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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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	546ea7e	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	156	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	157	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	158	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	159	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	160	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				163	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	164	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				165	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				166	<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]	167	</ol>
				168	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	169	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				170	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	171	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				172	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	174	</ol>
				175	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	176	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				177	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	178	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				179	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				182	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				183	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				184	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	185	</ol>
				186	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	187	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				188	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	189	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				190	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	194	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	197	</ol>
				198	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	199	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	200	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	202	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				203	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	205	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				206	<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]	207	</ol>
				208	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	209	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	210	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	211	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	212	<ol>
				213	<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]	214	</ol>
				215	</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	216	<li><a href="#int_atomics">Atomic intrinsics</a>
				217	<ol>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	218	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	219	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	220	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	221	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				222	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				223	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				224	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				225	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				226	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				227	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				228	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				229	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				230	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	231	</ol>
				232	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	233	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	234	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	235	<li><a href="#int_var_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	236	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	237	<li><a href="#int_annotation">
Tanya Lattner	08abc81	2007-09-22 00:01:26 +0000	[diff] [blame]	238	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	239	<li><a href="#int_trap">
				240	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	241	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	242	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	243	</ol>
				244	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	245	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	246
				247	<div class="doc_author">
				248	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				249	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	250	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	251
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	252	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	253	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				254	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	255
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	256	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	257	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	258	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	259	type safety, low-level operations, flexibility, and the capability of
				260	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	261	representation used throughout all phases of the LLVM compilation
				262	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	263	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	264
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	265	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	266	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				267	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	269	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	270
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	271	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	272	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]	273	representation (suitable for fast loading by a Just-In-Time compiler),
				274	and as a human readable assembly language representation. This allows
				275	LLVM to provide a powerful intermediate representation for efficient
				276	compiler transformations and analysis, while providing a natural means
				277	to debug and visualize the transformations. The three different forms
				278	of LLVM are all equivalent. This document describes the human readable
				279	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	280
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	281	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	282	while being expressive, typed, and extensible at the same time. It
				283	aims to be a "universal IR" of sorts, by being at a low enough level
				284	that high-level ideas may be cleanly mapped to it (similar to how
				285	microprocessors are "universal IR's", allowing many source languages to
				286	be mapped to them). By providing type information, LLVM can be used as
				287	the target of optimizations: for example, through pointer analysis, it
				288	can be proven that a C automatic variable is never accessed outside of
				289	the current function... allowing it to be promoted to a simple SSA
				290	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	291
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	292	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	293
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	294	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	295	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	296
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	297	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	298
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	299	<p>It is important to note that this document describes 'well formed'
				300	LLVM assembly language. There is a difference between what the parser
				301	accepts and what is considered 'well formed'. For example, the
				302	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	303
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	304	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	305	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	306	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	307	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	308	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	310	<p>...because the definition of <tt>%x</tt> does not dominate all of
				311	its uses. The LLVM infrastructure provides a verification pass that may
				312	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]	313	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	314	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	315	by the verifier pass indicate bugs in transformation passes or input to
				316	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	317	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	319	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	321	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	322	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	323	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	325	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	327	<p>LLVM identifiers come in two basic types: global and local. Global
				328	identifiers (functions, global variables) begin with the @ character. Local
				329	identifiers (register names, types) begin with the % character. Additionally,
				330	there are three different formats for identifiers, for different purposes:
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	331
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	332	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	333	<li>Named values are represented as a string of characters with their prefix.
				334	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				335	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]	336	Identifiers which require other characters in their names can be surrounded
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	337	with quotes. In this way, anything except a <tt>"</tt> character can
				338	be used in a named value.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	339
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	340	<li>Unnamed values are represented as an unsigned numeric value with their
				341	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	342
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	343	<li>Constants, which are described in a <a href="#constants">section about
				344	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	345	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	346
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<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]	348	don't need to worry about name clashes with reserved words, and the set of
				349	reserved words may be expanded in the future without penalty. Additionally,
				350	unnamed identifiers allow a compiler to quickly come up with a temporary
				351	variable without having to avoid symbol table conflicts.</p>
				352
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	353	<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]	354	languages. There are keywords for different opcodes
				355	('<tt><a href="#i_add">add</a></tt>',
				356	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				357	'<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]	358	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]	359	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	360	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	361
				362	<p>Here is an example of LLVM code to multiply the integer variable
				363	'<tt>%X</tt>' by 8:</p>
				364
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	365	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	366
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	367	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	368	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	369	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	370	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	371	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	372
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	373	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	374
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	375	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	376	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	377	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	378	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	379	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	380
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	381	<p>And the hard 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	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				386	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				387	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	388	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	389	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	391	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				392	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	394	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	395
				396	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				397	line.</li>
				398
				399	<li>Unnamed temporaries are created when the result of a computation is not
				400	assigned to a named value.</li>
				401
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	404	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	405
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	406	<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]	407	demonstrating instructions, we will follow an instruction with a comment that
				408	defines the type and name of value produced. Comments are shown in italic
				409	text.</p>
				410
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	411	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	412
				413	<!-- *********************************************************************** -->
				414	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				415	<!-- *********************************************************************** -->
				416
				417	<!-- ======================================================================= -->
				418	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				419	</div>
				420
				421	<div class="doc_text">
				422
				423	<p>LLVM programs are composed of "Module"s, each of which is a
				424	translation unit of the input programs. Each module consists of
				425	functions, global variables, and symbol table entries. Modules may be
				426	combined together with the LLVM linker, which merges function (and
				427	global variable) definitions, resolves forward declarations, and merges
				428	symbol table entries. Here is an example of the "hello world" module:</p>
				429
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	430	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	431	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	432	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				433	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]	434
				435	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	436	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	437
				438	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	439	define i32 @main() { <i>; i32()* </i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	440	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	441	%cast210 = <a
Chris Lattner	2150cde	2007-06-12 17:01:15 +0000	[diff] [blame]	442	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]	443
				444	<i>; Call puts function to write out the string to stdout...</i>
				445	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	446	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	447	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	448	href="#i_ret">ret</a> i32 0<br>}<br>
				449	</pre>
				450	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<p>This example is made up of a <a href="#globalvars">global variable</a>
				453	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				454	function, and a <a href="#functionstructure">function definition</a>
				455	for "<tt>main</tt>".</p>
				456
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	457	<p>In general, a module is made up of a list of global values,
				458	where both functions and global variables are global values. Global values are
				459	represented by a pointer to a memory location (in this case, a pointer to an
				460	array of char, and a pointer to a function), and have one of the following <a
				461	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	462
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	463	</div>
				464
				465	<!-- ======================================================================= -->
				466	<div class="doc_subsection">
				467	<a name="linkage">Linkage Types</a>
				468	</div>
				469
				470	<div class="doc_text">
				471
				472	<p>
				473	All Global Variables and Functions have one of the following types of linkage:
				474	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	475
				476	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	477
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	478	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	479
				480	<dd>Global values with internal linkage are only directly accessible by
				481	objects in the current module. In particular, linking code into a module with
				482	an internal global value may cause the internal to be renamed as necessary to
				483	avoid collisions. Because the symbol is internal to the module, all
				484	references can be updated. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	485	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	486	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	487
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	488	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	489
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	490	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				491	the same name when linkage occurs. This is typically used to implement
				492	inline functions, templates, or other code which must be generated in each
				493	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				494	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	495	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	496
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	497	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				498
				499	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				500	linkage, except that unreferenced <tt>common</tt> globals may not be
				501	discarded. This is used for globals that may be emitted in multiple
				502	translation units, but that are not guaranteed to be emitted into every
				503	translation unit that uses them. One example of this is tentative
				504	definitions in C, such as "<tt>int X;</tt>" at global scope.
				505	</dd>
				506
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	507	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	508
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				510	that some targets may choose to emit different assembly sequences for them
				511	for target-dependent reasons. This is used for globals that are declared
				512	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	513	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	514
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	515	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	516
				517	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				518	pointer to array type. When two global variables with appending linkage are
				519	linked together, the two global arrays are appended together. This is the
				520	LLVM, typesafe, equivalent of having the system linker append together
				521	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	522	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	523
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	524	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	525	<dd>The semantics of this linkage follow the ELF object file model: the
				526	symbol is weak until linked, if not linked, the symbol becomes null instead
				527	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	528	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	529
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	530	<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]	531
				532	<dd>If none of the above identifiers are used, the global is externally
				533	visible, meaning that it participates in linkage and can be used to resolve
				534	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	535	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	536	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	537
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	538	<p>
				539	The next two types of linkage are targeted for Microsoft Windows platform
				540	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	541	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	542	</p>
				543
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	544	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	545	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				546
				547	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				548	or variable via a global pointer to a pointer that is set up by the DLL
				549	exporting the symbol. On Microsoft Windows targets, the pointer name is
				550	formed by combining <code>_imp__</code> and the function or variable name.
				551	</dd>
				552
				553	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				554
				555	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				556	pointer to a pointer in a DLL, so that it can be referenced with the
				557	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				558	name is formed by combining <code>_imp__</code> and the function or variable
				559	name.
				560	</dd>
				561
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	562	</dl>
				563
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	564	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	565	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				566	variable and was linked with this one, one of the two would be renamed,
				567	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				568	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	569	outside of the current module.</p>
				570	<p>It is illegal for a function <i>declaration</i>
				571	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	572	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	573	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				574	linkages.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	575	</div>
				576
				577	<!-- ======================================================================= -->
				578	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	579	<a name="callingconv">Calling Conventions</a>
				580	</div>
				581
				582	<div class="doc_text">
				583
				584	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				585	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				586	specified for the call. The calling convention of any pair of dynamic
				587	caller/callee must match, or the behavior of the program is undefined. The
				588	following calling conventions are supported by LLVM, and more may be added in
				589	the future:</p>
				590
				591	<dl>
				592	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				593
				594	<dd>This calling convention (the default if no other calling convention is
				595	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	596	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	597	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				601
				602	<dd>This calling convention attempts to make calls as fast as possible
				603	(e.g. by passing things in registers). This calling convention allows the
				604	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]	605	without having to conform to an externally specified ABI (Application Binary
				606	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	607	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				608	supported. This calling convention does not support varargs and requires the
				609	prototype of all callees to exactly match the prototype of the function
				610	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	611	</dd>
				612
				613	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				614
				615	<dd>This calling convention attempts to make code in the caller as efficient
				616	as possible under the assumption that the call is not commonly executed. As
				617	such, these calls often preserve all registers so that the call does not break
				618	any live ranges in the caller side. This calling convention does not support
				619	varargs and requires the prototype of all callees to exactly match the
				620	prototype of the function definition.
				621	</dd>
				622
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	623	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	624
				625	<dd>Any calling convention may be specified by number, allowing
				626	target-specific calling conventions to be used. Target specific calling
				627	conventions start at 64.
				628	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	629	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	630
				631	<p>More calling conventions can be added/defined on an as-needed basis, to
				632	support pascal conventions or any other well-known target-independent
				633	convention.</p>
				634
				635	</div>
				636
				637	<!-- ======================================================================= -->
				638	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	639	<a name="visibility">Visibility Styles</a>
				640	</div>
				641
				642	<div class="doc_text">
				643
				644	<p>
				645	All Global Variables and Functions have one of the following visibility styles:
				646	</p>
				647
				648	<dl>
				649	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				650
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	651	<dd>On targets that use the ELF object file format, default visibility means
				652	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	653	modules and, in shared libraries, means that the declared entity may be
				654	overridden. On Darwin, default visibility means that the declaration is
				655	visible to other modules. Default visibility corresponds to "external
				656	linkage" in the language.
				657	</dd>
				658
				659	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				660
				661	<dd>Two declarations of an object with hidden visibility refer to the same
				662	object if they are in the same shared object. Usually, hidden visibility
				663	indicates that the symbol will not be placed into the dynamic symbol table,
				664	so no other module (executable or shared library) can reference it
				665	directly.
				666	</dd>
				667
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	668	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				669
				670	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				671	the dynamic symbol table, but that references within the defining module will
				672	bind to the local symbol. That is, the symbol cannot be overridden by another
				673	module.
				674	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	675	</dl>
				676
				677	</div>
				678
				679	<!-- ======================================================================= -->
				680	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	681	<a name="globalvars">Global Variables</a>
				682	</div>
				683
				684	<div class="doc_text">
				685
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	686	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	687	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	688	an explicit section to be placed in, and may have an optional explicit alignment
				689	specified. A variable may be defined as "thread_local", which means that it
				690	will not be shared by threads (each thread will have a separated copy of the
				691	variable). A variable may be defined as a global "constant," which indicates
				692	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]	693	optimization, allowing the global data to be placed in the read-only section of
				694	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	695	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]	696
				697	<p>
				698	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				699	constant, even if the final definition of the global is not. This capability
				700	can be used to enable slightly better optimization of the program, but requires
				701	the language definition to guarantee that optimizations based on the
				702	'constantness' are valid for the translation units that do not include the
				703	definition.
				704	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	705
				706	<p>As SSA values, global variables define pointer values that are in
				707	scope (i.e. they dominate) all basic blocks in the program. Global
				708	variables always define a pointer to their "content" type because they
				709	describe a region of memory, and all memory objects in LLVM are
				710	accessed through pointers.</p>
				711
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	712	<p>A global variable may be declared to reside in a target-specifc numbered
				713	address space. For targets that support them, address spaces may affect how
				714	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	715	the variable. The default address space is zero. The address space qualifier
				716	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	717
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	718	<p>LLVM allows an explicit section to be specified for globals. If the target
				719	supports it, it will emit globals to the section specified.</p>
				720
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	721	<p>An explicit alignment may be specified for a global. If not present, or if
				722	the alignment is set to zero, the alignment of the global is set by the target
				723	to whatever it feels convenient. If an explicit alignment is specified, the
				724	global is forced to have at least that much alignment. All alignments must be
				725	a power of 2.</p>
				726
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	727	<p>For example, the following defines a global in a numbered address space with
				728	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	729
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	730	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	731	<pre>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	732	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	733	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	734	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	735
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	736	</div>
				737
				738
				739	<!-- ======================================================================= -->
				740	<div class="doc_subsection">
				741	<a name="functionstructure">Functions</a>
				742	</div>
				743
				744	<div class="doc_text">
				745
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	746	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				747	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	748	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	749	<a href="#callingconv">calling convention</a>, a return type, an optional
				750	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				751	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	752	<a href="#paramattrs">parameter attributes</a>), optional
				753	<a href="#fnattrs">function attributes</a>, an optional section,
				754	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	755	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	756
				757	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				758	optional <a href="#linkage">linkage type</a>, an optional
				759	<a href="#visibility">visibility style</a>, an optional
				760	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	761	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	762	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	dc5cafb	2007-12-10 03:30:21 +0000	[diff] [blame]	763	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	764
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	765	<p>A function definition contains a list of basic blocks, forming the CFG
				766	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	767	the function. Each basic block may optionally start with a label (giving the
				768	basic block a symbol table entry), contains a list of instructions, and ends
				769	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				770	function return).</p>
				771
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	772	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	773	executed on entrance to the function, and it is not allowed to have predecessor
				774	basic blocks (i.e. there can not be any branches to the entry block of a
				775	function). Because the block can have no predecessors, it also cannot have any
				776	<a href="#i_phi">PHI nodes</a>.</p>
				777
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	778	<p>LLVM allows an explicit section to be specified for functions. If the target
				779	supports it, it will emit functions to the section specified.</p>
				780
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	781	<p>An explicit alignment may be specified for a function. If not present, or if
				782	the alignment is set to zero, the alignment of the function is set by the target
				783	to whatever it feels convenient. If an explicit alignment is specified, the
				784	function is forced to have at least that much alignment. All alignments must be
				785	a power of 2.</p>
				786
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	787	</div>
				788
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	789
				790	<!-- ======================================================================= -->
				791	<div class="doc_subsection">
				792	<a name="aliasstructure">Aliases</a>
				793	</div>
				794	<div class="doc_text">
				795	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	25b2e82	2008-03-22 08:36:14 +0000	[diff] [blame]	796	function, global variable, another alias or bitcast of global value). Aliases
				797	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	798	optional <a href="#visibility">visibility style</a>.</p>
				799
				800	<h5>Syntax:</h5>
				801
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	802	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	803	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	804	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	805	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	806	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	807
				808	</div>
				809
				810
				811
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	812	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	813	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				814	<div class="doc_text">
				815	<p>The return type and each parameter of a function type may have a set of
				816	<i>parameter attributes</i> associated with them. Parameter attributes are
				817	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	818	a function. Parameter attributes are considered to be part of the function,
				819	not of the function type, so functions with different parameter attributes
				820	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	821
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	822	<p>Parameter attributes are simple keywords that follow the type specified. If
				823	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	824	example:</p>
				825
				826	<div class="doc_code">
				827	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	828	declare i32 @printf(i8* noalias , ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	829	declare i32 @atoi(i8 zeroext)
				830	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	831	</pre>
				832	</div>
				833
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	834	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				835	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	836
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	837	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	838	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	840	<dd>This indicates to the code generator that the parameter or return value
				841	should be zero-extended to a 32-bit value by the caller (for a parameter)
				842	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	843
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	844	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	845	<dd>This indicates to the code generator that the parameter or return value
				846	should be sign-extended to a 32-bit value by the caller (for a parameter)
				847	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	848
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	849	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	850	<dd>This indicates that this parameter or return value should be treated
				851	in a special target-dependent fashion during while emitting code for a
				852	function call or return (usually, by putting it in a register as opposed
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	853	to memory, though some targets use it to distinguish between two different
				854	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	855
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	856	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	857	<dd>This indicates that the pointer parameter should really be passed by
				858	value to the function. The attribute implies that a hidden copy of the
				859	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	860	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	861	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	862	value, but is also valid on pointers to scalars. The copy is considered to
				863	belong to the caller not the callee (for example,
				864	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	865	<tt>byval</tt> parameters). This is not a valid attribute for return
				866	values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	867
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	868	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	869	<dd>This indicates that the pointer parameter specifies the address of a
				870	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]	871	This pointer must be guaranteed by the caller to be valid: loads and stores
				872	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^]	873	be applied to the first parameter. This is not a valid attribute for
				874	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	875
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	876	<dt><tt>noalias</tt></dt>
Owen Anderson	6110128	2008-02-18 04:09:01 +0000	[diff] [blame]	877	<dd>This indicates that the parameter does not alias any global or any other
				878	parameter. The caller is responsible for ensuring that this is the case,
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	879	usually by placing the value in a stack allocation. This is not a valid
				880	attribute for return values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	881
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	882	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	883	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	884	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				885	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	886	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	887
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	888	</div>
				889
				890	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	891	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	892	<a name="gc">Garbage Collector Names</a>
				893	</div>
				894
				895	<div class="doc_text">
				896	<p>Each function may specify a garbage collector name, which is simply a
				897	string.</p>
				898
				899	<div class="doc_code"><pre
				900	>define void @f() gc "name" { ...</pre></div>
				901
				902	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				903	collector which will cause the compiler to alter its output in order to support
				904	the named garbage collection algorithm.</p>
				905	</div>
				906
				907	<!-- ======================================================================= -->
				908	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	909	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	910	</div>
				911
				912	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	913
				914	<p>Function attributes are set to communicate additional information about
				915	a function. Function attributes are considered to be part of the function,
				916	not of the function type, so functions with different parameter attributes
				917	can have the same function type.</p>
				918
				919	<p>Function attributes are simple keywords that follow the type specified. If
				920	multiple attributes are needed, they are space separated. For
				921	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	922
				923	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	924	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	925	define void @f() noinline { ... }
				926	define void @f() alwaysinline { ... }
				927	define void @f() alwaysinline optsize { ... }
				928	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	929	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	930	</div>
				931
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	932	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	933	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	934	<dd>This attribute indicates that the inliner should attempt to inline this
				935	function into callers whenever possible, ignoring any active inlining size
				936	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	937
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	938	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	939	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	940	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	941	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	942
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	943	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	944	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	945	make choices that keep the code size of this function low, and otherwise do
				946	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	947
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	948	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	949	<dd>This function attribute indicates that the function never returns normally.
				950	This produces undefined behavior at runtime if the function ever does
				951	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	952
				953	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	954	<dd>This function attribute indicates that the function never returns with an
				955	unwind or exceptional control flow. If the function does unwind, its runtime
				956	behavior is undefined.</dd>
				957
				958	<dt><tt>readnone</tt></dt>
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	959	<dd>This attribute indicates that the function computes its result (or the
				960	exception it throws) based strictly on its arguments, without dereferencing any
				961	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				962	registers, etc) visible to caller functions. It does not write through any
				963	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				964	never changes any state visible to callers.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	965
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	966	<dt><tt><a name="readonly">readonly</a></tt></dt>
				967	<dd>This attribute indicates that the function does not write through any
				968	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				969	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				970	caller functions. It may dereference pointer arguments and read state that may
				971	be set in the caller. A readonly function always returns the same value (or
				972	throws the same exception) when called with the same set of arguments and global
				973	state.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	974	</dl>
				975
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	976	</div>
				977
				978	<!-- ======================================================================= -->
				979	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	980	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	981	</div>
				982
				983	<div class="doc_text">
				984	<p>
				985	Modules may contain "module-level inline asm" blocks, which corresponds to the
				986	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				987	LLVM and treated as a single unit, but may be separated in the .ll file if
				988	desired. The syntax is very simple:
				989	</p>
				990
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	991	<div class="doc_code">
				992	<pre>
				993	module asm "inline asm code goes here"
				994	module asm "more can go here"
				995	</pre>
				996	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	997
				998	<p>The strings can contain any character by escaping non-printable characters.
				999	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1000	for the number.
				1001	</p>
				1002
				1003	<p>
				1004	The inline asm code is simply printed to the machine code .s file when
				1005	assembly code is generated.
				1006	</p>
				1007	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1008
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1009	<!-- ======================================================================= -->
				1010	<div class="doc_subsection">
				1011	<a name="datalayout">Data Layout</a>
				1012	</div>
				1013
				1014	<div class="doc_text">
				1015	<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]	1016	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1017	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1018	<p>The <i>layout specification</i> consists of a list of specifications
				1019	separated by the minus sign character ('-'). Each specification starts with a
				1020	letter and may include other information after the letter to define some
				1021	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1022	<dl>
				1023	<dt><tt>E</tt></dt>
				1024	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1025	bits with the most significance have the lowest address location.</dd>
				1026	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1027	<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]	1028	the bits with the least significance have the lowest address location.</dd>
				1029	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1030	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1031	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1032	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1033	too.</dd>
				1034	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1035	<dd>This specifies the alignment for an integer type of a given bit
				1036	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1037	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1038	<dd>This specifies the alignment for a vector type of a given bit
				1039	<i>size</i>.</dd>
				1040	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1041	<dd>This specifies the alignment for a floating point type of a given bit
				1042	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1043	(double).</dd>
				1044	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1045	<dd>This specifies the alignment for an aggregate type of a given bit
				1046	<i>size</i>.</dd>
				1047	</dl>
				1048	<p>When constructing the data layout for a given target, LLVM starts with a
				1049	default set of specifications which are then (possibly) overriden by the
				1050	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1051	are given in this list:</p>
				1052	<ul>
				1053	<li><tt>E</tt> - big endian</li>
				1054	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1055	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1056	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1057	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1058	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1059	<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]	1060	alignment of 64-bits</li>
				1061	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1062	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1063	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1064	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1065	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1066	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1067	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1068	following rules:
				1069	<ol>
				1070	<li>If the type sought is an exact match for one of the specifications, that
				1071	specification is used.</li>
				1072	<li>If no match is found, and the type sought is an integer type, then the
				1073	smallest integer type that is larger than the bitwidth of the sought type is
				1074	used. If none of the specifications are larger than the bitwidth then the the
				1075	largest integer type is used. For example, given the default specifications
				1076	above, the i7 type will use the alignment of i8 (next largest) while both
				1077	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1078	<li>If no match is found, and the type sought is a vector type, then the
				1079	largest vector type that is smaller than the sought vector type will be used
				1080	as a fall back. This happens because <128 x double> can be implemented in
				1081	terms of 64 <2 x double>, for example.</li>
				1082	</ol>
				1083	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1084
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1085	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1086	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1087	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1088
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1089	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1090
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1091	<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]	1092	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1093	optimizations to be performed on the intermediate representation directly,
				1094	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1095	extra analyses on the side before the transformation. A strong type
				1096	system makes it easier to read the generated code and enables novel
				1097	analyses and transformations that are not feasible to perform on normal
				1098	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1099
				1100	</div>
				1101
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1102	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1103	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1104	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1105	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1106	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1107	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1108
				1109	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1110	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1111	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1112	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1113	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1114	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1115	</tr>
				1116	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1117	<td><a href="#t_floating">floating point</a></td>
				1118	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1119	</tr>
				1120	<tr>
				1121	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1122	<td><a href="#t_integer">integer</a>,
				1123	<a href="#t_floating">floating point</a>,
				1124	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1125	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1126	<a href="#t_struct">structure</a>,
				1127	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1128	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1129	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1130	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1131	<tr>
				1132	<td><a href="#t_primitive">primitive</a></td>
				1133	<td><a href="#t_label">label</a>,
				1134	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1135	<a href="#t_floating">floating point</a>.</td>
				1136	</tr>
				1137	<tr>
				1138	<td><a href="#t_derived">derived</a></td>
				1139	<td><a href="#t_integer">integer</a>,
				1140	<a href="#t_array">array</a>,
				1141	<a href="#t_function">function</a>,
				1142	<a href="#t_pointer">pointer</a>,
				1143	<a href="#t_struct">structure</a>,
				1144	<a href="#t_pstruct">packed structure</a>,
				1145	<a href="#t_vector">vector</a>,
				1146	<a href="#t_opaque">opaque</a>.
				1147	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1148	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1149	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1150
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1151	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1152	most important. Values of these types are the only ones which can be
				1153	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1154	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1155	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1156
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1157	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1158	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1159
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1160	<div class="doc_text">
				1161	<p>The primitive types are the fundamental building blocks of the LLVM
				1162	system.</p>
				1163
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1164	</div>
				1165
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1166	<!-- _______________________________________________________________________ -->
				1167	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1168
				1169	<div class="doc_text">
				1170	<table>
				1171	<tbody>
				1172	<tr><th>Type</th><th>Description</th></tr>
				1173	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1174	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1175	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1176	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1177	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1178	</tbody>
				1179	</table>
				1180	</div>
				1181
				1182	<!-- _______________________________________________________________________ -->
				1183	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1184
				1185	<div class="doc_text">
				1186	<h5>Overview:</h5>
				1187	<p>The void type does not represent any value and has no size.</p>
				1188
				1189	<h5>Syntax:</h5>
				1190
				1191	<pre>
				1192	void
				1193	</pre>
				1194	</div>
				1195
				1196	<!-- _______________________________________________________________________ -->
				1197	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1198
				1199	<div class="doc_text">
				1200	<h5>Overview:</h5>
				1201	<p>The label type represents code labels.</p>
				1202
				1203	<h5>Syntax:</h5>
				1204
				1205	<pre>
				1206	label
				1207	</pre>
				1208	</div>
				1209
				1210
				1211	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1212	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1213
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1214	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1215
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1216	<p>The real power in LLVM comes from the derived types in the system.
				1217	This is what allows a programmer to represent arrays, functions,
				1218	pointers, and other useful types. Note that these derived types may be
				1219	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]	1220
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1221	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1222
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1223	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1224	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1225
				1226	<div class="doc_text">
				1227
				1228	<h5>Overview:</h5>
				1229	<p>The integer type is a very simple derived type that simply specifies an
				1230	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1231	2^23-1 (about 8 million) can be specified.</p>
				1232
				1233	<h5>Syntax:</h5>
				1234
				1235	<pre>
				1236	iN
				1237	</pre>
				1238
				1239	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1240	value.</p>
				1241
				1242	<h5>Examples:</h5>
				1243	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1244	<tbody>
				1245	<tr>
				1246	<td><tt>i1</tt></td>
				1247	<td>a single-bit integer.</td>
				1248	</tr><tr>
				1249	<td><tt>i32</tt></td>
				1250	<td>a 32-bit integer.</td>
				1251	</tr><tr>
				1252	<td><tt>i1942652</tt></td>
				1253	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1254	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1255	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1256	</table>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1257	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1258
				1259	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1260	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1261
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1262	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1263
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1264	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1265
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1266	<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]	1267	sequentially in memory. The array type requires a size (number of
				1268	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1269
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1270	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1271
				1272	<pre>
				1273	[<# elements> x <elementtype>]
				1274	</pre>
				1275
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1276	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1277	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1278
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1279	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1280	<table class="layout">
				1281	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1282	<td class="left"><tt>[40 x i32]</tt></td>
				1283	<td class="left">Array of 40 32-bit integer values.</td>
				1284	</tr>
				1285	<tr class="layout">
				1286	<td class="left"><tt>[41 x i32]</tt></td>
				1287	<td class="left">Array of 41 32-bit integer values.</td>
				1288	</tr>
				1289	<tr class="layout">
				1290	<td class="left"><tt>[4 x i8]</tt></td>
				1291	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1292	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1293	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1294	<p>Here are some examples of multidimensional arrays:</p>
				1295	<table class="layout">
				1296	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1297	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1298	<td class="left">3x4 array of 32-bit integer values.</td>
				1299	</tr>
				1300	<tr class="layout">
				1301	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1302	<td class="left">12x10 array of single precision floating point values.</td>
				1303	</tr>
				1304	<tr class="layout">
				1305	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1306	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1307	</tr>
				1308	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1309
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1310	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1311	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]	1312	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1313	As a special case, however, zero length arrays are recognized to be variable
				1314	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1315	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1316
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1317	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1318
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1319	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1320	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1321	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1322
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1323	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1324
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1325	<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]	1326	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]	1327	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]	1328	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]	1329	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1330
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1331	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1332
				1333	<pre>
				1334	<returntype list> (<parameter list>)
				1335	</pre>
				1336
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1337	<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]	1338	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1339	which indicates that the function takes a variable number of arguments.
				1340	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1341	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1342	'<tt><returntype list></tt>' is a comma-separated list of
				1343	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1344
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1345	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1346	<table class="layout">
				1347	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1348	<td class="left"><tt>i32 (i32)</tt></td>
				1349	<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]	1350	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1351	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1352	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1353	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1354	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1355	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1356	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1357	<tt>float</tt>.
				1358	</td>
				1359	</tr><tr class="layout">
				1360	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1361	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1362	<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]	1363	which returns an integer. This is the signature for <tt>printf</tt> in
				1364	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1365	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1366	</tr><tr class="layout">
				1367	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	8dec6c2	2008-03-24 18:10:52 +0000	[diff] [blame]	1368	<td class="left">A function taking an <tt>i32></tt>, returning two
				1369	<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]	1370	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1371	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1372	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1373
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1374	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1375	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1376	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1377	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1378	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1379	<p>The structure type is used to represent a collection of data members
				1380	together in memory. The packing of the field types is defined to match
				1381	the ABI of the underlying processor. The elements of a structure may
				1382	be any type that has a size.</p>
				1383	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1384	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1385	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1386	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1387	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1388	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1389	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1390	<table class="layout">
				1391	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1392	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1393	<td class="left">A triple of three <tt>i32</tt> values</td>
				1394	</tr><tr class="layout">
				1395	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1396	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1397	second element is a <a href="#t_pointer">pointer</a> to a
				1398	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1399	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1400	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1401	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1402	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1403
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1404	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1405	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1406	</div>
				1407	<div class="doc_text">
				1408	<h5>Overview:</h5>
				1409	<p>The packed structure type is used to represent a collection of data members
				1410	together in memory. There is no padding between fields. Further, the alignment
				1411	of a packed structure is 1 byte. The elements of a packed structure may
				1412	be any type that has a size.</p>
				1413	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1414	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1415	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1416	instruction.</p>
				1417	<h5>Syntax:</h5>
				1418	<pre> < { <type list> } > <br></pre>
				1419	<h5>Examples:</h5>
				1420	<table class="layout">
				1421	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1422	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1423	<td class="left">A triple of three <tt>i32</tt> values</td>
				1424	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1425	<td class="left">
				1426	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1427	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1428	second element is a <a href="#t_pointer">pointer</a> to a
				1429	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1430	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1431	</tr>
				1432	</table>
				1433	</div>
				1434
				1435	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1436	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1437	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1438	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1439	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1440	reference to another object, which must live in memory. Pointer types may have
				1441	an optional address space attribute defining the target-specific numbered
				1442	address space where the pointed-to object resides. The default address space is
				1443	zero.</p>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1444	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1445	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1446	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1447	<table class="layout">
				1448	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1449	<td class="left"><tt>[4x i32]*</tt></td>
				1450	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1451	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1452	</tr>
				1453	<tr class="layout">
				1454	<td class="left"><tt>i32 (i32 ) </tt></td>
				1455	<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]	1456	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]	1457	<tt>i32</tt>.</td>
				1458	</tr>
				1459	<tr class="layout">
				1460	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1461	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1462	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1463	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1464	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1465	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1466
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1467	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1468	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1469	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1470
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1471	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1472
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1473	<p>A vector type is a simple derived type that represents a vector
				1474	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1475	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1476	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1477	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1478	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1479	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1480
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1481	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1482
				1483	<pre>
				1484	< <# elements> x <elementtype> >
				1485	</pre>
				1486
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1487	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1488	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1489
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1490	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1491
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1492	<table class="layout">
				1493	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1494	<td class="left"><tt><4 x i32></tt></td>
				1495	<td class="left">Vector of 4 32-bit integer values.</td>
				1496	</tr>
				1497	<tr class="layout">
				1498	<td class="left"><tt><8 x float></tt></td>
				1499	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1500	</tr>
				1501	<tr class="layout">
				1502	<td class="left"><tt><2 x i64></tt></td>
				1503	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1504	</tr>
				1505	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1506	</div>
				1507
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1508	<!-- _______________________________________________________________________ -->
				1509	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1510	<div class="doc_text">
				1511
				1512	<h5>Overview:</h5>
				1513
				1514	<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]	1515	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]	1516	In LLVM, opaque types can eventually be resolved to any type (not just a
				1517	structure type).</p>
				1518
				1519	<h5>Syntax:</h5>
				1520
				1521	<pre>
				1522	opaque
				1523	</pre>
				1524
				1525	<h5>Examples:</h5>
				1526
				1527	<table class="layout">
				1528	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1529	<td class="left"><tt>opaque</tt></td>
				1530	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1531	</tr>
				1532	</table>
				1533	</div>
				1534
				1535
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1536	<!-- *********************************************************************** -->
				1537	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1538	<!-- *********************************************************************** -->
				1539
				1540	<div class="doc_text">
				1541
				1542	<p>LLVM has several different basic types of constants. This section describes
				1543	them all and their syntax.</p>
				1544
				1545	</div>
				1546
				1547	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1548	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1549
				1550	<div class="doc_text">
				1551
				1552	<dl>
				1553	<dt><b>Boolean constants</b></dt>
				1554
				1555	<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]	1556	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1557	</dd>
				1558
				1559	<dt><b>Integer constants</b></dt>
				1560
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1561	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1562	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1563	integer types.
				1564	</dd>
				1565
				1566	<dt><b>Floating point constants</b></dt>
				1567
				1568	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1569	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1570	notation (see below). The assembler requires the exact decimal value of
				1571	a floating-point constant. For example, the assembler accepts 1.25 but
				1572	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1573	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]	1574
				1575	<dt><b>Null pointer constants</b></dt>
				1576
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1577	<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]	1578	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1579
				1580	</dl>
				1581
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1582	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1583	of floating point constants. For example, the form '<tt>double
				1584	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1585	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]	1586	(and the only time that they are generated by the disassembler) is when a
				1587	floating point constant must be emitted but it cannot be represented as a
				1588	decimal floating point number. For example, NaN's, infinities, and other
				1589	special values are represented in their IEEE hexadecimal format so that
				1590	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1591
				1592	</div>
				1593
				1594	<!-- ======================================================================= -->
				1595	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1596	</div>
				1597
				1598	<div class="doc_text">
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1599	<p>Aggregate constants arise from aggregation of simple constants
				1600	and smaller aggregate constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1601
				1602	<dl>
				1603	<dt><b>Structure constants</b></dt>
				1604
				1605	<dd>Structure constants are represented with notation similar to structure
				1606	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1607	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1608	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]	1609	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]	1610	types of elements must match those specified by the type.
				1611	</dd>
				1612
				1613	<dt><b>Array constants</b></dt>
				1614
				1615	<dd>Array constants are represented with notation similar to array type
				1616	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1617	(<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]	1618	constants must have <a href="#t_array">array type</a>, and the number and
				1619	types of elements must match those specified by the type.
				1620	</dd>
				1621
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1622	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1623
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1624	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1625	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1626	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1627	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1628	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]	1629	match those specified by the type.
				1630	</dd>
				1631
				1632	<dt><b>Zero initialization</b></dt>
				1633
				1634	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1635	value to zero of <em>any</em> type, including scalar and aggregate types.
				1636	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]	1637	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1638	initializers.
				1639	</dd>
				1640	</dl>
				1641
				1642	</div>
				1643
				1644	<!-- ======================================================================= -->
				1645	<div class="doc_subsection">
				1646	<a name="globalconstants">Global Variable and Function Addresses</a>
				1647	</div>
				1648
				1649	<div class="doc_text">
				1650
				1651	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1652	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1653	constants. These constants are explicitly referenced when the <a
				1654	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]	1655	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1656	file:</p>
				1657
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1658	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1659	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1660	@X = global i32 17
				1661	@Y = global i32 42
				1662	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1663	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1664	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1665
				1666	</div>
				1667
				1668	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1669	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1670	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1671	<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]	1672	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]	1673	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1674
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1675	<p>Undefined values indicate to the compiler that the program is well defined
				1676	no matter what value is used, giving the compiler more freedom to optimize.
				1677	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1678	</div>
				1679
				1680	<!-- ======================================================================= -->
				1681	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1682	</div>
				1683
				1684	<div class="doc_text">
				1685
				1686	<p>Constant expressions are used to allow expressions involving other constants
				1687	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1688	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]	1689	that does not have side effects (e.g. load and call are not supported). The
				1690	following is the syntax for constant expressions:</p>
				1691
				1692	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1693	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1694	<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]	1695	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1696
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1697	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1698	<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]	1699	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]	1700
				1701	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1702	<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]	1703	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]	1704
				1705	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1706	<dd>Truncate a floating point constant to another floating point type. The
				1707	size of CST must be larger than the size of TYPE. Both types must be
				1708	floating point.</dd>
				1709
				1710	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1711	<dd>Floating point extend a constant to another type. The size of CST must be
				1712	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1713
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1714	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1715	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1716	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1717	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1718	of the same number of elements. If the value won't fit in the integer type,
				1719	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1720
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1721	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1722	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1723	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1724	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1725	of the same number of elements. If the value won't fit in the integer type,
				1726	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1727
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1728	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1729	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1730	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1731	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1732	of the same number of elements. If the value won't fit in the floating point
				1733	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1734
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1735	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1736	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1737	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1738	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1739	of the same number of elements. If the value won't fit in the floating point
				1740	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1741
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1742	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1743	<dd>Convert a pointer typed constant to the corresponding integer constant
				1744	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1745	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1746
				1747	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1748	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1749	pointer type. CST must be of integer type. The CST value is zero extended,
				1750	truncated, or unchanged to make it fit in a pointer size. This one is
				1751	<i>really</i> dangerous!</dd>
				1752
				1753	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1754	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1755	identical (same number of bits). The conversion is done as if the CST value
				1756	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1757	with this operator, just the type. This can be used for conversion of
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1758	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	1759	pointers it is only valid to cast to another pointer type. It is not valid
				1760	to bitcast to or from an aggregate type.
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1761	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1762
				1763	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1764
				1765	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1766	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1767	instruction, the index list may have zero or more indexes, which are required
				1768	to make sense for the type of "CSTPTR".</dd>
				1769
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1770	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1771
				1772	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1773	constants.</dd>
				1774
				1775	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1776	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1777
				1778	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1779	<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]	1780
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	1781	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1782	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1783
				1784	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1785	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1786
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1787	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1788
				1789	<dd>Perform the <a href="#i_extractelement">extractelement
				1790	operation</a> on constants.
				1791
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1792	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1793
				1794	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1795	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	1796
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1797
				1798	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1799
				1800	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1801	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	1802
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1803	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1804
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1805	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1806	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]	1807	binary</a> operations. The constraints on operands are the same as those for
				1808	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1809	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1810	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1811	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	1812
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1813	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1814	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1815	<!-- *********************************************************************** -->
				1816
				1817	<!-- ======================================================================= -->
				1818	<div class="doc_subsection">
				1819	<a name="inlineasm">Inline Assembler Expressions</a>
				1820	</div>
				1821
				1822	<div class="doc_text">
				1823
				1824	<p>
				1825	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1826	Module-Level Inline Assembly</a>) through the use of a special value. This
				1827	value represents the inline assembler as a string (containing the instructions
				1828	to emit), a list of operand constraints (stored as a string), and a flag that
				1829	indicates whether or not the inline asm expression has side effects. An example
				1830	inline assembler expression is:
				1831	</p>
				1832
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1833	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1834	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1835	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1836	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1837	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1838
				1839	<p>
				1840	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1841	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1842	</p>
				1843
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1844	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1845	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1846	%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]	1847	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1848	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1849
				1850	<p>
				1851	Inline asms with side effects not visible in the constraint list must be marked
				1852	as having side effects. This is done through the use of the
				1853	'<tt>sideeffect</tt>' keyword, like so:
				1854	</p>
				1855
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1856	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1857	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1858	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1859	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1860	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1861
				1862	<p>TODO: The format of the asm and constraints string still need to be
				1863	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]	1864	need to be documented). This is probably best done by reference to another
				1865	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	1866	</p>
				1867
				1868	</div>
				1869
				1870	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1871	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1872	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1873
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1874	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1875
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1876	<p>The LLVM instruction set consists of several different
				1877	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1878	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1879	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1880	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1881	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1882
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1883	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1884
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1885	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1886	<div class="doc_subsection"> <a name="terminators">Terminator
				1887	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1888
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1889	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1890
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1891	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1892	basic block in a program ends with a "Terminator" instruction, which
				1893	indicates which block should be executed after the current block is
				1894	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1895	value: they produce control flow, not values (the one exception being
				1896	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1897	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1898	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1899	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	1900	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1901	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1902	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1903
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1904	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1905
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1906	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1907	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1908	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1909	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1910	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1911	<pre>
				1912	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]	1913	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1914	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1915
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1916	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1917
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1918	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				1919	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	1920	<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]	1921	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]	1922	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1923
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1924	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1925
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1926	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				1927	the return value. The type of the return value must be a
				1928	'<a href="#t_firstclass">first class</a>' type.</p>
				1929
				1930	<p>A function is not <a href="#wellformed">well formed</a> if
				1931	it it has a non-void return type and contains a '<tt>ret</tt>'
				1932	instruction with no return value or a return value with a type that
				1933	does not match its type, or if it has a void return type and contains
				1934	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1935
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1936	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1937
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1938	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1939	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]	1940	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1941	the instruction after the call. If the caller was an "<a
				1942	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1943	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1944	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1945	return value.
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1946
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1947	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1948
				1949	<pre>
				1950	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1951	ret void <i>; Return from a void function</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	1952	ret { i32, i8 } { i32 4, i8 2 } <i>; Return an aggregate of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1953	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1954	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1955	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1956	<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]	1957	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1958	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1959	<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]	1960	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1961	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1962	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1963	transfer to a different basic block in the current function. There are
				1964	two forms of this instruction, corresponding to a conditional branch
				1965	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1967	<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]	1968	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1969	unconditional form of the '<tt>br</tt>' instruction takes a single
				1970	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1971	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1972	<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]	1973	argument is evaluated. If the value is <tt>true</tt>, control flows
				1974	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1975	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1976	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1977	<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]	1978	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]	1979	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1980	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1981	<div class="doc_subsubsection">
				1982	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1983	</div>
				1984
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1985	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1986	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1987
				1988	<pre>
				1989	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1990	</pre>
				1991
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1992	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1993
				1994	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1995	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1996	instruction, allowing a branch to occur to one of many possible
				1997	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	1998
				1999
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2000	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2001
				2002	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2003	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2004	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2005	table is not allowed to contain duplicate constant entries.</p>
				2006
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2007	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2008
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2009	<p>The <tt>switch</tt> instruction specifies a table of values and
				2010	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2011	table is searched for the given value. If the value is found, control flow is
				2012	transfered to the corresponding destination; otherwise, control flow is
				2013	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2014
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2015	<h5>Implementation:</h5>
				2016
				2017	<p>Depending on properties of the target machine and the particular
				2018	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2019	ways. For example, it could be generated as a series of chained conditional
				2020	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2021
				2022	<h5>Example:</h5>
				2023
				2024	<pre>
				2025	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2026	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2027	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2028
				2029	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2030	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2031
				2032	<i>; Implement a jump table:</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2033	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2034	i32 1, label %onone
				2035	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2036	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2037	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2038
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2039	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2040	<div class="doc_subsubsection">
				2041	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2042	</div>
				2043
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2044	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2045
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2046	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2047
				2048	<pre>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	2049	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#pa\
				2050	ramattrs">RetAttrs</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2051	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2052	</pre>
				2053
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2054	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2055
				2056	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2057	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2058	'<tt>normal</tt>' label or the
				2059	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2060	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2061	"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]	2062	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2063	continued at the dynamically nearest "exception" label.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2064
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2065	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2066
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2067	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2068
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2069	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2070	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2071	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2072	convention</a> the call should use. If none is specified, the call defaults
				2073	to using C calling conventions.
				2074	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	2075
				2076	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2077	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2078	and '<tt>inreg</tt>' attributes are valid here.</li>
				2079
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2080	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2081	function value being invoked. In most cases, this is a direct function
				2082	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2083	an arbitrary pointer to function value.
				2084	</li>
				2085
				2086	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2087	function to be invoked. </li>
				2088
				2089	<li>'<tt>function args</tt>': argument list whose types match the function
				2090	signature argument types. If the function signature indicates the function
				2091	accepts a variable number of arguments, the extra arguments can be
				2092	specified. </li>
				2093
				2094	<li>'<tt>normal label</tt>': the label reached when the called function
				2095	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2096
				2097	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2098	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2099
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	2100	<li>The optional <a href="fnattrs">function attributes</a> list. Only
				2101	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2102	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2104
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2105	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2106
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2107	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2108	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2109	difference is that it establishes an association with a label, which is used by
				2110	the runtime library to unwind the stack.</p>
				2111
				2112	<p>This instruction is used in languages with destructors to ensure that proper
				2113	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2114	exception. Additionally, this is important for implementation of
				2115	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2116
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2117	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2118	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2119	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2120	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2121	%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]	2122	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2123	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2124	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2125
				2126
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2127	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2128
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2129	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2130	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2131
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2132	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2133
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2134	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2135	<pre>
				2136	unwind
				2137	</pre>
				2138
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2139	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2140
				2141	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2142	at the first callee in the dynamic call stack which used an <a
				2143	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2144	primarily used to implement exception handling.</p>
				2145
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2146	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2147
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2148	<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]	2149	immediately halt. The dynamic call stack is then searched for the first <a
				2150	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2151	execution continues at the "exceptional" destination block specified by the
				2152	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2153	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2154	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2155
				2156	<!-- _______________________________________________________________________ -->
				2157
				2158	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2159	Instruction</a> </div>
				2160
				2161	<div class="doc_text">
				2162
				2163	<h5>Syntax:</h5>
				2164	<pre>
				2165	unreachable
				2166	</pre>
				2167
				2168	<h5>Overview:</h5>
				2169
				2170	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2171	instruction is used to inform the optimizer that a particular portion of the
				2172	code is not reachable. This can be used to indicate that the code after a
				2173	no-return function cannot be reached, and other facts.</p>
				2174
				2175	<h5>Semantics:</h5>
				2176
				2177	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2178	</div>
				2179
				2180
				2181
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2183	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2184	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2185	<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]	2186	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]	2187	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2188	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]	2189	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2190	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2191	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2192	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2193	<div class="doc_subsubsection">
				2194	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2195	</div>
				2196
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2197	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2198
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2199	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2200
				2201	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2202	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2204
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2206
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2207	<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]	2208
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2209	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2210
				2211	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2212	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2213	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2214	types.</p>
				2215
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2216	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2217
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2218	<p>The value produced is the integer or floating point sum of the two
				2219	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2220
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2221	<p>If an integer sum has unsigned overflow, the result returned is the
				2222	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2223	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2224
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2225	<p>Because LLVM integers use a two's complement representation, this
				2226	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2227
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2229
				2230	<pre>
				2231	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2232	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2233	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2235	<div class="doc_subsubsection">
				2236	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2237	</div>
				2238
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2239	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2240
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2241	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2242
				2243	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2244	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2245	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2246
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2247	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2248
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2249	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2250	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2251
				2252	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2253	'<tt>neg</tt>' instruction present in most other intermediate
				2254	representations.</p>
				2255
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2257
				2258	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2259	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2260	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2261	types.</p>
				2262
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2264
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2265	<p>The value produced is the integer or floating point difference of
				2266	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2267
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2268	<p>If an integer difference has unsigned overflow, the result returned is the
				2269	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2270	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2271
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2272	<p>Because LLVM integers use a two's complement representation, this
				2273	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2274
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2276	<pre>
				2277	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2278	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2279	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2280	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2281
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2283	<div class="doc_subsubsection">
				2284	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2285	</div>
				2286
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2287	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2288
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2289	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2290	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2292	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2293	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2294	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2295
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2296	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2297
				2298	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2299	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2300	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2301	types.</p>
				2302
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2304
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2305	<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]	2306	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2307
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2308	<p>If the result of an integer multiplication has unsigned overflow,
				2309	the result returned is the mathematical result modulo
				2310	2<sup>n</sup>, where n is the bit width of the result.</p>
				2311	<p>Because LLVM integers use a two's complement representation, and the
				2312	result is the same width as the operands, this instruction returns the
				2313	correct result for both signed and unsigned integers. If a full product
				2314	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2315	should be sign-extended or zero-extended as appropriate to the
				2316	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2317	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2318	<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]	2319	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2320	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2321
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2322	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2323	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2324	</a></div>
				2325	<div class="doc_text">
				2326	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2327	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2328	</pre>
				2329	<h5>Overview:</h5>
				2330	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2331	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2332
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2333	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2334
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2335	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2336	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2337	values. Both arguments must have identical types.</p>
				2338
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2339	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2340
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2341	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2342	<p>Note that unsigned integer division and signed integer division are distinct
				2343	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2344	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2345	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2346	<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]	2347	</pre>
				2348	</div>
				2349	<!-- _______________________________________________________________________ -->
				2350	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2351	</a> </div>
				2352	<div class="doc_text">
				2353	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2354	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2355	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2356	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2357
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2358	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2359
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2360	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2361	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2362
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2363	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2364
				2365	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2366	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2367	values. Both arguments must have identical types.</p>
				2368
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2369	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2370	<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]	2371	<p>Note that signed integer division and unsigned integer division are distinct
				2372	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2373	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2374	undefined behavior; this is a rare case, but can occur, for example,
				2375	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2376	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2377	<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]	2378	</pre>
				2379	</div>
				2380	<!-- _______________________________________________________________________ -->
				2381	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2382	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2383	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2384	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2385	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2386	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2387	</pre>
				2388	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2389
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2390	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2391	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2392
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2393	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2394
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2395	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2396	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2397	of floating point values. Both arguments must have identical types.</p>
				2398
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2399	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2400
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2401	<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]	2402
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2403	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2404
				2405	<pre>
				2406	<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]	2407	</pre>
				2408	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2409
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2410	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2411	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2412	</div>
				2413	<div class="doc_text">
				2414	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2415	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2416	</pre>
				2417	<h5>Overview:</h5>
				2418	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2419	unsigned division of its two arguments.</p>
				2420	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2421	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2422	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2423	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2424	<h5>Semantics:</h5>
				2425	<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]	2426	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2427	<p>Note that unsigned integer remainder and signed integer remainder are
				2428	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2429	<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]	2430	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2431	<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]	2432	</pre>
				2433
				2434	</div>
				2435	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2436	<div class="doc_subsubsection">
				2437	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2438	</div>
				2439
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2440	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2441
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2442	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2443
				2444	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2445	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2446	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2447
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2448	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2449
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2450	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2451	signed division of its two operands. This instruction can also take
				2452	<a href="#t_vector">vector</a> versions of the values in which case
				2453	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2454
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2455	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2456
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2457	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2458	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2459	values. Both arguments must have identical types.</p>
				2460
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2461	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2462
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2463	<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]	2464	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2465	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]	2466	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2467	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]	2468	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]	2469	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2470	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2471	<p>Note that signed integer remainder and unsigned integer remainder are
				2472	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2473	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2474	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2475	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2476	(The remainder doesn't actually overflow, but this rule lets srem be
				2477	implemented using instructions that return both the result of the division
				2478	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2479	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2480	<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]	2481	</pre>
				2482
				2483	</div>
				2484	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2485	<div class="doc_subsubsection">
				2486	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2487
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2488	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2489
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2490	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2491	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2492	</pre>
				2493	<h5>Overview:</h5>
				2494	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2495	division of its two operands.</p>
				2496	<h5>Arguments:</h5>
				2497	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2498	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2499	of floating point values. Both arguments must have identical types.</p>
				2500
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2501	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2503	<p>This instruction returns the <i>remainder</i> of a division.
				2504	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2505
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2506	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2507
				2508	<pre>
				2509	<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]	2510	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2511	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2512
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2513	<!-- ======================================================================= -->
				2514	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2515	Operations</a> </div>
				2516	<div class="doc_text">
				2517	<p>Bitwise binary operators are used to do various forms of
				2518	bit-twiddling in a program. They are generally very efficient
				2519	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2520	instructions. They require two operands of the same type, execute an operation on them,
				2521	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]	2522	</div>
				2523
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2524	<!-- _______________________________________________________________________ -->
				2525	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2526	Instruction</a> </div>
				2527	<div class="doc_text">
				2528	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2529	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2530	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2531
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2532	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2533
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2534	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2535	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2536
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2537	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2538
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2539	<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]	2540	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]	2541	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2542
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2543	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2544
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2545	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2546	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2547	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2548
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2549	<h5>Example:</h5><pre>
				2550	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2551	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2552	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2553	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2554	</pre>
				2555	</div>
				2556	<!-- _______________________________________________________________________ -->
				2557	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2558	Instruction</a> </div>
				2559	<div class="doc_text">
				2560	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2561	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2562	</pre>
				2563
				2564	<h5>Overview:</h5>
				2565	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2566	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]	2567
				2568	<h5>Arguments:</h5>
				2569	<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]	2570	<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]	2571	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2572
				2573	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2574
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2575	<p>This instruction always performs a logical shift right operation. The most
				2576	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]	2577	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2578	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2579
				2580	<h5>Example:</h5>
				2581	<pre>
				2582	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2583	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2584	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2585	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2586	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2587	</pre>
				2588	</div>
				2589
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2590	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2591	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2592	Instruction</a> </div>
				2593	<div class="doc_text">
				2594
				2595	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2596	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2597	</pre>
				2598
				2599	<h5>Overview:</h5>
				2600	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2601	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]	2602
				2603	<h5>Arguments:</h5>
				2604	<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]	2605	<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]	2606	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2607
				2608	<h5>Semantics:</h5>
				2609	<p>This instruction always performs an arithmetic shift right operation,
				2610	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]	2611	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2612	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2613	</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2614
				2615	<h5>Example:</h5>
				2616	<pre>
				2617	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2618	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2619	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2620	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2621	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2622	</pre>
				2623	</div>
				2624
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2625	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2626	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2627	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2628
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2629	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2630
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2631	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2632
				2633	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2634	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2635	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2636
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2637	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2638
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2639	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2640	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2641
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2642	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2643
				2644	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2645	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2646	values. Both arguments must have identical types.</p>
				2647
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2648	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2649	<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]	2650	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2651	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2652	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2653	<tbody>
				2654	<tr>
				2655	<td>In0</td>
				2656	<td>In1</td>
				2657	<td>Out</td>
				2658	</tr>
				2659	<tr>
				2660	<td>0</td>
				2661	<td>0</td>
				2662	<td>0</td>
				2663	</tr>
				2664	<tr>
				2665	<td>0</td>
				2666	<td>1</td>
				2667	<td>0</td>
				2668	</tr>
				2669	<tr>
				2670	<td>1</td>
				2671	<td>0</td>
				2672	<td>0</td>
				2673	</tr>
				2674	<tr>
				2675	<td>1</td>
				2676	<td>1</td>
				2677	<td>1</td>
				2678	</tr>
				2679	</tbody>
				2680	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2681	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2682	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2683	<pre>
				2684	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2685	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2686	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2687	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2688	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2689	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2690	<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]	2691	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2692	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2693	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2694	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2695	<h5>Overview:</h5>
				2696	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2697	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2698	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2699
				2700	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2701	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2702	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2703	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2704	<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]	2705	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2706	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2707	<table border="1" cellspacing="0" cellpadding="4">
				2708	<tbody>
				2709	<tr>
				2710	<td>In0</td>
				2711	<td>In1</td>
				2712	<td>Out</td>
				2713	</tr>
				2714	<tr>
				2715	<td>0</td>
				2716	<td>0</td>
				2717	<td>0</td>
				2718	</tr>
				2719	<tr>
				2720	<td>0</td>
				2721	<td>1</td>
				2722	<td>1</td>
				2723	</tr>
				2724	<tr>
				2725	<td>1</td>
				2726	<td>0</td>
				2727	<td>1</td>
				2728	</tr>
				2729	<tr>
				2730	<td>1</td>
				2731	<td>1</td>
				2732	<td>1</td>
				2733	</tr>
				2734	</tbody>
				2735	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2736	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2737	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2738	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2739	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2740	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2741	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2742	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2743	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2744	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2745	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2746	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2747	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2748	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2749	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2750	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2751	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2752	or of its two operands. The <tt>xor</tt> is used to implement the
				2753	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2754	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2755	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2756	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2757	values. Both arguments must have identical types.</p>
				2758
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2759	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2760
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2761	<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]	2762	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2763	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2764	<table border="1" cellspacing="0" cellpadding="4">
				2765	<tbody>
				2766	<tr>
				2767	<td>In0</td>
				2768	<td>In1</td>
				2769	<td>Out</td>
				2770	</tr>
				2771	<tr>
				2772	<td>0</td>
				2773	<td>0</td>
				2774	<td>0</td>
				2775	</tr>
				2776	<tr>
				2777	<td>0</td>
				2778	<td>1</td>
				2779	<td>1</td>
				2780	</tr>
				2781	<tr>
				2782	<td>1</td>
				2783	<td>0</td>
				2784	<td>1</td>
				2785	</tr>
				2786	<tr>
				2787	<td>1</td>
				2788	<td>1</td>
				2789	<td>0</td>
				2790	</tr>
				2791	</tbody>
				2792	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2793	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2794	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2795	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2796	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2797	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2798	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2799	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2800	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2801	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2802
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2803	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	2804	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2805	<a name="vectorops">Vector Operations</a>
				2806	</div>
				2807
				2808	<div class="doc_text">
				2809
				2810	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2811	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2812	vector-specific operations needed to process vectors effectively. While LLVM
				2813	does directly support these vector operations, many sophisticated algorithms
				2814	will want to use target-specific intrinsics to take full advantage of a specific
				2815	target.</p>
				2816
				2817	</div>
				2818
				2819	<!-- _______________________________________________________________________ -->
				2820	<div class="doc_subsubsection">
				2821	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2822	</div>
				2823
				2824	<div class="doc_text">
				2825
				2826	<h5>Syntax:</h5>
				2827
				2828	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2829	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2830	</pre>
				2831
				2832	<h5>Overview:</h5>
				2833
				2834	<p>
				2835	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2836	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2837	</p>
				2838
				2839
				2840	<h5>Arguments:</h5>
				2841
				2842	<p>
				2843	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2844	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]	2845	an index indicating the position from which to extract the element.
				2846	The index may be a variable.</p>
				2847
				2848	<h5>Semantics:</h5>
				2849
				2850	<p>
				2851	The result is a scalar of the same type as the element type of
				2852	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2853	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2854	results are undefined.
				2855	</p>
				2856
				2857	<h5>Example:</h5>
				2858
				2859	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2860	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2861	</pre>
				2862	</div>
				2863
				2864
				2865	<!-- _______________________________________________________________________ -->
				2866	<div class="doc_subsubsection">
				2867	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2868	</div>
				2869
				2870	<div class="doc_text">
				2871
				2872	<h5>Syntax:</h5>
				2873
				2874	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	2875	<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]	2876	</pre>
				2877
				2878	<h5>Overview:</h5>
				2879
				2880	<p>
				2881	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2882	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2883	</p>
				2884
				2885
				2886	<h5>Arguments:</h5>
				2887
				2888	<p>
				2889	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2890	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]	2891	scalar value whose type must equal the element type of the first
				2892	operand. The third operand is an index indicating the position at
				2893	which to insert the value. The index may be a variable.</p>
				2894
				2895	<h5>Semantics:</h5>
				2896
				2897	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2898	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]	2899	element values are those of <tt>val</tt> except at position
				2900	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2901	exceeds the length of <tt>val</tt>, the results are undefined.
				2902	</p>
				2903
				2904	<h5>Example:</h5>
				2905
				2906	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2907	%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]	2908	</pre>
				2909	</div>
				2910
				2911	<!-- _______________________________________________________________________ -->
				2912	<div class="doc_subsubsection">
				2913	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2914	</div>
				2915
				2916	<div class="doc_text">
				2917
				2918	<h5>Syntax:</h5>
				2919
				2920	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2921	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2922	</pre>
				2923
				2924	<h5>Overview:</h5>
				2925
				2926	<p>
				2927	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2928	from two input vectors, returning a vector of the same type.
				2929	</p>
				2930
				2931	<h5>Arguments:</h5>
				2932
				2933	<p>
				2934	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2935	with types that match each other and types that match the result of the
				2936	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2937	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2938	</p>
				2939
				2940	<p>
				2941	The shuffle mask operand is required to be a constant vector with either
				2942	constant integer or undef values.
				2943	</p>
				2944
				2945	<h5>Semantics:</h5>
				2946
				2947	<p>
				2948	The elements of the two input vectors are numbered from left to right across
				2949	both of the vectors. The shuffle mask operand specifies, for each element of
				2950	the result vector, which element of the two input registers the result element
				2951	gets. The element selector may be undef (meaning "don't care") and the second
				2952	operand may be undef if performing a shuffle from only one vector.
				2953	</p>
				2954
				2955	<h5>Example:</h5>
				2956
				2957	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2958	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2959	<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]	2960	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2961	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2962	</pre>
				2963	</div>
				2964
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	2965
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	2966	<!-- ======================================================================= -->
				2967	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2968	<a name="aggregateops">Aggregate Operations</a>
				2969	</div>
				2970
				2971	<div class="doc_text">
				2972
				2973	<p>LLVM supports several instructions for working with aggregate values.
				2974	</p>
				2975
				2976	</div>
				2977
				2978	<!-- _______________________________________________________________________ -->
				2979	<div class="doc_subsubsection">
				2980	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2981	</div>
				2982
				2983	<div class="doc_text">
				2984
				2985	<h5>Syntax:</h5>
				2986
				2987	<pre>
				2988	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2989	</pre>
				2990
				2991	<h5>Overview:</h5>
				2992
				2993	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	2994	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2995	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	2996	</p>
				2997
				2998
				2999	<h5>Arguments:</h5>
				3000
				3001	<p>
				3002	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3003	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]	3004	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3005	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3006	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3007	</p>
				3008
				3009	<h5>Semantics:</h5>
				3010
				3011	<p>
				3012	The result is the value at the position in the aggregate specified by
				3013	the index operands.
				3014	</p>
				3015
				3016	<h5>Example:</h5>
				3017
				3018	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3019	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3020	</pre>
				3021	</div>
				3022
				3023
				3024	<!-- _______________________________________________________________________ -->
				3025	<div class="doc_subsubsection">
				3026	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3027	</div>
				3028
				3029	<div class="doc_text">
				3030
				3031	<h5>Syntax:</h5>
				3032
				3033	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3034	<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]	3035	</pre>
				3036
				3037	<h5>Overview:</h5>
				3038
				3039	<p>
				3040	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3041	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3042	</p>
				3043
				3044
				3045	<h5>Arguments:</h5>
				3046
				3047	<p>
				3048	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3049	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3050	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3051	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3052	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]	3053	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3054	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3055	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]	3056	by the indices.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3057
				3058	<h5>Semantics:</h5>
				3059
				3060	<p>
				3061	The result is an aggregate of the same type as <tt>val</tt>. Its
				3062	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]	3063	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3064	</p>
				3065
				3066	<h5>Example:</h5>
				3067
				3068	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3069	%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]	3070	</pre>
				3071	</div>
				3072
				3073
				3074	<!-- ======================================================================= -->
				3075	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3076	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3077	</div>
				3078
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3079	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3080
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3081	<p>A key design point of an SSA-based representation is how it
				3082	represents memory. In LLVM, no memory locations are in SSA form, which
				3083	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3084	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3085
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3086	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3087
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3088	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3089	<div class="doc_subsubsection">
				3090	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3091	</div>
				3092
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3093	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3094
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3096
				3097	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3098	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3100
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3102
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3103	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3104	heap and returns a pointer to it. The object is always allocated in the generic
				3105	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3106
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3107	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3108
				3109	<p>The '<tt>malloc</tt>' instruction allocates
				3110	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3111	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]	3112	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3113	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3114	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]	3115	be aligned to at least that boundary. If not specified, or if zero, the target can
				3116	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3117
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3118	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3119
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3120	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3121
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3122	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3123	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3124	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3125
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3126	<h5>Example:</h5>
				3127
				3128	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3129	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3130
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3131	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3132	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3133	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3134	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3135	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3136	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3137	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3138
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3139	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3140	<div class="doc_subsubsection">
				3141	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3142	</div>
				3143
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3144	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3145
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3146	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3147
				3148	<pre>
				3149	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3151
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3152	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3153
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3154	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3155	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3156
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3158
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3159	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3160	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3161	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3162
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3164
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3165	<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]	3166	after this instruction executes. If the pointer is null, the operation
				3167	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3168
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3169	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3170
				3171	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3172	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3173	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3174	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3175	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3176
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3177	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3178	<div class="doc_subsubsection">
				3179	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3180	</div>
				3181
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3182	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3183
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3184	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3185
				3186	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3187	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3188	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3189
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3190	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3191
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3192	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3193	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3194	returns to its caller. The object is always allocated in the generic address
				3195	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3196
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3197	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3198
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3199	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3200	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3201	appropriate type to the program. If "NumElements" is specified, it is the
				3202	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3203	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]	3204	to be aligned to at least that boundary. If not specified, or if zero, the target
				3205	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3206
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3207	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3208
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3210
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3211	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3212	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3213	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3214	instruction is commonly used to represent automatic variables that must
				3215	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]	3216	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]	3217	instructions), the memory is reclaimed. Allocating zero bytes
				3218	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3219
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3220	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3221
				3222	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3223	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3224	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3225	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3226	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3227	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3228	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3229
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3230	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3231	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3232	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3233	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3234	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3235	<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]	3236	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3237	<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]	3238	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3239	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3240	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3241	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]	3242	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]	3243	the number or order of execution of this <tt>load</tt> with other
				3244	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3245	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3246	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3247	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3248	(that is, the alignment of the memory address). A value of 0 or an
				3249	omitted "align" argument means that the operation has the preferential
				3250	alignment for the target. It is the responsibility of the code emitter
				3251	to ensure that the alignment information is correct. Overestimating
				3252	the alignment results in an undefined behavior. Underestimating the
				3253	alignment may produce less efficient code. An alignment of 1 is always
				3254	safe.
				3255	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3256	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3257	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3258	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3259	<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]	3260	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3261	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3262	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3263	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3264	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3265	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3266	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3267	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3268	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3269	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3270	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3271	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3272	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3273	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3274	<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]	3275	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3276	<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]	3277	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]	3278	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3279	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3280	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]	3281	optimizer is not allowed to modify the number or order of execution of
				3282	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3283	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3284	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3285	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3286	(that is, the alignment of the memory address). A value of 0 or an
				3287	omitted "align" argument means that the operation has the preferential
				3288	alignment for the target. It is the responsibility of the code emitter
				3289	to ensure that the alignment information is correct. Overestimating
				3290	the alignment results in an undefined behavior. Underestimating the
				3291	alignment may produce less efficient code. An alignment of 1 is always
				3292	safe.
				3293	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3294	<h5>Semantics:</h5>
				3295	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3296	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3297	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3298	<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]	3299	store i32 3, i32* %ptr <i>; yields {void}</i>
				3300	%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]	3301	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3302	</div>
				3303
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3304	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3305	<div class="doc_subsubsection">
				3306	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3307	</div>
				3308
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3309	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3310	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3311	<pre>
				3312	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3313	</pre>
				3314
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3315	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3316
				3317	<p>
				3318	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3319	subelement of an aggregate data structure.</p>
				3320
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3321	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3322
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3323	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3324	elements of the aggregate object to index to. The actual types of the arguments
				3325	provided depend on the type of the first pointer argument. The
				3326	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	3327	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3328	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3329	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3330	values will be sign extended to 64-bits if required.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3331
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3332	<p>For example, let's consider a C code fragment and how it gets
				3333	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3334
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3335	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3336	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3337	struct RT {
				3338	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3339	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3340	char C;
				3341	};
				3342	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3343	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3344	double Y;
				3345	struct RT Z;
				3346	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3347
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3348	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3349	return &s[1].Z.B[5][13];
				3350	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3351	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3352	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3353
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3354	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3355
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3356	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3357	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3358	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3359	%ST = type { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3360
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3361	define i32* %foo(%ST* %s) {
				3362	entry:
				3363	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3364	ret i32* %reg
				3365	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3366	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3367	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3368
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3369	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3370
				3371	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3372	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	cee005c	2006-12-04 21:29:24 +0000	[diff] [blame]	3373	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	c031269	2006-12-03 16:53:48 +0000	[diff] [blame]	3374	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3375	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3376	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3377
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3378	<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]	3379	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]	3380	}</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]	3381	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3382	i8 }</tt>' type, another structure. The third index indexes into the second
				3383	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]	3384	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3385	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3386	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]	3387
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3388	<p>Note that it is perfectly legal to index partially through a
				3389	structure, returning a pointer to an inner element. Because of this,
				3390	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3391
				3392	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3393	define i32* %foo(%ST* %s) {
				3394	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3395	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3396	%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]	3397	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3398	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3399	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3400	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3401	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3402
				3403	<p>Note that it is undefined to access an array out of bounds: array and
				3404	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	3405	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3406	defined to be accessible as variable length arrays, which requires access
				3407	beyond the zero'th element.</p>
				3408
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3409	<p>The getelementptr instruction is often confusing. For some more insight
				3410	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3411	FAQ</a>.</p>
				3412
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3413	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3414
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3415	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3416	<i>; yields [12 x i8]*:aptr</i>
				3417	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3418	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3419	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3420
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3421	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3422	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3423	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3424	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3425	<p>The instructions in this category are the conversion instructions (casting)
				3426	which all take a single operand and a type. They perform various bit conversions
				3427	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3428	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3429
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3430	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3431	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3432	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3433	</div>
				3434	<div class="doc_text">
				3435
				3436	<h5>Syntax:</h5>
				3437	<pre>
				3438	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3439	</pre>
				3440
				3441	<h5>Overview:</h5>
				3442	<p>
				3443	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3444	</p>
				3445
				3446	<h5>Arguments:</h5>
				3447	<p>
				3448	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3449	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]	3450	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]	3451	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3452	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3453
				3454	<h5>Semantics:</h5>
				3455	<p>
				3456	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]	3457	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3458	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3459	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3460
				3461	<h5>Example:</h5>
				3462	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3463	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3464	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3465	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3466	</pre>
				3467	</div>
				3468
				3469	<!-- _______________________________________________________________________ -->
				3470	<div class="doc_subsubsection">
				3471	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3472	</div>
				3473	<div class="doc_text">
				3474
				3475	<h5>Syntax:</h5>
				3476	<pre>
				3477	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3478	</pre>
				3479
				3480	<h5>Overview:</h5>
				3481	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3482	<tt>ty2</tt>.</p>
				3483
				3484
				3485	<h5>Arguments:</h5>
				3486	<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]	3487	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3488	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]	3489	<tt>value</tt> must be smaller than the bit size of the destination type,
				3490	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3491
				3492	<h5>Semantics:</h5>
				3493	<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]	3494	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]	3495
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3496	<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]	3497
				3498	<h5>Example:</h5>
				3499	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3500	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3501	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3502	</pre>
				3503	</div>
				3504
				3505	<!-- _______________________________________________________________________ -->
				3506	<div class="doc_subsubsection">
				3507	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3508	</div>
				3509	<div class="doc_text">
				3510
				3511	<h5>Syntax:</h5>
				3512	<pre>
				3513	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3514	</pre>
				3515
				3516	<h5>Overview:</h5>
				3517	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3518
				3519	<h5>Arguments:</h5>
				3520	<p>
				3521	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]	3522	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3523	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]	3524	<tt>value</tt> must be smaller than the bit size of the destination type,
				3525	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3526
				3527	<h5>Semantics:</h5>
				3528	<p>
				3529	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3530	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]	3531	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3532
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3533	<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]	3534
				3535	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3536	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3537	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3538	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3539	</pre>
				3540	</div>
				3541
				3542	<!-- _______________________________________________________________________ -->
				3543	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3544	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3545	</div>
				3546
				3547	<div class="doc_text">
				3548
				3549	<h5>Syntax:</h5>
				3550
				3551	<pre>
				3552	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3553	</pre>
				3554
				3555	<h5>Overview:</h5>
				3556	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3557	<tt>ty2</tt>.</p>
				3558
				3559
				3560	<h5>Arguments:</h5>
				3561	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3562	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3563	cast it to. The size of <tt>value</tt> must be larger than the size of
				3564	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3565	<i>no-op cast</i>.</p>
				3566
				3567	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3568	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3569	<a href="#t_floating">floating point</a> type to a smaller
				3570	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3571	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3572
				3573	<h5>Example:</h5>
				3574	<pre>
				3575	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3576	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3577	</pre>
				3578	</div>
				3579
				3580	<!-- _______________________________________________________________________ -->
				3581	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3582	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3583	</div>
				3584	<div class="doc_text">
				3585
				3586	<h5>Syntax:</h5>
				3587	<pre>
				3588	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3589	</pre>
				3590
				3591	<h5>Overview:</h5>
				3592	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3593	floating point value.</p>
				3594
				3595	<h5>Arguments:</h5>
				3596	<p>The '<tt>fpext</tt>' instruction takes a
				3597	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3598	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3599	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3600
				3601	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3602	<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]	3603	<a href="#t_floating">floating point</a> type to a larger
				3604	<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]	3605	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]	3606	<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]	3607
				3608	<h5>Example:</h5>
				3609	<pre>
				3610	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3611	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3612	</pre>
				3613	</div>
				3614
				3615	<!-- _______________________________________________________________________ -->
				3616	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3617	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3618	</div>
				3619	<div class="doc_text">
				3620
				3621	<h5>Syntax:</h5>
				3622	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3623	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3624	</pre>
				3625
				3626	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3627	<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]	3628	unsigned integer equivalent of type <tt>ty2</tt>.
				3629	</p>
				3630
				3631	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3632	<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]	3633	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3634	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3635	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3636	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]	3637
				3638	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3639	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3640	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3641	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3642	the results are undefined.</p>
				3643
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3644	<h5>Example:</h5>
				3645	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3646	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3647	%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]	3648	%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]	3649	</pre>
				3650	</div>
				3651
				3652	<!-- _______________________________________________________________________ -->
				3653	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3654	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3655	</div>
				3656	<div class="doc_text">
				3657
				3658	<h5>Syntax:</h5>
				3659	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3660	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3661	</pre>
				3662
				3663	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3664	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3665	<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]	3666	</p>
				3667
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3668	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3669	<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]	3670	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3671	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3672	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3673	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]	3674
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3675	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3676	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3677	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3678	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3679	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3680
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3681	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3682	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3683	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3684	%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]	3685	%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]	3686	</pre>
				3687	</div>
				3688
				3689	<!-- _______________________________________________________________________ -->
				3690	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3691	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3692	</div>
				3693	<div class="doc_text">
				3694
				3695	<h5>Syntax:</h5>
				3696	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3697	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3698	</pre>
				3699
				3700	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3701	<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]	3702	integer and converts that value to the <tt>ty2</tt> type.</p>
				3703
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3704	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3705	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3706	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3707	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3708	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3709	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]	3710
				3711	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3712	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3713	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3714	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]	3715
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3716	<h5>Example:</h5>
				3717	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3718	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3719	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3720	</pre>
				3721	</div>
				3722
				3723	<!-- _______________________________________________________________________ -->
				3724	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3725	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3726	</div>
				3727	<div class="doc_text">
				3728
				3729	<h5>Syntax:</h5>
				3730	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3731	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3732	</pre>
				3733
				3734	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3735	<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]	3736	integer and converts that value to the <tt>ty2</tt> type.</p>
				3737
				3738	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	3739	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3740	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3741	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3742	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3743	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]	3744
				3745	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3746	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3747	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	3748	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]	3749
				3750	<h5>Example:</h5>
				3751	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3752	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3753	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3754	</pre>
				3755	</div>
				3756
				3757	<!-- _______________________________________________________________________ -->
				3758	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3759	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3760	</div>
				3761	<div class="doc_text">
				3762
				3763	<h5>Syntax:</h5>
				3764	<pre>
				3765	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3766	</pre>
				3767
				3768	<h5>Overview:</h5>
				3769	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3770	the integer type <tt>ty2</tt>.</p>
				3771
				3772	<h5>Arguments:</h5>
				3773	<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]	3774	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3775	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3776
				3777	<h5>Semantics:</h5>
				3778	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3779	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3780	truncating or zero extending that value to the size of the integer type. If
				3781	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3782	<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]	3783	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3784	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3785
				3786	<h5>Example:</h5>
				3787	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3788	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3789	%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]	3790	</pre>
				3791	</div>
				3792
				3793	<!-- _______________________________________________________________________ -->
				3794	<div class="doc_subsubsection">
				3795	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3796	</div>
				3797	<div class="doc_text">
				3798
				3799	<h5>Syntax:</h5>
				3800	<pre>
				3801	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3802	</pre>
				3803
				3804	<h5>Overview:</h5>
				3805	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3806	a pointer type, <tt>ty2</tt>.</p>
				3807
				3808	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	3809	<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]	3810	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	3811	<a href="#t_pointer">pointer</a> type.
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3812
				3813	<h5>Semantics:</h5>
				3814	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3815	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3816	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3817	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3818	the size of a pointer then a zero extension is done. If they are the same size,
				3819	nothing is done (<i>no-op cast</i>).</p>
				3820
				3821	<h5>Example:</h5>
				3822	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3823	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3824	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3825	%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]	3826	</pre>
				3827	</div>
				3828
				3829	<!-- _______________________________________________________________________ -->
				3830	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3831	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3832	</div>
				3833	<div class="doc_text">
				3834
				3835	<h5>Syntax:</h5>
				3836	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3837	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3838	</pre>
				3839
				3840	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3841
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3842	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3843	<tt>ty2</tt> without changing any bits.</p>
				3844
				3845	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3846
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3847	<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]	3848	a non-aggregate first class value, and a type to cast it to, which must also be
				3849	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3850	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	3851	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]	3852	type is a pointer, the destination type must also be a pointer. This
				3853	instruction supports bitwise conversion of vectors to integers and to vectors
				3854	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3855
				3856	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	3857	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	3858	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3859	this conversion. The conversion is done as if the <tt>value</tt> had been
				3860	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3861	converted to other pointer types with this instruction. To convert pointers to
				3862	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3863	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3864
				3865	<h5>Example:</h5>
				3866	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3867	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3868	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3869	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3870	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3871	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3872
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3873	<!-- ======================================================================= -->
				3874	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3875	<div class="doc_text">
				3876	<p>The instructions in this category are the "miscellaneous"
				3877	instructions, which defy better classification.</p>
				3878	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3879
				3880	<!-- _______________________________________________________________________ -->
				3881	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3882	</div>
				3883	<div class="doc_text">
				3884	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3885	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3886	</pre>
				3887	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3888	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3889	a vector of boolean values based on comparison
				3890	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3891	<h5>Arguments:</h5>
				3892	<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]	3893	the condition code indicating the kind of comparison to perform. It is not
				3894	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3895	<ol>
				3896	<li><tt>eq</tt>: equal</li>
				3897	<li><tt>ne</tt>: not equal </li>
				3898	<li><tt>ugt</tt>: unsigned greater than</li>
				3899	<li><tt>uge</tt>: unsigned greater or equal</li>
				3900	<li><tt>ult</tt>: unsigned less than</li>
				3901	<li><tt>ule</tt>: unsigned less or equal</li>
				3902	<li><tt>sgt</tt>: signed greater than</li>
				3903	<li><tt>sge</tt>: signed greater or equal</li>
				3904	<li><tt>slt</tt>: signed less than</li>
				3905	<li><tt>sle</tt>: signed less or equal</li>
				3906	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3907	<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]	3908	<a href="#t_pointer">pointer</a>
				3909	or integer <a href="#t_vector">vector</a> typed.
				3910	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3911	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3912	<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]	3913	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3914	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3915	<ol>
				3916	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3917	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3918	</li>
				3919	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3920	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3921	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3922	<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]	3923	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3924	<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]	3925	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3926	<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]	3927	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3928	<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]	3929	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3930	<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]	3931	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3932	<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]	3933	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3934	<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]	3935	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3936	<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]	3937	</ol>
				3938	<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]	3939	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3940	<p>If the operands are integer vectors, then they are compared
				3941	element by element. The result is an <tt>i1</tt> vector with
				3942	the same number of elements as the values being compared.
				3943	Otherwise, the result is an <tt>i1</tt>.
				3944	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3945
				3946	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3947	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3948	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3949	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3950	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3951	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3952	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3953	</pre>
				3954	</div>
				3955
				3956	<!-- _______________________________________________________________________ -->
				3957	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3958	</div>
				3959	<div class="doc_text">
				3960	<h5>Syntax:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3961	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3962	</pre>
				3963	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3964	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3965	or vector of boolean values based on comparison
				3966	of its operands.
				3967	<p>
				3968	If the operands are floating point scalars, then the result
				3969	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3970	</p>
				3971	<p>If the operands are floating point vectors, then the result type
				3972	is a vector of boolean with the same number of elements as the
				3973	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3974	<h5>Arguments:</h5>
				3975	<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]	3976	the condition code indicating the kind of comparison to perform. It is not
				3977	a value, just a keyword. The possible condition code are:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3978	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3979	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3980	<li><tt>oeq</tt>: ordered and equal</li>
				3981	<li><tt>ogt</tt>: ordered and greater than </li>
				3982	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3983	<li><tt>olt</tt>: ordered and less than </li>
				3984	<li><tt>ole</tt>: ordered and less than or equal</li>
				3985	<li><tt>one</tt>: ordered and not equal</li>
				3986	<li><tt>ord</tt>: ordered (no nans)</li>
				3987	<li><tt>ueq</tt>: unordered or equal</li>
				3988	<li><tt>ugt</tt>: unordered or greater than </li>
				3989	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3990	<li><tt>ult</tt>: unordered or less than </li>
				3991	<li><tt>ule</tt>: unordered or less than or equal</li>
				3992	<li><tt>une</tt>: unordered or not equal</li>
				3993	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	3994	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	3995	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	3996	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	3997	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	3998	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3999	either a <a href="#t_floating">floating point</a> type
				4000	or a <a href="#t_vector">vector</a> of floating point type.
				4001	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4002	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4003	<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]	4004	according to the condition code given as <tt>cond</tt>.
				4005	If the operands are vectors, then the vectors are compared
				4006	element by element.
				4007	Each comparison performed
				4008	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4009	<ol>
				4010	<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]	4011	<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]	4012	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4013	<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]	4014	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4015	<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]	4016	<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]	4017	<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]	4018	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4019	<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]	4020	<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]	4021	<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]	4022	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4023	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4024	<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]	4025	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4026	<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]	4027	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4028	<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]	4029	<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]	4030	<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]	4031	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4032	<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]	4033	<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]	4034	<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]	4035	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4036	<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]	4037	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4038	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4039
				4040	<h5>Example:</h5>
				4041	<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]	4042	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4043	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4044	<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]	4045	</pre>
				4046	</div>
				4047
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4048	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4049	<div class="doc_subsubsection">
				4050	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4051	</div>
				4052	<div class="doc_text">
				4053	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4054	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4055	</pre>
				4056	<h5>Overview:</h5>
				4057	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4058	element-wise comparison of its two integer vector operands.</p>
				4059	<h5>Arguments:</h5>
				4060	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4061	the condition code indicating the kind of comparison to perform. It is not
				4062	a value, just a keyword. The possible condition code are:
				4063	<ol>
				4064	<li><tt>eq</tt>: equal</li>
				4065	<li><tt>ne</tt>: not equal </li>
				4066	<li><tt>ugt</tt>: unsigned greater than</li>
				4067	<li><tt>uge</tt>: unsigned greater or equal</li>
				4068	<li><tt>ult</tt>: unsigned less than</li>
				4069	<li><tt>ule</tt>: unsigned less or equal</li>
				4070	<li><tt>sgt</tt>: signed greater than</li>
				4071	<li><tt>sge</tt>: signed greater or equal</li>
				4072	<li><tt>slt</tt>: signed less than</li>
				4073	<li><tt>sle</tt>: signed less or equal</li>
				4074	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4075	<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]	4076	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4077	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4078	<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]	4079	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4080	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4081	identical type as the values being compared. The most significant bit in each
				4082	element is 1 if the element-wise comparison evaluates to true, and is 0
				4083	otherwise. All other bits of the result are undefined. The condition codes
				4084	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4085	instruction</a>.
				4086
				4087	<h5>Example:</h5>
				4088	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4089	<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>
				4090	<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]	4091	</pre>
				4092	</div>
				4093
				4094	<!-- _______________________________________________________________________ -->
				4095	<div class="doc_subsubsection">
				4096	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4097	</div>
				4098	<div class="doc_text">
				4099	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4100	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4101	<h5>Overview:</h5>
				4102	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4103	element-wise comparison of its two floating point vector operands. The output
				4104	elements have the same width as the input elements.</p>
				4105	<h5>Arguments:</h5>
				4106	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4107	the condition code indicating the kind of comparison to perform. It is not
				4108	a value, just a keyword. The possible condition code are:
				4109	<ol>
				4110	<li><tt>false</tt>: no comparison, always returns false</li>
				4111	<li><tt>oeq</tt>: ordered and equal</li>
				4112	<li><tt>ogt</tt>: ordered and greater than </li>
				4113	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4114	<li><tt>olt</tt>: ordered and less than </li>
				4115	<li><tt>ole</tt>: ordered and less than or equal</li>
				4116	<li><tt>one</tt>: ordered and not equal</li>
				4117	<li><tt>ord</tt>: ordered (no nans)</li>
				4118	<li><tt>ueq</tt>: unordered or equal</li>
				4119	<li><tt>ugt</tt>: unordered or greater than </li>
				4120	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4121	<li><tt>ult</tt>: unordered or less than </li>
				4122	<li><tt>ule</tt>: unordered or less than or equal</li>
				4123	<li><tt>une</tt>: unordered or not equal</li>
				4124	<li><tt>uno</tt>: unordered (either nans)</li>
				4125	<li><tt>true</tt>: no comparison, always returns true</li>
				4126	</ol>
				4127	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4128	<a href="#t_floating">floating point</a> typed. They must also be identical
				4129	types.</p>
				4130	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4131	<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]	4132	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4133	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4134	an identical number of elements as the values being compared, and each element
				4135	having identical with to the width of the floating point elements. The most
				4136	significant bit in each element is 1 if the element-wise comparison evaluates to
				4137	true, and is 0 otherwise. All other bits of the result are undefined. The
				4138	condition codes are evaluated identically to the
				4139	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4140
				4141	<h5>Example:</h5>
				4142	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4143	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4144	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4145	</pre>
				4146	</div>
				4147
				4148	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4149	<div class="doc_subsubsection">
				4150	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4151	</div>
				4152
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4153	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4154
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4155	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4156
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4157	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4158	<h5>Overview:</h5>
				4159	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4160	the SSA graph representing the function.</p>
				4161	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4162
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4163	<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]	4164	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4165	as arguments, with one pair for each predecessor basic block of the
				4166	current block. Only values of <a href="#t_firstclass">first class</a>
				4167	type may be used as the value arguments to the PHI node. Only labels
				4168	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4169
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4170	<p>There must be no non-phi instructions between the start of a basic
				4171	block and the PHI instructions: i.e. PHI instructions must be first in
				4172	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4173
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4174	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4175
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4176	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4177	specified by the pair corresponding to the predecessor basic block that executed
				4178	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4179
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4180	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4181	<pre>
				4182	Loop: ; Infinite loop that counts from 0 on up...
				4183	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4184	%nextindvar = add i32 %indvar, 1
				4185	br label %Loop
				4186	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4187	</div>
				4188
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4189	<!-- _______________________________________________________________________ -->
				4190	<div class="doc_subsubsection">
				4191	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4192	</div>
				4193
				4194	<div class="doc_text">
				4195
				4196	<h5>Syntax:</h5>
				4197
				4198	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4199	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4200
				4201	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4202	</pre>
				4203
				4204	<h5>Overview:</h5>
				4205
				4206	<p>
				4207	The '<tt>select</tt>' instruction is used to choose one value based on a
				4208	condition, without branching.
				4209	</p>
				4210
				4211
				4212	<h5>Arguments:</h5>
				4213
				4214	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4215	The '<tt>select</tt>' instruction requires an 'i1' value or
				4216	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4217	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]	4218	type. If the val1/val2 are vectors and
				4219	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4220	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4221	</p>
				4222
				4223	<h5>Semantics:</h5>
				4224
				4225	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4226	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]	4227	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4228	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4229	<p>
				4230	If the condition is a vector of i1, then the value arguments must
				4231	be vectors of the same size, and the selection is done element
				4232	by element.
				4233	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4234
				4235	<h5>Example:</h5>
				4236
				4237	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4238	%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]	4239	</pre>
				4240	</div>
				4241
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4242
				4243	<!-- _______________________________________________________________________ -->
				4244	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4245	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4246	</div>
				4247
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4248	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4249
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4250	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4251	<pre>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	4252	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">RetAttrs</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4253	</pre>
				4254
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4255	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4256
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4257	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4258
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4259	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4260
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4261	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4262
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4263	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4264	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4265	<p>The optional "tail" marker indicates whether the callee function accesses
				4266	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]	4267	function call is eligible for tail call optimization. Note that calls may
				4268	be marked "tail" even if they do not occur before a <a
				4269	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4270	</li>
				4271	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4272	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4273	convention</a> the call should use. If none is specified, the call defaults
				4274	to using C calling conventions.
				4275	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	4276
				4277	<li>
				4278	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4279	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4280	and '<tt>inreg</tt>' attributes are valid here.</p>
				4281	</li>
				4282
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4283	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4284	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4285	the type of the return value. Functions that return no value are marked
				4286	<tt><a href="#t_void">void</a></tt>.</p>
				4287	</li>
				4288	<li>
				4289	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4290	value being invoked. The argument types must match the types implied by
				4291	this signature. This type can be omitted if the function is not varargs
				4292	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]	4293	</li>
				4294	<li>
				4295	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4296	be invoked. In most cases, this is a direct function invocation, but
				4297	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]	4298	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4299	</li>
				4300	<li>
				4301	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4302	function signature argument types. All arguments must be of
				4303	<a href="#t_firstclass">first class</a> type. If the function signature
				4304	indicates the function accepts a variable number of arguments, the extra
				4305	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4306	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	4307	<li>
				4308	<p>The optional <a href="fnattrs">function attributes</a> list. Only
				4309	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4310	'<tt>readnone</tt>' attributes are valid here.</p>
				4311	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4312	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4313
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4314	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4315
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4316	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4317	transfer to a specified function, with its incoming arguments bound to
				4318	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4319	instruction in the called function, control flow continues with the
				4320	instruction after the function call, and the return value of the
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4321	function is bound to the result argument.
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4322
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4323	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4324
				4325	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4326	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4327	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4328	%X = tail call i32 @foo() <i>; yields i32</i>
				4329	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4330	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4331
				4332	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	4333	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4334	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4335	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame^]	4336	%Z = call void @foo() noreturn <i>; indicates that foo never returns nomrally
				4337	%ZZ = call zeroext i32 @bar() <i>; Return value is zero extended
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4338	</pre>
				4339
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4340	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4341
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4342	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4343	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4344	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4345	</div>
				4346
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4347	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4348
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4349	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4350
				4351	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4352	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4353	</pre>
				4354
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4355	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4356
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4357	<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]	4358	the "variable argument" area of a function call. It is used to implement the
				4359	<tt>va_arg</tt> macro in C.</p>
				4360
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4361	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4362
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4363	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4364	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4365	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]	4366	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4367
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4368	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4369
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4370	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4371	type from the specified <tt>va_list</tt> and causes the
				4372	<tt>va_list</tt> to point to the next argument. For more information,
				4373	see the variable argument handling <a href="#int_varargs">Intrinsic
				4374	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4375
				4376	<p>It is legal for this instruction to be called in a function which does not
				4377	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4378	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4379
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4380	<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]	4381	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4382	argument.</p>
				4383
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4384	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4385
				4386	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4387
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4388	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4389
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4390	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4391	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4392	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4393
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4394	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4395
				4396	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4397	well known names and semantics and are required to follow certain restrictions.
				4398	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4399	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]	4400	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]	4401
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4402	<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]	4403	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4404	begin with this prefix. Intrinsic functions must always be external functions:
				4405	you cannot define the body of intrinsic functions. Intrinsic functions may
				4406	only be used in call or invoke instructions: it is illegal to take the address
				4407	of an intrinsic function. Additionally, because intrinsic functions are part
				4408	of the LLVM language, it is required if any are added that they be documented
				4409	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4410
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4411	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4412	a family of functions that perform the same operation but on different data
				4413	types. Because LLVM can represent over 8 million different integer types,
				4414	overloading is used commonly to allow an intrinsic function to operate on any
				4415	integer type. One or more of the argument types or the result type can be
				4416	overloaded to accept any integer type. Argument types may also be defined as
				4417	exactly matching a previous argument's type or the result type. This allows an
				4418	intrinsic function which accepts multiple arguments, but needs all of them to
				4419	be of the same type, to only be overloaded with respect to a single argument or
				4420	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4421
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4422	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4423	encoded into its function name, each preceded by a period. Only those types
				4424	which are overloaded result in a name suffix. Arguments whose type is matched
				4425	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4426	take an integer of any width and returns an integer of exactly the same integer
				4427	width. This leads to a family of functions such as
				4428	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4429	Only one type, the return type, is overloaded, and only one type suffix is
				4430	required. Because the argument's type is matched against the return type, it
				4431	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4432
				4433	<p>To learn how to add an intrinsic function, please see the
				4434	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4435	</p>
				4436
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4437	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4438
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4439	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4440	<div class="doc_subsection">
				4441	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4442	</div>
				4443
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4444	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4445
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4446	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4447	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]	4448	intrinsic functions. These functions are related to the similarly
				4449	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4450
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4451	<p>All of these functions operate on arguments that use a
				4452	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4453	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4454	transformations should be prepared to handle these functions regardless of
				4455	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4456
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4457	<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]	4458	instruction and the variable argument handling intrinsic functions are
				4459	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4460
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4461	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4462	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4463	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4464	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4465	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4466	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4467	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4468
				4469	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4470	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4471
				4472	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4473	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4474	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4475	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4476	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4477
				4478	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4479	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4480	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4481	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4482
				4483	declare void @llvm.va_start(i8*)
				4484	declare void @llvm.va_copy(i8, i8)
				4485	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4486	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4487	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4488
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4489	</div>
				4490
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4491	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4492	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4493	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4494	</div>
				4495
				4496
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4497	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4498	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4499	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4500	<h5>Overview:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4501	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4502	<tt>*<arglist></tt> for subsequent use by <tt><a
				4503	href="#i_va_arg">va_arg</a></tt>.</p>
				4504
				4505	<h5>Arguments:</h5>
				4506
				4507	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4508
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4509	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4510
				4511	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4512	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4513	<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]	4514	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4515	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]	4516	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]	4517
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4518	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4519
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4520	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4521	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4522	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4523	</div>
				4524
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4525	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4526	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4527	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4528	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4529
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4530	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4531	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]	4532	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]	4533
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4534	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4535
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4536	<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]	4537
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4538	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4539
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4540	<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]	4541	macro available in C. In a target-dependent way, it destroys the
				4542	<tt>va_list</tt> element to which the argument points. Calls to <a
				4543	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4544	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4545	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4546
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4547	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4548
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4549	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4550	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4551	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4552	</div>
				4553
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4554	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4555
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4556	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4557
				4558	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4559	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4560	</pre>
				4561
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4562	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4563
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4564	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4565	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4566
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4567	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4568
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4569	<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]	4570	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]	4571
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4572
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4573	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4574
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4575	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4576	macro available in C. In a target-dependent way, it copies the source
				4577	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4578	intrinsic is necessary because the <tt><a href="#int_va_start">
				4579	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4580	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4581
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4582	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4583
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4584	<!-- ======================================================================= -->
				4585	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4586	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4587	</div>
				4588
				4589	<div class="doc_text">
				4590
				4591	<p>
				4592	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4593	Collection</a> (GC) requires the implementation and generation of these
				4594	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4595	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]	4596	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4597	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]	4598	Front-ends for type-safe garbage collected languages should generate these
				4599	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4600	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4601	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4602
				4603	<p>The garbage collection intrinsics only operate on objects in the generic
				4604	address space (address space zero).</p>
				4605
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4606	</div>
				4607
				4608	<!-- _______________________________________________________________________ -->
				4609	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4610	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4611	</div>
				4612
				4613	<div class="doc_text">
				4614
				4615	<h5>Syntax:</h5>
				4616
				4617	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4618	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4619	</pre>
				4620
				4621	<h5>Overview:</h5>
				4622
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4623	<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]	4624	the code generator, and allows some metadata to be associated with it.</p>
				4625
				4626	<h5>Arguments:</h5>
				4627
				4628	<p>The first argument specifies the address of a stack object that contains the
				4629	root pointer. The second pointer (which must be either a constant or a global
				4630	value address) contains the meta-data to be associated with the root.</p>
				4631
				4632	<h5>Semantics:</h5>
				4633
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4634	<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]	4635	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4636	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4637	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4638	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4639
				4640	</div>
				4641
				4642
				4643	<!-- _______________________________________________________________________ -->
				4644	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4645	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4646	</div>
				4647
				4648	<div class="doc_text">
				4649
				4650	<h5>Syntax:</h5>
				4651
				4652	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4653	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4654	</pre>
				4655
				4656	<h5>Overview:</h5>
				4657
				4658	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4659	locations, allowing garbage collector implementations that require read
				4660	barriers.</p>
				4661
				4662	<h5>Arguments:</h5>
				4663
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4664	<p>The second argument is the address to read from, which should be an address
				4665	allocated from the garbage collector. The first object is a pointer to the
				4666	start of the referenced object, if needed by the language runtime (otherwise
				4667	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4668
				4669	<h5>Semantics:</h5>
				4670
				4671	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4672	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4673	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4674	may only be used in a function which <a href="#gc">specifies a GC
				4675	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4676
				4677	</div>
				4678
				4679
				4680	<!-- _______________________________________________________________________ -->
				4681	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4682	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4683	</div>
				4684
				4685	<div class="doc_text">
				4686
				4687	<h5>Syntax:</h5>
				4688
				4689	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4690	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4691	</pre>
				4692
				4693	<h5>Overview:</h5>
				4694
				4695	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4696	locations, allowing garbage collector implementations that require write
				4697	barriers (such as generational or reference counting collectors).</p>
				4698
				4699	<h5>Arguments:</h5>
				4700
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4701	<p>The first argument is the reference to store, the second is the start of the
				4702	object to store it to, and the third is the address of the field of Obj to
				4703	store to. If the runtime does not require a pointer to the object, Obj may be
				4704	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4705
				4706	<h5>Semantics:</h5>
				4707
				4708	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4709	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4710	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4711	may only be used in a function which <a href="#gc">specifies a GC
				4712	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4713
				4714	</div>
				4715
				4716
				4717
				4718	<!-- ======================================================================= -->
				4719	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4720	<a name="int_codegen">Code Generator Intrinsics</a>
				4721	</div>
				4722
				4723	<div class="doc_text">
				4724	<p>
				4725	These intrinsics are provided by LLVM to expose special features that may only
				4726	be implemented with code generator support.
				4727	</p>
				4728
				4729	</div>
				4730
				4731	<!-- _______________________________________________________________________ -->
				4732	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4733	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4734	</div>
				4735
				4736	<div class="doc_text">
				4737
				4738	<h5>Syntax:</h5>
				4739	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4740	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4741	</pre>
				4742
				4743	<h5>Overview:</h5>
				4744
				4745	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4746	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4747	target-specific value indicating the return address of the current function
				4748	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4749	</p>
				4750
				4751	<h5>Arguments:</h5>
				4752
				4753	<p>
				4754	The argument to this intrinsic indicates which function to return the address
				4755	for. Zero indicates the calling function, one indicates its caller, etc. The
				4756	argument is <b>required</b> to be a constant integer value.
				4757	</p>
				4758
				4759	<h5>Semantics:</h5>
				4760
				4761	<p>
				4762	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4763	the return address of the specified call frame, or zero if it cannot be
				4764	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4765	for arguments other than zero, so it should only be used for debugging purposes.
				4766	</p>
				4767
				4768	<p>
				4769	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4770	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]	4771	source-language caller.
				4772	</p>
				4773	</div>
				4774
				4775
				4776	<!-- _______________________________________________________________________ -->
				4777	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4778	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4779	</div>
				4780
				4781	<div class="doc_text">
				4782
				4783	<h5>Syntax:</h5>
				4784	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4785	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4786	</pre>
				4787
				4788	<h5>Overview:</h5>
				4789
				4790	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	4791	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4792	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	4793	</p>
				4794
				4795	<h5>Arguments:</h5>
				4796
				4797	<p>
				4798	The argument to this intrinsic indicates which function to return the frame
				4799	pointer for. Zero indicates the calling function, one indicates its caller,
				4800	etc. The argument is <b>required</b> to be a constant integer value.
				4801	</p>
				4802
				4803	<h5>Semantics:</h5>
				4804
				4805	<p>
				4806	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4807	the frame address of the specified call frame, or zero if it cannot be
				4808	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4809	for arguments other than zero, so it should only be used for debugging purposes.
				4810	</p>
				4811
				4812	<p>
				4813	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	4814	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]	4815	source-language caller.
				4816	</p>
				4817	</div>
				4818
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4819	<!-- _______________________________________________________________________ -->
				4820	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4821	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4822	</div>
				4823
				4824	<div class="doc_text">
				4825
				4826	<h5>Syntax:</h5>
				4827	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4828	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4829	</pre>
				4830
				4831	<h5>Overview:</h5>
				4832
				4833	<p>
				4834	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]	4835	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4836	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4837	features like scoped automatic variable sized arrays in C99.
				4838	</p>
				4839
				4840	<h5>Semantics:</h5>
				4841
				4842	<p>
				4843	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]	4844	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4845	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4846	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4847	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4848	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4849	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4850	</p>
				4851
				4852	</div>
				4853
				4854	<!-- _______________________________________________________________________ -->
				4855	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4856	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4857	</div>
				4858
				4859	<div class="doc_text">
				4860
				4861	<h5>Syntax:</h5>
				4862	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4863	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4864	</pre>
				4865
				4866	<h5>Overview:</h5>
				4867
				4868	<p>
				4869	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4870	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]	4871	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	4872	useful for implementing language features like scoped automatic variable sized
				4873	arrays in C99.
				4874	</p>
				4875
				4876	<h5>Semantics:</h5>
				4877
				4878	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4879	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]	4880	</p>
				4881
				4882	</div>
				4883
				4884
				4885	<!-- _______________________________________________________________________ -->
				4886	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4887	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4888	</div>
				4889
				4890	<div class="doc_text">
				4891
				4892	<h5>Syntax:</h5>
				4893	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4894	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4895	</pre>
				4896
				4897	<h5>Overview:</h5>
				4898
				4899
				4900	<p>
				4901	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]	4902	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4903	no
				4904	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	4905	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	4906	</p>
				4907
				4908	<h5>Arguments:</h5>
				4909
				4910	<p>
				4911	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4912	determining if the fetch should be for a read (0) or write (1), and
				4913	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	4914	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]	4915	<tt>locality</tt> arguments must be constant integers.
				4916	</p>
				4917
				4918	<h5>Semantics:</h5>
				4919
				4920	<p>
				4921	This intrinsic does not modify the behavior of the program. In particular,
				4922	prefetches cannot trap and do not produce a value. On targets that support this
				4923	intrinsic, the prefetch can provide hints to the processor cache for better
				4924	performance.
				4925	</p>
				4926
				4927	</div>
				4928
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4929	<!-- _______________________________________________________________________ -->
				4930	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4931	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4932	</div>
				4933
				4934	<div class="doc_text">
				4935
				4936	<h5>Syntax:</h5>
				4937	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4938	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4939	</pre>
				4940
				4941	<h5>Overview:</h5>
				4942
				4943
				4944	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4945	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]	4946	(PC) in a region of
				4947	code to simulators and other tools. The method is target specific, but it is
				4948	expected that the marker will use exported symbols to transmit the PC of the
				4949	marker.
				4950	The marker makes no guarantees that it will remain with any specific instruction
				4951	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]	4952	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4953	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	4954	</p>
				4955
				4956	<h5>Arguments:</h5>
				4957
				4958	<p>
				4959	<tt>id</tt> is a numerical id identifying the marker.
				4960	</p>
				4961
				4962	<h5>Semantics:</h5>
				4963
				4964	<p>
				4965	This intrinsic does not modify the behavior of the program. Backends that do not
				4966	support this intrinisic may ignore it.
				4967	</p>
				4968
				4969	</div>
				4970
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4971	<!-- _______________________________________________________________________ -->
				4972	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4973	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4974	</div>
				4975
				4976	<div class="doc_text">
				4977
				4978	<h5>Syntax:</h5>
				4979	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4980	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	4981	</pre>
				4982
				4983	<h5>Overview:</h5>
				4984
				4985
				4986	<p>
				4987	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4988	counter register (or similar low latency, high accuracy clocks) on those targets
				4989	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4990	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4991	should only be used for small timings.
				4992	</p>
				4993
				4994	<h5>Semantics:</h5>
				4995
				4996	<p>
				4997	When directly supported, reading the cycle counter should not modify any memory.
				4998	Implementations are allowed to either return a application specific value or a
				4999	system wide value. On backends without support, this is lowered to a constant 0.
				5000	</p>
				5001
				5002	</div>
				5003
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5004	<!-- ======================================================================= -->
				5005	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5006	<a name="int_libc">Standard C Library Intrinsics</a>
				5007	</div>
				5008
				5009	<div class="doc_text">
				5010	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5011	LLVM provides intrinsics for a few important standard C library functions.
				5012	These intrinsics allow source-language front-ends to pass information about the
				5013	alignment of the pointer arguments to the code generator, providing opportunity
				5014	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5015	</p>
				5016
				5017	</div>
				5018
				5019	<!-- _______________________________________________________________________ -->
				5020	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5021	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5022	</div>
				5023
				5024	<div class="doc_text">
				5025
				5026	<h5>Syntax:</h5>
				5027	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5028	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5029	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5030	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5031	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5032	</pre>
				5033
				5034	<h5>Overview:</h5>
				5035
				5036	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5037	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]	5038	location to the destination location.
				5039	</p>
				5040
				5041	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5042	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5043	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5044	</p>
				5045
				5046	<h5>Arguments:</h5>
				5047
				5048	<p>
				5049	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]	5050	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5051	specifying the number of bytes to copy, and the fourth argument is the alignment
				5052	of the source and destination locations.
				5053	</p>
				5054
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5055	<p>
				5056	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]	5057	the caller guarantees that both the source and destination pointers are aligned
				5058	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5059	</p>
				5060
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5061	<h5>Semantics:</h5>
				5062
				5063	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5064	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]	5065	location to the destination location, which are not allowed to overlap. It
				5066	copies "len" bytes of memory over. If the argument is known to be aligned to
				5067	some boundary, this can be specified as the fourth argument, otherwise it should
				5068	be set to 0 or 1.
				5069	</p>
				5070	</div>
				5071
				5072
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5073	<!-- _______________________________________________________________________ -->
				5074	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5075	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5076	</div>
				5077
				5078	<div class="doc_text">
				5079
				5080	<h5>Syntax:</h5>
				5081	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5082	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5083	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5084	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5085	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5086	</pre>
				5087
				5088	<h5>Overview:</h5>
				5089
				5090	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5091	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5092	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5093	'<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]	5094	</p>
				5095
				5096	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5097	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5098	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5099	</p>
				5100
				5101	<h5>Arguments:</h5>
				5102
				5103	<p>
				5104	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]	5105	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5106	specifying the number of bytes to copy, and the fourth argument is the alignment
				5107	of the source and destination locations.
				5108	</p>
				5109
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5110	<p>
				5111	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]	5112	the caller guarantees that the source and destination pointers are aligned to
				5113	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5114	</p>
				5115
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5116	<h5>Semantics:</h5>
				5117
				5118	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5119	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]	5120	location to the destination location, which may overlap. It
				5121	copies "len" bytes of memory over. If the argument is known to be aligned to
				5122	some boundary, this can be specified as the fourth argument, otherwise it should
				5123	be set to 0 or 1.
				5124	</p>
				5125	</div>
				5126
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5127
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5128	<!-- _______________________________________________________________________ -->
				5129	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5130	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5131	</div>
				5132
				5133	<div class="doc_text">
				5134
				5135	<h5>Syntax:</h5>
				5136	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5137	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5138	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5139	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5140	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5141	</pre>
				5142
				5143	<h5>Overview:</h5>
				5144
				5145	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5146	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]	5147	byte value.
				5148	</p>
				5149
				5150	<p>
				5151	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5152	does not return a value, and takes an extra alignment argument.
				5153	</p>
				5154
				5155	<h5>Arguments:</h5>
				5156
				5157	<p>
				5158	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]	5159	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5160	argument specifying the number of bytes to fill, and the fourth argument is the
				5161	known alignment of destination location.
				5162	</p>
				5163
				5164	<p>
				5165	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]	5166	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5167	</p>
				5168
				5169	<h5>Semantics:</h5>
				5170
				5171	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5172	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5173	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5174	destination location. If the argument is known to be aligned to some boundary,
				5175	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5176	1.
				5177	</p>
				5178	</div>
				5179
				5180
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5181	<!-- _______________________________________________________________________ -->
				5182	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5183	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5184	</div>
				5185
				5186	<div class="doc_text">
				5187
				5188	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5189	<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]	5190	floating point or vector of floating point type. Not all targets support all
				5191	types however.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5192	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5193	declare float @llvm.sqrt.f32(float %Val)
				5194	declare double @llvm.sqrt.f64(double %Val)
				5195	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5196	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5197	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5198	</pre>
				5199
				5200	<h5>Overview:</h5>
				5201
				5202	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5203	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]	5204	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]	5205	<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]	5206	negative numbers other than -0.0 (which allows for better optimization, because
				5207	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5208	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5209	</p>
				5210
				5211	<h5>Arguments:</h5>
				5212
				5213	<p>
				5214	The argument and return value are floating point numbers of the same type.
				5215	</p>
				5216
				5217	<h5>Semantics:</h5>
				5218
				5219	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5220	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]	5221	floating point number.
				5222	</p>
				5223	</div>
				5224
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5225	<!-- _______________________________________________________________________ -->
				5226	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5227	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5228	</div>
				5229
				5230	<div class="doc_text">
				5231
				5232	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5233	<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]	5234	floating point or vector of floating point type. Not all targets support all
				5235	types however.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5236	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5237	declare float @llvm.powi.f32(float %Val, i32 %power)
				5238	declare double @llvm.powi.f64(double %Val, i32 %power)
				5239	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5240	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5241	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5242	</pre>
				5243
				5244	<h5>Overview:</h5>
				5245
				5246	<p>
				5247	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5248	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5249	multiplications is not defined. When a vector of floating point type is
				5250	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5251	</p>
				5252
				5253	<h5>Arguments:</h5>
				5254
				5255	<p>
				5256	The second argument is an integer power, and the first is a value to raise to
				5257	that power.
				5258	</p>
				5259
				5260	<h5>Semantics:</h5>
				5261
				5262	<p>
				5263	This function returns the first value raised to the second power with an
				5264	unspecified sequence of rounding operations.</p>
				5265	</div>
				5266
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5267	<!-- _______________________________________________________________________ -->
				5268	<div class="doc_subsubsection">
				5269	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5270	</div>
				5271
				5272	<div class="doc_text">
				5273
				5274	<h5>Syntax:</h5>
				5275	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5276	floating point or vector of floating point type. Not all targets support all
				5277	types however.
				5278	<pre>
				5279	declare float @llvm.sin.f32(float %Val)
				5280	declare double @llvm.sin.f64(double %Val)
				5281	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5282	declare fp128 @llvm.sin.f128(fp128 %Val)
				5283	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5284	</pre>
				5285
				5286	<h5>Overview:</h5>
				5287
				5288	<p>
				5289	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5290	</p>
				5291
				5292	<h5>Arguments:</h5>
				5293
				5294	<p>
				5295	The argument and return value are floating point numbers of the same type.
				5296	</p>
				5297
				5298	<h5>Semantics:</h5>
				5299
				5300	<p>
				5301	This function returns the sine of the specified operand, returning the
				5302	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]	5303	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5304	</div>
				5305
				5306	<!-- _______________________________________________________________________ -->
				5307	<div class="doc_subsubsection">
				5308	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5309	</div>
				5310
				5311	<div class="doc_text">
				5312
				5313	<h5>Syntax:</h5>
				5314	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5315	floating point or vector of floating point type. Not all targets support all
				5316	types however.
				5317	<pre>
				5318	declare float @llvm.cos.f32(float %Val)
				5319	declare double @llvm.cos.f64(double %Val)
				5320	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5321	declare fp128 @llvm.cos.f128(fp128 %Val)
				5322	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5323	</pre>
				5324
				5325	<h5>Overview:</h5>
				5326
				5327	<p>
				5328	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5329	</p>
				5330
				5331	<h5>Arguments:</h5>
				5332
				5333	<p>
				5334	The argument and return value are floating point numbers of the same type.
				5335	</p>
				5336
				5337	<h5>Semantics:</h5>
				5338
				5339	<p>
				5340	This function returns the cosine of the specified operand, returning the
				5341	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]	5342	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5343	</div>
				5344
				5345	<!-- _______________________________________________________________________ -->
				5346	<div class="doc_subsubsection">
				5347	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5348	</div>
				5349
				5350	<div class="doc_text">
				5351
				5352	<h5>Syntax:</h5>
				5353	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5354	floating point or vector of floating point type. Not all targets support all
				5355	types however.
				5356	<pre>
				5357	declare float @llvm.pow.f32(float %Val, float %Power)
				5358	declare double @llvm.pow.f64(double %Val, double %Power)
				5359	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5360	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5361	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5362	</pre>
				5363
				5364	<h5>Overview:</h5>
				5365
				5366	<p>
				5367	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5368	specified (positive or negative) power.
				5369	</p>
				5370
				5371	<h5>Arguments:</h5>
				5372
				5373	<p>
				5374	The second argument is a floating point power, and the first is a value to
				5375	raise to that power.
				5376	</p>
				5377
				5378	<h5>Semantics:</h5>
				5379
				5380	<p>
				5381	This function returns the first value raised to the second power,
				5382	returning the
				5383	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]	5384	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5385	</div>
				5386
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5387
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5388	<!-- ======================================================================= -->
				5389	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5390	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5391	</div>
				5392
				5393	<div class="doc_text">
				5394	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5395	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5396	These allow efficient code generation for some algorithms.
				5397	</p>
				5398
				5399	</div>
				5400
				5401	<!-- _______________________________________________________________________ -->
				5402	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5403	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5404	</div>
				5405
				5406	<div class="doc_text">
				5407
				5408	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5409	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5410	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5411	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5412	declare i16 @llvm.bswap.i16(i16 <id>)
				5413	declare i32 @llvm.bswap.i32(i32 <id>)
				5414	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5415	</pre>
				5416
				5417	<h5>Overview:</h5>
				5418
				5419	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5420	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]	5421	values with an even number of bytes (positive multiple of 16 bits). These are
				5422	useful for performing operations on data that is not in the target's native
				5423	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5424	</p>
				5425
				5426	<h5>Semantics:</h5>
				5427
				5428	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5429	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]	5430	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5431	intrinsic returns an i32 value that has the four bytes of the input i32
				5432	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]	5433	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5434	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5435	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5436	</p>
				5437
				5438	</div>
				5439
				5440	<!-- _______________________________________________________________________ -->
				5441	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5442	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5443	</div>
				5444
				5445	<div class="doc_text">
				5446
				5447	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5448	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5449	width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5450	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5451	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5452	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5453	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5454	declare i64 @llvm.ctpop.i64(i64 <src>)
				5455	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5456	</pre>
				5457
				5458	<h5>Overview:</h5>
				5459
				5460	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5461	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5462	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5463	</p>
				5464
				5465	<h5>Arguments:</h5>
				5466
				5467	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5468	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]	5469	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5470	</p>
				5471
				5472	<h5>Semantics:</h5>
				5473
				5474	<p>
				5475	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5476	</p>
				5477	</div>
				5478
				5479	<!-- _______________________________________________________________________ -->
				5480	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5481	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5482	</div>
				5483
				5484	<div class="doc_text">
				5485
				5486	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5487	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5488	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5489	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5490	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5491	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5492	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5493	declare i64 @llvm.ctlz.i64(i64 <src>)
				5494	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5495	</pre>
				5496
				5497	<h5>Overview:</h5>
				5498
				5499	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5500	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5501	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5502	</p>
				5503
				5504	<h5>Arguments:</h5>
				5505
				5506	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5507	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]	5508	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5509	</p>
				5510
				5511	<h5>Semantics:</h5>
				5512
				5513	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5514	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5515	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]	5516	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5517	</p>
				5518	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5519
				5520
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5521
				5522	<!-- _______________________________________________________________________ -->
				5523	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5524	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5525	</div>
				5526
				5527	<div class="doc_text">
				5528
				5529	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5530	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5531	integer bit width. Not all targets support all bit widths however.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5532	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5533	declare i8 @llvm.cttz.i8 (i8 <src>)
				5534	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5535	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5536	declare i64 @llvm.cttz.i64(i64 <src>)
				5537	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5538	</pre>
				5539
				5540	<h5>Overview:</h5>
				5541
				5542	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5543	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5544	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5545	</p>
				5546
				5547	<h5>Arguments:</h5>
				5548
				5549	<p>
				5550	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]	5551	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5552	</p>
				5553
				5554	<h5>Semantics:</h5>
				5555
				5556	<p>
				5557	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5558	in a variable. If the src == 0 then the result is the size in bits of the type
				5559	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5560	</p>
				5561	</div>
				5562
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5563	<!-- _______________________________________________________________________ -->
				5564	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5565	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5566	</div>
				5567
				5568	<div class="doc_text">
				5569
				5570	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5571	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5572	on any integer bit width.
				5573	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5574	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5575	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5576	</pre>
				5577
				5578	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5579	<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]	5580	range of bits from an integer value and returns them in the same bit width as
				5581	the original value.</p>
				5582
				5583	<h5>Arguments:</h5>
				5584	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5585	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]	5586	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]	5587
				5588	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5589	<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]	5590	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5591	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5592	operates in forward mode.</p>
				5593	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5594	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]	5595	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5596	<ol>
				5597	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5598	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5599	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5600	to determine the number of bits to retain.</li>
				5601	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5602	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5603	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5604	<p>In reverse mode, a similar computation is made except that the bits are
				5605	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5606	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5607	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5608	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5609	</div>
				5610
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5611	<div class="doc_subsubsection">
				5612	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5613	</div>
				5614
				5615	<div class="doc_text">
				5616
				5617	<h5>Syntax:</h5>
				5618	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5619	on any integer bit width.
				5620	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5621	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5622	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5623	</pre>
				5624
				5625	<h5>Overview:</h5>
				5626	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5627	of bits in an integer value with another integer value. It returns the integer
				5628	with the replaced bits.</p>
				5629
				5630	<h5>Arguments:</h5>
				5631	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5632	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5633	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5634	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5635	type since they specify only a bit index.</p>
				5636
				5637	<h5>Semantics:</h5>
				5638	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5639	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5640	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5641	operates in forward mode.</p>
				5642	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5643	truncating it down to the size of the replacement area or zero extending it
				5644	up to that size.</p>
				5645	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5646	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5647	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5648	to the <tt>%hi</tt>th bit.
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5649	<p>In reverse mode, a similar computation is made except that the bits are
				5650	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5651	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5652	<h5>Examples:</h5>
				5653	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5654	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5655	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5656	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5657	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	5658	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	5659	</pre>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5660	</div>
				5661
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5662	<!-- ======================================================================= -->
				5663	<div class="doc_subsection">
				5664	<a name="int_debugger">Debugger Intrinsics</a>
				5665	</div>
				5666
				5667	<div class="doc_text">
				5668	<p>
				5669	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5670	are described in the <a
				5671	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5672	Debugging</a> document.
				5673	</p>
				5674	</div>
				5675
				5676
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	5677	<!-- ======================================================================= -->
				5678	<div class="doc_subsection">
				5679	<a name="int_eh">Exception Handling Intrinsics</a>
				5680	</div>
				5681
				5682	<div class="doc_text">
				5683	<p> The LLVM exception handling intrinsics (which all start with
				5684	<tt>llvm.eh.</tt> prefix), are described in the <a
				5685	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5686	Handling</a> document. </p>
				5687	</div>
				5688
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	5689	<!-- ======================================================================= -->
				5690	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5691	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5692	</div>
				5693
				5694	<div class="doc_text">
				5695	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5696	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5697	the <tt>nest</tt> attribute, from a function. The result is a callable
				5698	function pointer lacking the nest parameter - the caller does not need
				5699	to provide a value for it. Instead, the value to use is stored in
				5700	advance in a "trampoline", a block of memory usually allocated
				5701	on the stack, which also contains code to splice the nest value into the
				5702	argument list. This is used to implement the GCC nested function address
				5703	extension.
				5704	</p>
				5705	<p>
				5706	For example, if the function is
				5707	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5708	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]	5709	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5710	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5711	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5712	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5713	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5714	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	5715	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5716	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5717	</div>
				5718
				5719	<!-- _______________________________________________________________________ -->
				5720	<div class="doc_subsubsection">
				5721	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5722	</div>
				5723	<div class="doc_text">
				5724	<h5>Syntax:</h5>
				5725	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5726	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5727	</pre>
				5728	<h5>Overview:</h5>
				5729	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5730	This fills the memory pointed to by <tt>tramp</tt> with code
				5731	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5732	</p>
				5733	<h5>Arguments:</h5>
				5734	<p>
				5735	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5736	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5737	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	f2bcd37	2007-08-22 23:39:54 +0000	[diff] [blame]	5738	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5739	currently provides no portable way of determining them, so a front-end that
				5740	generates this intrinsic needs to have some target-specific knowledge.
				5741	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5742	</p>
				5743	<h5>Semantics:</h5>
				5744	<p>
				5745	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]	5746	dependent code, turning it into a function. A pointer to this function is
				5747	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5748	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	5749	before being called. The new function's signature is the same as that of
				5750	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5751	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5752	of pointer type. Calling the new function is equivalent to calling
				5753	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5754	missing <tt>nest</tt> argument. If, after calling
				5755	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5756	modified, then the effect of any later call to the returned function pointer is
				5757	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	5758	</p>
				5759	</div>
				5760
				5761	<!-- ======================================================================= -->
				5762	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5763	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5764	</div>
				5765
				5766	<div class="doc_text">
				5767	<p>
				5768	These intrinsic functions expand the "universal IR" of LLVM to represent
				5769	hardware constructs for atomic operations and memory synchronization. This
				5770	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5771	is aimed at a low enough level to allow any programming models or APIs
				5772	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	5773	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5774	hardware behavior. Just as hardware provides a "universal IR" for source
				5775	languages, it also provides a starting point for developing a "universal"
				5776	atomic operation and synchronization IR.
				5777	</p>
				5778	<p>
				5779	These do <em>not</em> form an API such as high-level threading libraries,
				5780	software transaction memory systems, atomic primitives, and intrinsic
				5781	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5782	application libraries. The hardware interface provided by LLVM should allow
				5783	a clean implementation of all of these APIs and parallel programming models.
				5784	No one model or paradigm should be selected above others unless the hardware
				5785	itself ubiquitously does so.
				5786
				5787	</p>
				5788	</div>
				5789
				5790	<!-- _______________________________________________________________________ -->
				5791	<div class="doc_subsubsection">
				5792	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5793	</div>
				5794	<div class="doc_text">
				5795	<h5>Syntax:</h5>
				5796	<pre>
				5797	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5798	i1 <device> )
				5799
				5800	</pre>
				5801	<h5>Overview:</h5>
				5802	<p>
				5803	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5804	specific pairs of memory access types.
				5805	</p>
				5806	<h5>Arguments:</h5>
				5807	<p>
				5808	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5809	The first four arguments enables a specific barrier as listed below. The fith
				5810	argument specifies that the barrier applies to io or device or uncached memory.
				5811
				5812	</p>
				5813	<ul>
				5814	<li><tt>ll</tt>: load-load barrier</li>
				5815	<li><tt>ls</tt>: load-store barrier</li>
				5816	<li><tt>sl</tt>: store-load barrier</li>
				5817	<li><tt>ss</tt>: store-store barrier</li>
				5818	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5819	</ul>
				5820	<h5>Semantics:</h5>
				5821	<p>
				5822	This intrinsic causes the system to enforce some ordering constraints upon
				5823	the loads and stores of the program. This barrier does not indicate
				5824	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5825	which they occur. For any of the specified pairs of load and store operations
				5826	(f.ex. load-load, or store-load), all of the first operations preceding the
				5827	barrier will complete before any of the second operations succeeding the
				5828	barrier begin. Specifically the semantics for each pairing is as follows:
				5829	</p>
				5830	<ul>
				5831	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5832	after the barrier begins.</li>
				5833
				5834	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5835	store after the barrier begins.</li>
				5836	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5837	store after the barrier begins.</li>
				5838	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5839	load after the barrier begins.</li>
				5840	</ul>
				5841	<p>
				5842	These semantics are applied with a logical "and" behavior when more than one
				5843	is enabled in a single memory barrier intrinsic.
				5844	</p>
				5845	<p>
				5846	Backends may implement stronger barriers than those requested when they do not
				5847	support as fine grained a barrier as requested. Some architectures do not
				5848	need all types of barriers and on such architectures, these become noops.
				5849	</p>
				5850	<h5>Example:</h5>
				5851	<pre>
				5852	%ptr = malloc i32
				5853	store i32 4, %ptr
				5854
				5855	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5856	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5857	<i>; guarantee the above finishes</i>
				5858	store i32 8, %ptr <i>; before this begins</i>
				5859	</pre>
				5860	</div>
				5861
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5862	<!-- _______________________________________________________________________ -->
				5863	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5864	<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]	5865	</div>
				5866	<div class="doc_text">
				5867	<h5>Syntax:</h5>
				5868	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5869	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5870	any integer bit width and for different address spaces. Not all targets
				5871	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5872
				5873	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5874	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5875	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5876	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5877	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]	5878
				5879	</pre>
				5880	<h5>Overview:</h5>
				5881	<p>
				5882	This loads a value in memory and compares it to a given value. If they are
				5883	equal, it stores a new value into the memory.
				5884	</p>
				5885	<h5>Arguments:</h5>
				5886	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5887	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]	5888	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5889	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5890	this integer type. While any bit width integer may be used, targets may only
				5891	lower representations they support in hardware.
				5892
				5893	</p>
				5894	<h5>Semantics:</h5>
				5895	<p>
				5896	This entire intrinsic must be executed atomically. It first loads the value
				5897	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5898	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5899	loaded value is yielded in all cases. This provides the equivalent of an
				5900	atomic compare-and-swap operation within the SSA framework.
				5901	</p>
				5902	<h5>Examples:</h5>
				5903
				5904	<pre>
				5905	%ptr = malloc i32
				5906	store i32 4, %ptr
				5907
				5908	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5909	%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]	5910	<i>; yields {i32}:result1 = 4</i>
				5911	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5912	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5913
				5914	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5915	%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]	5916	<i>; yields {i32}:result2 = 8</i>
				5917	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5918
				5919	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5920	</pre>
				5921	</div>
				5922
				5923	<!-- _______________________________________________________________________ -->
				5924	<div class="doc_subsubsection">
				5925	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5926	</div>
				5927	<div class="doc_text">
				5928	<h5>Syntax:</h5>
				5929
				5930	<p>
				5931	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5932	integer bit width. Not all targets support all bit widths however.</p>
				5933	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5934	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5935	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5936	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5937	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5938
				5939	</pre>
				5940	<h5>Overview:</h5>
				5941	<p>
				5942	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5943	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5944	at <tt>ptr</tt>.
				5945	</p>
				5946	<h5>Arguments:</h5>
				5947
				5948	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5949	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5950	<tt>val</tt> argument and the result must be integers of the same bit width.
				5951	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5952	integer type. The targets may only lower integer representations they
				5953	support.
				5954	</p>
				5955	<h5>Semantics:</h5>
				5956	<p>
				5957	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5958	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5959	equivalent of an atomic swap operation within the SSA framework.
				5960
				5961	</p>
				5962	<h5>Examples:</h5>
				5963	<pre>
				5964	%ptr = malloc i32
				5965	store i32 4, %ptr
				5966
				5967	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5968	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5969	<i>; yields {i32}:result1 = 4</i>
				5970	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5971	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5972
				5973	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5974	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5975	<i>; yields {i32}:result2 = 8</i>
				5976
				5977	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5978	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5979	</pre>
				5980	</div>
				5981
				5982	<!-- _______________________________________________________________________ -->
				5983	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5984	<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]	5985
				5986	</div>
				5987	<div class="doc_text">
				5988	<h5>Syntax:</h5>
				5989	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	5990	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]	5991	integer bit width. Not all targets support all bit widths however.</p>
				5992	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	5993	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				5994	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				5995	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				5996	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	5997
				5998	</pre>
				5999	<h5>Overview:</h5>
				6000	<p>
				6001	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6002	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6003	</p>
				6004	<h5>Arguments:</h5>
				6005	<p>
				6006
				6007	The intrinsic takes two arguments, the first a pointer to an integer value
				6008	and the second an integer value. The result is also an integer value. These
				6009	integer types can have any bit width, but they must all have the same bit
				6010	width. The targets may only lower integer representations they support.
				6011	</p>
				6012	<h5>Semantics:</h5>
				6013	<p>
				6014	This intrinsic does a series of operations atomically. It first loads the
				6015	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6016	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6017	</p>
				6018
				6019	<h5>Examples:</h5>
				6020	<pre>
				6021	%ptr = malloc i32
				6022	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6023	%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]	6024	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6025	%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]	6026	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6027	%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]	6028	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6029	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6030	</pre>
				6031	</div>
				6032
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6033	<!-- _______________________________________________________________________ -->
				6034	<div class="doc_subsubsection">
				6035	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6036
				6037	</div>
				6038	<div class="doc_text">
				6039	<h5>Syntax:</h5>
				6040	<p>
				6041	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6042	any integer bit width and for different address spaces. Not all targets
				6043	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6044	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6045	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6046	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6047	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6048	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]	6049
				6050	</pre>
				6051	<h5>Overview:</h5>
				6052	<p>
				6053	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6054	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6055	</p>
				6056	<h5>Arguments:</h5>
				6057	<p>
				6058
				6059	The intrinsic takes two arguments, the first a pointer to an integer value
				6060	and the second an integer value. The result is also an integer value. These
				6061	integer types can have any bit width, but they must all have the same bit
				6062	width. The targets may only lower integer representations they support.
				6063	</p>
				6064	<h5>Semantics:</h5>
				6065	<p>
				6066	This intrinsic does a series of operations atomically. It first loads the
				6067	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6068	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6069	</p>
				6070
				6071	<h5>Examples:</h5>
				6072	<pre>
				6073	%ptr = malloc i32
				6074	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6075	%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]	6076	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6077	%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]	6078	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6079	%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]	6080	<i>; yields {i32}:result3 = 2</i>
				6081	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6082	</pre>
				6083	</div>
				6084
				6085	<!-- _______________________________________________________________________ -->
				6086	<div class="doc_subsubsection">
				6087	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6088	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6089	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6090	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6091
				6092	</div>
				6093	<div class="doc_text">
				6094	<h5>Syntax:</h5>
				6095	<p>
				6096	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6097	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6098	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6099	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6100	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6101	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6102	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6103	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6104	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]	6105
				6106	</pre>
				6107
				6108	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6109	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6110	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6111	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6112	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]	6113
				6114	</pre>
				6115
				6116	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6117	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6118	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6119	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6120	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]	6121
				6122	</pre>
				6123
				6124	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6125	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6126	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6127	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6128	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]	6129
				6130	</pre>
				6131	<h5>Overview:</h5>
				6132	<p>
				6133	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6134	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6135	at <tt>ptr</tt>.
				6136	</p>
				6137	<h5>Arguments:</h5>
				6138	<p>
				6139
				6140	These intrinsics take two arguments, the first a pointer to an integer value
				6141	and the second an integer value. The result is also an integer value. These
				6142	integer types can have any bit width, but they must all have the same bit
				6143	width. The targets may only lower integer representations they support.
				6144	</p>
				6145	<h5>Semantics:</h5>
				6146	<p>
				6147	These intrinsics does a series of operations atomically. They first load the
				6148	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6149	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6150	value stored at <tt>ptr</tt>.
				6151	</p>
				6152
				6153	<h5>Examples:</h5>
				6154	<pre>
				6155	%ptr = malloc i32
				6156	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6157	%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]	6158	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6159	%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]	6160	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6161	%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]	6162	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6163	%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]	6164	<i>; yields {i32}:result3 = FF</i>
				6165	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6166	</pre>
				6167	</div>
				6168
				6169
				6170	<!-- _______________________________________________________________________ -->
				6171	<div class="doc_subsubsection">
				6172	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6173	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6174	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6175	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6176
				6177	</div>
				6178	<div class="doc_text">
				6179	<h5>Syntax:</h5>
				6180	<p>
				6181	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6182	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6183	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6184	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6185	support all bit widths however.</p>
				6186	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6187	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6188	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6189	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6190	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]	6191
				6192	</pre>
				6193
				6194	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6195	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6196	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6197	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6198	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]	6199
				6200	</pre>
				6201
				6202	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6203	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6204	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6205	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6206	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]	6207
				6208	</pre>
				6209
				6210	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6211	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6212	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6213	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6214	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]	6215
				6216	</pre>
				6217	<h5>Overview:</h5>
				6218	<p>
				6219	These intrinsics takes the signed or unsigned minimum or maximum of
				6220	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6221	original value at <tt>ptr</tt>.
				6222	</p>
				6223	<h5>Arguments:</h5>
				6224	<p>
				6225
				6226	These intrinsics take two arguments, the first a pointer to an integer value
				6227	and the second an integer value. The result is also an integer value. These
				6228	integer types can have any bit width, but they must all have the same bit
				6229	width. The targets may only lower integer representations they support.
				6230	</p>
				6231	<h5>Semantics:</h5>
				6232	<p>
				6233	These intrinsics does a series of operations atomically. They first load the
				6234	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6235	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6236	the original value stored at <tt>ptr</tt>.
				6237	</p>
				6238
				6239	<h5>Examples:</h5>
				6240	<pre>
				6241	%ptr = malloc i32
				6242	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6243	%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]	6244	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6245	%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]	6246	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6247	%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]	6248	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6249	%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]	6250	<i>; yields {i32}:result3 = 8</i>
				6251	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6252	</pre>
				6253	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6254
				6255	<!-- ======================================================================= -->
				6256	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6257	<a name="int_general">General Intrinsics</a>
				6258	</div>
				6259
				6260	<div class="doc_text">
				6261	<p> This class of intrinsics is designed to be generic and has
				6262	no specific purpose. </p>
				6263	</div>
				6264
				6265	<!-- _______________________________________________________________________ -->
				6266	<div class="doc_subsubsection">
				6267	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6268	</div>
				6269
				6270	<div class="doc_text">
				6271
				6272	<h5>Syntax:</h5>
				6273	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6274	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]	6275	</pre>
				6276
				6277	<h5>Overview:</h5>
				6278
				6279	<p>
				6280	The '<tt>llvm.var.annotation</tt>' intrinsic
				6281	</p>
				6282
				6283	<h5>Arguments:</h5>
				6284
				6285	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6286	The first argument is a pointer to a value, the second is a pointer to a
				6287	global string, the third is a pointer to a global string which is the source
				6288	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6289	</p>
				6290
				6291	<h5>Semantics:</h5>
				6292
				6293	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6294	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6295	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]	6296	annotations. These have no other defined use, they are ignored by code
				6297	generation and optimization.
				6298	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6299	</div>
				6300
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6301	<!-- _______________________________________________________________________ -->
				6302	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6303	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6304	</div>
				6305
				6306	<div class="doc_text">
				6307
				6308	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6309	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6310	any integer bit width.
				6311	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6312	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6313	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6314	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6315	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6316	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6317	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]	6318	</pre>
				6319
				6320	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6321
				6322	<p>
				6323	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6324	</p>
				6325
				6326	<h5>Arguments:</h5>
				6327
				6328	<p>
				6329	The first argument is an integer value (result of some expression),
				6330	the second is a pointer to a global string, the third is a pointer to a global
				6331	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]	6332	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6333	</p>
				6334
				6335	<h5>Semantics:</h5>
				6336
				6337	<p>
				6338	This intrinsic allows annotations to be put on arbitrary expressions
				6339	with arbitrary strings. This can be useful for special purpose optimizations
				6340	that want to look for these annotations. These have no other defined use, they
				6341	are ignored by code generation and optimization.
				6342	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6343
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6344	<!-- _______________________________________________________________________ -->
				6345	<div class="doc_subsubsection">
				6346	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6347	</div>
				6348
				6349	<div class="doc_text">
				6350
				6351	<h5>Syntax:</h5>
				6352	<pre>
				6353	declare void @llvm.trap()
				6354	</pre>
				6355
				6356	<h5>Overview:</h5>
				6357
				6358	<p>
				6359	The '<tt>llvm.trap</tt>' intrinsic
				6360	</p>
				6361
				6362	<h5>Arguments:</h5>
				6363
				6364	<p>
				6365	None
				6366	</p>
				6367
				6368	<h5>Semantics:</h5>
				6369
				6370	<p>
				6371	This intrinsics is lowered to the target dependent trap instruction. If the
				6372	target does not have a trap instruction, this intrinsic will be lowered to the
				6373	call of the abort() function.
				6374	</p>
				6375	</div>
				6376
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6377	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	6378	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6379	<address>
				6380	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6381	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6382	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6383	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6384
				6385	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	6386	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	6387	Last modified: $Date$
				6388	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	6389
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	6390	</body>
				6391	</html>