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6624	</pre>
				6625	</div>
				6626
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6627	<!-- _______________________________________________________________________ -->
				6628	<div class="doc_subsubsection">
				6629	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6630
				6631	</div>
				6632	<div class="doc_text">
				6633	<h5>Syntax:</h5>
				6634	<p>
				6635	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]	6636	any integer bit width and for different address spaces. Not all targets
				6637	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6638	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6639	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6640	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6641	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6642	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]	6643
				6644	</pre>
				6645	<h5>Overview:</h5>
				6646	<p>
				6647	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6648	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6649	</p>
				6650	<h5>Arguments:</h5>
				6651	<p>
				6652
				6653	The intrinsic takes two arguments, the first a pointer to an integer value
				6654	and the second an integer value. The result is also an integer value. These
				6655	integer types can have any bit width, but they must all have the same bit
				6656	width. The targets may only lower integer representations they support.
				6657	</p>
				6658	<h5>Semantics:</h5>
				6659	<p>
				6660	This intrinsic does a series of operations atomically. It first loads the
				6661	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6662	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6663	</p>
				6664
				6665	<h5>Examples:</h5>
				6666	<pre>
				6667	%ptr = malloc i32
				6668	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6669	%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]	6670	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6671	%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]	6672	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6673	%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]	6674	<i>; yields {i32}:result3 = 2</i>
				6675	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6676	</pre>
				6677	</div>
				6678
				6679	<!-- _______________________________________________________________________ -->
				6680	<div class="doc_subsubsection">
				6681	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6682	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6683	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6684	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6685
				6686	</div>
				6687	<div class="doc_text">
				6688	<h5>Syntax:</h5>
				6689	<p>
				6690	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6691	<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]	6692	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6693	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6694	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6695	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6696	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6697	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6698	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]	6699
				6700	</pre>
				6701
				6702	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6703	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6704	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6705	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6706	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]	6707
				6708	</pre>
				6709
				6710	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6711	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6712	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6713	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6714	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]	6715
				6716	</pre>
				6717
				6718	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6719	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6720	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6721	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6722	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]	6723
				6724	</pre>
				6725	<h5>Overview:</h5>
				6726	<p>
				6727	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6728	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6729	at <tt>ptr</tt>.
				6730	</p>
				6731	<h5>Arguments:</h5>
				6732	<p>
				6733
				6734	These intrinsics take two arguments, the first a pointer to an integer value
				6735	and the second an integer value. The result is also an integer value. These
				6736	integer types can have any bit width, but they must all have the same bit
				6737	width. The targets may only lower integer representations they support.
				6738	</p>
				6739	<h5>Semantics:</h5>
				6740	<p>
				6741	These intrinsics does a series of operations atomically. They first load the
				6742	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6743	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6744	value stored at <tt>ptr</tt>.
				6745	</p>
				6746
				6747	<h5>Examples:</h5>
				6748	<pre>
				6749	%ptr = malloc i32
				6750	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6751	%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]	6752	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6753	%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]	6754	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6755	%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]	6756	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6757	%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]	6758	<i>; yields {i32}:result3 = FF</i>
				6759	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6760	</pre>
				6761	</div>
				6762
				6763
				6764	<!-- _______________________________________________________________________ -->
				6765	<div class="doc_subsubsection">
				6766	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6767	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6768	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6769	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6770
				6771	</div>
				6772	<div class="doc_text">
				6773	<h5>Syntax:</h5>
				6774	<p>
				6775	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6776	<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]	6777	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6778	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6779	support all bit widths however.</p>
				6780	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6781	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6782	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6783	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6784	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]	6785
				6786	</pre>
				6787
				6788	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6789	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6790	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6791	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6792	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]	6793
				6794	</pre>
				6795
				6796	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6797	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6798	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6799	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6800	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]	6801
				6802	</pre>
				6803
				6804	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6805	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6806	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6807	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6808	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]	6809
				6810	</pre>
				6811	<h5>Overview:</h5>
				6812	<p>
				6813	These intrinsics takes the signed or unsigned minimum or maximum of
				6814	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6815	original value at <tt>ptr</tt>.
				6816	</p>
				6817	<h5>Arguments:</h5>
				6818	<p>
				6819
				6820	These intrinsics take two arguments, the first a pointer to an integer value
				6821	and the second an integer value. The result is also an integer value. These
				6822	integer types can have any bit width, but they must all have the same bit
				6823	width. The targets may only lower integer representations they support.
				6824	</p>
				6825	<h5>Semantics:</h5>
				6826	<p>
				6827	These intrinsics does a series of operations atomically. They first load the
				6828	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6829	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6830	the original value stored at <tt>ptr</tt>.
				6831	</p>
				6832
				6833	<h5>Examples:</h5>
				6834	<pre>
				6835	%ptr = malloc i32
				6836	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6837	%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]	6838	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6839	%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]	6840	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6841	%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]	6842	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6843	%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]	6844	<i>; yields {i32}:result3 = 8</i>
				6845	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6846	</pre>
				6847	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6848
				6849	<!-- ======================================================================= -->
				6850	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6851	<a name="int_general">General Intrinsics</a>
				6852	</div>
				6853
				6854	<div class="doc_text">
				6855	<p> This class of intrinsics is designed to be generic and has
				6856	no specific purpose. </p>
				6857	</div>
				6858
				6859	<!-- _______________________________________________________________________ -->
				6860	<div class="doc_subsubsection">
				6861	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6862	</div>
				6863
				6864	<div class="doc_text">
				6865
				6866	<h5>Syntax:</h5>
				6867	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6868	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]	6869	</pre>
				6870
				6871	<h5>Overview:</h5>
				6872
				6873	<p>
				6874	The '<tt>llvm.var.annotation</tt>' intrinsic
				6875	</p>
				6876
				6877	<h5>Arguments:</h5>
				6878
				6879	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6880	The first argument is a pointer to a value, the second is a pointer to a
				6881	global string, the third is a pointer to a global string which is the source
				6882	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6883	</p>
				6884
				6885	<h5>Semantics:</h5>
				6886
				6887	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6888	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6889	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]	6890	annotations. These have no other defined use, they are ignored by code
				6891	generation and optimization.
				6892	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6893	</div>
				6894
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6895	<!-- _______________________________________________________________________ -->
				6896	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6897	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6898	</div>
				6899
				6900	<div class="doc_text">
				6901
				6902	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6903	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6904	any integer bit width.
				6905	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6906	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6907	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6908	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6909	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6910	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6911	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]	6912	</pre>
				6913
				6914	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6915
				6916	<p>
				6917	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6918	</p>
				6919
				6920	<h5>Arguments:</h5>
				6921
				6922	<p>
				6923	The first argument is an integer value (result of some expression),
				6924	the second is a pointer to a global string, the third is a pointer to a global
				6925	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]	6926	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6927	</p>
				6928
				6929	<h5>Semantics:</h5>
				6930
				6931	<p>
				6932	This intrinsic allows annotations to be put on arbitrary expressions
				6933	with arbitrary strings. This can be useful for special purpose optimizations
				6934	that want to look for these annotations. These have no other defined use, they
				6935	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6936	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6937	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6938
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6939	<!-- _______________________________________________________________________ -->
				6940	<div class="doc_subsubsection">
				6941	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6942	</div>
				6943
				6944	<div class="doc_text">
				6945
				6946	<h5>Syntax:</h5>
				6947	<pre>
				6948	declare void @llvm.trap()
				6949	</pre>
				6950
				6951	<h5>Overview:</h5>
				6952
				6953	<p>
				6954	The '<tt>llvm.trap</tt>' intrinsic
				6955	</p>
				6956
				6957	<h5>Arguments:</h5>
				6958
				6959	<p>
				6960	None
				6961	</p>
				6962
				6963	<h5>Semantics:</h5>
				6964
				6965	<p>
				6966	This intrinsics is lowered to the target dependent trap instruction. If the
				6967	target does not have a trap instruction, this intrinsic will be lowered to the
				6968	call of the abort() function.
				6969	</p>
				6970	</div>
				6971
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	6972	<!-- _______________________________________________________________________ -->
				6973	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	6974	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	6975	</div>
				6976	<div class="doc_text">
				6977	<h5>Syntax:</h5>
				6978	<pre>
				6979	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6980
				6981	</pre>
				6982	<h5>Overview:</h5>
				6983	<p>
				6984	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				6985	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				6986	it is placed on the stack before local variables.
				6987	</p>
				6988	<h5>Arguments:</h5>
				6989	<p>
				6990	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				6991	first argument is the value loaded from the stack guard
				6992	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				6993	has enough space to hold the value of the guard.
				6994	</p>
				6995	<h5>Semantics:</h5>
				6996	<p>
				6997	This intrinsic causes the prologue/epilogue inserter to force the position of
				6998	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				6999	stack. This is to ensure that if a local variable on the stack is overwritten,
				7000	it will destroy the value of the guard. When the function exits, the guard on
				7001	the stack is checked against the original guard. If they're different, then
				7002	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7003	</p>
				7004	</div>
				7005
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7006	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7007	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7008	<address>
				7009	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7010	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7011	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7012	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7013
				7014	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7015	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7016	Last modified: $Date$
				7017	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7018
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7019	</body>
				7020	</html>