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Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	cb84e43	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	44	</ol>
				45	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	46	<li><a href="#t_derived">Derived Types</a>
				47	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	48	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	49	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	50	<li><a href="#t_function">Function Type</a></li>
				51	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	52	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	53	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	54	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	55	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	56	</ol>
				57	</li>
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	58	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	59	</ol>
				60	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	61	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	62	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	63	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	64	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	65	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				66	<li><a href="#undefvalues">Undefined Values</a></li>
				67	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	68	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	69	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	70	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	71	<li><a href="#othervalues">Other Values</a>
				72	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	73	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	74	</ol>
				75	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	76	<li><a href="#instref">Instruction Reference</a>
				77	<ol>
				78	<li><a href="#terminators">Terminator Instructions</a>
				79	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	80	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				81	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	82	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				83	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	84	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	85	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	86	</ol>
				87	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	88	<li><a href="#binaryops">Binary Operations</a>
				89	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	90	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				91	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				92	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	93	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				94	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				95	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	96	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				97	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				98	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	99	</ol>
				100	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	101	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				102	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	103	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				104	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				105	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	106	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	107	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	108	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	109	</ol>
				110	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	111	<li><a href="#vectorops">Vector Operations</a>
				112	<ol>
				113	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				114	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				115	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	116	</ol>
				117	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	118	<li><a href="#aggregateops">Aggregate Operations</a>
				119	<ol>
				120	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				121	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				122	</ol>
				123	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	124	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	125	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	126	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				127	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				128	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	129	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				130	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				131	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	132	</ol>
				133	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	134	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	135	<ol>
				136	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	141	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	145	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	147	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	148	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	149	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	150	<li><a href="#otherops">Other Operations</a>
				151	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	152	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				153	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	154	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				155	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	156	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	157	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	159	<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]	160	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	161	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	162	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	163	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	164	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	165	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	166	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				167	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	168	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				169	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				170	<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]	171	</ol>
				172	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	173	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				174	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	175	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				176	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				177	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	178	</ol>
				179	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	180	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				181	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	182	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				183	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				184	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				185	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				186	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				187	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				188	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	189	</ol>
				190	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	191	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				192	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	193	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	198	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	201	</ol>
				202	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	203	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	204	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	205	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	206	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				208	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	209	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				210	<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]	211	</ol>
				212	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	213	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				214	<ol>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	215	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	220	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	221	</ol>
				222	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	223	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	224	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	225	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	226	<ol>
				227	<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]	228	</ol>
				229	</li>
Bill Wendling	f85850f	2008-11-18 22:10:53 +0000	[diff] [blame]	230	<li><a href="#int_atomics">Atomic intrinsics</a>
				231	<ol>
				232	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				233	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				234	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				235	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				236	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				237	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				238	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				239	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				240	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				241	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				242	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				243	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				244	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				245	</ol>
				246	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	247	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	248	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	250	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	251	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	253	<li><a href="#int_trap">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				255	<li><a href="#int_stackprotector">
				256	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	257	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	258	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	259	</ol>
				260	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	261	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	262
				263	<div class="doc_author">
				264	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				265	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	266	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	267
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	268	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	269	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				270	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	272	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	274	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	275	type safety, low-level operations, flexibility, and the capability of
				276	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	277	representation used throughout all phases of the LLVM compilation
				278	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	279	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	280
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	281	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	282	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				283	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	285	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	287	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	288	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]	289	representation (suitable for fast loading by a Just-In-Time compiler),
				290	and as a human readable assembly language representation. This allows
				291	LLVM to provide a powerful intermediate representation for efficient
				292	compiler transformations and analysis, while providing a natural means
				293	to debug and visualize the transformations. The three different forms
				294	of LLVM are all equivalent. This document describes the human readable
				295	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	296
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	297	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	298	while being expressive, typed, and extensible at the same time. It
				299	aims to be a "universal IR" of sorts, by being at a low enough level
				300	that high-level ideas may be cleanly mapped to it (similar to how
				301	microprocessors are "universal IR's", allowing many source languages to
				302	be mapped to them). By providing type information, LLVM can be used as
				303	the target of optimizations: for example, through pointer analysis, it
				304	can be proven that a C automatic variable is never accessed outside of
				305	the current function... allowing it to be promoted to a simple SSA
				306	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	307
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	308	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	310	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	312
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	313	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<p>It is important to note that this document describes 'well formed'
				316	LLVM assembly language. There is a difference between what the parser
				317	accepts and what is considered 'well formed'. For example, the
				318	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	320	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	321	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	322	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	323	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	324	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	326	<p>...because the definition of <tt>%x</tt> does not dominate all of
				327	its uses. The LLVM infrastructure provides a verification pass that may
				328	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]	329	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	330	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	331	by the verifier pass indicate bugs in transformation passes or input to
				332	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	333	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	334
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	335	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	337	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	338	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	341	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	343	<p>LLVM identifiers come in two basic types: global and local. Global
				344	identifiers (functions, global variables) begin with the @ character. Local
				345	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	346	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	347
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	348	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	349	<li>Named values are represented as a string of characters with their prefix.
				350	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				351	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]	352	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	2008-10-14 23:51:43 +0000	[diff] [blame]	353	with quotes. Special characters may be escaped using "\xx" where xx is the
				354	ASCII code for the character in hexadecimal. In this way, any character can
				355	be used in a name value, even quotes themselves.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	356
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	357	<li>Unnamed values are represented as an unsigned numeric value with their
				358	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	359
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	360	<li>Constants, which are described in a <a href="#constants">section about
				361	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	362	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	364	<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]	365	don't need to worry about name clashes with reserved words, and the set of
				366	reserved words may be expanded in the future without penalty. Additionally,
				367	unnamed identifiers allow a compiler to quickly come up with a temporary
				368	variable without having to avoid symbol table conflicts.</p>
				369
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	370	<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]	371	languages. There are keywords for different opcodes
				372	('<tt><a href="#i_add">add</a></tt>',
				373	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				374	'<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]	375	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]	376	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	377	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	378
				379	<p>Here is an example of LLVM code to multiply the integer variable
				380	'<tt>%X</tt>' by 8:</p>
				381
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	386	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	387	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	388	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	389
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	390	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	392	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	393	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	394	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	395	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	396	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	397
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	398	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	400	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	401	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	402	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				403	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				404	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	405	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	406	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	407
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	408	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				409	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	410
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	411	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	412
				413	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				414	line.</li>
				415
				416	<li>Unnamed temporaries are created when the result of a computation is not
				417	assigned to a named value.</li>
				418
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	419	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	420
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	421	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	422
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	423	<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]	424	demonstrating instructions, we will follow an instruction with a comment that
				425	defines the type and name of value produced. Comments are shown in italic
				426	text.</p>
				427
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	428	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	429
				430	<!-- *********************************************************************** -->
				431	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				432	<!-- *********************************************************************** -->
				433
				434	<!-- ======================================================================= -->
				435	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				436	</div>
				437
				438	<div class="doc_text">
				439
				440	<p>LLVM programs are composed of "Module"s, each of which is a
				441	translation unit of the input programs. Each module consists of
				442	functions, global variables, and symbol table entries. Modules may be
				443	combined together with the LLVM linker, which merges function (and
				444	global variable) definitions, resolves forward declarations, and merges
				445	symbol table entries. Here is an example of the "hello world" module:</p>
				446
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	447	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	449	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				450	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]	451
				452	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	454
				455	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	456	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	457	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	458	%cast210 = <a
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	459	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]	460
				461	<i>; Call puts function to write out the string to stdout...</i>
				462	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	463	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	464	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	465	href="#i_ret">ret</a> i32 0<br>}<br>
				466	</pre>
				467	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	468
				469	<p>This example is made up of a <a href="#globalvars">global variable</a>
				470	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				471	function, and a <a href="#functionstructure">function definition</a>
				472	for "<tt>main</tt>".</p>
				473
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	474	<p>In general, a module is made up of a list of global values,
				475	where both functions and global variables are global values. Global values are
				476	represented by a pointer to a memory location (in this case, a pointer to an
				477	array of char, and a pointer to a function), and have one of the following <a
				478	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	479
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	480	</div>
				481
				482	<!-- ======================================================================= -->
				483	<div class="doc_subsection">
				484	<a name="linkage">Linkage Types</a>
				485	</div>
				486
				487	<div class="doc_text">
				488
				489	<p>
				490	All Global Variables and Functions have one of the following types of linkage:
				491	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	492
				493	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	494
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	495	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				496
				497	<dd>Global values with private linkage are only directly accessible by
				498	objects in the current module. In particular, linking code into a module with
				499	an private global value may cause the private to be renamed as necessary to
				500	avoid collisions. Because the symbol is private to the module, all
				501	references can be updated. This doesn't show up in any symbol table in the
				502	object file.
				503	</dd>
				504
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	505	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Duncan Sands	35e43c1	2009-01-16 09:29:46 +0000	[diff] [blame]	507	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	508	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	509	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	510	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	512	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				513	</dt>
				514
				515	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				516	into the object file corresponding to the LLVM module. They exist to
				517	allow inlining and other optimizations to take place given knowledge of the
				518	definition of the global, which is known to be somewhere outside the module.
				519	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				520	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				521	type is only allowed on definitions, not declarations.</dd>
				522
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	523	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	525	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				526	the same name when linkage occurs. This is typically used to implement
				527	inline functions, templates, or other code which must be generated in each
				528	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				529	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	530	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	532	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				533
				534	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				535	linkage, except that unreferenced <tt>common</tt> globals may not be
				536	discarded. This is used for globals that may be emitted in multiple
				537	translation units, but that are not guaranteed to be emitted into every
				538	translation unit that uses them. One example of this is tentative
				539	definitions in C, such as "<tt>int X;</tt>" at global scope.
				540	</dd>
				541
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	542	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	543
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	544	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				545	that some targets may choose to emit different assembly sequences for them
				546	for target-dependent reasons. This is used for globals that are declared
				547	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	548	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	549
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	550	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	551
				552	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				553	pointer to array type. When two global variables with appending linkage are
				554	linked together, the two global arrays are appended together. This is the
				555	LLVM, typesafe, equivalent of having the system linker append together
				556	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	557	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	558
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	559	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	560
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	561	<dd>The semantics of this linkage follow the ELF object file model: the
				562	symbol is weak until linked, if not linked, the symbol becomes null instead
				563	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	564	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	565
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	566	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	567	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	568	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	569	functions with different semantics. Other languages, such as <tt>C++</tt>,
				570	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	571	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4581beb	2009-03-11 20:14:15 +0000	[diff] [blame]	572	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				573	be merged with equivalent globals. These linkage types are otherwise the
				574	same as their non-<tt>odr</tt> versions.
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	575	</dd>
				576
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	577	<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]	578
				579	<dd>If none of the above identifiers are used, the global is externally
				580	visible, meaning that it participates in linkage and can be used to resolve
				581	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	582	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	583	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	584
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	585	<p>
				586	The next two types of linkage are targeted for Microsoft Windows platform
				587	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	588	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	589	</p>
				590
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	591	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	592	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				593
				594	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				595	or variable via a global pointer to a pointer that is set up by the DLL
				596	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	597	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				601
				602	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				603	pointer to a pointer in a DLL, so that it can be referenced with the
				604	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	605	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	606	name.
				607	</dd>
				608
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	609	</dl>
				610
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	611	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	612	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				613	variable and was linked with this one, one of the two would be renamed,
				614	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				615	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	616	outside of the current module.</p>
				617	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	e288105	2009-03-11 08:08:06 +0000	[diff] [blame]	618	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				619	or <tt>extern_weak</tt>.</p>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	620	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				621	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	622	</div>
				623
				624	<!-- ======================================================================= -->
				625	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	626	<a name="callingconv">Calling Conventions</a>
				627	</div>
				628
				629	<div class="doc_text">
				630
				631	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				632	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				633	specified for the call. The calling convention of any pair of dynamic
				634	caller/callee must match, or the behavior of the program is undefined. The
				635	following calling conventions are supported by LLVM, and more may be added in
				636	the future:</p>
				637
				638	<dl>
				639	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				640
				641	<dd>This calling convention (the default if no other calling convention is
				642	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	643	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	644	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	645	</dd>
				646
				647	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				648
				649	<dd>This calling convention attempts to make calls as fast as possible
				650	(e.g. by passing things in registers). This calling convention allows the
				651	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]	652	without having to conform to an externally specified ABI (Application Binary
				653	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	654	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				655	supported. This calling convention does not support varargs and requires the
				656	prototype of all callees to exactly match the prototype of the function
				657	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	658	</dd>
				659
				660	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				661
				662	<dd>This calling convention attempts to make code in the caller as efficient
				663	as possible under the assumption that the call is not commonly executed. As
				664	such, these calls often preserve all registers so that the call does not break
				665	any live ranges in the caller side. This calling convention does not support
				666	varargs and requires the prototype of all callees to exactly match the
				667	prototype of the function definition.
				668	</dd>
				669
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	670	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	671
				672	<dd>Any calling convention may be specified by number, allowing
				673	target-specific calling conventions to be used. Target specific calling
				674	conventions start at 64.
				675	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	676	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	677
				678	<p>More calling conventions can be added/defined on an as-needed basis, to
				679	support pascal conventions or any other well-known target-independent
				680	convention.</p>
				681
				682	</div>
				683
				684	<!-- ======================================================================= -->
				685	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	686	<a name="visibility">Visibility Styles</a>
				687	</div>
				688
				689	<div class="doc_text">
				690
				691	<p>
				692	All Global Variables and Functions have one of the following visibility styles:
				693	</p>
				694
				695	<dl>
				696	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				697
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	698	<dd>On targets that use the ELF object file format, default visibility means
				699	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	700	modules and, in shared libraries, means that the declared entity may be
				701	overridden. On Darwin, default visibility means that the declaration is
				702	visible to other modules. Default visibility corresponds to "external
				703	linkage" in the language.
				704	</dd>
				705
				706	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				707
				708	<dd>Two declarations of an object with hidden visibility refer to the same
				709	object if they are in the same shared object. Usually, hidden visibility
				710	indicates that the symbol will not be placed into the dynamic symbol table,
				711	so no other module (executable or shared library) can reference it
				712	directly.
				713	</dd>
				714
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	715	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				716
				717	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				718	the dynamic symbol table, but that references within the defining module will
				719	bind to the local symbol. That is, the symbol cannot be overridden by another
				720	module.
				721	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	722	</dl>
				723
				724	</div>
				725
				726	<!-- ======================================================================= -->
				727	<div class="doc_subsection">
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	728	<a name="namedtypes">Named Types</a>
				729	</div>
				730
				731	<div class="doc_text">
				732
				733	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				734	it easier to read the IR and make the IR more condensed (particularly when
				735	recursive types are involved). An example of a name specification is:
				736	</p>
				737
				738	<div class="doc_code">
				739	<pre>
				740	%mytype = type { %mytype*, i32 }
				741	</pre>
				742	</div>
				743
				744	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				745	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				746	expected with the syntax "%mytype".</p>
				747
				748	<p>Note that type names are aliases for the structural type that they indicate,
				749	and that you can therefore specify multiple names for the same type. This often
				750	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				751	structural typing, the name is not part of the type. When printing out LLVM IR,
				752	the printer will pick <em>one name</em> to render all types of a particular
				753	shape. This means that if you have code where two different source types end up
				754	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				755	unexpected type. This is an important design point and isn't going to
				756	change.</p>
				757
				758	</div>
				759
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	760	<!-- ======================================================================= -->
				761	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	762	<a name="globalvars">Global Variables</a>
				763	</div>
				764
				765	<div class="doc_text">
				766
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	767	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	768	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	769	an explicit section to be placed in, and may have an optional explicit alignment
				770	specified. A variable may be defined as "thread_local", which means that it
				771	will not be shared by threads (each thread will have a separated copy of the
				772	variable). A variable may be defined as a global "constant," which indicates
				773	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]	774	optimization, allowing the global data to be placed in the read-only section of
				775	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	776	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]	777
				778	<p>
				779	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				780	constant, even if the final definition of the global is not. This capability
				781	can be used to enable slightly better optimization of the program, but requires
				782	the language definition to guarantee that optimizations based on the
				783	'constantness' are valid for the translation units that do not include the
				784	definition.
				785	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	786
				787	<p>As SSA values, global variables define pointer values that are in
				788	scope (i.e. they dominate) all basic blocks in the program. Global
				789	variables always define a pointer to their "content" type because they
				790	describe a region of memory, and all memory objects in LLVM are
				791	accessed through pointers.</p>
				792
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	793	<p>A global variable may be declared to reside in a target-specifc numbered
				794	address space. For targets that support them, address spaces may affect how
				795	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	796	the variable. The default address space is zero. The address space qualifier
				797	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	798
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	799	<p>LLVM allows an explicit section to be specified for globals. If the target
				800	supports it, it will emit globals to the section specified.</p>
				801
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	802	<p>An explicit alignment may be specified for a global. If not present, or if
				803	the alignment is set to zero, the alignment of the global is set by the target
				804	to whatever it feels convenient. If an explicit alignment is specified, the
				805	global is forced to have at least that much alignment. All alignments must be
				806	a power of 2.</p>
				807
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	808	<p>For example, the following defines a global in a numbered address space with
				809	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	810
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	811	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	812	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	813	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	814	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	815	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	816
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	817	</div>
				818
				819
				820	<!-- ======================================================================= -->
				821	<div class="doc_subsection">
				822	<a name="functionstructure">Functions</a>
				823	</div>
				824
				825	<div class="doc_text">
				826
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	827	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				828	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	829	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	830	<a href="#callingconv">calling convention</a>, a return type, an optional
				831	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				832	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	833	<a href="#paramattrs">parameter attributes</a>), optional
				834	<a href="#fnattrs">function attributes</a>, an optional section,
				835	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	836	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]	837
				838	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				839	optional <a href="#linkage">linkage type</a>, an optional
				840	<a href="#visibility">visibility style</a>, an optional
				841	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	842	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	843	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]	844	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	845
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	846	<p>A function definition contains a list of basic blocks, forming the CFG
				847	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	848	the function. Each basic block may optionally start with a label (giving the
				849	basic block a symbol table entry), contains a list of instructions, and ends
				850	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				851	function return).</p>
				852
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	853	<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]	854	executed on entrance to the function, and it is not allowed to have predecessor
				855	basic blocks (i.e. there can not be any branches to the entry block of a
				856	function). Because the block can have no predecessors, it also cannot have any
				857	<a href="#i_phi">PHI nodes</a>.</p>
				858
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	859	<p>LLVM allows an explicit section to be specified for functions. If the target
				860	supports it, it will emit functions to the section specified.</p>
				861
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	862	<p>An explicit alignment may be specified for a function. If not present, or if
				863	the alignment is set to zero, the alignment of the function is set by the target
				864	to whatever it feels convenient. If an explicit alignment is specified, the
				865	function is forced to have at least that much alignment. All alignments must be
				866	a power of 2.</p>
				867
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	868	<h5>Syntax:</h5>
				869
				870	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	871	<tt>
				872	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				873	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				874	<ResultType> @<FunctionName> ([argument list])
				875	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				876	[<a href="#gc">gc</a>] { ... }
				877	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	878	</div>
				879
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	880	</div>
				881
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	882
				883	<!-- ======================================================================= -->
				884	<div class="doc_subsection">
				885	<a name="aliasstructure">Aliases</a>
				886	</div>
				887	<div class="doc_text">
				888	<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]	889	function, global variable, another alias or bitcast of global value). Aliases
				890	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	891	optional <a href="#visibility">visibility style</a>.</p>
				892
				893	<h5>Syntax:</h5>
				894
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	895	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	896	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	897	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	898	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	899	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	900
				901	</div>
				902
				903
				904
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	905	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	906	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				907	<div class="doc_text">
				908	<p>The return type and each parameter of a function type may have a set of
				909	<i>parameter attributes</i> associated with them. Parameter attributes are
				910	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	911	a function. Parameter attributes are considered to be part of the function,
				912	not of the function type, so functions with different parameter attributes
				913	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	914
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	915	<p>Parameter attributes are simple keywords that follow the type specified. If
				916	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	917	example:</p>
				918
				919	<div class="doc_code">
				920	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	921	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	922	declare i32 @atoi(i8 zeroext)
				923	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	924	</pre>
				925	</div>
				926
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	927	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				928	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	929
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	930	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	931	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	932	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	933	<dd>This indicates to the code generator that the parameter or return value
				934	should be zero-extended to a 32-bit value by the caller (for a parameter)
				935	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	936
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	937	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	938	<dd>This indicates to the code generator that the parameter or return value
				939	should be sign-extended to a 32-bit value by the caller (for a parameter)
				940	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	941
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	942	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	943	<dd>This indicates that this parameter or return value should be treated
				944	in a special target-dependent fashion during while emitting code for a
				945	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]	946	to memory, though some targets use it to distinguish between two different
				947	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	948
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	949	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	950	<dd>This indicates that the pointer parameter should really be passed by
				951	value to the function. The attribute implies that a hidden copy of the
				952	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]	953	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]	954	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	955	value, but is also valid on pointers to scalars. The copy is considered to
				956	belong to the caller not the callee (for example,
				957	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	958	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	2009-02-05 05:42:28 +0000	[diff] [blame]	959	values. The byval attribute also supports specifying an alignment with the
				960	align attribute. This has a target-specific effect on the code generator
				961	that usually indicates a desired alignment for the synthesized stack
				962	slot.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	963
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	964	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	965	<dd>This indicates that the pointer parameter specifies the address of a
				966	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]	967	This pointer must be guaranteed by the caller to be valid: loads and stores
				968	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]	969	be applied to the first parameter. This is not a valid attribute for
				970	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	971
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	972	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	973	<dd>This indicates that the pointer does not alias any global or any other
				974	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	d59572c	2008-11-24 05:00:44 +0000	[diff] [blame]	975	case. On a function return value, <tt>noalias</tt> additionally indicates
				976	that the pointer does not alias any other pointers visible to the
Nick Lewycky	2abb108	2008-12-19 06:39:12 +0000	[diff] [blame]	977	caller. For further details, please see the discussion of the NoAlias
				978	response in
				979	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				980	analysis</a>.</dd>
				981
				982	<dt><tt>nocapture</tt></dt>
				983	<dd>This indicates that the callee does not make any copies of the pointer
				984	that outlive the callee itself. This is not a valid attribute for return
				985	values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	986
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	987	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	988	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	989	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				990	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	991	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	992
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	993	</div>
				994
				995	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	996	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	997	<a name="gc">Garbage Collector Names</a>
				998	</div>
				999
				1000	<div class="doc_text">
				1001	<p>Each function may specify a garbage collector name, which is simply a
				1002	string.</p>
				1003
				1004	<div class="doc_code"><pre
				1005	>define void @f() gc "name" { ...</pre></div>
				1006
				1007	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1008	collector which will cause the compiler to alter its output in order to support
				1009	the named garbage collection algorithm.</p>
				1010	</div>
				1011
				1012	<!-- ======================================================================= -->
				1013	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1014	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1015	</div>
				1016
				1017	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1018
				1019	<p>Function attributes are set to communicate additional information about
				1020	a function. Function attributes are considered to be part of the function,
				1021	not of the function type, so functions with different parameter attributes
				1022	can have the same function type.</p>
				1023
				1024	<p>Function attributes are simple keywords that follow the type specified. If
				1025	multiple attributes are needed, they are space separated. For
				1026	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1027
				1028	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1029	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1030	define void @f() noinline { ... }
				1031	define void @f() alwaysinline { ... }
				1032	define void @f() alwaysinline optsize { ... }
				1033	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1034	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1035	</div>
				1036
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1037	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1038	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1039	<dd>This attribute indicates that the inliner should attempt to inline this
				1040	function into callers whenever possible, ignoring any active inlining size
				1041	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1042
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1043	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1044	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1045	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1046	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1047
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1048	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1049	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	make choices that keep the code size of this function low, and otherwise do
				1051	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1052
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1053	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	<dd>This function attribute indicates that the function never returns normally.
				1055	This produces undefined behavior at runtime if the function ever does
				1056	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1057
				1058	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1059	<dd>This function attribute indicates that the function never returns with an
				1060	unwind or exceptional control flow. If the function does unwind, its runtime
				1061	behavior is undefined.</dd>
				1062
				1063	<dt><tt>readnone</tt></dt>
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1064	<dd>This attribute indicates that the function computes its result (or the
				1065	exception it throws) based strictly on its arguments, without dereferencing any
				1066	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1067	registers, etc) visible to caller functions. It does not write through any
				1068	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
				1069	never changes any state visible to callers.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1070
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1071	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1072	<dd>This attribute indicates that the function does not write through any
				1073	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1074	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1075	caller functions. It may dereference pointer arguments and read state that may
				1076	be set in the caller. A readonly function always returns the same value (or
				1077	throws the same exception) when called with the same set of arguments and global
				1078	state.</dd>
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1079
				1080	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1081	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1082	protector. It is in the form of a "canary"—a random value placed on the
				1083	stack before the local variables that's checked upon return from the function to
				1084	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1085	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1087	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1088	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1089	have an <tt>ssp</tt> attribute.</p></dd>
				1090
				1091	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1092	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1093	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1094	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1095
				1096	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1097	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1098	an <tt>ssp</tt> attribute, then the resulting function will have
				1099	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1100	</dl>
				1101
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1102	</div>
				1103
				1104	<!-- ======================================================================= -->
				1105	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1106	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1107	</div>
				1108
				1109	<div class="doc_text">
				1110	<p>
				1111	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1112	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1113	LLVM and treated as a single unit, but may be separated in the .ll file if
				1114	desired. The syntax is very simple:
				1115	</p>
				1116
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1117	<div class="doc_code">
				1118	<pre>
				1119	module asm "inline asm code goes here"
				1120	module asm "more can go here"
				1121	</pre>
				1122	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1123
				1124	<p>The strings can contain any character by escaping non-printable characters.
				1125	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1126	for the number.
				1127	</p>
				1128
				1129	<p>
				1130	The inline asm code is simply printed to the machine code .s file when
				1131	assembly code is generated.
				1132	</p>
				1133	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1134
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1135	<!-- ======================================================================= -->
				1136	<div class="doc_subsection">
				1137	<a name="datalayout">Data Layout</a>
				1138	</div>
				1139
				1140	<div class="doc_text">
				1141	<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]	1142	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1143	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1144	<p>The <i>layout specification</i> consists of a list of specifications
				1145	separated by the minus sign character ('-'). Each specification starts with a
				1146	letter and may include other information after the letter to define some
				1147	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1148	<dl>
				1149	<dt><tt>E</tt></dt>
				1150	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1151	bits with the most significance have the lowest address location.</dd>
				1152	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1153	<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]	1154	the bits with the least significance have the lowest address location.</dd>
				1155	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1156	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1157	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1158	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1159	too.</dd>
				1160	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1161	<dd>This specifies the alignment for an integer type of a given bit
				1162	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1163	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1164	<dd>This specifies the alignment for a vector type of a given bit
				1165	<i>size</i>.</dd>
				1166	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1167	<dd>This specifies the alignment for a floating point type of a given bit
				1168	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1169	(double).</dd>
				1170	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the alignment for an aggregate type of a given bit
				1172	<i>size</i>.</dd>
				1173	</dl>
				1174	<p>When constructing the data layout for a given target, LLVM starts with a
				1175	default set of specifications which are then (possibly) overriden by the
				1176	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1177	are given in this list:</p>
				1178	<ul>
				1179	<li><tt>E</tt> - big endian</li>
				1180	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1181	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1182	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1183	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1184	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1185	<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]	1186	alignment of 64-bits</li>
				1187	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1188	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1189	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1190	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1191	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1192	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1193	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1194	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1195	<ol>
				1196	<li>If the type sought is an exact match for one of the specifications, that
				1197	specification is used.</li>
				1198	<li>If no match is found, and the type sought is an integer type, then the
				1199	smallest integer type that is larger than the bitwidth of the sought type is
				1200	used. If none of the specifications are larger than the bitwidth then the the
				1201	largest integer type is used. For example, given the default specifications
				1202	above, the i7 type will use the alignment of i8 (next largest) while both
				1203	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1204	<li>If no match is found, and the type sought is a vector type, then the
				1205	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1206	as a fall back. This happens because <128 x double> can be implemented
				1207	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1208	</ol>
				1209	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1210
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1211	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1212	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1213	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1214
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1215	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1216
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1217	<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]	1218	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1219	optimizations to be performed on the intermediate representation directly,
				1220	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1221	extra analyses on the side before the transformation. A strong type
				1222	system makes it easier to read the generated code and enables novel
				1223	analyses and transformations that are not feasible to perform on normal
				1224	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1225
				1226	</div>
				1227
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1228	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1229	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1230	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1231	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1232	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1233	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1234
				1235	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1236	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1237	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1238	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1239	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1240	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	</tr>
				1242	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1243	<td><a href="#t_floating">floating point</a></td>
				1244	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1245	</tr>
				1246	<tr>
				1247	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1248	<td><a href="#t_integer">integer</a>,
				1249	<a href="#t_floating">floating point</a>,
				1250	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1251	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1252	<a href="#t_struct">structure</a>,
				1253	<a href="#t_array">array</a>,
Dan Gohman	da52d21	2008-05-23 22:50:26 +0000	[diff] [blame]	1254	<a href="#t_label">label</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1255	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1257	<tr>
				1258	<td><a href="#t_primitive">primitive</a></td>
				1259	<td><a href="#t_label">label</a>,
				1260	<a href="#t_void">void</a>,
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1261	<a href="#t_floating">floating point</a>.</td>
				1262	</tr>
				1263	<tr>
				1264	<td><a href="#t_derived">derived</a></td>
				1265	<td><a href="#t_integer">integer</a>,
				1266	<a href="#t_array">array</a>,
				1267	<a href="#t_function">function</a>,
				1268	<a href="#t_pointer">pointer</a>,
				1269	<a href="#t_struct">structure</a>,
				1270	<a href="#t_pstruct">packed structure</a>,
				1271	<a href="#t_vector">vector</a>,
				1272	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1273	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1274	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1275	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1276	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1277
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1278	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1279	most important. Values of these types are the only ones which can be
				1280	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1281	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1282	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1283
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1284	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1285	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1286
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1287	<div class="doc_text">
				1288	<p>The primitive types are the fundamental building blocks of the LLVM
				1289	system.</p>
				1290
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1291	</div>
				1292
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1293	<!-- _______________________________________________________________________ -->
				1294	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1295
				1296	<div class="doc_text">
				1297	<table>
				1298	<tbody>
				1299	<tr><th>Type</th><th>Description</th></tr>
				1300	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1301	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1302	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1303	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1304	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1305	</tbody>
				1306	</table>
				1307	</div>
				1308
				1309	<!-- _______________________________________________________________________ -->
				1310	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1311
				1312	<div class="doc_text">
				1313	<h5>Overview:</h5>
				1314	<p>The void type does not represent any value and has no size.</p>
				1315
				1316	<h5>Syntax:</h5>
				1317
				1318	<pre>
				1319	void
				1320	</pre>
				1321	</div>
				1322
				1323	<!-- _______________________________________________________________________ -->
				1324	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1325
				1326	<div class="doc_text">
				1327	<h5>Overview:</h5>
				1328	<p>The label type represents code labels.</p>
				1329
				1330	<h5>Syntax:</h5>
				1331
				1332	<pre>
				1333	label
				1334	</pre>
				1335	</div>
				1336
				1337
				1338	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1339	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1340
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1341	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1342
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1343	<p>The real power in LLVM comes from the derived types in the system.
				1344	This is what allows a programmer to represent arrays, functions,
				1345	pointers, and other useful types. Note that these derived types may be
				1346	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]	1347
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1348	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1349
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1350	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1351	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1352
				1353	<div class="doc_text">
				1354
				1355	<h5>Overview:</h5>
				1356	<p>The integer type is a very simple derived type that simply specifies an
				1357	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1358	2^23-1 (about 8 million) can be specified.</p>
				1359
				1360	<h5>Syntax:</h5>
				1361
				1362	<pre>
				1363	iN
				1364	</pre>
				1365
				1366	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1367	value.</p>
				1368
				1369	<h5>Examples:</h5>
				1370	<table class="layout">
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1371	<tbody>
				1372	<tr>
				1373	<td><tt>i1</tt></td>
				1374	<td>a single-bit integer.</td>
				1375	</tr><tr>
				1376	<td><tt>i32</tt></td>
				1377	<td>a 32-bit integer.</td>
				1378	</tr><tr>
				1379	<td><tt>i1942652</tt></td>
				1380	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1381	</tr>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	1382	</tbody>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1383	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1384
				1385	<p>Note that the code generator does not yet support large integer types
				1386	to be used as function return types. The specific limit on how large a
				1387	return type the code generator can currently handle is target-dependent;
				1388	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1389	targets.</p>
				1390
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1391	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1392
				1393	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1394	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1395
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1396	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1397
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1398	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1399
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1400	<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]	1401	sequentially in memory. The array type requires a size (number of
				1402	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1403
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1404	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1405
				1406	<pre>
				1407	[<# elements> x <elementtype>]
				1408	</pre>
				1409
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1410	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1411	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1412
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1413	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1414	<table class="layout">
				1415	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1416	<td class="left"><tt>[40 x i32]</tt></td>
				1417	<td class="left">Array of 40 32-bit integer values.</td>
				1418	</tr>
				1419	<tr class="layout">
				1420	<td class="left"><tt>[41 x i32]</tt></td>
				1421	<td class="left">Array of 41 32-bit integer values.</td>
				1422	</tr>
				1423	<tr class="layout">
				1424	<td class="left"><tt>[4 x i8]</tt></td>
				1425	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1426	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1427	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1428	<p>Here are some examples of multidimensional arrays:</p>
				1429	<table class="layout">
				1430	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1431	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1432	<td class="left">3x4 array of 32-bit integer values.</td>
				1433	</tr>
				1434	<tr class="layout">
				1435	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1436	<td class="left">12x10 array of single precision floating point values.</td>
				1437	</tr>
				1438	<tr class="layout">
				1439	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1440	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1441	</tr>
				1442	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1443
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1444	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1445	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]	1446	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1447	As a special case, however, zero length arrays are recognized to be variable
				1448	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1449	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1450
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1451	<p>Note that the code generator does not yet support large aggregate types
				1452	to be used as function return types. The specific limit on how large an
				1453	aggregate return type the code generator can currently handle is
				1454	target-dependent, and also dependent on the aggregate element types.</p>
				1455
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1456	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1457
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1458	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1459	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1461
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1462	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1463
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1464	<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]	1465	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]	1466	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]	1467	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]	1468	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1469
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1470	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1471
				1472	<pre>
				1473	<returntype list> (<parameter list>)
				1474	</pre>
				1475
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1476	<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]	1477	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1478	which indicates that the function takes a variable number of arguments.
				1479	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1480	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1481	'<tt><returntype list></tt>' is a comma-separated list of
				1482	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1483
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1484	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1485	<table class="layout">
				1486	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1487	<td class="left"><tt>i32 (i32)</tt></td>
				1488	<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]	1489	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1490	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1491	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1492	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1493	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1494	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1495	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1496	<tt>float</tt>.
				1497	</td>
				1498	</tr><tr class="layout">
				1499	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1500	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1501	<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]	1502	which returns an integer. This is the signature for <tt>printf</tt> in
				1503	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1504	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1505	</tr><tr class="layout">
				1506	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1507	<td class="left">A function taking an <tt>i32</tt>, returning two
				1508	<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]	1509	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1510	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1511	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1512
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1513	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1514	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1515	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1516	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1517	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1518	<p>The structure type is used to represent a collection of data members
				1519	together in memory. The packing of the field types is defined to match
				1520	the ABI of the underlying processor. The elements of a structure may
				1521	be any type that has a size.</p>
				1522	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1523	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1524	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1525	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1526	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1527	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1528	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1529	<table class="layout">
				1530	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1531	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1532	<td class="left">A triple of three <tt>i32</tt> values</td>
				1533	</tr><tr class="layout">
				1534	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1535	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1536	second element is a <a href="#t_pointer">pointer</a> to a
				1537	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1538	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1539	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1540	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1541
				1542	<p>Note that the code generator does not yet support large aggregate types
				1543	to be used as function return types. The specific limit on how large an
				1544	aggregate return type the code generator can currently handle is
				1545	target-dependent, and also dependent on the aggregate element types.</p>
				1546
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1547	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1548
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1549	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1550	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1551	</div>
				1552	<div class="doc_text">
				1553	<h5>Overview:</h5>
				1554	<p>The packed structure type is used to represent a collection of data members
				1555	together in memory. There is no padding between fields. Further, the alignment
				1556	of a packed structure is 1 byte. The elements of a packed structure may
				1557	be any type that has a size.</p>
				1558	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1559	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1560	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1561	instruction.</p>
				1562	<h5>Syntax:</h5>
				1563	<pre> < { <type list> } > <br></pre>
				1564	<h5>Examples:</h5>
				1565	<table class="layout">
				1566	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1567	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1568	<td class="left">A triple of three <tt>i32</tt> values</td>
				1569	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1570	<td class="left">
				1571	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1572	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1573	second element is a <a href="#t_pointer">pointer</a> to a
				1574	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1575	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1576	</tr>
				1577	</table>
				1578	</div>
				1579
				1580	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1581	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1582	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1583	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1584	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1585	reference to another object, which must live in memory. Pointer types may have
				1586	an optional address space attribute defining the target-specific numbered
				1587	address space where the pointed-to object resides. The default address space is
				1588	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1589
				1590	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	d1d4cff	2009-02-08 22:21:28 +0000	[diff] [blame]	1591	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1592
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1593	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1594	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1595	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1596	<table class="layout">
				1597	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1598	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1599	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1600	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1601	</tr>
				1602	<tr class="layout">
				1603	<td class="left"><tt>i32 (i32 ) </tt></td>
				1604	<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]	1605	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]	1606	<tt>i32</tt>.</td>
				1607	</tr>
				1608	<tr class="layout">
				1609	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1610	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1611	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1612	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1613	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1614	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1615
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1616	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1617	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1618	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1619
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1620	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1621
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1622	<p>A vector type is a simple derived type that represents a vector
				1623	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1624	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1625	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1626	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1627	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1628	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1629
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1630	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1631
				1632	<pre>
				1633	< <# elements> x <elementtype> >
				1634	</pre>
				1635
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1636	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1637	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1638
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1639	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1640
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1641	<table class="layout">
				1642	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1643	<td class="left"><tt><4 x i32></tt></td>
				1644	<td class="left">Vector of 4 32-bit integer values.</td>
				1645	</tr>
				1646	<tr class="layout">
				1647	<td class="left"><tt><8 x float></tt></td>
				1648	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1649	</tr>
				1650	<tr class="layout">
				1651	<td class="left"><tt><2 x i64></tt></td>
				1652	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1653	</tr>
				1654	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1655
				1656	<p>Note that the code generator does not yet support large vector types
				1657	to be used as function return types. The specific limit on how large a
				1658	vector return type codegen can currently handle is target-dependent;
				1659	currently it's often a few times longer than a hardware vector register.</p>
				1660
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1661	</div>
				1662
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1663	<!-- _______________________________________________________________________ -->
				1664	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1665	<div class="doc_text">
				1666
				1667	<h5>Overview:</h5>
				1668
				1669	<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]	1670	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]	1671	In LLVM, opaque types can eventually be resolved to any type (not just a
				1672	structure type).</p>
				1673
				1674	<h5>Syntax:</h5>
				1675
				1676	<pre>
				1677	opaque
				1678	</pre>
				1679
				1680	<h5>Examples:</h5>
				1681
				1682	<table class="layout">
				1683	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1684	<td class="left"><tt>opaque</tt></td>
				1685	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1686	</tr>
				1687	</table>
				1688	</div>
				1689
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1690	<!-- ======================================================================= -->
				1691	<div class="doc_subsection">
				1692	<a name="t_uprefs">Type Up-references</a>
				1693	</div>
				1694
				1695	<div class="doc_text">
				1696	<h5>Overview:</h5>
				1697	<p>
				1698	An "up reference" allows you to refer to a lexically enclosing type without
				1699	requiring it to have a name. For instance, a structure declaration may contain a
				1700	pointer to any of the types it is lexically a member of. Example of up
				1701	references (with their equivalent as named type declarations) include:</p>
				1702
				1703	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1704	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1705	{ \2 }* %y = type { %y }*
				1706	\1* %z = type %z*
				1707	</pre>
				1708
				1709	<p>
				1710	An up reference is needed by the asmprinter for printing out cyclic types when
				1711	there is no declared name for a type in the cycle. Because the asmprinter does
				1712	not want to print out an infinite type string, it needs a syntax to handle
				1713	recursive types that have no names (all names are optional in llvm IR).
				1714	</p>
				1715
				1716	<h5>Syntax:</h5>
				1717	<pre>
				1718	\<level>
				1719	</pre>
				1720
				1721	<p>
				1722	The level is the count of the lexical type that is being referred to.
				1723	</p>
				1724
				1725	<h5>Examples:</h5>
				1726
				1727	<table class="layout">
				1728	<tr class="layout">
				1729	<td class="left"><tt>\1*</tt></td>
				1730	<td class="left">Self-referential pointer.</td>
				1731	</tr>
				1732	<tr class="layout">
				1733	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1734	<td class="left">Recursive structure where the upref refers to the out-most
				1735	structure.</td>
				1736	</tr>
				1737	</table>
				1738	</div>
				1739
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1740
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1741	<!-- *********************************************************************** -->
				1742	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1743	<!-- *********************************************************************** -->
				1744
				1745	<div class="doc_text">
				1746
				1747	<p>LLVM has several different basic types of constants. This section describes
				1748	them all and their syntax.</p>
				1749
				1750	</div>
				1751
				1752	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1753	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1754
				1755	<div class="doc_text">
				1756
				1757	<dl>
				1758	<dt><b>Boolean constants</b></dt>
				1759
				1760	<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]	1761	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1762	</dd>
				1763
				1764	<dt><b>Integer constants</b></dt>
				1765
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1766	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1767	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1768	integer types.
				1769	</dd>
				1770
				1771	<dt><b>Floating point constants</b></dt>
				1772
				1773	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1774	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1775	notation (see below). The assembler requires the exact decimal value of
				1776	a floating-point constant. For example, the assembler accepts 1.25 but
				1777	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1778	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]	1779
				1780	<dt><b>Null pointer constants</b></dt>
				1781
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1782	<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]	1783	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1784
				1785	</dl>
				1786
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1787	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1788	of floating point constants. For example, the form '<tt>double
				1789	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1790	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]	1791	(and the only time that they are generated by the disassembler) is when a
				1792	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1793	decimal floating point number in a reasonable number of digits. For example,
				1794	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1795	special values are represented in their IEEE hexadecimal format so that
				1796	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1797	<p>When using the hexadecimal form, constants of types float and double are
				1798	represented using the 16-digit form shown above (which matches the IEEE754
				1799	representation for double); float values must, however, be exactly representable
				1800	as IEE754 single precision.
				1801	Hexadecimal format is always used for long
				1802	double, and there are three forms of long double. The 80-bit
				1803	format used by x86 is represented as <tt>0xK</tt>
				1804	followed by 20 hexadecimal digits.
				1805	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1806	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1807	format is represented
				1808	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1809	target uses this format. Long doubles will only work if they match
				1810	the long double format on your target. All hexadecimal formats are big-endian
				1811	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1812	</div>
				1813
				1814	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1815	<div class="doc_subsection">
				1816	<a name="aggregateconstants"> <!-- old anchor -->
				1817	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1818	</div>
				1819
				1820	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1821	<p>Complex constants are a (potentially recursive) combination of simple
				1822	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1823
				1824	<dl>
				1825	<dt><b>Structure constants</b></dt>
				1826
				1827	<dd>Structure constants are represented with notation similar to structure
				1828	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1829	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1830	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]	1831	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]	1832	types of elements must match those specified by the type.
				1833	</dd>
				1834
				1835	<dt><b>Array constants</b></dt>
				1836
				1837	<dd>Array constants are represented with notation similar to array type
				1838	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1839	(<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]	1840	constants must have <a href="#t_array">array type</a>, and the number and
				1841	types of elements must match those specified by the type.
				1842	</dd>
				1843
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1844	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1845
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1846	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1847	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1848	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1849	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1850	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]	1851	match those specified by the type.
				1852	</dd>
				1853
				1854	<dt><b>Zero initialization</b></dt>
				1855
				1856	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1857	value to zero of <em>any</em> type, including scalar and aggregate types.
				1858	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]	1859	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1860	initializers.
				1861	</dd>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1862
				1863	<dt><b>Metadata node</b></dt>
				1864
				1865	<dd>A metadata node is a structure-like constant with the type of an empty
				1866	struct. For example: "<tt>{ } !{ i32 0, { } !"test" }</tt>". Unlike other
				1867	constants that are meant to be interpreted as part of the instruction stream,
				1868	metadata is a place to attach additional information such as debug info.
				1869	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1870	</dl>
				1871
				1872	</div>
				1873
				1874	<!-- ======================================================================= -->
				1875	<div class="doc_subsection">
				1876	<a name="globalconstants">Global Variable and Function Addresses</a>
				1877	</div>
				1878
				1879	<div class="doc_text">
				1880
				1881	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1882	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1883	constants. These constants are explicitly referenced when the <a
				1884	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]	1885	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1886	file:</p>
				1887
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1888	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1889	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1890	@X = global i32 17
				1891	@Y = global i32 42
				1892	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1893	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1894	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1895
				1896	</div>
				1897
				1898	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1899	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1900	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1901	<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]	1902	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]	1903	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1904
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1905	<p>Undefined values indicate to the compiler that the program is well defined
				1906	no matter what value is used, giving the compiler more freedom to optimize.
				1907	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1908	</div>
				1909
				1910	<!-- ======================================================================= -->
				1911	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1912	</div>
				1913
				1914	<div class="doc_text">
				1915
				1916	<p>Constant expressions are used to allow expressions involving other constants
				1917	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1918	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]	1919	that does not have side effects (e.g. load and call are not supported). The
				1920	following is the syntax for constant expressions:</p>
				1921
				1922	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1923	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1924	<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]	1925	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1926
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1927	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1928	<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]	1929	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]	1930
				1931	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1932	<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]	1933	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]	1934
				1935	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1936	<dd>Truncate a floating point constant to another floating point type. The
				1937	size of CST must be larger than the size of TYPE. Both types must be
				1938	floating point.</dd>
				1939
				1940	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1941	<dd>Floating point extend a constant to another type. The size of CST must be
				1942	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1943
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1944	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1945	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1946	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1947	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1948	of the same number of elements. If the value won't fit in the integer type,
				1949	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1950
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1951	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1952	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1953	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1954	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1955	of the same number of elements. If the value won't fit in the integer type,
				1956	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1957
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1958	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1959	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1960	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1961	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1962	of the same number of elements. If the value won't fit in the floating point
				1963	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1964
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1965	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1966	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1967	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1968	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1969	of the same number of elements. If the value won't fit in the floating point
				1970	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1971
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1972	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1973	<dd>Convert a pointer typed constant to the corresponding integer constant
				1974	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1975	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1976
				1977	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1978	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1979	pointer type. CST must be of integer type. The CST value is zero extended,
				1980	truncated, or unchanged to make it fit in a pointer size. This one is
				1981	<i>really</i> dangerous!</dd>
				1982
				1983	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	1984	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				1985	are the same as those for the <a href="#i_bitcast">bitcast
				1986	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1987
				1988	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1989
				1990	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1991	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1992	instruction, the index list may have zero or more indexes, which are required
				1993	to make sense for the type of "CSTPTR".</dd>
				1994
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	1995	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1996
				1997	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	1998	constants.</dd>
				1999
				2000	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2001	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2002
				2003	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2004	<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]	2005
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	2006	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2007	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2008
				2009	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2010	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2011
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2012	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2013
				2014	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2015	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2016
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2017	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2018
				2019	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2020	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2021
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2022
				2023	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2024
				2025	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2026	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2027
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2028	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2029
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2030	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2031	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]	2032	binary</a> operations. The constraints on operands are the same as those for
				2033	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2034	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2035	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2036	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2037
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2038	<!-- ======================================================================= -->
				2039	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2040	</div>
				2041
				2042	<div class="doc_text">
				2043
				2044	<p>Embedded metadata provides a way to attach arbitrary data to the
				2045	instruction stream without affecting the behaviour of the program. There are
				2046	two metadata primitives, strings and nodes. All metadata has the type of an
				2047	empty struct and is identified in syntax by a preceding exclamation point
				2048	('<tt>!</tt>').
				2049	</p>
				2050
				2051	<p>A metadata string is a string surrounded by double quotes. It can contain
				2052	any character by escaping non-printable characters with "\xx" where "xx" is
				2053	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2054	</p>
				2055
				2056	<p>Metadata nodes are represented with notation similar to structure constants
				2057	(a comma separated list of elements, surrounded by braces and preceeded by an
				2058	exclamation point). For example: "<tt>!{ { } !"test\00", i32 10}</tt>".
				2059	</p>
				2060
				2061	<p>Optimizations may rely on metadata to provide additional information about
				2062	the program that isn't available in the instructions, or that isn't easily
				2063	computable. Similarly, the code generator may expect a certain metadata format
				2064	to be used to express debugging information.</p>
				2065	</div>
				2066
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2067	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2068	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2069	<!-- *********************************************************************** -->
				2070
				2071	<!-- ======================================================================= -->
				2072	<div class="doc_subsection">
				2073	<a name="inlineasm">Inline Assembler Expressions</a>
				2074	</div>
				2075
				2076	<div class="doc_text">
				2077
				2078	<p>
				2079	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2080	Module-Level Inline Assembly</a>) through the use of a special value. This
				2081	value represents the inline assembler as a string (containing the instructions
				2082	to emit), a list of operand constraints (stored as a string), and a flag that
				2083	indicates whether or not the inline asm expression has side effects. An example
				2084	inline assembler expression is:
				2085	</p>
				2086
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2087	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2088	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2089	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2090	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2091	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2092
				2093	<p>
				2094	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2095	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2096	</p>
				2097
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2098	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2099	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2100	%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]	2101	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2102	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2103
				2104	<p>
				2105	Inline asms with side effects not visible in the constraint list must be marked
				2106	as having side effects. This is done through the use of the
				2107	'<tt>sideeffect</tt>' keyword, like so:
				2108	</p>
				2109
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2110	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2111	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2112	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2113	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2114	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2115
				2116	<p>TODO: The format of the asm and constraints string still need to be
				2117	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]	2118	need to be documented). This is probably best done by reference to another
				2119	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2120	</p>
				2121
				2122	</div>
				2123
				2124	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2125	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2126	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2127
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2128	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2129
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2130	<p>The LLVM instruction set consists of several different
				2131	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2132	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2133	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2134	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2135	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2136
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2137	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2138
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2139	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2140	<div class="doc_subsection"> <a name="terminators">Terminator
				2141	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2142
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2143	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2144
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2145	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2146	basic block in a program ends with a "Terminator" instruction, which
				2147	indicates which block should be executed after the current block is
				2148	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2149	value: they produce control flow, not values (the one exception being
				2150	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2151	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2152	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2153	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2154	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2155	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2156	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2157
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2158	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2159
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2161	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2162	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2163	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2164	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2165	<pre>
				2166	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]	2167	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2169
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2170	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2171
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2172	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2173	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2174	<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]	2175	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]	2176	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2177
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2179
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2180	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2181	the return value. The type of the return value must be a
				2182	'<a href="#t_firstclass">first class</a>' type.</p>
				2183
				2184	<p>A function is not <a href="#wellformed">well formed</a> if
				2185	it it has a non-void return type and contains a '<tt>ret</tt>'
				2186	instruction with no return value or a return value with a type that
				2187	does not match its type, or if it has a void return type and contains
				2188	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2189
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2190	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2191
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2192	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2193	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]	2194	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	the instruction after the call. If the caller was an "<a
				2196	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2197	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2198	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2199	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2200
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2202
				2203	<pre>
				2204	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2205	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2206	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2208
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2209	<p>Note that the code generator does not yet fully support large
				2210	return values. The specific sizes that are currently supported are
				2211	dependent on the target. For integers, on 32-bit targets the limit
				2212	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2213	For aggregate types, the current limits are dependent on the element
				2214	types; for example targets are often limited to 2 total integer
				2215	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2216
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2217	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2218	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2219	<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]	2220	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2222	<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]	2223	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2225	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2226	transfer to a different basic block in the current function. There are
				2227	two forms of this instruction, corresponding to a conditional branch
				2228	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2230	<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]	2231	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2232	unconditional form of the '<tt>br</tt>' instruction takes a single
				2233	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2235	<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]	2236	argument is evaluated. If the value is <tt>true</tt>, control flows
				2237	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2238	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2239	<h5>Example:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2240	<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]	2241	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]	2242	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2244	<div class="doc_subsubsection">
				2245	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2246	</div>
				2247
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2248	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2249	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2250
				2251	<pre>
				2252	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2253	</pre>
				2254
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2255	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2256
				2257	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2258	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2259	instruction, allowing a branch to occur to one of many possible
				2260	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2261
				2262
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2264
				2265	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2266	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2267	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2268	table is not allowed to contain duplicate constant entries.</p>
				2269
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2271
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2272	<p>The <tt>switch</tt> instruction specifies a table of values and
				2273	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2274	table is searched for the given value. If the value is found, control flow is
				2275	transfered to the corresponding destination; otherwise, control flow is
				2276	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2277
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2278	<h5>Implementation:</h5>
				2279
				2280	<p>Depending on properties of the target machine and the particular
				2281	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2282	ways. For example, it could be generated as a series of chained conditional
				2283	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2284
				2285	<h5>Example:</h5>
				2286
				2287	<pre>
				2288	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2289	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2290	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2293	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2294
				2295	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2296	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2297	i32 1, label %onone
				2298	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2299	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2300	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2301
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2302	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2303	<div class="doc_subsubsection">
				2304	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2305	</div>
				2306
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2307	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2308
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2309	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2310
				2311	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2312	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2313	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2314	</pre>
				2315
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2316	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2317
				2318	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2319	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2320	'<tt>normal</tt>' label or the
				2321	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2322	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2323	"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]	2324	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2325	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2326
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2327	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2328
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2329	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2330
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2331	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2332	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2333	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2334	convention</a> the call should use. If none is specified, the call defaults
				2335	to using C calling conventions.
				2336	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2337
				2338	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2339	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2340	and '<tt>inreg</tt>' attributes are valid here.</li>
				2341
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2342	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2343	function value being invoked. In most cases, this is a direct function
				2344	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2345	an arbitrary pointer to function value.
				2346	</li>
				2347
				2348	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2349	function to be invoked. </li>
				2350
				2351	<li>'<tt>function args</tt>': argument list whose types match the function
				2352	signature argument types. If the function signature indicates the function
				2353	accepts a variable number of arguments, the extra arguments can be
				2354	specified. </li>
				2355
				2356	<li>'<tt>normal label</tt>': the label reached when the called function
				2357	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2358
				2359	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2360	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2361
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2362	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2363	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2364	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2365	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2366
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2367	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2368
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2369	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2370	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2371	difference is that it establishes an association with a label, which is used by
				2372	the runtime library to unwind the stack.</p>
				2373
				2374	<p>This instruction is used in languages with destructors to ensure that proper
				2375	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2376	exception. Additionally, this is important for implementation of
				2377	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2378
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2379	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2380	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2381	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2382	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2383	%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]	2384	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2385	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2386	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2387
				2388
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2389	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2390
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2391	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2392	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2393
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2394	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2395
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2396	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2397	<pre>
				2398	unwind
				2399	</pre>
				2400
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2401	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2402
				2403	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2404	at the first callee in the dynamic call stack which used an <a
				2405	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2406	primarily used to implement exception handling.</p>
				2407
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2408	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2409
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2410	<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]	2411	immediately halt. The dynamic call stack is then searched for the first <a
				2412	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2413	execution continues at the "exceptional" destination block specified by the
				2414	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2415	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2416	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2417
				2418	<!-- _______________________________________________________________________ -->
				2419
				2420	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2421	Instruction</a> </div>
				2422
				2423	<div class="doc_text">
				2424
				2425	<h5>Syntax:</h5>
				2426	<pre>
				2427	unreachable
				2428	</pre>
				2429
				2430	<h5>Overview:</h5>
				2431
				2432	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2433	instruction is used to inform the optimizer that a particular portion of the
				2434	code is not reachable. This can be used to indicate that the code after a
				2435	no-return function cannot be reached, and other facts.</p>
				2436
				2437	<h5>Semantics:</h5>
				2438
				2439	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2440	</div>
				2441
				2442
				2443
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2444	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2445	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2446	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2447	<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]	2448	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]	2449	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2450	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]	2451	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2452	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2453	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2454	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2455	<div class="doc_subsubsection">
				2456	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2457	</div>
				2458
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2459	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2460
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2461	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2462
				2463	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2464	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2465	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2466
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2467	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2469	<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]	2470
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2471	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2472
				2473	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2474	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2475	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2476	types.</p>
				2477
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2478	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2479
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2480	<p>The value produced is the integer or floating point sum of the two
				2481	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2482
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2483	<p>If an integer sum has unsigned overflow, the result returned is the
				2484	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2485	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2486
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2487	<p>Because LLVM integers use a two's complement representation, this
				2488	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2489
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2490	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2491
				2492	<pre>
				2493	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2494	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2495	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2497	<div class="doc_subsubsection">
				2498	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2499	</div>
				2500
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2503	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
				2505	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2506	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2511	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2512	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
				2514	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2515	'<tt>neg</tt>' instruction present in most other intermediate
				2516	representations.</p>
				2517
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2519
				2520	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2521	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2522	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2523	types.</p>
				2524
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2525	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2527	<p>The value produced is the integer or floating point difference of
				2528	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2529
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2530	<p>If an integer difference has unsigned overflow, the result returned is the
				2531	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2532	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2534	<p>Because LLVM integers use a two's complement representation, this
				2535	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2537	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2538	<pre>
				2539	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2540	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2542	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2543
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2544	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2545	<div class="doc_subsubsection">
				2546	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2547	</div>
				2548
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2549	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2550
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2551	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2552	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2553	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2554	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2555	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2556	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2557
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2558	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2559
				2560	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2561	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2562	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2563	types.</p>
				2564
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2565	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2566
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2567	<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]	2568	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2569
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2570	<p>If the result of an integer multiplication has unsigned overflow,
				2571	the result returned is the mathematical result modulo
				2572	2<sup>n</sup>, where n is the bit width of the result.</p>
				2573	<p>Because LLVM integers use a two's complement representation, and the
				2574	result is the same width as the operands, this instruction returns the
				2575	correct result for both signed and unsigned integers. If a full product
				2576	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2577	should be sign-extended or zero-extended as appropriate to the
				2578	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2579	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2580	<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]	2581	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2582	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2584	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2585	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2586	</a></div>
				2587	<div class="doc_text">
				2588	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2589	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2590	</pre>
				2591	<h5>Overview:</h5>
				2592	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2593	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2594
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2595	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2596
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2597	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2598	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2599	values. Both arguments must have identical types.</p>
				2600
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2601	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2602
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2603	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2604	<p>Note that unsigned integer division and signed integer division are distinct
				2605	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2606	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2607	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2608	<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]	2609	</pre>
				2610	</div>
				2611	<!-- _______________________________________________________________________ -->
				2612	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2613	</a> </div>
				2614	<div class="doc_text">
				2615	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2616	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2617	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2618	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2619
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2620	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2622	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2623	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2624
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2625	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2626
				2627	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2628	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2629	values. Both arguments must have identical types.</p>
				2630
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2631	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2632	<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]	2633	<p>Note that signed integer division and unsigned integer division are distinct
				2634	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2635	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2636	undefined behavior; this is a rare case, but can occur, for example,
				2637	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2638	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2639	<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]	2640	</pre>
				2641	</div>
				2642	<!-- _______________________________________________________________________ -->
				2643	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2644	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2645	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2646	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2647	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2648	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2649	</pre>
				2650	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2651
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2652	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2653	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2654
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2655	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2656
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2657	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2658	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2659	of floating point values. Both arguments must have identical types.</p>
				2660
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2661	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2662
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2663	<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]	2664
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2665	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2666
				2667	<pre>
				2668	<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]	2669	</pre>
				2670	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2671
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2673	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2674	</div>
				2675	<div class="doc_text">
				2676	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2677	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2678	</pre>
				2679	<h5>Overview:</h5>
				2680	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2681	unsigned division of its two arguments.</p>
				2682	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2683	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2684	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2685	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2686	<h5>Semantics:</h5>
				2687	<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]	2688	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2689	<p>Note that unsigned integer remainder and signed integer remainder are
				2690	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2691	<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]	2692	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2693	<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]	2694	</pre>
				2695
				2696	</div>
				2697	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2698	<div class="doc_subsubsection">
				2699	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2700	</div>
				2701
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2702	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2703
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2704	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2705
				2706	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2707	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2708	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2709
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2710	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2711
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2712	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2713	signed division of its two operands. This instruction can also take
				2714	<a href="#t_vector">vector</a> versions of the values in which case
				2715	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2716
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2717	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2718
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2719	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2720	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2721	values. Both arguments must have identical types.</p>
				2722
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2723	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2724
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2725	<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]	2726	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2727	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]	2728	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2729	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]	2730	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]	2731	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2732	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2733	<p>Note that signed integer remainder and unsigned integer remainder are
				2734	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2735	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2736	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2737	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2738	(The remainder doesn't actually overflow, but this rule lets srem be
				2739	implemented using instructions that return both the result of the division
				2740	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2741	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2742	<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]	2743	</pre>
				2744
				2745	</div>
				2746	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2747	<div class="doc_subsubsection">
				2748	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2749
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2750	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2751
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2752	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2753	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2754	</pre>
				2755	<h5>Overview:</h5>
				2756	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2757	division of its two operands.</p>
				2758	<h5>Arguments:</h5>
				2759	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2760	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2761	of floating point values. Both arguments must have identical types.</p>
				2762
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2763	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2764
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2765	<p>This instruction returns the <i>remainder</i> of a division.
				2766	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2767
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2768	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2769
				2770	<pre>
				2771	<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]	2772	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2773	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2774
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2775	<!-- ======================================================================= -->
				2776	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2777	Operations</a> </div>
				2778	<div class="doc_text">
				2779	<p>Bitwise binary operators are used to do various forms of
				2780	bit-twiddling in a program. They are generally very efficient
				2781	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2782	instructions. They require two operands of the same type, execute an operation on them,
				2783	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]	2784	</div>
				2785
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2786	<!-- _______________________________________________________________________ -->
				2787	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2788	Instruction</a> </div>
				2789	<div class="doc_text">
				2790	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2791	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2792	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2793
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2794	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2795
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2796	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2797	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2798
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2799	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2800
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2801	<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]	2802	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]	2803	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2804
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2805	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2806
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2807	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2808	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2809	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2810	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2811	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2812
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2813	<h5>Example:</h5><pre>
				2814	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2815	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2816	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2817	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2818	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2819	</pre>
				2820	</div>
				2821	<!-- _______________________________________________________________________ -->
				2822	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2823	Instruction</a> </div>
				2824	<div class="doc_text">
				2825	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2826	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2827	</pre>
				2828
				2829	<h5>Overview:</h5>
				2830	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2831	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]	2832
				2833	<h5>Arguments:</h5>
				2834	<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]	2835	<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]	2836	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2837
				2838	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2839
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2840	<p>This instruction always performs a logical shift right operation. The most
				2841	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]	2842	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2843	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2844	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2845	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2846
				2847	<h5>Example:</h5>
				2848	<pre>
				2849	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2850	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2851	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2852	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2853	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2854	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2855	</pre>
				2856	</div>
				2857
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2858	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2859	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2860	Instruction</a> </div>
				2861	<div class="doc_text">
				2862
				2863	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2864	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2865	</pre>
				2866
				2867	<h5>Overview:</h5>
				2868	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2869	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]	2870
				2871	<h5>Arguments:</h5>
				2872	<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]	2873	<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]	2874	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2875
				2876	<h5>Semantics:</h5>
				2877	<p>This instruction always performs an arithmetic shift right operation,
				2878	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]	2879	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2880	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2881	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2882	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2883
				2884	<h5>Example:</h5>
				2885	<pre>
				2886	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2887	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2888	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2889	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2890	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2891	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2892	</pre>
				2893	</div>
				2894
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2895	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2896	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2897	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2898
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2899	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2900
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2901	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2902
				2903	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2904	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2905	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2906
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2907	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2908
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2909	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2910	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2911
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2912	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2913
				2914	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2915	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2916	values. Both arguments must have identical types.</p>
				2917
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2918	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2919	<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]	2920	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2921	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2922	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2923	<tbody>
				2924	<tr>
				2925	<td>In0</td>
				2926	<td>In1</td>
				2927	<td>Out</td>
				2928	</tr>
				2929	<tr>
				2930	<td>0</td>
				2931	<td>0</td>
				2932	<td>0</td>
				2933	</tr>
				2934	<tr>
				2935	<td>0</td>
				2936	<td>1</td>
				2937	<td>0</td>
				2938	</tr>
				2939	<tr>
				2940	<td>1</td>
				2941	<td>0</td>
				2942	<td>0</td>
				2943	</tr>
				2944	<tr>
				2945	<td>1</td>
				2946	<td>1</td>
				2947	<td>1</td>
				2948	</tr>
				2949	</tbody>
				2950	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2951	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2952	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2953	<pre>
				2954	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2955	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2956	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2957	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2958	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2959	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2960	<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]	2961	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2962	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2963	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2964	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2965	<h5>Overview:</h5>
				2966	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2967	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2968	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2969
				2970	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2971	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2972	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2973	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2974	<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]	2975	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2976	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2977	<table border="1" cellspacing="0" cellpadding="4">
				2978	<tbody>
				2979	<tr>
				2980	<td>In0</td>
				2981	<td>In1</td>
				2982	<td>Out</td>
				2983	</tr>
				2984	<tr>
				2985	<td>0</td>
				2986	<td>0</td>
				2987	<td>0</td>
				2988	</tr>
				2989	<tr>
				2990	<td>0</td>
				2991	<td>1</td>
				2992	<td>1</td>
				2993	</tr>
				2994	<tr>
				2995	<td>1</td>
				2996	<td>0</td>
				2997	<td>1</td>
				2998	</tr>
				2999	<tr>
				3000	<td>1</td>
				3001	<td>1</td>
				3002	<td>1</td>
				3003	</tr>
				3004	</tbody>
				3005	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3006	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3007	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3008	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3009	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3010	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3011	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3012	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3013	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3014	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3015	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3016	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3017	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3018	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3019	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3020	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3021	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3022	or of its two operands. The <tt>xor</tt> is used to implement the
				3023	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3024	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3025	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3026	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3027	values. Both arguments must have identical types.</p>
				3028
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3029	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3030
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3031	<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]	3032	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3033	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3034	<table border="1" cellspacing="0" cellpadding="4">
				3035	<tbody>
				3036	<tr>
				3037	<td>In0</td>
				3038	<td>In1</td>
				3039	<td>Out</td>
				3040	</tr>
				3041	<tr>
				3042	<td>0</td>
				3043	<td>0</td>
				3044	<td>0</td>
				3045	</tr>
				3046	<tr>
				3047	<td>0</td>
				3048	<td>1</td>
				3049	<td>1</td>
				3050	</tr>
				3051	<tr>
				3052	<td>1</td>
				3053	<td>0</td>
				3054	<td>1</td>
				3055	</tr>
				3056	<tr>
				3057	<td>1</td>
				3058	<td>1</td>
				3059	<td>0</td>
				3060	</tr>
				3061	</tbody>
				3062	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3063	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3064	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3065	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3066	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3067	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3068	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3069	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3070	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3071	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3072
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3073	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3074	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3075	<a name="vectorops">Vector Operations</a>
				3076	</div>
				3077
				3078	<div class="doc_text">
				3079
				3080	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3081	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3082	vector-specific operations needed to process vectors effectively. While LLVM
				3083	does directly support these vector operations, many sophisticated algorithms
				3084	will want to use target-specific intrinsics to take full advantage of a specific
				3085	target.</p>
				3086
				3087	</div>
				3088
				3089	<!-- _______________________________________________________________________ -->
				3090	<div class="doc_subsubsection">
				3091	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3092	</div>
				3093
				3094	<div class="doc_text">
				3095
				3096	<h5>Syntax:</h5>
				3097
				3098	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3099	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3100	</pre>
				3101
				3102	<h5>Overview:</h5>
				3103
				3104	<p>
				3105	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3106	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3107	</p>
				3108
				3109
				3110	<h5>Arguments:</h5>
				3111
				3112	<p>
				3113	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3114	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3115	an index indicating the position from which to extract the element.
				3116	The index may be a variable.</p>
				3117
				3118	<h5>Semantics:</h5>
				3119
				3120	<p>
				3121	The result is a scalar of the same type as the element type of
				3122	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3123	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3124	results are undefined.
				3125	</p>
				3126
				3127	<h5>Example:</h5>
				3128
				3129	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3130	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3131	</pre>
				3132	</div>
				3133
				3134
				3135	<!-- _______________________________________________________________________ -->
				3136	<div class="doc_subsubsection">
				3137	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3138	</div>
				3139
				3140	<div class="doc_text">
				3141
				3142	<h5>Syntax:</h5>
				3143
				3144	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3145	<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]	3146	</pre>
				3147
				3148	<h5>Overview:</h5>
				3149
				3150	<p>
				3151	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3152	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3153	</p>
				3154
				3155
				3156	<h5>Arguments:</h5>
				3157
				3158	<p>
				3159	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3160	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]	3161	scalar value whose type must equal the element type of the first
				3162	operand. The third operand is an index indicating the position at
				3163	which to insert the value. The index may be a variable.</p>
				3164
				3165	<h5>Semantics:</h5>
				3166
				3167	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3168	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]	3169	element values are those of <tt>val</tt> except at position
				3170	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3171	exceeds the length of <tt>val</tt>, the results are undefined.
				3172	</p>
				3173
				3174	<h5>Example:</h5>
				3175
				3176	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3177	%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]	3178	</pre>
				3179	</div>
				3180
				3181	<!-- _______________________________________________________________________ -->
				3182	<div class="doc_subsubsection">
				3183	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3184	</div>
				3185
				3186	<div class="doc_text">
				3187
				3188	<h5>Syntax:</h5>
				3189
				3190	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3191	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3192	</pre>
				3193
				3194	<h5>Overview:</h5>
				3195
				3196	<p>
				3197	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3198	from two input vectors, returning a vector with the same element type as
				3199	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3200	</p>
				3201
				3202	<h5>Arguments:</h5>
				3203
				3204	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3205	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3206	with types that match each other. The third argument is a shuffle mask whose
				3207	element type is always 'i32'. The result of the instruction is a vector whose
				3208	length is the same as the shuffle mask and whose element type is the same as
				3209	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3210	</p>
				3211
				3212	<p>
				3213	The shuffle mask operand is required to be a constant vector with either
				3214	constant integer or undef values.
				3215	</p>
				3216
				3217	<h5>Semantics:</h5>
				3218
				3219	<p>
				3220	The elements of the two input vectors are numbered from left to right across
				3221	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3222	the result vector, which element of the two input vectors the result element
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3223	gets. The element selector may be undef (meaning "don't care") and the second
				3224	operand may be undef if performing a shuffle from only one vector.
				3225	</p>
				3226
				3227	<h5>Example:</h5>
				3228
				3229	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3230	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3231	<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]	3232	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3233	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3234	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3235	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3236	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3237	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3238	</pre>
				3239	</div>
				3240
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3241
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3242	<!-- ======================================================================= -->
				3243	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3244	<a name="aggregateops">Aggregate Operations</a>
				3245	</div>
				3246
				3247	<div class="doc_text">
				3248
				3249	<p>LLVM supports several instructions for working with aggregate values.
				3250	</p>
				3251
				3252	</div>
				3253
				3254	<!-- _______________________________________________________________________ -->
				3255	<div class="doc_subsubsection">
				3256	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3257	</div>
				3258
				3259	<div class="doc_text">
				3260
				3261	<h5>Syntax:</h5>
				3262
				3263	<pre>
				3264	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3265	</pre>
				3266
				3267	<h5>Overview:</h5>
				3268
				3269	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3270	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3271	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3272	</p>
				3273
				3274
				3275	<h5>Arguments:</h5>
				3276
				3277	<p>
				3278	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3279	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]	3280	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3281	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3282	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3283	</p>
				3284
				3285	<h5>Semantics:</h5>
				3286
				3287	<p>
				3288	The result is the value at the position in the aggregate specified by
				3289	the index operands.
				3290	</p>
				3291
				3292	<h5>Example:</h5>
				3293
				3294	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3295	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3296	</pre>
				3297	</div>
				3298
				3299
				3300	<!-- _______________________________________________________________________ -->
				3301	<div class="doc_subsubsection">
				3302	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3303	</div>
				3304
				3305	<div class="doc_text">
				3306
				3307	<h5>Syntax:</h5>
				3308
				3309	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3310	<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]	3311	</pre>
				3312
				3313	<h5>Overview:</h5>
				3314
				3315	<p>
				3316	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3317	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3318	</p>
				3319
				3320
				3321	<h5>Arguments:</h5>
				3322
				3323	<p>
				3324	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3325	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3326	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3327	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3328	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]	3329	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3330	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3331	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]	3332	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3333	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3334
				3335	<h5>Semantics:</h5>
				3336
				3337	<p>
				3338	The result is an aggregate of the same type as <tt>val</tt>. Its
				3339	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]	3340	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3341	</p>
				3342
				3343	<h5>Example:</h5>
				3344
				3345	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3346	%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]	3347	</pre>
				3348	</div>
				3349
				3350
				3351	<!-- ======================================================================= -->
				3352	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3353	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3354	</div>
				3355
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3356	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3357
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3358	<p>A key design point of an SSA-based representation is how it
				3359	represents memory. In LLVM, no memory locations are in SSA form, which
				3360	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3361	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3362
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3363	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3364
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3365	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3366	<div class="doc_subsubsection">
				3367	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3368	</div>
				3369
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3370	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3371
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3372	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3373
				3374	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3375	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3376	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3377
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3378	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3379
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3380	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3381	heap and returns a pointer to it. The object is always allocated in the generic
				3382	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3383
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3384	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3385
				3386	<p>The '<tt>malloc</tt>' instruction allocates
				3387	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3388	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]	3389	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3390	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3391	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]	3392	be aligned to at least that boundary. If not specified, or if zero, the target can
				3393	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3394
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3395	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3396
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3397	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3398
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3399	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3400	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3401	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3402
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3403	<h5>Example:</h5>
				3404
				3405	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3406	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3407
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3408	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3409	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3410	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3411	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3412	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3413	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3414
				3415	<p>Note that the code generator does not yet respect the
				3416	alignment value.</p>
				3417
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3418	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3419
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3420	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3421	<div class="doc_subsubsection">
				3422	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3423	</div>
				3424
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3425	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3427	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3428
				3429	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3430	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3431	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3432
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3433	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3434
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3435	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3436	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3437
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3438	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3439
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3440	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3441	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3442	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3443
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3444	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3445
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3446	<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]	3447	after this instruction executes. If the pointer is null, the operation
				3448	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3449
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3450	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3451
				3452	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3453	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3454	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3455	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3456	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3457
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3458	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3459	<div class="doc_subsubsection">
				3460	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3461	</div>
				3462
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3463	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3464
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3465	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3466
				3467	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3468	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3469	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3470
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3471	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3472
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3473	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3474	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3475	returns to its caller. The object is always allocated in the generic address
				3476	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3477
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3478	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3479
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3480	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3481	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3482	appropriate type to the program. If "NumElements" is specified, it is the
				3483	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3484	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]	3485	to be aligned to at least that boundary. If not specified, or if zero, the target
				3486	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3487
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3488	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3489
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3490	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3491
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3492	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3493	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3494	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3495	instruction is commonly used to represent automatic variables that must
				3496	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]	3497	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]	3498	instructions), the memory is reclaimed. Allocating zero bytes
				3499	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3500
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3501	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3502
				3503	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3504	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3505	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3506	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3507	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3508	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3509	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3510
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3511	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3512	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3513	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3514	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3515	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3516	<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]	3517	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3518	<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]	3519	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3520	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3521	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3522	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]	3523	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]	3524	the number or order of execution of this <tt>load</tt> with other
				3525	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3526	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3527	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3528	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3529	(that is, the alignment of the memory address). A value of 0 or an
				3530	omitted "align" argument means that the operation has the preferential
				3531	alignment for the target. It is the responsibility of the code emitter
				3532	to ensure that the alignment information is correct. Overestimating
				3533	the alignment results in an undefined behavior. Underestimating the
				3534	alignment may produce less efficient code. An alignment of 1 is always
				3535	safe.
				3536	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3537	<h5>Semantics:</h5>
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3538	<p>The location of memory pointed to is loaded. If the value being loaded
				3539	is of scalar type then the number of bytes read does not exceed the minimum
				3540	number of bytes needed to hold all bits of the type. For example, loading an
				3541	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3542	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3543	is undefined if the value was not originally written using a store of the
				3544	same type.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3545	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3546	<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]	3547	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3548	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3549	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3550	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3551	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3552	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3553	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3554	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3555	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3556	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3557	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3558	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3559	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3560	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3561	<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]	3562	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3563	<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]	3564	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]	3565	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3566	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3567	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]	3568	optimizer is not allowed to modify the number or order of execution of
				3569	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3570	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3571	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3572	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3573	(that is, the alignment of the memory address). A value of 0 or an
				3574	omitted "align" argument means that the operation has the preferential
				3575	alignment for the target. It is the responsibility of the code emitter
				3576	to ensure that the alignment information is correct. Overestimating
				3577	the alignment results in an undefined behavior. Underestimating the
				3578	alignment may produce less efficient code. An alignment of 1 is always
				3579	safe.
				3580	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3581	<h5>Semantics:</h5>
				3582	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3583	at the location specified by the '<tt><pointer></tt>' operand.
				3584	If '<tt><value></tt>' is of scalar type then the number of bytes
				3585	written does not exceed the minimum number of bytes needed to hold all
				3586	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3587	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3588	size that is not an integral number of bytes, it is unspecified what
				3589	happens to the extra bits that do not belong to the type, but they will
				3590	typically be overwritten.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3591	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3592	<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]	3593	store i32 3, i32* %ptr <i>; yields {void}</i>
				3594	%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]	3595	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3596	</div>
				3597
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3598	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3599	<div class="doc_subsubsection">
				3600	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3601	</div>
				3602
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3603	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3604	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3605	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3606	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3607	</pre>
				3608
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3609	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3610
				3611	<p>
				3612	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3613	subelement of an aggregate data structure. It performs address calculation only
				3614	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3615
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3616	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3617
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3618	<p>The first argument is always a pointer, and forms the basis of the
				3619	calculation. The remaining arguments are indices, that indicate which of the
				3620	elements of the aggregate object are indexed. The interpretation of each index
				3621	is dependent on the type being indexed into. The first index always indexes the
				3622	pointer value given as the first argument, the second index indexes a value of
				3623	the type pointed to (not necessarily the value directly pointed to, since the
				3624	first index can be non-zero), etc. The first type indexed into must be a pointer
				3625	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3626	types being indexed into can never be pointers, since that would require loading
				3627	the pointer before continuing calculation.</p>
				3628
				3629	<p>The type of each index argument depends on the type it is indexing into.
				3630	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3631	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	1f8555a	2009-04-27 03:21:00 +0000	[diff] [blame^]	3632	integers of any width are allowed (also non-constants).</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3633
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3634	<p>For example, let's consider a C code fragment and how it gets
				3635	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3636
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3637	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3638	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3639	struct RT {
				3640	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3641	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3642	char C;
				3643	};
				3644	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3645	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3646	double Y;
				3647	struct RT Z;
				3648	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3649
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3650	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3651	return &s[1].Z.B[5][13];
				3652	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3653	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3654	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3655
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3656	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3657
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3658	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3659	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3660	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3661	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3662
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3663	define i32* %foo(%ST* %s) {
				3664	entry:
				3665	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3666	ret i32* %reg
				3667	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3668	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3669	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3670
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3671	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3672
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3673	<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]	3674	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]	3675	}</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]	3676	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3677	i8 }</tt>' type, another structure. The third index indexes into the second
				3678	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]	3679	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3680	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3681	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]	3682
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3683	<p>Note that it is perfectly legal to index partially through a
				3684	structure, returning a pointer to an inner element. Because of this,
				3685	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3686
				3687	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3688	define i32* %foo(%ST* %s) {
				3689	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3690	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3691	%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]	3692	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3693	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3694	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3695	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3696	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3697
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3698	<p>Note that it is undefined to access an array out of bounds: array
				3699	and pointer indexes must always be within the defined bounds of the
				3700	array type when accessed with an instruction that dereferences the
				3701	pointer (e.g. a load or store instruction). The one exception for
				3702	this rule is zero length arrays. These arrays are defined to be
				3703	accessible as variable length arrays, which requires access beyond the
				3704	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3705
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3706	<p>The getelementptr instruction is often confusing. For some more insight
				3707	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3708	FAQ</a>.</p>
				3709
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3710	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3711
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3712	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3713	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3714	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3715	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3716	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3717	<i>; yields i8*:eptr</i>
				3718	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	0c155e6	2009-04-25 07:27:44 +0000	[diff] [blame]	3719	<i>; yields i32*:iptr</i>
Sanjiv Gupta	77abea0	2009-04-24 16:38:13 +0000	[diff] [blame]	3720	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3721	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3722	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3723
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3724	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3725	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3726	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3727	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3728	<p>The instructions in this category are the conversion instructions (casting)
				3729	which all take a single operand and a type. They perform various bit conversions
				3730	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3731	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3732
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3733	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3734	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3735	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3736	</div>
				3737	<div class="doc_text">
				3738
				3739	<h5>Syntax:</h5>
				3740	<pre>
				3741	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3742	</pre>
				3743
				3744	<h5>Overview:</h5>
				3745	<p>
				3746	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3747	</p>
				3748
				3749	<h5>Arguments:</h5>
				3750	<p>
				3751	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3752	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]	3753	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]	3754	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3755	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3756
				3757	<h5>Semantics:</h5>
				3758	<p>
				3759	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]	3760	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3761	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3762	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3763
				3764	<h5>Example:</h5>
				3765	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3766	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3767	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3768	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3769	</pre>
				3770	</div>
				3771
				3772	<!-- _______________________________________________________________________ -->
				3773	<div class="doc_subsubsection">
				3774	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3775	</div>
				3776	<div class="doc_text">
				3777
				3778	<h5>Syntax:</h5>
				3779	<pre>
				3780	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3781	</pre>
				3782
				3783	<h5>Overview:</h5>
				3784	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3785	<tt>ty2</tt>.</p>
				3786
				3787
				3788	<h5>Arguments:</h5>
				3789	<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]	3790	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3791	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]	3792	<tt>value</tt> must be smaller than the bit size of the destination type,
				3793	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3794
				3795	<h5>Semantics:</h5>
				3796	<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]	3797	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]	3798
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3799	<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]	3800
				3801	<h5>Example:</h5>
				3802	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3803	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3804	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3805	</pre>
				3806	</div>
				3807
				3808	<!-- _______________________________________________________________________ -->
				3809	<div class="doc_subsubsection">
				3810	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3811	</div>
				3812	<div class="doc_text">
				3813
				3814	<h5>Syntax:</h5>
				3815	<pre>
				3816	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3817	</pre>
				3818
				3819	<h5>Overview:</h5>
				3820	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3821
				3822	<h5>Arguments:</h5>
				3823	<p>
				3824	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]	3825	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3826	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]	3827	<tt>value</tt> must be smaller than the bit size of the destination type,
				3828	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3829
				3830	<h5>Semantics:</h5>
				3831	<p>
				3832	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3833	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]	3834	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3835
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3836	<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]	3837
				3838	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3839	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3840	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3841	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3842	</pre>
				3843	</div>
				3844
				3845	<!-- _______________________________________________________________________ -->
				3846	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3847	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3848	</div>
				3849
				3850	<div class="doc_text">
				3851
				3852	<h5>Syntax:</h5>
				3853
				3854	<pre>
				3855	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3856	</pre>
				3857
				3858	<h5>Overview:</h5>
				3859	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3860	<tt>ty2</tt>.</p>
				3861
				3862
				3863	<h5>Arguments:</h5>
				3864	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3865	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3866	cast it to. The size of <tt>value</tt> must be larger than the size of
				3867	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3868	<i>no-op cast</i>.</p>
				3869
				3870	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3871	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3872	<a href="#t_floating">floating point</a> type to a smaller
				3873	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3874	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3875
				3876	<h5>Example:</h5>
				3877	<pre>
				3878	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3879	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3880	</pre>
				3881	</div>
				3882
				3883	<!-- _______________________________________________________________________ -->
				3884	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3885	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3886	</div>
				3887	<div class="doc_text">
				3888
				3889	<h5>Syntax:</h5>
				3890	<pre>
				3891	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3892	</pre>
				3893
				3894	<h5>Overview:</h5>
				3895	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3896	floating point value.</p>
				3897
				3898	<h5>Arguments:</h5>
				3899	<p>The '<tt>fpext</tt>' instruction takes a
				3900	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3901	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3902	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3903
				3904	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3905	<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]	3906	<a href="#t_floating">floating point</a> type to a larger
				3907	<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]	3908	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]	3909	<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]	3910
				3911	<h5>Example:</h5>
				3912	<pre>
				3913	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3914	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3915	</pre>
				3916	</div>
				3917
				3918	<!-- _______________________________________________________________________ -->
				3919	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3920	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3921	</div>
				3922	<div class="doc_text">
				3923
				3924	<h5>Syntax:</h5>
				3925	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3926	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3927	</pre>
				3928
				3929	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3930	<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]	3931	unsigned integer equivalent of type <tt>ty2</tt>.
				3932	</p>
				3933
				3934	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3935	<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]	3936	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3937	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3938	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3939	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]	3940
				3941	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3942	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3943	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3944	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3945	the results are undefined.</p>
				3946
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3947	<h5>Example:</h5>
				3948	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3949	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3950	%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]	3951	%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]	3952	</pre>
				3953	</div>
				3954
				3955	<!-- _______________________________________________________________________ -->
				3956	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3957	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3958	</div>
				3959	<div class="doc_text">
				3960
				3961	<h5>Syntax:</h5>
				3962	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3963	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3964	</pre>
				3965
				3966	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3967	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3968	<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]	3969	</p>
				3970
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3971	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3972	<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]	3973	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3974	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3975	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3976	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]	3977
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3978	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3979	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3980	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3981	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3982	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3983
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	3984	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3985	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3986	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3987	%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]	3988	%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]	3989	</pre>
				3990	</div>
				3991
				3992	<!-- _______________________________________________________________________ -->
				3993	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3994	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3995	</div>
				3996	<div class="doc_text">
				3997
				3998	<h5>Syntax:</h5>
				3999	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4000	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4001	</pre>
				4002
				4003	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4004	<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]	4005	integer and converts that value to the <tt>ty2</tt> type.</p>
				4006
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4007	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4008	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4009	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4010	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4011	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4012	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]	4013
				4014	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4015	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4016	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4017	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]	4018
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4019	<h5>Example:</h5>
				4020	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4021	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4022	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4023	</pre>
				4024	</div>
				4025
				4026	<!-- _______________________________________________________________________ -->
				4027	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4028	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4029	</div>
				4030	<div class="doc_text">
				4031
				4032	<h5>Syntax:</h5>
				4033	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4034	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4035	</pre>
				4036
				4037	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4038	<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]	4039	integer and converts that value to the <tt>ty2</tt> type.</p>
				4040
				4041	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4042	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4043	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4044	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4045	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4046	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]	4047
				4048	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4049	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4050	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4051	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]	4052
				4053	<h5>Example:</h5>
				4054	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4055	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4056	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4057	</pre>
				4058	</div>
				4059
				4060	<!-- _______________________________________________________________________ -->
				4061	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4062	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4063	</div>
				4064	<div class="doc_text">
				4065
				4066	<h5>Syntax:</h5>
				4067	<pre>
				4068	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4069	</pre>
				4070
				4071	<h5>Overview:</h5>
				4072	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4073	the integer type <tt>ty2</tt>.</p>
				4074
				4075	<h5>Arguments:</h5>
				4076	<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]	4077	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4078	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4079
				4080	<h5>Semantics:</h5>
				4081	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4082	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4083	truncating or zero extending that value to the size of the integer type. If
				4084	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4085	<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]	4086	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4087	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4088
				4089	<h5>Example:</h5>
				4090	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4091	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4092	%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]	4093	</pre>
				4094	</div>
				4095
				4096	<!-- _______________________________________________________________________ -->
				4097	<div class="doc_subsubsection">
				4098	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4099	</div>
				4100	<div class="doc_text">
				4101
				4102	<h5>Syntax:</h5>
				4103	<pre>
				4104	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4105	</pre>
				4106
				4107	<h5>Overview:</h5>
				4108	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4109	a pointer type, <tt>ty2</tt>.</p>
				4110
				4111	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4112	<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]	4113	value to cast, and a type to cast it to, which must be a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4114	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4115
				4116	<h5>Semantics:</h5>
				4117	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4118	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4119	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4120	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4121	the size of a pointer then a zero extension is done. If they are the same size,
				4122	nothing is done (<i>no-op cast</i>).</p>
				4123
				4124	<h5>Example:</h5>
				4125	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4126	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4127	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4128	%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]	4129	</pre>
				4130	</div>
				4131
				4132	<!-- _______________________________________________________________________ -->
				4133	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4134	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4135	</div>
				4136	<div class="doc_text">
				4137
				4138	<h5>Syntax:</h5>
				4139	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4140	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4141	</pre>
				4142
				4143	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4144
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4145	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4146	<tt>ty2</tt> without changing any bits.</p>
				4147
				4148	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4149
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4150	<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]	4151	a non-aggregate first class value, and a type to cast it to, which must also be
				4152	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4153	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4154	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]	4155	type is a pointer, the destination type must also be a pointer. This
				4156	instruction supports bitwise conversion of vectors to integers and to vectors
				4157	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4158
				4159	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4160	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4161	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4162	this conversion. The conversion is done as if the <tt>value</tt> had been
				4163	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4164	converted to other pointer types with this instruction. To convert pointers to
				4165	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4166	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4167
				4168	<h5>Example:</h5>
				4169	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4170	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4171	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4172	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4173	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4174	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4175
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4176	<!-- ======================================================================= -->
				4177	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4178	<div class="doc_text">
				4179	<p>The instructions in this category are the "miscellaneous"
				4180	instructions, which defy better classification.</p>
				4181	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4182
				4183	<!-- _______________________________________________________________________ -->
				4184	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4185	</div>
				4186	<div class="doc_text">
				4187	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4188	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4189	</pre>
				4190	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4191	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4192	a vector of boolean values based on comparison
				4193	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4194	<h5>Arguments:</h5>
				4195	<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]	4196	the condition code indicating the kind of comparison to perform. It is not
				4197	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4198	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4199	<ol>
				4200	<li><tt>eq</tt>: equal</li>
				4201	<li><tt>ne</tt>: not equal </li>
				4202	<li><tt>ugt</tt>: unsigned greater than</li>
				4203	<li><tt>uge</tt>: unsigned greater or equal</li>
				4204	<li><tt>ult</tt>: unsigned less than</li>
				4205	<li><tt>ule</tt>: unsigned less or equal</li>
				4206	<li><tt>sgt</tt>: signed greater than</li>
				4207	<li><tt>sge</tt>: signed greater or equal</li>
				4208	<li><tt>slt</tt>: signed less than</li>
				4209	<li><tt>sle</tt>: signed less or equal</li>
				4210	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4211	<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]	4212	<a href="#t_pointer">pointer</a>
				4213	or integer <a href="#t_vector">vector</a> typed.
				4214	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4215	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4216	<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]	4217	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4218	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4219	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4220	<ol>
				4221	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4222	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4223	</li>
				4224	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4225	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4226	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4227	<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]	4228	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4229	<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]	4230	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4231	<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]	4232	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4233	<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]	4234	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4235	<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]	4236	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4237	<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]	4238	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4239	<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]	4240	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4241	<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]	4242	</ol>
				4243	<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]	4244	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4245	<p>If the operands are integer vectors, then they are compared
				4246	element by element. The result is an <tt>i1</tt> vector with
				4247	the same number of elements as the values being compared.
				4248	Otherwise, the result is an <tt>i1</tt>.
				4249	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4250
				4251	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4252	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4253	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4254	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4255	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4256	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4257	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4258	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4259
				4260	<p>Note that the code generator does not yet support vector types with
				4261	the <tt>icmp</tt> instruction.</p>
				4262
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4263	</div>
				4264
				4265	<!-- _______________________________________________________________________ -->
				4266	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4267	</div>
				4268	<div class="doc_text">
				4269	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4270	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4271	</pre>
				4272	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4273	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4274	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4275	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4276	<p>
				4277	If the operands are floating point scalars, then the result
				4278	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4279	</p>
				4280	<p>If the operands are floating point vectors, then the result type
				4281	is a vector of boolean with the same number of elements as the
				4282	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4283	<h5>Arguments:</h5>
				4284	<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]	4285	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4286	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4287	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4288	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4289	<li><tt>oeq</tt>: ordered and equal</li>
				4290	<li><tt>ogt</tt>: ordered and greater than </li>
				4291	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4292	<li><tt>olt</tt>: ordered and less than </li>
				4293	<li><tt>ole</tt>: ordered and less than or equal</li>
				4294	<li><tt>one</tt>: ordered and not equal</li>
				4295	<li><tt>ord</tt>: ordered (no nans)</li>
				4296	<li><tt>ueq</tt>: unordered or equal</li>
				4297	<li><tt>ugt</tt>: unordered or greater than </li>
				4298	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4299	<li><tt>ult</tt>: unordered or less than </li>
				4300	<li><tt>ule</tt>: unordered or less than or equal</li>
				4301	<li><tt>une</tt>: unordered or not equal</li>
				4302	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4303	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4304	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4305	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4306	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4307	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4308	either a <a href="#t_floating">floating point</a> type
				4309	or a <a href="#t_vector">vector</a> of floating point type.
				4310	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4311	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4312	<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]	4313	according to the condition code given as <tt>cond</tt>.
				4314	If the operands are vectors, then the vectors are compared
				4315	element by element.
				4316	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4317	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4318	<ol>
				4319	<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]	4320	<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]	4321	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4322	<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]	4323	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4324	<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]	4325	<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]	4326	<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]	4327	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4328	<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]	4329	<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]	4330	<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]	4331	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4332	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4333	<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]	4334	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4335	<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]	4336	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4337	<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]	4338	<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]	4339	<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]	4340	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4341	<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]	4342	<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]	4343	<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]	4344	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4345	<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]	4346	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4347	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4348
				4349	<h5>Example:</h5>
				4350	<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]	4351	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4352	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4353	<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]	4354	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4355
				4356	<p>Note that the code generator does not yet support vector types with
				4357	the <tt>fcmp</tt> instruction.</p>
				4358
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4359	</div>
				4360
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4361	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4362	<div class="doc_subsubsection">
				4363	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4364	</div>
				4365	<div class="doc_text">
				4366	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4367	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4368	</pre>
				4369	<h5>Overview:</h5>
				4370	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4371	element-wise comparison of its two integer vector operands.</p>
				4372	<h5>Arguments:</h5>
				4373	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4374	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4375	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4376	<ol>
				4377	<li><tt>eq</tt>: equal</li>
				4378	<li><tt>ne</tt>: not equal </li>
				4379	<li><tt>ugt</tt>: unsigned greater than</li>
				4380	<li><tt>uge</tt>: unsigned greater or equal</li>
				4381	<li><tt>ult</tt>: unsigned less than</li>
				4382	<li><tt>ule</tt>: unsigned less or equal</li>
				4383	<li><tt>sgt</tt>: signed greater than</li>
				4384	<li><tt>sge</tt>: signed greater or equal</li>
				4385	<li><tt>slt</tt>: signed less than</li>
				4386	<li><tt>sle</tt>: signed less or equal</li>
				4387	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4388	<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]	4389	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4390	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4391	<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]	4392	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4393	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4394	identical type as the values being compared. The most significant bit in each
				4395	element is 1 if the element-wise comparison evaluates to true, and is 0
				4396	otherwise. All other bits of the result are undefined. The condition codes
				4397	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4398	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4399
				4400	<h5>Example:</h5>
				4401	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4402	<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>
				4403	<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]	4404	</pre>
				4405	</div>
				4406
				4407	<!-- _______________________________________________________________________ -->
				4408	<div class="doc_subsubsection">
				4409	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4410	</div>
				4411	<div class="doc_text">
				4412	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4413	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4414	<h5>Overview:</h5>
				4415	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4416	element-wise comparison of its two floating point vector operands. The output
				4417	elements have the same width as the input elements.</p>
				4418	<h5>Arguments:</h5>
				4419	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4420	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4421	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4422	<ol>
				4423	<li><tt>false</tt>: no comparison, always returns false</li>
				4424	<li><tt>oeq</tt>: ordered and equal</li>
				4425	<li><tt>ogt</tt>: ordered and greater than </li>
				4426	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4427	<li><tt>olt</tt>: ordered and less than </li>
				4428	<li><tt>ole</tt>: ordered and less than or equal</li>
				4429	<li><tt>one</tt>: ordered and not equal</li>
				4430	<li><tt>ord</tt>: ordered (no nans)</li>
				4431	<li><tt>ueq</tt>: unordered or equal</li>
				4432	<li><tt>ugt</tt>: unordered or greater than </li>
				4433	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4434	<li><tt>ult</tt>: unordered or less than </li>
				4435	<li><tt>ule</tt>: unordered or less than or equal</li>
				4436	<li><tt>une</tt>: unordered or not equal</li>
				4437	<li><tt>uno</tt>: unordered (either nans)</li>
				4438	<li><tt>true</tt>: no comparison, always returns true</li>
				4439	</ol>
				4440	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4441	<a href="#t_floating">floating point</a> typed. They must also be identical
				4442	types.</p>
				4443	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4444	<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]	4445	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4446	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4447	an identical number of elements as the values being compared, and each element
				4448	having identical with to the width of the floating point elements. The most
				4449	significant bit in each element is 1 if the element-wise comparison evaluates to
				4450	true, and is 0 otherwise. All other bits of the result are undefined. The
				4451	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4452	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4453
				4454	<h5>Example:</h5>
				4455	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4456	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4457	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4458
				4459	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4460	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4461	</pre>
				4462	</div>
				4463
				4464	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4465	<div class="doc_subsubsection">
				4466	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4467	</div>
				4468
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4469	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4470
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4471	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4472
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4473	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4474	<h5>Overview:</h5>
				4475	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4476	the SSA graph representing the function.</p>
				4477	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4478
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4479	<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]	4480	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4481	as arguments, with one pair for each predecessor basic block of the
				4482	current block. Only values of <a href="#t_firstclass">first class</a>
				4483	type may be used as the value arguments to the PHI node. Only labels
				4484	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4485
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4486	<p>There must be no non-phi instructions between the start of a basic
				4487	block and the PHI instructions: i.e. PHI instructions must be first in
				4488	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4489
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4490	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4491
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4492	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4493	specified by the pair corresponding to the predecessor basic block that executed
				4494	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4495
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4496	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4497	<pre>
				4498	Loop: ; Infinite loop that counts from 0 on up...
				4499	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4500	%nextindvar = add i32 %indvar, 1
				4501	br label %Loop
				4502	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4503	</div>
				4504
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4505	<!-- _______________________________________________________________________ -->
				4506	<div class="doc_subsubsection">
				4507	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4508	</div>
				4509
				4510	<div class="doc_text">
				4511
				4512	<h5>Syntax:</h5>
				4513
				4514	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4515	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4516
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4517	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4518	</pre>
				4519
				4520	<h5>Overview:</h5>
				4521
				4522	<p>
				4523	The '<tt>select</tt>' instruction is used to choose one value based on a
				4524	condition, without branching.
				4525	</p>
				4526
				4527
				4528	<h5>Arguments:</h5>
				4529
				4530	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4531	The '<tt>select</tt>' instruction requires an 'i1' value or
				4532	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4533	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]	4534	type. If the val1/val2 are vectors and
				4535	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4536	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4537	</p>
				4538
				4539	<h5>Semantics:</h5>
				4540
				4541	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4542	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]	4543	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4544	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4545	<p>
				4546	If the condition is a vector of i1, then the value arguments must
				4547	be vectors of the same size, and the selection is done element
				4548	by element.
				4549	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4550
				4551	<h5>Example:</h5>
				4552
				4553	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4554	%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]	4555	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4556
				4557	<p>Note that the code generator does not yet support conditions
				4558	with vector type.</p>
				4559
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4560	</div>
				4561
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4562
				4563	<!-- _______________________________________________________________________ -->
				4564	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4565	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4566	</div>
				4567
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4568	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4569
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4570	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4571	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4572	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4573	</pre>
				4574
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4575	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4576
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4577	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4578
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4579	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4580
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4581	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4582
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4583	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4584	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4585	<p>The optional "tail" marker indicates whether the callee function accesses
				4586	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]	4587	function call is eligible for tail call optimization. Note that calls may
				4588	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4589	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4590	</li>
				4591	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4592	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4593	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4594	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4595	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4596
				4597	<li>
				4598	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4599	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4600	and '<tt>inreg</tt>' attributes are valid here.</p>
				4601	</li>
				4602
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4603	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4604	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4605	the type of the return value. Functions that return no value are marked
				4606	<tt><a href="#t_void">void</a></tt>.</p>
				4607	</li>
				4608	<li>
				4609	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4610	value being invoked. The argument types must match the types implied by
				4611	this signature. This type can be omitted if the function is not varargs
				4612	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]	4613	</li>
				4614	<li>
				4615	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4616	be invoked. In most cases, this is a direct function invocation, but
				4617	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]	4618	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4619	</li>
				4620	<li>
				4621	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4622	function signature argument types. All arguments must be of
				4623	<a href="#t_firstclass">first class</a> type. If the function signature
				4624	indicates the function accepts a variable number of arguments, the extra
				4625	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4626	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4627	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4628	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4629	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4630	'<tt>readnone</tt>' attributes are valid here.</p>
				4631	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4632	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4633
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4634	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4635
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4636	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4637	transfer to a specified function, with its incoming arguments bound to
				4638	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4639	instruction in the called function, control flow continues with the
				4640	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4641	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4642
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4643	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4644
				4645	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4646	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4647	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4648	%X = tail call i32 @foo() <i>; yields i32</i>
				4649	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4650	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4651
				4652	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4653	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4654	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4655	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4656	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	eefa7df	2008-10-07 10:03:45 +0000	[diff] [blame]	4657	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4658	</pre>
				4659
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4660	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4661
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4662	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4663	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4664	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4665	</div>
				4666
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4667	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4668
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4669	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4670
				4671	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4672	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4673	</pre>
				4674
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4675	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4676
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4677	<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]	4678	the "variable argument" area of a function call. It is used to implement the
				4679	<tt>va_arg</tt> macro in C.</p>
				4680
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4681	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4682
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4683	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4684	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4685	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]	4686	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4687
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4688	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4689
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4690	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4691	type from the specified <tt>va_list</tt> and causes the
				4692	<tt>va_list</tt> to point to the next argument. For more information,
				4693	see the variable argument handling <a href="#int_varargs">Intrinsic
				4694	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4695
				4696	<p>It is legal for this instruction to be called in a function which does not
				4697	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4698	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4699
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4700	<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]	4701	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4702	argument.</p>
				4703
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4704	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4705
				4706	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4707
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4708	<p>Note that the code generator does not yet fully support va_arg
				4709	on many targets. Also, it does not currently support va_arg with
				4710	aggregate types on any target.</p>
				4711
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4712	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4713
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4714	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4715	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4716	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4717
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4718	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4719
				4720	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4721	well known names and semantics and are required to follow certain restrictions.
				4722	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4723	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]	4724	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]	4725
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4726	<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]	4727	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4728	begin with this prefix. Intrinsic functions must always be external functions:
				4729	you cannot define the body of intrinsic functions. Intrinsic functions may
				4730	only be used in call or invoke instructions: it is illegal to take the address
				4731	of an intrinsic function. Additionally, because intrinsic functions are part
				4732	of the LLVM language, it is required if any are added that they be documented
				4733	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4734
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4735	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4736	a family of functions that perform the same operation but on different data
				4737	types. Because LLVM can represent over 8 million different integer types,
				4738	overloading is used commonly to allow an intrinsic function to operate on any
				4739	integer type. One or more of the argument types or the result type can be
				4740	overloaded to accept any integer type. Argument types may also be defined as
				4741	exactly matching a previous argument's type or the result type. This allows an
				4742	intrinsic function which accepts multiple arguments, but needs all of them to
				4743	be of the same type, to only be overloaded with respect to a single argument or
				4744	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4745
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4746	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4747	encoded into its function name, each preceded by a period. Only those types
				4748	which are overloaded result in a name suffix. Arguments whose type is matched
				4749	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4750	take an integer of any width and returns an integer of exactly the same integer
				4751	width. This leads to a family of functions such as
				4752	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4753	Only one type, the return type, is overloaded, and only one type suffix is
				4754	required. Because the argument's type is matched against the return type, it
				4755	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4756
				4757	<p>To learn how to add an intrinsic function, please see the
				4758	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4759	</p>
				4760
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4761	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4762
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4763	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4764	<div class="doc_subsection">
				4765	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4766	</div>
				4767
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4768	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4769
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4770	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4771	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]	4772	intrinsic functions. These functions are related to the similarly
				4773	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4774
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4775	<p>All of these functions operate on arguments that use a
				4776	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4777	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4778	transformations should be prepared to handle these functions regardless of
				4779	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4780
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4781	<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]	4782	instruction and the variable argument handling intrinsic functions are
				4783	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4784
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4785	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4786	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4787	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4788	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4789	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4790	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4791	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4792
				4793	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4794	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4795
				4796	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4797	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4798	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4799	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4800	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4801
				4802	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4803	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4804	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4805	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4806
				4807	declare void @llvm.va_start(i8*)
				4808	declare void @llvm.va_copy(i8, i8)
				4809	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4810	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4811	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4812
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4813	</div>
				4814
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4815	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4816	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4817	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4818	</div>
				4819
				4820
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4821	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4822	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4823	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4824	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4825	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4826	<tt>*<arglist></tt> for subsequent use by <tt><a
				4827	href="#i_va_arg">va_arg</a></tt>.</p>
				4828
				4829	<h5>Arguments:</h5>
				4830
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4831	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4832
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4833	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4834
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4835	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4836	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4837	<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]	4838	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4839	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]	4840	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]	4841
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4842	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4843
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4844	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4845	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4846	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4847	</div>
				4848
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4849	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4850	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4851	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4852	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4853
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4854	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4855	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]	4856	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]	4857
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4858	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4859
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4860	<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]	4861
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4862	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4863
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4864	<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]	4865	macro available in C. In a target-dependent way, it destroys the
				4866	<tt>va_list</tt> element to which the argument points. Calls to <a
				4867	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4868	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4869	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4870
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4871	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4872
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4873	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4874	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4875	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4876	</div>
				4877
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4878	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4879
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4880	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4881
				4882	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4883	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4884	</pre>
				4885
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4886	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4887
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4888	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4889	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4890
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4891	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4892
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4893	<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]	4894	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]	4895
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4896
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4897	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4898
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4899	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4900	macro available in C. In a target-dependent way, it copies the source
				4901	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4902	intrinsic is necessary because the <tt><a href="#int_va_start">
				4903	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4904	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4905
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4906	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4907
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4908	<!-- ======================================================================= -->
				4909	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4910	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4911	</div>
				4912
				4913	<div class="doc_text">
				4914
				4915	<p>
				4916	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4917	Collection</a> (GC) requires the implementation and generation of these
				4918	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4919	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]	4920	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4921	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]	4922	Front-ends for type-safe garbage collected languages should generate these
				4923	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4924	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4925	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4926
				4927	<p>The garbage collection intrinsics only operate on objects in the generic
				4928	address space (address space zero).</p>
				4929
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4930	</div>
				4931
				4932	<!-- _______________________________________________________________________ -->
				4933	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4934	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4935	</div>
				4936
				4937	<div class="doc_text">
				4938
				4939	<h5>Syntax:</h5>
				4940
				4941	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4942	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4943	</pre>
				4944
				4945	<h5>Overview:</h5>
				4946
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4947	<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]	4948	the code generator, and allows some metadata to be associated with it.</p>
				4949
				4950	<h5>Arguments:</h5>
				4951
				4952	<p>The first argument specifies the address of a stack object that contains the
				4953	root pointer. The second pointer (which must be either a constant or a global
				4954	value address) contains the meta-data to be associated with the root.</p>
				4955
				4956	<h5>Semantics:</h5>
				4957
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4958	<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]	4959	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4960	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4961	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4962	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4963
				4964	</div>
				4965
				4966
				4967	<!-- _______________________________________________________________________ -->
				4968	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4969	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4970	</div>
				4971
				4972	<div class="doc_text">
				4973
				4974	<h5>Syntax:</h5>
				4975
				4976	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4977	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4978	</pre>
				4979
				4980	<h5>Overview:</h5>
				4981
				4982	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4983	locations, allowing garbage collector implementations that require read
				4984	barriers.</p>
				4985
				4986	<h5>Arguments:</h5>
				4987
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	4988	<p>The second argument is the address to read from, which should be an address
				4989	allocated from the garbage collector. The first object is a pointer to the
				4990	start of the referenced object, if needed by the language runtime (otherwise
				4991	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4992
				4993	<h5>Semantics:</h5>
				4994
				4995	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4996	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4997	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4998	may only be used in a function which <a href="#gc">specifies a GC
				4999	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5000
				5001	</div>
				5002
				5003
				5004	<!-- _______________________________________________________________________ -->
				5005	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5006	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5007	</div>
				5008
				5009	<div class="doc_text">
				5010
				5011	<h5>Syntax:</h5>
				5012
				5013	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5014	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5015	</pre>
				5016
				5017	<h5>Overview:</h5>
				5018
				5019	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5020	locations, allowing garbage collector implementations that require write
				5021	barriers (such as generational or reference counting collectors).</p>
				5022
				5023	<h5>Arguments:</h5>
				5024
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5025	<p>The first argument is the reference to store, the second is the start of the
				5026	object to store it to, and the third is the address of the field of Obj to
				5027	store to. If the runtime does not require a pointer to the object, Obj may be
				5028	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5029
				5030	<h5>Semantics:</h5>
				5031
				5032	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5033	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5034	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5035	may only be used in a function which <a href="#gc">specifies a GC
				5036	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5037
				5038	</div>
				5039
				5040
				5041
				5042	<!-- ======================================================================= -->
				5043	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5044	<a name="int_codegen">Code Generator Intrinsics</a>
				5045	</div>
				5046
				5047	<div class="doc_text">
				5048	<p>
				5049	These intrinsics are provided by LLVM to expose special features that may only
				5050	be implemented with code generator support.
				5051	</p>
				5052
				5053	</div>
				5054
				5055	<!-- _______________________________________________________________________ -->
				5056	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5057	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5058	</div>
				5059
				5060	<div class="doc_text">
				5061
				5062	<h5>Syntax:</h5>
				5063	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5064	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5065	</pre>
				5066
				5067	<h5>Overview:</h5>
				5068
				5069	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5070	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5071	target-specific value indicating the return address of the current function
				5072	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5073	</p>
				5074
				5075	<h5>Arguments:</h5>
				5076
				5077	<p>
				5078	The argument to this intrinsic indicates which function to return the address
				5079	for. Zero indicates the calling function, one indicates its caller, etc. The
				5080	argument is <b>required</b> to be a constant integer value.
				5081	</p>
				5082
				5083	<h5>Semantics:</h5>
				5084
				5085	<p>
				5086	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5087	the return address of the specified call frame, or zero if it cannot be
				5088	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5089	for arguments other than zero, so it should only be used for debugging purposes.
				5090	</p>
				5091
				5092	<p>
				5093	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5094	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]	5095	source-language caller.
				5096	</p>
				5097	</div>
				5098
				5099
				5100	<!-- _______________________________________________________________________ -->
				5101	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5102	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5103	</div>
				5104
				5105	<div class="doc_text">
				5106
				5107	<h5>Syntax:</h5>
				5108	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5109	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5110	</pre>
				5111
				5112	<h5>Overview:</h5>
				5113
				5114	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5115	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5116	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5117	</p>
				5118
				5119	<h5>Arguments:</h5>
				5120
				5121	<p>
				5122	The argument to this intrinsic indicates which function to return the frame
				5123	pointer for. Zero indicates the calling function, one indicates its caller,
				5124	etc. The argument is <b>required</b> to be a constant integer value.
				5125	</p>
				5126
				5127	<h5>Semantics:</h5>
				5128
				5129	<p>
				5130	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5131	the frame address of the specified call frame, or zero if it cannot be
				5132	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5133	for arguments other than zero, so it should only be used for debugging purposes.
				5134	</p>
				5135
				5136	<p>
				5137	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5138	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]	5139	source-language caller.
				5140	</p>
				5141	</div>
				5142
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5143	<!-- _______________________________________________________________________ -->
				5144	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5145	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5146	</div>
				5147
				5148	<div class="doc_text">
				5149
				5150	<h5>Syntax:</h5>
				5151	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5152	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5153	</pre>
				5154
				5155	<h5>Overview:</h5>
				5156
				5157	<p>
				5158	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]	5159	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5160	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5161	features like scoped automatic variable sized arrays in C99.
				5162	</p>
				5163
				5164	<h5>Semantics:</h5>
				5165
				5166	<p>
				5167	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]	5168	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5169	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5170	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5171	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5172	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5173	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5174	</p>
				5175
				5176	</div>
				5177
				5178	<!-- _______________________________________________________________________ -->
				5179	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5180	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5181	</div>
				5182
				5183	<div class="doc_text">
				5184
				5185	<h5>Syntax:</h5>
				5186	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5187	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5188	</pre>
				5189
				5190	<h5>Overview:</h5>
				5191
				5192	<p>
				5193	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5194	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]	5195	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5196	useful for implementing language features like scoped automatic variable sized
				5197	arrays in C99.
				5198	</p>
				5199
				5200	<h5>Semantics:</h5>
				5201
				5202	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5203	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]	5204	</p>
				5205
				5206	</div>
				5207
				5208
				5209	<!-- _______________________________________________________________________ -->
				5210	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5211	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5212	</div>
				5213
				5214	<div class="doc_text">
				5215
				5216	<h5>Syntax:</h5>
				5217	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5218	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5219	</pre>
				5220
				5221	<h5>Overview:</h5>
				5222
				5223
				5224	<p>
				5225	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]	5226	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5227	no
				5228	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5229	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5230	</p>
				5231
				5232	<h5>Arguments:</h5>
				5233
				5234	<p>
				5235	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5236	determining if the fetch should be for a read (0) or write (1), and
				5237	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5238	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]	5239	<tt>locality</tt> arguments must be constant integers.
				5240	</p>
				5241
				5242	<h5>Semantics:</h5>
				5243
				5244	<p>
				5245	This intrinsic does not modify the behavior of the program. In particular,
				5246	prefetches cannot trap and do not produce a value. On targets that support this
				5247	intrinsic, the prefetch can provide hints to the processor cache for better
				5248	performance.
				5249	</p>
				5250
				5251	</div>
				5252
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5253	<!-- _______________________________________________________________________ -->
				5254	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5255	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5256	</div>
				5257
				5258	<div class="doc_text">
				5259
				5260	<h5>Syntax:</h5>
				5261	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5262	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5263	</pre>
				5264
				5265	<h5>Overview:</h5>
				5266
				5267
				5268	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5269	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]	5270	(PC) in a region of
				5271	code to simulators and other tools. The method is target specific, but it is
				5272	expected that the marker will use exported symbols to transmit the PC of the
				5273	marker.
				5274	The marker makes no guarantees that it will remain with any specific instruction
				5275	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]	5276	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5277	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5278	</p>
				5279
				5280	<h5>Arguments:</h5>
				5281
				5282	<p>
				5283	<tt>id</tt> is a numerical id identifying the marker.
				5284	</p>
				5285
				5286	<h5>Semantics:</h5>
				5287
				5288	<p>
				5289	This intrinsic does not modify the behavior of the program. Backends that do not
				5290	support this intrinisic may ignore it.
				5291	</p>
				5292
				5293	</div>
				5294
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5295	<!-- _______________________________________________________________________ -->
				5296	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5297	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5298	</div>
				5299
				5300	<div class="doc_text">
				5301
				5302	<h5>Syntax:</h5>
				5303	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5304	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5305	</pre>
				5306
				5307	<h5>Overview:</h5>
				5308
				5309
				5310	<p>
				5311	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5312	counter register (or similar low latency, high accuracy clocks) on those targets
				5313	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5314	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5315	should only be used for small timings.
				5316	</p>
				5317
				5318	<h5>Semantics:</h5>
				5319
				5320	<p>
				5321	When directly supported, reading the cycle counter should not modify any memory.
				5322	Implementations are allowed to either return a application specific value or a
				5323	system wide value. On backends without support, this is lowered to a constant 0.
				5324	</p>
				5325
				5326	</div>
				5327
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5328	<!-- ======================================================================= -->
				5329	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5330	<a name="int_libc">Standard C Library Intrinsics</a>
				5331	</div>
				5332
				5333	<div class="doc_text">
				5334	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5335	LLVM provides intrinsics for a few important standard C library functions.
				5336	These intrinsics allow source-language front-ends to pass information about the
				5337	alignment of the pointer arguments to the code generator, providing opportunity
				5338	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5339	</p>
				5340
				5341	</div>
				5342
				5343	<!-- _______________________________________________________________________ -->
				5344	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5345	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5346	</div>
				5347
				5348	<div class="doc_text">
				5349
				5350	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5351	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5352	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5353	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5354	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5355	i8 <len>, i32 <align>)
				5356	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5357	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5358	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5359	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5360	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5361	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5362	</pre>
				5363
				5364	<h5>Overview:</h5>
				5365
				5366	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5367	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5368	location to the destination location.
				5369	</p>
				5370
				5371	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5372	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5373	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5374	</p>
				5375
				5376	<h5>Arguments:</h5>
				5377
				5378	<p>
				5379	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]	5380	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5381	specifying the number of bytes to copy, and the fourth argument is the alignment
				5382	of the source and destination locations.
				5383	</p>
				5384
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5385	<p>
				5386	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]	5387	the caller guarantees that both the source and destination pointers are aligned
				5388	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5389	</p>
				5390
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5391	<h5>Semantics:</h5>
				5392
				5393	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5394	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]	5395	location to the destination location, which are not allowed to overlap. It
				5396	copies "len" bytes of memory over. If the argument is known to be aligned to
				5397	some boundary, this can be specified as the fourth argument, otherwise it should
				5398	be set to 0 or 1.
				5399	</p>
				5400	</div>
				5401
				5402
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5403	<!-- _______________________________________________________________________ -->
				5404	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5405	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5406	</div>
				5407
				5408	<div class="doc_text">
				5409
				5410	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5411	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5412	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5413	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5414	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5415	i8 <len>, i32 <align>)
				5416	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5417	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5418	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5419	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5420	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5421	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5422	</pre>
				5423
				5424	<h5>Overview:</h5>
				5425
				5426	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5427	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5428	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5429	'<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]	5430	</p>
				5431
				5432	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5433	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5434	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5435	</p>
				5436
				5437	<h5>Arguments:</h5>
				5438
				5439	<p>
				5440	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]	5441	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5442	specifying the number of bytes to copy, and the fourth argument is the alignment
				5443	of the source and destination locations.
				5444	</p>
				5445
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5446	<p>
				5447	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5448	the caller guarantees that the source and destination pointers are aligned to
				5449	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5450	</p>
				5451
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5452	<h5>Semantics:</h5>
				5453
				5454	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5455	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]	5456	location to the destination location, which may overlap. It
				5457	copies "len" bytes of memory over. If the argument is known to be aligned to
				5458	some boundary, this can be specified as the fourth argument, otherwise it should
				5459	be set to 0 or 1.
				5460	</p>
				5461	</div>
				5462
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5463
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5464	<!-- _______________________________________________________________________ -->
				5465	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5466	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5467	</div>
				5468
				5469	<div class="doc_text">
				5470
				5471	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5472	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5473	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5474	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5475	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5476	i8 <len>, i32 <align>)
				5477	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5478	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5479	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5480	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5481	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5482	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5483	</pre>
				5484
				5485	<h5>Overview:</h5>
				5486
				5487	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5488	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]	5489	byte value.
				5490	</p>
				5491
				5492	<p>
				5493	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5494	does not return a value, and takes an extra alignment argument.
				5495	</p>
				5496
				5497	<h5>Arguments:</h5>
				5498
				5499	<p>
				5500	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]	5501	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5502	argument specifying the number of bytes to fill, and the fourth argument is the
				5503	known alignment of destination location.
				5504	</p>
				5505
				5506	<p>
				5507	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]	5508	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5509	</p>
				5510
				5511	<h5>Semantics:</h5>
				5512
				5513	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5514	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5515	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5516	destination location. If the argument is known to be aligned to some boundary,
				5517	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5518	1.
				5519	</p>
				5520	</div>
				5521
				5522
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5523	<!-- _______________________________________________________________________ -->
				5524	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5525	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5526	</div>
				5527
				5528	<div class="doc_text">
				5529
				5530	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5531	<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]	5532	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5533	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5534	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5535	declare float @llvm.sqrt.f32(float %Val)
				5536	declare double @llvm.sqrt.f64(double %Val)
				5537	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5538	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5539	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5540	</pre>
				5541
				5542	<h5>Overview:</h5>
				5543
				5544	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5545	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]	5546	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]	5547	<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]	5548	negative numbers other than -0.0 (which allows for better optimization, because
				5549	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5550	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5551	</p>
				5552
				5553	<h5>Arguments:</h5>
				5554
				5555	<p>
				5556	The argument and return value are floating point numbers of the same type.
				5557	</p>
				5558
				5559	<h5>Semantics:</h5>
				5560
				5561	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5562	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]	5563	floating point number.
				5564	</p>
				5565	</div>
				5566
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5567	<!-- _______________________________________________________________________ -->
				5568	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5569	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5570	</div>
				5571
				5572	<div class="doc_text">
				5573
				5574	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5575	<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]	5576	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5577	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5578	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5579	declare float @llvm.powi.f32(float %Val, i32 %power)
				5580	declare double @llvm.powi.f64(double %Val, i32 %power)
				5581	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5582	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5583	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5584	</pre>
				5585
				5586	<h5>Overview:</h5>
				5587
				5588	<p>
				5589	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5590	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5591	multiplications is not defined. When a vector of floating point type is
				5592	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5593	</p>
				5594
				5595	<h5>Arguments:</h5>
				5596
				5597	<p>
				5598	The second argument is an integer power, and the first is a value to raise to
				5599	that power.
				5600	</p>
				5601
				5602	<h5>Semantics:</h5>
				5603
				5604	<p>
				5605	This function returns the first value raised to the second power with an
				5606	unspecified sequence of rounding operations.</p>
				5607	</div>
				5608
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5609	<!-- _______________________________________________________________________ -->
				5610	<div class="doc_subsubsection">
				5611	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5612	</div>
				5613
				5614	<div class="doc_text">
				5615
				5616	<h5>Syntax:</h5>
				5617	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5618	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5619	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5620	<pre>
				5621	declare float @llvm.sin.f32(float %Val)
				5622	declare double @llvm.sin.f64(double %Val)
				5623	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5624	declare fp128 @llvm.sin.f128(fp128 %Val)
				5625	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5626	</pre>
				5627
				5628	<h5>Overview:</h5>
				5629
				5630	<p>
				5631	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5632	</p>
				5633
				5634	<h5>Arguments:</h5>
				5635
				5636	<p>
				5637	The argument and return value are floating point numbers of the same type.
				5638	</p>
				5639
				5640	<h5>Semantics:</h5>
				5641
				5642	<p>
				5643	This function returns the sine of the specified operand, returning the
				5644	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]	5645	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5646	</div>
				5647
				5648	<!-- _______________________________________________________________________ -->
				5649	<div class="doc_subsubsection">
				5650	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5651	</div>
				5652
				5653	<div class="doc_text">
				5654
				5655	<h5>Syntax:</h5>
				5656	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5657	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5658	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5659	<pre>
				5660	declare float @llvm.cos.f32(float %Val)
				5661	declare double @llvm.cos.f64(double %Val)
				5662	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5663	declare fp128 @llvm.cos.f128(fp128 %Val)
				5664	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5665	</pre>
				5666
				5667	<h5>Overview:</h5>
				5668
				5669	<p>
				5670	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5671	</p>
				5672
				5673	<h5>Arguments:</h5>
				5674
				5675	<p>
				5676	The argument and return value are floating point numbers of the same type.
				5677	</p>
				5678
				5679	<h5>Semantics:</h5>
				5680
				5681	<p>
				5682	This function returns the cosine of the specified operand, returning the
				5683	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]	5684	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5685	</div>
				5686
				5687	<!-- _______________________________________________________________________ -->
				5688	<div class="doc_subsubsection">
				5689	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5690	</div>
				5691
				5692	<div class="doc_text">
				5693
				5694	<h5>Syntax:</h5>
				5695	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5696	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5697	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5698	<pre>
				5699	declare float @llvm.pow.f32(float %Val, float %Power)
				5700	declare double @llvm.pow.f64(double %Val, double %Power)
				5701	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5702	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5703	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5704	</pre>
				5705
				5706	<h5>Overview:</h5>
				5707
				5708	<p>
				5709	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5710	specified (positive or negative) power.
				5711	</p>
				5712
				5713	<h5>Arguments:</h5>
				5714
				5715	<p>
				5716	The second argument is a floating point power, and the first is a value to
				5717	raise to that power.
				5718	</p>
				5719
				5720	<h5>Semantics:</h5>
				5721
				5722	<p>
				5723	This function returns the first value raised to the second power,
				5724	returning the
				5725	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]	5726	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5727	</div>
				5728
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5729
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5730	<!-- ======================================================================= -->
				5731	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5732	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5733	</div>
				5734
				5735	<div class="doc_text">
				5736	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5737	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5738	These allow efficient code generation for some algorithms.
				5739	</p>
				5740
				5741	</div>
				5742
				5743	<!-- _______________________________________________________________________ -->
				5744	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5745	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5746	</div>
				5747
				5748	<div class="doc_text">
				5749
				5750	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5751	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5752	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5753	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5754	declare i16 @llvm.bswap.i16(i16 <id>)
				5755	declare i32 @llvm.bswap.i32(i32 <id>)
				5756	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5757	</pre>
				5758
				5759	<h5>Overview:</h5>
				5760
				5761	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5762	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]	5763	values with an even number of bytes (positive multiple of 16 bits). These are
				5764	useful for performing operations on data that is not in the target's native
				5765	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5766	</p>
				5767
				5768	<h5>Semantics:</h5>
				5769
				5770	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5771	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]	5772	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5773	intrinsic returns an i32 value that has the four bytes of the input i32
				5774	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]	5775	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5776	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5777	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5778	</p>
				5779
				5780	</div>
				5781
				5782	<!-- _______________________________________________________________________ -->
				5783	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5784	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5785	</div>
				5786
				5787	<div class="doc_text">
				5788
				5789	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5790	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5791	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5792	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5793	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5794	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5795	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5796	declare i64 @llvm.ctpop.i64(i64 <src>)
				5797	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5798	</pre>
				5799
				5800	<h5>Overview:</h5>
				5801
				5802	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5803	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5804	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5805	</p>
				5806
				5807	<h5>Arguments:</h5>
				5808
				5809	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5810	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]	5811	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5812	</p>
				5813
				5814	<h5>Semantics:</h5>
				5815
				5816	<p>
				5817	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5818	</p>
				5819	</div>
				5820
				5821	<!-- _______________________________________________________________________ -->
				5822	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5823	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5824	</div>
				5825
				5826	<div class="doc_text">
				5827
				5828	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5829	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5830	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5831	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5832	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5833	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5834	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5835	declare i64 @llvm.ctlz.i64(i64 <src>)
				5836	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5837	</pre>
				5838
				5839	<h5>Overview:</h5>
				5840
				5841	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5842	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5843	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5844	</p>
				5845
				5846	<h5>Arguments:</h5>
				5847
				5848	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5849	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]	5850	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5851	</p>
				5852
				5853	<h5>Semantics:</h5>
				5854
				5855	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5856	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5857	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]	5858	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5859	</p>
				5860	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5861
				5862
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5863
				5864	<!-- _______________________________________________________________________ -->
				5865	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5866	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5867	</div>
				5868
				5869	<div class="doc_text">
				5870
				5871	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5872	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5873	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5874	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5875	declare i8 @llvm.cttz.i8 (i8 <src>)
				5876	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5877	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5878	declare i64 @llvm.cttz.i64(i64 <src>)
				5879	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5880	</pre>
				5881
				5882	<h5>Overview:</h5>
				5883
				5884	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5885	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5886	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5887	</p>
				5888
				5889	<h5>Arguments:</h5>
				5890
				5891	<p>
				5892	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]	5893	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5894	</p>
				5895
				5896	<h5>Semantics:</h5>
				5897
				5898	<p>
				5899	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5900	in a variable. If the src == 0 then the result is the size in bits of the type
				5901	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5902	</p>
				5903	</div>
				5904
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5905	<!-- _______________________________________________________________________ -->
				5906	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5907	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5908	</div>
				5909
				5910	<div class="doc_text">
				5911
				5912	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5913	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5914	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5915	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5916	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5917	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5918	</pre>
				5919
				5920	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5921	<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]	5922	range of bits from an integer value and returns them in the same bit width as
				5923	the original value.</p>
				5924
				5925	<h5>Arguments:</h5>
				5926	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5927	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]	5928	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]	5929
				5930	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5931	<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]	5932	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5933	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5934	operates in forward mode.</p>
				5935	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5936	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]	5937	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5938	<ol>
				5939	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5940	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5941	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5942	to determine the number of bits to retain.</li>
				5943	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5944	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5945	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5946	<p>In reverse mode, a similar computation is made except that the bits are
				5947	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5948	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5949	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5950	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5951	</div>
				5952
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5953	<div class="doc_subsubsection">
				5954	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5955	</div>
				5956
				5957	<div class="doc_text">
				5958
				5959	<h5>Syntax:</h5>
				5960	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5961	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5962	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5963	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5964	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]	5965	</pre>
				5966
				5967	<h5>Overview:</h5>
				5968	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5969	of bits in an integer value with another integer value. It returns the integer
				5970	with the replaced bits.</p>
				5971
				5972	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5973	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				5974	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5975	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5976	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5977	type since they specify only a bit index.</p>
				5978
				5979	<h5>Semantics:</h5>
				5980	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5981	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5982	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5983	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5984
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5985	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5986	truncating it down to the size of the replacement area or zero extending it
				5987	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5988
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5989	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5990	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5991	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5992	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5993
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	5994	<p>In reverse mode, a similar computation is made except that the bits are
				5995	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5996	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5997
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5998	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5999
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6000	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6001	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6002	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6003	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6004	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6005	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	6006	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6007
				6008	</div>
				6009
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6010	<!-- ======================================================================= -->
				6011	<div class="doc_subsection">
				6012	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6013	</div>
				6014
				6015	<div class="doc_text">
				6016	<p>
				6017	LLVM provides intrinsics for some arithmetic with overflow operations.
				6018	</p>
				6019
				6020	</div>
				6021
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6022	<!-- _______________________________________________________________________ -->
				6023	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6024	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6025	</div>
				6026
				6027	<div class="doc_text">
				6028
				6029	<h5>Syntax:</h5>
				6030
				6031	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6032	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6033
				6034	<pre>
				6035	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6036	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6037	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6038	</pre>
				6039
				6040	<h5>Overview:</h5>
				6041
				6042	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6043	a signed addition of the two arguments, and indicate whether an overflow
				6044	occurred during the signed summation.</p>
				6045
				6046	<h5>Arguments:</h5>
				6047
				6048	<p>The arguments (%a and %b) and the first element of the result structure may
				6049	be of integer types of any bit width, but they must have the same bit width. The
				6050	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6051	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6052
				6053	<h5>Semantics:</h5>
				6054
				6055	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6056	a signed addition of the two variables. They return a structure — the
				6057	first element of which is the signed summation, and the second element of which
				6058	is a bit specifying if the signed summation resulted in an overflow.</p>
				6059
				6060	<h5>Examples:</h5>
				6061	<pre>
				6062	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6063	%sum = extractvalue {i32, i1} %res, 0
				6064	%obit = extractvalue {i32, i1} %res, 1
				6065	br i1 %obit, label %overflow, label %normal
				6066	</pre>
				6067
				6068	</div>
				6069
				6070	<!-- _______________________________________________________________________ -->
				6071	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6072	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6073	</div>
				6074
				6075	<div class="doc_text">
				6076
				6077	<h5>Syntax:</h5>
				6078
				6079	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6080	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6081
				6082	<pre>
				6083	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6084	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6085	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6086	</pre>
				6087
				6088	<h5>Overview:</h5>
				6089
				6090	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6091	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6092	during the unsigned summation.</p>
				6093
				6094	<h5>Arguments:</h5>
				6095
				6096	<p>The arguments (%a and %b) and the first element of the result structure may
				6097	be of integer types of any bit width, but they must have the same bit width. The
				6098	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6099	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6100
				6101	<h5>Semantics:</h5>
				6102
				6103	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6104	an unsigned addition of the two arguments. They return a structure — the
				6105	first element of which is the sum, and the second element of which is a bit
				6106	specifying if the unsigned summation resulted in a carry.</p>
				6107
				6108	<h5>Examples:</h5>
				6109	<pre>
				6110	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6111	%sum = extractvalue {i32, i1} %res, 0
				6112	%obit = extractvalue {i32, i1} %res, 1
				6113	br i1 %obit, label %carry, label %normal
				6114	</pre>
				6115
				6116	</div>
				6117
				6118	<!-- _______________________________________________________________________ -->
				6119	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6120	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6121	</div>
				6122
				6123	<div class="doc_text">
				6124
				6125	<h5>Syntax:</h5>
				6126
				6127	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6128	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6129
				6130	<pre>
				6131	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6132	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6133	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6134	</pre>
				6135
				6136	<h5>Overview:</h5>
				6137
				6138	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6139	a signed subtraction of the two arguments, and indicate whether an overflow
				6140	occurred during the signed subtraction.</p>
				6141
				6142	<h5>Arguments:</h5>
				6143
				6144	<p>The arguments (%a and %b) and the first element of the result structure may
				6145	be of integer types of any bit width, but they must have the same bit width. The
				6146	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6147	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6148
				6149	<h5>Semantics:</h5>
				6150
				6151	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6152	a signed subtraction of the two arguments. They return a structure — the
				6153	first element of which is the subtraction, and the second element of which is a bit
				6154	specifying if the signed subtraction resulted in an overflow.</p>
				6155
				6156	<h5>Examples:</h5>
				6157	<pre>
				6158	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6159	%sum = extractvalue {i32, i1} %res, 0
				6160	%obit = extractvalue {i32, i1} %res, 1
				6161	br i1 %obit, label %overflow, label %normal
				6162	</pre>
				6163
				6164	</div>
				6165
				6166	<!-- _______________________________________________________________________ -->
				6167	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6168	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6169	</div>
				6170
				6171	<div class="doc_text">
				6172
				6173	<h5>Syntax:</h5>
				6174
				6175	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6176	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6177
				6178	<pre>
				6179	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6180	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6181	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6182	</pre>
				6183
				6184	<h5>Overview:</h5>
				6185
				6186	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6187	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6188	occurred during the unsigned subtraction.</p>
				6189
				6190	<h5>Arguments:</h5>
				6191
				6192	<p>The arguments (%a and %b) and the first element of the result structure may
				6193	be of integer types of any bit width, but they must have the same bit width. The
				6194	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6195	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6196
				6197	<h5>Semantics:</h5>
				6198
				6199	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6200	an unsigned subtraction of the two arguments. They return a structure — the
				6201	first element of which is the subtraction, and the second element of which is a bit
				6202	specifying if the unsigned subtraction resulted in an overflow.</p>
				6203
				6204	<h5>Examples:</h5>
				6205	<pre>
				6206	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6207	%sum = extractvalue {i32, i1} %res, 0
				6208	%obit = extractvalue {i32, i1} %res, 1
				6209	br i1 %obit, label %overflow, label %normal
				6210	</pre>
				6211
				6212	</div>
				6213
				6214	<!-- _______________________________________________________________________ -->
				6215	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6216	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6217	</div>
				6218
				6219	<div class="doc_text">
				6220
				6221	<h5>Syntax:</h5>
				6222
				6223	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6224	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6225
				6226	<pre>
				6227	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6228	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6229	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6230	</pre>
				6231
				6232	<h5>Overview:</h5>
				6233
				6234	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6235	a signed multiplication of the two arguments, and indicate whether an overflow
				6236	occurred during the signed multiplication.</p>
				6237
				6238	<h5>Arguments:</h5>
				6239
				6240	<p>The arguments (%a and %b) and the first element of the result structure may
				6241	be of integer types of any bit width, but they must have the same bit width. The
				6242	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6243	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6244
				6245	<h5>Semantics:</h5>
				6246
				6247	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6248	a signed multiplication of the two arguments. They return a structure —
				6249	the first element of which is the multiplication, and the second element of
				6250	which is a bit specifying if the signed multiplication resulted in an
				6251	overflow.</p>
				6252
				6253	<h5>Examples:</h5>
				6254	<pre>
				6255	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6256	%sum = extractvalue {i32, i1} %res, 0
				6257	%obit = extractvalue {i32, i1} %res, 1
				6258	br i1 %obit, label %overflow, label %normal
				6259	</pre>
				6260
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6261	</div>
				6262
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6263	<!-- _______________________________________________________________________ -->
				6264	<div class="doc_subsubsection">
				6265	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6266	</div>
				6267
				6268	<div class="doc_text">
				6269
				6270	<h5>Syntax:</h5>
				6271
				6272	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6273	on any integer bit width.</p>
				6274
				6275	<pre>
				6276	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6277	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6278	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6279	</pre>
				6280
				6281	<h5>Overview:</h5>
				6282
				6283	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6284	actively being fixed, but it should not currently be used!</i></p>
				6285
				6286	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6287	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6288	occurred during the unsigned multiplication.</p>
				6289
				6290	<h5>Arguments:</h5>
				6291
				6292	<p>The arguments (%a and %b) and the first element of the result structure may
				6293	be of integer types of any bit width, but they must have the same bit width. The
				6294	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6295	and <tt>%b</tt> are the two values that will undergo unsigned
				6296	multiplication.</p>
				6297
				6298	<h5>Semantics:</h5>
				6299
				6300	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6301	an unsigned multiplication of the two arguments. They return a structure —
				6302	the first element of which is the multiplication, and the second element of
				6303	which is a bit specifying if the unsigned multiplication resulted in an
				6304	overflow.</p>
				6305
				6306	<h5>Examples:</h5>
				6307	<pre>
				6308	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6309	%sum = extractvalue {i32, i1} %res, 0
				6310	%obit = extractvalue {i32, i1} %res, 1
				6311	br i1 %obit, label %overflow, label %normal
				6312	</pre>
				6313
				6314	</div>
				6315
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6316	<!-- ======================================================================= -->
				6317	<div class="doc_subsection">
				6318	<a name="int_debugger">Debugger Intrinsics</a>
				6319	</div>
				6320
				6321	<div class="doc_text">
				6322	<p>
				6323	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6324	are described in the <a
				6325	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6326	Debugging</a> document.
				6327	</p>
				6328	</div>
				6329
				6330
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6331	<!-- ======================================================================= -->
				6332	<div class="doc_subsection">
				6333	<a name="int_eh">Exception Handling Intrinsics</a>
				6334	</div>
				6335
				6336	<div class="doc_text">
				6337	<p> The LLVM exception handling intrinsics (which all start with
				6338	<tt>llvm.eh.</tt> prefix), are described in the <a
				6339	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6340	Handling</a> document. </p>
				6341	</div>
				6342
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6343	<!-- ======================================================================= -->
				6344	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6345	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6346	</div>
				6347
				6348	<div class="doc_text">
				6349	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6350	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6351	the <tt>nest</tt> attribute, from a function. The result is a callable
				6352	function pointer lacking the nest parameter - the caller does not need
				6353	to provide a value for it. Instead, the value to use is stored in
				6354	advance in a "trampoline", a block of memory usually allocated
				6355	on the stack, which also contains code to splice the nest value into the
				6356	argument list. This is used to implement the GCC nested function address
				6357	extension.
				6358	</p>
				6359	<p>
				6360	For example, if the function is
				6361	<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]	6362	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]	6363	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6364	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6365	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6366	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6367	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6368	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6369	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6370	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]	6371	</div>
				6372
				6373	<!-- _______________________________________________________________________ -->
				6374	<div class="doc_subsubsection">
				6375	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6376	</div>
				6377	<div class="doc_text">
				6378	<h5>Syntax:</h5>
				6379	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6380	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6381	</pre>
				6382	<h5>Overview:</h5>
				6383	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6384	This fills the memory pointed to by <tt>tramp</tt> with code
				6385	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6386	</p>
				6387	<h5>Arguments:</h5>
				6388	<p>
				6389	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6390	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6391	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]	6392	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6393	currently provides no portable way of determining them, so a front-end that
				6394	generates this intrinsic needs to have some target-specific knowledge.
				6395	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]	6396	</p>
				6397	<h5>Semantics:</h5>
				6398	<p>
				6399	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]	6400	dependent code, turning it into a function. A pointer to this function is
				6401	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6402	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6403	before being called. The new function's signature is the same as that of
				6404	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6405	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6406	of pointer type. Calling the new function is equivalent to calling
				6407	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6408	missing <tt>nest</tt> argument. If, after calling
				6409	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6410	modified, then the effect of any later call to the returned function pointer is
				6411	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6412	</p>
				6413	</div>
				6414
				6415	<!-- ======================================================================= -->
				6416	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6417	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6418	</div>
				6419
				6420	<div class="doc_text">
				6421	<p>
				6422	These intrinsic functions expand the "universal IR" of LLVM to represent
				6423	hardware constructs for atomic operations and memory synchronization. This
				6424	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]	6425	is aimed at a low enough level to allow any programming models or APIs
				6426	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6427	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6428	hardware behavior. Just as hardware provides a "universal IR" for source
				6429	languages, it also provides a starting point for developing a "universal"
				6430	atomic operation and synchronization IR.
				6431	</p>
				6432	<p>
				6433	These do <em>not</em> form an API such as high-level threading libraries,
				6434	software transaction memory systems, atomic primitives, and intrinsic
				6435	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6436	application libraries. The hardware interface provided by LLVM should allow
				6437	a clean implementation of all of these APIs and parallel programming models.
				6438	No one model or paradigm should be selected above others unless the hardware
				6439	itself ubiquitously does so.
				6440
				6441	</p>
				6442	</div>
				6443
				6444	<!-- _______________________________________________________________________ -->
				6445	<div class="doc_subsubsection">
				6446	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6447	</div>
				6448	<div class="doc_text">
				6449	<h5>Syntax:</h5>
				6450	<pre>
				6451	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6452	i1 <device> )
				6453
				6454	</pre>
				6455	<h5>Overview:</h5>
				6456	<p>
				6457	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6458	specific pairs of memory access types.
				6459	</p>
				6460	<h5>Arguments:</h5>
				6461	<p>
				6462	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6463	The first four arguments enables a specific barrier as listed below. The fith
				6464	argument specifies that the barrier applies to io or device or uncached memory.
				6465
				6466	</p>
				6467	<ul>
				6468	<li><tt>ll</tt>: load-load barrier</li>
				6469	<li><tt>ls</tt>: load-store barrier</li>
				6470	<li><tt>sl</tt>: store-load barrier</li>
				6471	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6472	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6473	</ul>
				6474	<h5>Semantics:</h5>
				6475	<p>
				6476	This intrinsic causes the system to enforce some ordering constraints upon
				6477	the loads and stores of the program. This barrier does not indicate
				6478	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6479	which they occur. For any of the specified pairs of load and store operations
				6480	(f.ex. load-load, or store-load), all of the first operations preceding the
				6481	barrier will complete before any of the second operations succeeding the
				6482	barrier begin. Specifically the semantics for each pairing is as follows:
				6483	</p>
				6484	<ul>
				6485	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6486	after the barrier begins.</li>
				6487
				6488	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6489	store after the barrier begins.</li>
				6490	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6491	store after the barrier begins.</li>
				6492	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6493	load after the barrier begins.</li>
				6494	</ul>
				6495	<p>
				6496	These semantics are applied with a logical "and" behavior when more than one
				6497	is enabled in a single memory barrier intrinsic.
				6498	</p>
				6499	<p>
				6500	Backends may implement stronger barriers than those requested when they do not
				6501	support as fine grained a barrier as requested. Some architectures do not
				6502	need all types of barriers and on such architectures, these become noops.
				6503	</p>
				6504	<h5>Example:</h5>
				6505	<pre>
				6506	%ptr = malloc i32
				6507	store i32 4, %ptr
				6508
				6509	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6510	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6511	<i>; guarantee the above finishes</i>
				6512	store i32 8, %ptr <i>; before this begins</i>
				6513	</pre>
				6514	</div>
				6515
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6516	<!-- _______________________________________________________________________ -->
				6517	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6518	<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]	6519	</div>
				6520	<div class="doc_text">
				6521	<h5>Syntax:</h5>
				6522	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6523	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6524	any integer bit width and for different address spaces. Not all targets
				6525	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6526
				6527	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6528	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6529	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6530	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6531	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]	6532
				6533	</pre>
				6534	<h5>Overview:</h5>
				6535	<p>
				6536	This loads a value in memory and compares it to a given value. If they are
				6537	equal, it stores a new value into the memory.
				6538	</p>
				6539	<h5>Arguments:</h5>
				6540	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6541	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]	6542	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6543	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6544	this integer type. While any bit width integer may be used, targets may only
				6545	lower representations they support in hardware.
				6546
				6547	</p>
				6548	<h5>Semantics:</h5>
				6549	<p>
				6550	This entire intrinsic must be executed atomically. It first loads the value
				6551	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6552	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6553	loaded value is yielded in all cases. This provides the equivalent of an
				6554	atomic compare-and-swap operation within the SSA framework.
				6555	</p>
				6556	<h5>Examples:</h5>
				6557
				6558	<pre>
				6559	%ptr = malloc i32
				6560	store i32 4, %ptr
				6561
				6562	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6563	%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]	6564	<i>; yields {i32}:result1 = 4</i>
				6565	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6566	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6567
				6568	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6569	%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]	6570	<i>; yields {i32}:result2 = 8</i>
				6571	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6572
				6573	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6574	</pre>
				6575	</div>
				6576
				6577	<!-- _______________________________________________________________________ -->
				6578	<div class="doc_subsubsection">
				6579	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6580	</div>
				6581	<div class="doc_text">
				6582	<h5>Syntax:</h5>
				6583
				6584	<p>
				6585	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6586	integer bit width. Not all targets support all bit widths however.</p>
				6587	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6588	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6589	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6590	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6591	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6592
				6593	</pre>
				6594	<h5>Overview:</h5>
				6595	<p>
				6596	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6597	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6598	at <tt>ptr</tt>.
				6599	</p>
				6600	<h5>Arguments:</h5>
				6601
				6602	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6603	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6604	<tt>val</tt> argument and the result must be integers of the same bit width.
				6605	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6606	integer type. The targets may only lower integer representations they
				6607	support.
				6608	</p>
				6609	<h5>Semantics:</h5>
				6610	<p>
				6611	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6612	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6613	equivalent of an atomic swap operation within the SSA framework.
				6614
				6615	</p>
				6616	<h5>Examples:</h5>
				6617	<pre>
				6618	%ptr = malloc i32
				6619	store i32 4, %ptr
				6620
				6621	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6622	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6623	<i>; yields {i32}:result1 = 4</i>
				6624	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6625	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6626
				6627	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6628	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6629	<i>; yields {i32}:result2 = 8</i>
				6630
				6631	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6632	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6633	</pre>
				6634	</div>
				6635
				6636	<!-- _______________________________________________________________________ -->
				6637	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6638	<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]	6639
				6640	</div>
				6641	<div class="doc_text">
				6642	<h5>Syntax:</h5>
				6643	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6644	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]	6645	integer bit width. Not all targets support all bit widths however.</p>
				6646	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6647	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6648	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6649	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6650	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6651
				6652	</pre>
				6653	<h5>Overview:</h5>
				6654	<p>
				6655	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6656	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6657	</p>
				6658	<h5>Arguments:</h5>
				6659	<p>
				6660
				6661	The intrinsic takes two arguments, the first a pointer to an integer value
				6662	and the second an integer value. The result is also an integer value. These
				6663	integer types can have any bit width, but they must all have the same bit
				6664	width. The targets may only lower integer representations they support.
				6665	</p>
				6666	<h5>Semantics:</h5>
				6667	<p>
				6668	This intrinsic does a series of operations atomically. It first loads the
				6669	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6670	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6671	</p>
				6672
				6673	<h5>Examples:</h5>
				6674	<pre>
				6675	%ptr = malloc i32
				6676	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6677	%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]	6678	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6679	%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]	6680	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6681	%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]	6682	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6683	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6684	</pre>
				6685	</div>
				6686
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6687	<!-- _______________________________________________________________________ -->
				6688	<div class="doc_subsubsection">
				6689	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6690
				6691	</div>
				6692	<div class="doc_text">
				6693	<h5>Syntax:</h5>
				6694	<p>
				6695	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]	6696	any integer bit width and for different address spaces. Not all targets
				6697	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6698	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6699	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6700	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6701	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6702	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]	6703
				6704	</pre>
				6705	<h5>Overview:</h5>
				6706	<p>
				6707	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6708	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6709	</p>
				6710	<h5>Arguments:</h5>
				6711	<p>
				6712
				6713	The intrinsic takes two arguments, the first a pointer to an integer value
				6714	and the second an integer value. The result is also an integer value. These
				6715	integer types can have any bit width, but they must all have the same bit
				6716	width. The targets may only lower integer representations they support.
				6717	</p>
				6718	<h5>Semantics:</h5>
				6719	<p>
				6720	This intrinsic does a series of operations atomically. It first loads the
				6721	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6722	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6723	</p>
				6724
				6725	<h5>Examples:</h5>
				6726	<pre>
				6727	%ptr = malloc i32
				6728	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6729	%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]	6730	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6731	%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]	6732	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6733	%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]	6734	<i>; yields {i32}:result3 = 2</i>
				6735	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6736	</pre>
				6737	</div>
				6738
				6739	<!-- _______________________________________________________________________ -->
				6740	<div class="doc_subsubsection">
				6741	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6742	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6743	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6744	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6745
				6746	</div>
				6747	<div class="doc_text">
				6748	<h5>Syntax:</h5>
				6749	<p>
				6750	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6751	<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]	6752	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6753	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6754	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6755	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6756	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6757	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6758	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]	6759
				6760	</pre>
				6761
				6762	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6763	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6764	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6765	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6766	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]	6767
				6768	</pre>
				6769
				6770	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6771	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6772	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6773	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6774	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]	6775
				6776	</pre>
				6777
				6778	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6779	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6780	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6781	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6782	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]	6783
				6784	</pre>
				6785	<h5>Overview:</h5>
				6786	<p>
				6787	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6788	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6789	at <tt>ptr</tt>.
				6790	</p>
				6791	<h5>Arguments:</h5>
				6792	<p>
				6793
				6794	These intrinsics take two arguments, the first a pointer to an integer value
				6795	and the second an integer value. The result is also an integer value. These
				6796	integer types can have any bit width, but they must all have the same bit
				6797	width. The targets may only lower integer representations they support.
				6798	</p>
				6799	<h5>Semantics:</h5>
				6800	<p>
				6801	These intrinsics does a series of operations atomically. They first load the
				6802	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6803	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6804	value stored at <tt>ptr</tt>.
				6805	</p>
				6806
				6807	<h5>Examples:</h5>
				6808	<pre>
				6809	%ptr = malloc i32
				6810	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6811	%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]	6812	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6813	%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]	6814	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6815	%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]	6816	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6817	%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]	6818	<i>; yields {i32}:result3 = FF</i>
				6819	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6820	</pre>
				6821	</div>
				6822
				6823
				6824	<!-- _______________________________________________________________________ -->
				6825	<div class="doc_subsubsection">
				6826	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6827	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6828	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6829	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6830
				6831	</div>
				6832	<div class="doc_text">
				6833	<h5>Syntax:</h5>
				6834	<p>
				6835	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6836	<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]	6837	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6838	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6839	support all bit widths however.</p>
				6840	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6841	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6842	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6843	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6844	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]	6845
				6846	</pre>
				6847
				6848	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6849	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6850	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6851	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6852	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]	6853
				6854	</pre>
				6855
				6856	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6857	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6858	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6859	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6860	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]	6861
				6862	</pre>
				6863
				6864	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6865	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6866	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6867	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6868	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]	6869
				6870	</pre>
				6871	<h5>Overview:</h5>
				6872	<p>
				6873	These intrinsics takes the signed or unsigned minimum or maximum of
				6874	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6875	original value at <tt>ptr</tt>.
				6876	</p>
				6877	<h5>Arguments:</h5>
				6878	<p>
				6879
				6880	These intrinsics take two arguments, the first a pointer to an integer value
				6881	and the second an integer value. The result is also an integer value. These
				6882	integer types can have any bit width, but they must all have the same bit
				6883	width. The targets may only lower integer representations they support.
				6884	</p>
				6885	<h5>Semantics:</h5>
				6886	<p>
				6887	These intrinsics does a series of operations atomically. They first load the
				6888	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6889	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6890	the original value stored at <tt>ptr</tt>.
				6891	</p>
				6892
				6893	<h5>Examples:</h5>
				6894	<pre>
				6895	%ptr = malloc i32
				6896	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6897	%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]	6898	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6899	%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]	6900	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6901	%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]	6902	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6903	%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]	6904	<i>; yields {i32}:result3 = 8</i>
				6905	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6906	</pre>
				6907	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6908
				6909	<!-- ======================================================================= -->
				6910	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6911	<a name="int_general">General Intrinsics</a>
				6912	</div>
				6913
				6914	<div class="doc_text">
				6915	<p> This class of intrinsics is designed to be generic and has
				6916	no specific purpose. </p>
				6917	</div>
				6918
				6919	<!-- _______________________________________________________________________ -->
				6920	<div class="doc_subsubsection">
				6921	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6922	</div>
				6923
				6924	<div class="doc_text">
				6925
				6926	<h5>Syntax:</h5>
				6927	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6928	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]	6929	</pre>
				6930
				6931	<h5>Overview:</h5>
				6932
				6933	<p>
				6934	The '<tt>llvm.var.annotation</tt>' intrinsic
				6935	</p>
				6936
				6937	<h5>Arguments:</h5>
				6938
				6939	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6940	The first argument is a pointer to a value, the second is a pointer to a
				6941	global string, the third is a pointer to a global string which is the source
				6942	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6943	</p>
				6944
				6945	<h5>Semantics:</h5>
				6946
				6947	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6948	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6949	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]	6950	annotations. These have no other defined use, they are ignored by code
				6951	generation and optimization.
				6952	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6953	</div>
				6954
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6955	<!-- _______________________________________________________________________ -->
				6956	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6957	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6958	</div>
				6959
				6960	<div class="doc_text">
				6961
				6962	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6963	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6964	any integer bit width.
				6965	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6966	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6967	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6968	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6969	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6970	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6971	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]	6972	</pre>
				6973
				6974	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6975
				6976	<p>
				6977	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6978	</p>
				6979
				6980	<h5>Arguments:</h5>
				6981
				6982	<p>
				6983	The first argument is an integer value (result of some expression),
				6984	the second is a pointer to a global string, the third is a pointer to a global
				6985	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]	6986	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6987	</p>
				6988
				6989	<h5>Semantics:</h5>
				6990
				6991	<p>
				6992	This intrinsic allows annotations to be put on arbitrary expressions
				6993	with arbitrary strings. This can be useful for special purpose optimizations
				6994	that want to look for these annotations. These have no other defined use, they
				6995	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6996	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6997	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6998
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6999	<!-- _______________________________________________________________________ -->
				7000	<div class="doc_subsubsection">
				7001	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7002	</div>
				7003
				7004	<div class="doc_text">
				7005
				7006	<h5>Syntax:</h5>
				7007	<pre>
				7008	declare void @llvm.trap()
				7009	</pre>
				7010
				7011	<h5>Overview:</h5>
				7012
				7013	<p>
				7014	The '<tt>llvm.trap</tt>' intrinsic
				7015	</p>
				7016
				7017	<h5>Arguments:</h5>
				7018
				7019	<p>
				7020	None
				7021	</p>
				7022
				7023	<h5>Semantics:</h5>
				7024
				7025	<p>
				7026	This intrinsics is lowered to the target dependent trap instruction. If the
				7027	target does not have a trap instruction, this intrinsic will be lowered to the
				7028	call of the abort() function.
				7029	</p>
				7030	</div>
				7031
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7032	<!-- _______________________________________________________________________ -->
				7033	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	7034	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7035	</div>
				7036	<div class="doc_text">
				7037	<h5>Syntax:</h5>
				7038	<pre>
				7039	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7040
				7041	</pre>
				7042	<h5>Overview:</h5>
				7043	<p>
				7044	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7045	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7046	it is placed on the stack before local variables.
				7047	</p>
				7048	<h5>Arguments:</h5>
				7049	<p>
				7050	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7051	first argument is the value loaded from the stack guard
				7052	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7053	has enough space to hold the value of the guard.
				7054	</p>
				7055	<h5>Semantics:</h5>
				7056	<p>
				7057	This intrinsic causes the prologue/epilogue inserter to force the position of
				7058	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7059	stack. This is to ensure that if a local variable on the stack is overwritten,
				7060	it will destroy the value of the guard. When the function exits, the guard on
				7061	the stack is checked against the original guard. If they're different, then
				7062	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7063	</p>
				7064	</div>
				7065
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7066	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7067	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7068	<address>
				7069	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7070	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7071	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7072	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7073
				7074	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7075	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7076	Last modified: $Date$
				7077	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7078
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7079	</body>
				7080	</html>