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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	44	</ol>
				45	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	46	<li><a href="#t_derived">Derived Types</a>
				47	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	48	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	49	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	50	<li><a href="#t_function">Function Type</a></li>
				51	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	52	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	53	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	54	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	55	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	56	</ol>
				57	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	58	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	59	</ol>
				60	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	61	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	62	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	63	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	64	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	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	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	68	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	69	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	70	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	71	<li><a href="#othervalues">Other Values</a>
				72	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	73	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	74	</ol>
				75	</li>
Chris Lattner	0095054	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	261efe9	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	9d0919f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	84	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	85	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	86	</ol>
				87	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	88	<li><a href="#binaryops">Binary Operations</a>
				89	<ol>
Chris Lattner	261efe9	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	1628cec	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	0a783f7	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	99	</ol>
				100	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	101	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				102	<ol>
Reid Spencer	8e11bf8	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	106	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	107	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	108	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	109	</ol>
				110	</li>
Chris Lattner	3df241e	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	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	116	</ol>
				117	</li>
Dan Gohman	a334d5f	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	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	124	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	125	<ol>
Chris Lattner	261efe9	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	7b81c75	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	132	</ol>
				133	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	134	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	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	d444879	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	7267925	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	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	147	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	148	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	149	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	150	<li><a href="#otherops">Other Operations</a>
				151	<ol>
Reid Spencer	f3a70a6	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	ac80ade	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	156	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	157	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	160	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	161	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	162	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	164	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	165	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	166	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				167	<ol>
Reid Spencer	a3e435f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	171	</ol>
				172	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	173	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				174	<ol>
Reid Spencer	a3e435f	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	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	178	</ol>
				179	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	180	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				181	<ol>
Reid Spencer	a3e435f	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	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	189	</ol>
				190	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	191	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				192	<ol>
Reid Spencer	a3e435f	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	91c284c	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	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	201	</ol>
				202	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	203	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	204	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	205	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	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	f86037f	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	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	211	</ol>
				212	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	213	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				214	<ol>
Bill Wendling	da01af7	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	41b485c	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	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	221	</ol>
				222	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	223	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	224	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	225	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	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	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	228	</ol>
				229	</li>
Bill Wendling	3c44f5b	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	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	247	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	248	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	250	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	251	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	253	<li><a href="#int_trap">
Bill Wendling	69e4adb	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	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	257	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	258	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	259	</ol>
				260	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	261	</ol>
Chris Lattner	d792391	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	266	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	268	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	269	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				270	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	272	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	274	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	representation used throughout all phases of the LLVM compilation
				278	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	279	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	281	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				283	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	285	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	287	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	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	261efe9	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	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	297	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	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	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	310	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	312
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	313	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Chris Lattner	261efe9	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	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	320	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	322	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Chris Lattner	261efe9	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	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	329	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	330	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	333	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	334
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	335	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	337	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	338	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	341	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Reid Spencer	2c45228	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	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	346	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	347
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	348	<ol>
Reid Spencer	2c45228	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	352	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	356
Reid Spencer	2c45228	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359
Reid Spencer	cc16dc3	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	362	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	2c45228	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	e5d947b	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	261efe9	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	5c0ef47	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	ca86e16	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	377	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	386	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	390	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	394	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	398	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401	<pre>
Bill Wendling	2f7a8b0	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	406	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407
Chris Lattner	261efe9	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	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	410
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	411	<ol>
Chris Lattner	e5d947b	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	419	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	420
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	421	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422
John Criswell	e4c57cc	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	e5d947b	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	428	</div>
Chris Lattner	fa73021	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	447	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	454
				455	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	456	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	457	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458	%cast210 = <a
Dan Gohman	2a08c53	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	fa73021	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	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	463	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	464	<a
Bill Wendling	2f7a8b0	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	fa73021	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	e5d947b	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479
Chris Lattner	e5d947b	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	492
				493	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	494
Rafael Espindola	bb46f52	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	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	505	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Duncan Sands	81d05c2	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	bb46f52	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	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	509	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	510	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Chris Lattner	266c7bb	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Chris Lattner	4887bd8	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	2307a7f	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	542	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	543
Dale Johannesen	2307a7f	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	548	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	549
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	550	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	557	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	558
Anton Korobeynikov	7f70559	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	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	560
Chris Lattner	d3eda89	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	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	564	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565
Duncan Sands	667d4b8	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	667d4b8	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	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame^]	568	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	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	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame^]	571	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	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	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	575	</dd>
				576
Chris Lattner	fa73021	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	e5d947b	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	582	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	583	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	584
Anton Korobeynikov	b74ed07	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	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	588	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	589	</p>
				590
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	591	<dl>
Anton Korobeynikov	b74ed07	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	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	597	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	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	7956412	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	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	606	name.
				607	</dd>
				608
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	609	</dl>
				610
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	611	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	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	ac8d276	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	5f4ee1f	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	667d4b8	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	622	</div>
				623
				624	<!-- ======================================================================= -->
				625	<div class="doc_subsection">
Chris Lattner	bad10ee	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	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	643	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	644	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	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	d3eda89	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	9097d14	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	bad10ee	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	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	670	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	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	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	676	</dl>
Chris Lattner	bad10ee	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	8cea37b	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	d3eda89	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	8cea37b	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	6f9896f	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	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	722	</dl>
				723
				724	</div>
				725
				726	<!-- ======================================================================= -->
				727	<div class="doc_subsection">
Chris Lattner	e7886e4	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	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	760	<!-- ======================================================================= -->
				761	<div class="doc_subsection">
Chris Lattner	fa73021	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	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	767	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	768	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	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	3689a34	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	0ec250c	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	3689a34	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	fa73021	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	284d992	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	d49e18d	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	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	798
Chris Lattner	88f6c46	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	2cbdc45	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	284d992	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	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	810
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	811	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	812	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	813	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	815	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816
Chris Lattner	fa73021	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	ca86e16	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	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	829	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	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	f642f47	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	0c46a7d	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	8cea37b	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	842	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	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	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	844	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	845
Chris Lattner	d3eda89	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	fa73021	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	4a3c901	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	fa73021	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	88f6c46	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	2cbdc45	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	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	868	<h5>Syntax:</h5>
				869
				870	<div class="doc_code">
Chris Lattner	50ad45c	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	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	878	</div>
				879
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	880	</div>
				881
Anton Korobeynikov	8b0a8c8	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	726d45c	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	8b0a8c8	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	895	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	896	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	897	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	898	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	899	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	900
				901	</div>
				902
				903
				904
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	905	<!-- ======================================================================= -->
Reid Spencer	ca86e16	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	dc02467	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	914
Reid Spencer	950e9f8	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	917	example:</p>
				918
				919	<div class="doc_code">
				920	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	921	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	922	declare i32 @atoi(i8 zeroext)
				923	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	924	</pre>
				925	</div>
				926
Duncan Sands	dc02467	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	929
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	930	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	931	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	932	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	936
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	937	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	941
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	942	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	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	66d922c	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	948
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	949	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	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	ebec678	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	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	954	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	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	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	958	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	963
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	964	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	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	66d922c	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	f642f47	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	971
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	972	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	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	b2b32fd	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	f23d0d3	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	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	986
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	987	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	988	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	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	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	991	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	992
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	993	</div>
				994
				995	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	996	<div class="doc_subsection">
Gordon Henriksen	80a75bf	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	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1014	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1015	</div>
				1016
				1017	<div class="doc_text">
Devang Patel	2c9c3e7	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	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1027
				1028	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1029	<pre>
Devang Patel	2c9c3e7	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	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1034	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1035	</div>
				1036
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1037	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1038	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	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	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1042
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1043	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1044	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1045	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1046	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1047
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1048	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1049	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	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	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1052
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1053	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	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	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1057
				1058	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	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	edb05df	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	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1070
Duncan Sands	edb05df	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	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1079
				1080	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1081	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	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	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1085	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
Bill Wendling	fbaa7ed	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	baa39d8	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	31359ba	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	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1094	function attribute.
Bill Wendling	fbaa7ed	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	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1100	</dl>
				1101
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1102	</div>
				1103
				1104	<!-- ======================================================================= -->
				1105	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1106	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	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	2f7a8b0	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	4e9aba7	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1134
Reid Spencer	de15194	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	c891084	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	de15194	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	d3eda89	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	de15194	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	d3eda89	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	de15194	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	ebec678	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	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1194	following rules:</p>
Reid Spencer	de15194	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	0e451ce	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	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1208	</ol>
				1209	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1210
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1211	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1212	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1213	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1214
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1215	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1216
Misha Brukman	9d0919f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1218	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	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	261efe9	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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1225
				1226	</div>
				1227
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1228	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1229	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1230	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1231	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1232	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1233	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1234
				1235	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1236	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1237	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1238	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1239	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1240	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	</tr>
				1242	<tr>
Chris Lattner	4f69f46	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	261efe9	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	4f69f46	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	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1251	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	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	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1254	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1255	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	</tr>
Chris Lattner	4f69f46	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	4f69f46	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	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1273	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1274	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1275	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1276	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1277
Chris Lattner	261efe9	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	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1281	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1282	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1283
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1284	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1285	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1286
Chris Lattner	4f69f46	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	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1291	</div>
				1292
Chris Lattner	4f69f46	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1339	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1341	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1342
Chris Lattner	261efe9	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1347
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1348	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1349
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1350	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	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	b9488a6	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	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1381	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1382	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1383	</table>
Dan Gohman	d8791e5	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1391	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1392
				1393	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1394	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1395
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1396	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1397
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1398	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1399
Misha Brukman	9d0919f	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	261efe9	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1403
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1404	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1405
				1406	<pre>
				1407	[<# elements> x <elementtype>]
				1408	</pre>
				1409
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1410	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1411	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1412
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1413	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1414	<table class="layout">
				1415	<tr class="layout">
Chris Lattner	23ff1f9	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1426	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1427	</table>
Reid Spencer	d3f876c	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	23ff1f9	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1441	</tr>
				1442	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1443
John Criswell	0ec250c	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	e67a951	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1449	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1450
Dan Gohman	d8791e5	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1456	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1457
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1458	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1459	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1461
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1462	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1463
Chris Lattner	261efe9	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	a582f40	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	f4cde4e	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	7a3ad1a	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	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1468	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1469
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1470	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1471
				1472	<pre>
				1473	<returntype list> (<parameter list>)
				1474	</pre>
				1475
John Criswell	0ec250c	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	c24b758	2004-08-12 20:16:08 +0000	[diff] [blame]	1477	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	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	c3fc6df	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	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1483
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1484	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1485	<table class="layout">
				1486	<tr class="layout">
Reid Spencer	92f8230	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1489	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1490	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1491	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1492	</tt></td>
Reid Spencer	92f8230	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1495	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	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	a517338	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	92f8230	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1504	</td>
Devang Patel	a582f40	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	b0a57aa	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	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1509	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1510	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1511	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1512
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1513	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1514	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1515	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1516	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1517	<h5>Overview:</h5>
Chris Lattner	261efe9	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1526	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1527	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1528	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1529	<table class="layout">
				1530	<tr class="layout">
Jeff Cohen	6f1cc77	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1539	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1540	</table>
Dan Gohman	d8791e5	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1547	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1548
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1549	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	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	6f1cc77	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	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1570	<td class="left">
				1571	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	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	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1576	</tr>
				1577	</table>
				1578	</div>
				1579
				1580	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1581	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1582	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1583	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1584	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	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	0fd4a27	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	e220e8c	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	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1592
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1593	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1594	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1595	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1596	<table class="layout">
				1597	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1598	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	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	ca86e16	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	23ff1f9	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1612	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1613	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1614	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1615
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1616	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1617	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1618	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1619
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1620	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1621
Reid Spencer	485bad1	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	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1624	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1625	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1626	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1627	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1628	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1629
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1630	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1631
				1632	<pre>
				1633	< <# elements> x <elementtype> >
				1634	</pre>
				1635
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1636	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1637	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1638
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1639	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1640
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1641	<table class="layout">
				1642	<tr class="layout">
Chris Lattner	23ff1f9	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	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1653	</tr>
				1654	</table>
Dan Gohman	d8791e5	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1661	</div>
				1662
Chris Lattner	69c11bb	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	8ac04ff	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	69c11bb	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	23ff1f9	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	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1686	</tr>
				1687	</table>
				1688	</div>
				1689
Chris Lattner	242d61d	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	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1704	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	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	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1740
Chris Lattner	c3f5976	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	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1753	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	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	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1761	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1762	</dd>
				1763
				1764	<dt><b>Integer constants</b></dt>
				1765
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1766	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1767	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	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	a73afe0	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1779
				1780	<dt><b>Null pointer constants</b></dt>
				1781
John Criswell	9e2485c	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	c3f5976	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	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1787	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	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	cc16dc3	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	bd5e5a8	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	cc16dc3	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	bd5e5a8	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1812	</div>
				1813
				1814	<!-- ======================================================================= -->
Chris Lattner	7088279	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1818	</div>
				1819
				1820	<div class="doc_text">
Chris Lattner	7088279	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	c3f5976	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	64910ee	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	d4f6b17	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	c3f5976	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	ca86e16	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	c3f5976	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	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1844	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1845
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1846	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1847	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1848	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1849	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	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	c3f5976	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	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1859	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1860	initializers.
				1861	</dd>
Nick Lewycky	21cc446	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	c3f5976	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	9e2485c	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	c3f5976	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1888	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1889	<pre>
Chris Lattner	a18a424	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1893	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1894	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1895
				1896	</div>
				1897
				1898	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1899	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1900	<div class="doc_text">
Reid Spencer	2dc45b8	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	c1f786c	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	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1903	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1904
Reid Spencer	2dc45b8	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	c3f5976	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	c1f786c	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	c3f5976	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	9dee3ac	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	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1925	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1926
Reid Spencer	9dee3ac	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	3b19d65	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	9dee3ac	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	3b19d65	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	9dee3ac	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	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1944	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1945	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	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	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1950
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1951	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1952	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	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	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1957
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1958	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1959	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	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	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1964
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1965	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1966	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	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	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1971
Reid Spencer	5c0ef47	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	03bbad6	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	c3f5976	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	9fbe145	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	01c4259	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	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2005
Nate Begeman	ac80ade	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	9fbe145	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	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2015	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2016
Robert Bocchino	05ccd70	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	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2020	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2021
Chris Lattner	c198954	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	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2026	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2027
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2028	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2029
Reid Spencer	2dc45b8	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	c3f5976	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	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2034	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2035	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2036	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2037
Nick Lewycky	21cc446	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2067	<!-- *********************************************************************** -->
Chris Lattner	e87d653	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2087	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2088	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2089	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2090	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2091	</div>
Chris Lattner	e87d653	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2098	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2099	<pre>
Bill Wendling	2f7a8b0	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	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2101	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2102	</div>
Chris Lattner	e87d653	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	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2110	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2111	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2112	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2113	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2114	</div>
Chris Lattner	e87d653	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	4f99335	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	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2120	</p>
				2121
				2122	</div>
				2123
				2124	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2125	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2126	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2127
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2128	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2129
Chris Lattner	261efe9	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	c1f786c	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	261efe9	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2136
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2137	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2138
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2139	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2140	<div class="doc_subsection"> <a name="terminators">Terminator
				2141	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2142
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2143	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2144
Chris Lattner	261efe9	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	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2151	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	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	35eca58	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	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2157
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2158	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2159
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2160	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2163	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2164	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	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	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2167	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2168	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2169
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2170	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2171
Dan Gohman	b1e6b96	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	4457dc9	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	b1e6b96	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2176	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2177
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2179
Dan Gohman	b1e6b96	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	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2189
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2190	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2191
Chris Lattner	261efe9	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	fa08187	2004-06-25 15:16:57 +0000	[diff] [blame]	2194	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	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	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2197	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	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	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2199	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2200
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Example:</h5>
Chris Lattner	f4cde4e	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	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2205	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2208
Dan Gohman	d8791e5	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	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2216
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2217	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2218	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2220	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Syntax:</h5>
Reid Spencer	c78f337	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2223	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Overview:</h5>
Chris Lattner	261efe9	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Arguments:</h5>
Chris Lattner	261efe9	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	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2231	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	<h5>Semantics:</h5>
Reid Spencer	c78f337	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	261efe9	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2239	<h5>Example:</h5>
Reid Spencer	c78f337	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	ca86e16	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2242	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2248	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2249	<h5>Syntax:</h5>
Chris Lattner	c88c17b	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2255	<h5>Overview:</h5>
Chris Lattner	c88c17b	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	9d0919f	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	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2261
				2262
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Arguments:</h5>
Chris Lattner	c88c17b	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2271
Chris Lattner	261efe9	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	8411475	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2277
Chris Lattner	c88c17b	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	8411475	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	c88c17b	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	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2289	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2290	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2293	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2294
				2295	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2299	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2300	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2301
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2302	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2307	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2308
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2309	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2310
				2311	<pre>
Devang Patel	307e8ab	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	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2313	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2314	</pre>
				2315
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2316	<h5>Overview:</h5>
Chris Lattner	bad10ee	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	e4c57cc	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	bad10ee	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	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2324	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2325	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2326
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2327	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2328
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2329	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2330
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2331	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2332	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2333	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	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	f642f47	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	bad10ee	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	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2362	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2365	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2366
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2367	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2368
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2369	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2379	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2380	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2381	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2382	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	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	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2384	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2385	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2386	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2387
				2388
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2389	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2390
Chris Lattner	261efe9	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	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2393
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2394	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2395
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2396	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2397	<pre>
				2398	unwind
				2399	</pre>
				2400
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2401	<h5>Overview:</h5>
Chris Lattner	35eca58	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	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2408	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2409
Chris Lattner	72ed200	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	35eca58	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2416	</div>
Chris Lattner	35eca58	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2444	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2445	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2446	<div class="doc_text">
Chris Lattner	261efe9	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	5a15814	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	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2449	produce a single value. The operands might represent
Reid Spencer	485bad1	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	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2451	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2452	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2453	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2454	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2459	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2460
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2461	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2462
				2463	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2464	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2465	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2466
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2467	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2468
Misha Brukman	9d0919f	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2470
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2471	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2478	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2479
Misha Brukman	9d0919f	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2482
Chris Lattner	5ec8983	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2486
Chris Lattner	5ec8983	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2489
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2490	<h5>Example:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2494	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2495	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2503	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
				2505	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2506	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
Misha Brukman	9d0919f	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	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2525	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
Chris Lattner	261efe9	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2529
Chris Lattner	5ec8983	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Chris Lattner	5ec8983	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2537	<h5>Example:</h5>
Bill Wendling	aac388b	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2540	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2542	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2543
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2544	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2549	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2550
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2551	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2552	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2553	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2554	<h5>Overview:</h5>
Chris Lattner	261efe9	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2557
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2558	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2565	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2566
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2568	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2569
Chris Lattner	5ec8983	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2579	<h5>Example:</h5>
Reid Spencer	ca86e16	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2581	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2582	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2584	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2589	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2594
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2595	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2596
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2597	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	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	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2601	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2602
Chris Lattner	5ec8983	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	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2607	<h5>Example:</h5>
Reid Spencer	ca86e16	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	1628cec	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2616	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2617	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2618	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2619
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2620	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Reid Spencer	1628cec	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2624
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2625	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2631	<h5>Semantics:</h5>
Chris Lattner	a73afe0	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	5ec8983	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	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2638	<h5>Example:</h5>
Reid Spencer	ca86e16	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	1628cec	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2644	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2645	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2646	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2647	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2648	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2649	</pre>
				2650	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2651
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2652	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2653	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2654
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2655	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2656
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2657	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2661	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2662
Reid Spencer	1628cec	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2664
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2665	<h5>Example:</h5>
Chris Lattner	5568e94	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2669	</pre>
				2670	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2671
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2677	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	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	5568e94	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	0a783f7	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	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2688	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	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	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2692	<h5>Example:</h5>
Reid Spencer	ca86e16	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	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2694	</pre>
				2695
				2696	</div>
				2697	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2702	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2703
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2704	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2705
				2706	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2707	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2708	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2709
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2710	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2711
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2712	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	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	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2716
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2717	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2718
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2719	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2723	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2724
Reid Spencer	0a783f7	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	fb224a2	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	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2728	a value. For more information about the difference, see <a
Chris Lattner	261efe9	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	c9fdfc8	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	64f5c6c	2007-03-24 22:40:44 +0000	[diff] [blame]	2731	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2732	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2741	<h5>Example:</h5>
Reid Spencer	ca86e16	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	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2743	</pre>
				2744
				2745	</div>
				2746	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	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	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2750	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2751
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2752	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2753	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	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	5568e94	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	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2763	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2764
Chris Lattner	a73afe0	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2767
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2768	<h5>Example:</h5>
Chris Lattner	5568e94	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2772	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2773	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2774
Reid Spencer	8e11bf8	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	a73afe0	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	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2784	</div>
				2785
Reid Spencer	569f2fa	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2791	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2792	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2793
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2794	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2795
Reid Spencer	569f2fa	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	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2798
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2799	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2800
Reid Spencer	569f2fa	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	5bc1ea0	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2803	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2804
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2805	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2806
Gabor Greif	fb224a2	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	01f8d09	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	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2812
Reid Spencer	569f2fa	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	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2817	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	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	569f2fa	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2826	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	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	6f1cc77	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	569f2fa	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	5bc1ea0	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2836	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2837
				2838	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2839
Reid Spencer	569f2fa	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	fb224a2	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	01f8d09	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	569f2fa	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	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2853	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	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	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2855	</pre>
				2856	</div>
				2857
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2858	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2864	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	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	6f1cc77	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	569f2fa	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	5bc1ea0	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	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2874	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	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	fb224a2	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	01f8d09	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	569f2fa	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	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2890	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	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	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2892	</pre>
				2893	</div>
				2894
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2895	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2898
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2899	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2900
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2901	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2902
				2903	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2904	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2905	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2906
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2907	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2908
Chris Lattner	261efe9	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	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2911
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2912	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2918	<h5>Semantics:</h5>
Misha Brukman	9d0919f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2920	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2921	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2922	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	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	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2951	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2952	<h5>Example:</h5>
Chris Lattner	5568e94	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	ca86e16	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2957	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2958	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2959	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2961	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2962	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2963	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2964	</pre>
Chris Lattner	261efe9	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2968	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2973	<h5>Semantics:</h5>
Misha Brukman	9d0919f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2975	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2976	<div>
Chris Lattner	261efe9	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	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3006	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3007	<h5>Example:</h5>
Reid Spencer	ca86e16	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3011	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3012	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3013	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3016	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3017	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3018	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3019	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3020	<h5>Overview:</h5>
Chris Lattner	261efe9	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3024	<h5>Arguments:</h5>
Chris Lattner	5568e94	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3029	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3030
Misha Brukman	9d0919f	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3032	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3033	<div>
Chris Lattner	261efe9	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	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3063	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3064	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3065	<h5>Example:</h5>
Reid Spencer	ca86e16	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3070	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3071	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3072
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3073	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3074	<div class="doc_subsection">
Chris Lattner	3df241e	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	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3081	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3099	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	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	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3106	element from a vector at a specified index.
Chris Lattner	3df241e	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	485bad1	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	3df241e	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3130	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	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	f3480b9	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	3df241e	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	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3152	element into a vector at a specified index.
Chris Lattner	3df241e	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	485bad1	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	3df241e	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	485bad1	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	3df241e	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	ca86e16	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	3df241e	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	aeb06d2	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	3df241e	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	aeb06d2	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	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3200	</p>
				3201
				3202	<h5>Arguments:</h5>
				3203
				3204	<p>
Mon P Wang	aeb06d2	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	3df241e	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	aeb06d2	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	3df241e	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3230	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	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	ca86e16	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	aeb06d2	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	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3238	</pre>
				3239	</div>
				3240
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3241
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3242	<!-- ======================================================================= -->
				3243	<div class="doc_subsection">
Dan Gohman	a334d5f	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	c3dac5c	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	a334d5f	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	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3280	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3281	in a similar manner as indices in a
Dan Gohman	a334d5f	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	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3295	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	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	81a0c0b	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	a334d5f	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	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3317	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	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	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3327	The following operands are constant indices
Dan Gohman	81a0c0b	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	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3329	indices in a
Dan Gohman	a334d5f	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	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3332	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3333	</p>
Dan Gohman	a334d5f	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	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3340	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3341	</p>
				3342
				3343	<h5>Example:</h5>
				3344
				3345	<pre>
Dan Gohman	52bb2db	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	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3347	</pre>
				3348	</div>
				3349
				3350
				3351	<!-- ======================================================================= -->
				3352	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3353	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3354	</div>
				3355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3356	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3357
Chris Lattner	261efe9	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	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3361	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3362
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3363	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3364
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3365	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3370	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3371
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3372	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3373
				3374	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3375	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3376	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3377
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3378	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3379
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3380	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3383
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3384	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	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	6e4ca61	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3389	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3390	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	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	1acd2ee	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3394
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3395	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3396
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3397	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3398
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3399	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	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	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3401	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3402
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3403	<h5>Example:</h5>
				3404
				3405	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3406	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3407
Bill Wendling	aac388b	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3413	</pre>
Dan Gohman	f3e60bd	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3418	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3419
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3420	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3425	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3426
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3427	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3428
				3429	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3430	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3431	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3432
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3433	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3434
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3435	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3436	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3437
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3438	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3439
Chris Lattner	261efe9	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3443
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3444	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3445
John Criswell	9e2485c	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	e0db56d	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3449
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3450	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3451
				3452	<pre>
Dan Gohman	81e2167	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	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3454	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3455	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3456	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3457
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3458	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3463	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3464
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3465	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3466
				3467	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3468	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3469	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3470
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3471	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3472
Jeff Cohen	6f1cc77	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	303dae9	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3477
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3478	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3479
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3480	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3481	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	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	4316dec	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	1acd2ee	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3487
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3488	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3489
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3490	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3491
Chris Lattner	72ed200	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	261efe9	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	dae2e93	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	4316dec	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	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3500
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3501	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3502
				3503	<pre>
Dan Gohman	81e2167	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	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3508	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3509	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3510
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3511	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3514	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3515	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3517	<h5>Overview:</h5>
Misha Brukman	9d0919f	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3519	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3520	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3521	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	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	0ec250c	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	261efe9	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	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3527	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3528	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3537	<h5>Semantics:</h5>
Duncan Sands	19527c6	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3545	<h5>Examples:</h5>
Reid Spencer	ca86e16	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	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3547	<a
Reid Spencer	ca86e16	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3550	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3551	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3552	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	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	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3555	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3556	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3559	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3560	<h5>Overview:</h5>
Misha Brukman	9d0919f	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3562	<h5>Arguments:</h5>
Chris Lattner	261efe9	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	6f1cc77	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	4316dec	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	c1f786c	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	261efe9	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	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3571	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3572	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	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	261efe9	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	19527c6	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3591	<h5>Example:</h5>
Reid Spencer	ca86e16	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	8c6c72d	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	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3595	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3596	</div>
				3597
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3598	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	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	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3603	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3604	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3605	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3606	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3607	</pre>
				3608
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3609	<h5>Overview:</h5>
Chris Lattner	f74d5c7	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	e49d0bc	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	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3615
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3616	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3617
Matthijs Kooijman	e49d0bc	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,
				3632	only integers of 32 or 64 bits are allowed (also non-constants). 32-bit values
				3633	will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3634
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3635	<p>For example, let's consider a C code fragment and how it gets
				3636	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3637
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3638	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3639	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3640	struct RT {
				3641	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3642	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3643	char C;
				3644	};
				3645	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3646	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3647	double Y;
				3648	struct RT Z;
				3649	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3650
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3651	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3652	return &s[1].Z.B[5][13];
				3653	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3654	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3655	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3656
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3657	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3658
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3659	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3660	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3661	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3662	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3663
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3664	define i32* %foo(%ST* %s) {
				3665	entry:
				3666	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3667	ret i32* %reg
				3668	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3669	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3670	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3671
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3672	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3673
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3674	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3675	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3676	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3677	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3678	i8 }</tt>' type, another structure. The third index indexes into the second
				3679	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3680	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3681	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3682	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3683
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3684	<p>Note that it is perfectly legal to index partially through a
				3685	structure, returning a pointer to an inner element. Because of this,
				3686	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3687
				3688	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3689	define i32* %foo(%ST* %s) {
				3690	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3691	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3692	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3693	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3694	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3695	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3696	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3697	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3698
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3699	<p>Note that it is undefined to access an array out of bounds: array
				3700	and pointer indexes must always be within the defined bounds of the
				3701	array type when accessed with an instruction that dereferences the
				3702	pointer (e.g. a load or store instruction). The one exception for
				3703	this rule is zero length arrays. These arrays are defined to be
				3704	accessible as variable length arrays, which requires access beyond the
				3705	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3706
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3707	<p>The getelementptr instruction is often confusing. For some more insight
				3708	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3709	FAQ</a>.</p>
				3710
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3711	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3712
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3713	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3714	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3715	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3716	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3717	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3718	<i>; yields i8*:eptr</i>
				3719	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3720	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3721	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3722
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3723	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3724	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3725	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3726	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3727	<p>The instructions in this category are the conversion instructions (casting)
				3728	which all take a single operand and a type. They perform various bit conversions
				3729	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3730	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3731
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3732	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3733	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3734	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3735	</div>
				3736	<div class="doc_text">
				3737
				3738	<h5>Syntax:</h5>
				3739	<pre>
				3740	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3741	</pre>
				3742
				3743	<h5>Overview:</h5>
				3744	<p>
				3745	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3746	</p>
				3747
				3748	<h5>Arguments:</h5>
				3749	<p>
				3750	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3751	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3752	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3753	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3754	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3755
				3756	<h5>Semantics:</h5>
				3757	<p>
				3758	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3759	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3760	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3761	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3762
				3763	<h5>Example:</h5>
				3764	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3765	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3766	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3767	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3768	</pre>
				3769	</div>
				3770
				3771	<!-- _______________________________________________________________________ -->
				3772	<div class="doc_subsubsection">
				3773	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3774	</div>
				3775	<div class="doc_text">
				3776
				3777	<h5>Syntax:</h5>
				3778	<pre>
				3779	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3780	</pre>
				3781
				3782	<h5>Overview:</h5>
				3783	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3784	<tt>ty2</tt>.</p>
				3785
				3786
				3787	<h5>Arguments:</h5>
				3788	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3789	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3790	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3791	<tt>value</tt> must be smaller than the bit size of the destination type,
				3792	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3793
				3794	<h5>Semantics:</h5>
				3795	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3796	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3797
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3798	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3799
				3800	<h5>Example:</h5>
				3801	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3802	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3803	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3804	</pre>
				3805	</div>
				3806
				3807	<!-- _______________________________________________________________________ -->
				3808	<div class="doc_subsubsection">
				3809	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3810	</div>
				3811	<div class="doc_text">
				3812
				3813	<h5>Syntax:</h5>
				3814	<pre>
				3815	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3816	</pre>
				3817
				3818	<h5>Overview:</h5>
				3819	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3820
				3821	<h5>Arguments:</h5>
				3822	<p>
				3823	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3824	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3825	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3826	<tt>value</tt> must be smaller than the bit size of the destination type,
				3827	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3828
				3829	<h5>Semantics:</h5>
				3830	<p>
				3831	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3832	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3833	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3834
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3835	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3836
				3837	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3838	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3839	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3840	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3841	</pre>
				3842	</div>
				3843
				3844	<!-- _______________________________________________________________________ -->
				3845	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3846	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3847	</div>
				3848
				3849	<div class="doc_text">
				3850
				3851	<h5>Syntax:</h5>
				3852
				3853	<pre>
				3854	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3855	</pre>
				3856
				3857	<h5>Overview:</h5>
				3858	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3859	<tt>ty2</tt>.</p>
				3860
				3861
				3862	<h5>Arguments:</h5>
				3863	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3864	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3865	cast it to. The size of <tt>value</tt> must be larger than the size of
				3866	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3867	<i>no-op cast</i>.</p>
				3868
				3869	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3870	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3871	<a href="#t_floating">floating point</a> type to a smaller
				3872	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3873	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3874
				3875	<h5>Example:</h5>
				3876	<pre>
				3877	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3878	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3879	</pre>
				3880	</div>
				3881
				3882	<!-- _______________________________________________________________________ -->
				3883	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3884	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3885	</div>
				3886	<div class="doc_text">
				3887
				3888	<h5>Syntax:</h5>
				3889	<pre>
				3890	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3891	</pre>
				3892
				3893	<h5>Overview:</h5>
				3894	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3895	floating point value.</p>
				3896
				3897	<h5>Arguments:</h5>
				3898	<p>The '<tt>fpext</tt>' instruction takes a
				3899	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3900	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3901	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3902
				3903	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3904	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3905	<a href="#t_floating">floating point</a> type to a larger
				3906	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3907	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3908	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3909
				3910	<h5>Example:</h5>
				3911	<pre>
				3912	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3913	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3914	</pre>
				3915	</div>
				3916
				3917	<!-- _______________________________________________________________________ -->
				3918	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3919	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3920	</div>
				3921	<div class="doc_text">
				3922
				3923	<h5>Syntax:</h5>
				3924	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3925	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3926	</pre>
				3927
				3928	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3929	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3930	unsigned integer equivalent of type <tt>ty2</tt>.
				3931	</p>
				3932
				3933	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3934	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3935	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3936	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3937	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3938	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3939
				3940	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3941	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3942	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3943	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3944	the results are undefined.</p>
				3945
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3946	<h5>Example:</h5>
				3947	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3948	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3949	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3950	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3951	</pre>
				3952	</div>
				3953
				3954	<!-- _______________________________________________________________________ -->
				3955	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3956	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3957	</div>
				3958	<div class="doc_text">
				3959
				3960	<h5>Syntax:</h5>
				3961	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3962	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3963	</pre>
				3964
				3965	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3966	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3967	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3968	</p>
				3969
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3970	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3971	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3972	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3973	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3974	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3975	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3976
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3977	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3978	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3979	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3980	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3981	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3982
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3983	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3984	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3985	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3986	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3987	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3988	</pre>
				3989	</div>
				3990
				3991	<!-- _______________________________________________________________________ -->
				3992	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3993	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3994	</div>
				3995	<div class="doc_text">
				3996
				3997	<h5>Syntax:</h5>
				3998	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3999	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4000	</pre>
				4001
				4002	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4003	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4004	integer and converts that value to the <tt>ty2</tt> type.</p>
				4005
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4006	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4007	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4008	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4009	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4010	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4011	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4012
				4013	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4014	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4015	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4016	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4017
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4018	<h5>Example:</h5>
				4019	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4020	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4021	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4022	</pre>
				4023	</div>
				4024
				4025	<!-- _______________________________________________________________________ -->
				4026	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4027	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4028	</div>
				4029	<div class="doc_text">
				4030
				4031	<h5>Syntax:</h5>
				4032	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4033	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4034	</pre>
				4035
				4036	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4037	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4038	integer and converts that value to the <tt>ty2</tt> type.</p>
				4039
				4040	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4041	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4042	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4043	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4044	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4045	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4046
				4047	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4048	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4049	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4050	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4051
				4052	<h5>Example:</h5>
				4053	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4054	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4055	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4056	</pre>
				4057	</div>
				4058
				4059	<!-- _______________________________________________________________________ -->
				4060	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4061	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4062	</div>
				4063	<div class="doc_text">
				4064
				4065	<h5>Syntax:</h5>
				4066	<pre>
				4067	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4068	</pre>
				4069
				4070	<h5>Overview:</h5>
				4071	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4072	the integer type <tt>ty2</tt>.</p>
				4073
				4074	<h5>Arguments:</h5>
				4075	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4076	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4077	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4078
				4079	<h5>Semantics:</h5>
				4080	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4081	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4082	truncating or zero extending that value to the size of the integer type. If
				4083	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4084	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4085	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4086	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4087
				4088	<h5>Example:</h5>
				4089	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4090	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4091	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4092	</pre>
				4093	</div>
				4094
				4095	<!-- _______________________________________________________________________ -->
				4096	<div class="doc_subsubsection">
				4097	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4098	</div>
				4099	<div class="doc_text">
				4100
				4101	<h5>Syntax:</h5>
				4102	<pre>
				4103	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4104	</pre>
				4105
				4106	<h5>Overview:</h5>
				4107	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4108	a pointer type, <tt>ty2</tt>.</p>
				4109
				4110	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4111	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4112	value to cast, and a type to cast it to, which must be a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4113	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4114
				4115	<h5>Semantics:</h5>
				4116	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4117	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4118	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4119	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4120	the size of a pointer then a zero extension is done. If they are the same size,
				4121	nothing is done (<i>no-op cast</i>).</p>
				4122
				4123	<h5>Example:</h5>
				4124	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4125	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4126	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4127	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4128	</pre>
				4129	</div>
				4130
				4131	<!-- _______________________________________________________________________ -->
				4132	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4133	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4134	</div>
				4135	<div class="doc_text">
				4136
				4137	<h5>Syntax:</h5>
				4138	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4139	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4140	</pre>
				4141
				4142	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4143
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4144	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4145	<tt>ty2</tt> without changing any bits.</p>
				4146
				4147	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4148
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4149	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	4150	a non-aggregate first class value, and a type to cast it to, which must also be
				4151	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4152	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4153	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4154	type is a pointer, the destination type must also be a pointer. This
				4155	instruction supports bitwise conversion of vectors to integers and to vectors
				4156	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4157
				4158	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4159	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4160	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4161	this conversion. The conversion is done as if the <tt>value</tt> had been
				4162	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4163	converted to other pointer types with this instruction. To convert pointers to
				4164	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4165	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4166
				4167	<h5>Example:</h5>
				4168	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4169	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4170	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4171	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4172	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4173	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4174
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4175	<!-- ======================================================================= -->
				4176	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4177	<div class="doc_text">
				4178	<p>The instructions in this category are the "miscellaneous"
				4179	instructions, which defy better classification.</p>
				4180	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4181
				4182	<!-- _______________________________________________________________________ -->
				4183	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4184	</div>
				4185	<div class="doc_text">
				4186	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4187	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4188	</pre>
				4189	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4190	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4191	a vector of boolean values based on comparison
				4192	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4193	<h5>Arguments:</h5>
				4194	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4195	the condition code indicating the kind of comparison to perform. It is not
				4196	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4197	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4198	<ol>
				4199	<li><tt>eq</tt>: equal</li>
				4200	<li><tt>ne</tt>: not equal </li>
				4201	<li><tt>ugt</tt>: unsigned greater than</li>
				4202	<li><tt>uge</tt>: unsigned greater or equal</li>
				4203	<li><tt>ult</tt>: unsigned less than</li>
				4204	<li><tt>ule</tt>: unsigned less or equal</li>
				4205	<li><tt>sgt</tt>: signed greater than</li>
				4206	<li><tt>sge</tt>: signed greater or equal</li>
				4207	<li><tt>slt</tt>: signed less than</li>
				4208	<li><tt>sle</tt>: signed less or equal</li>
				4209	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4210	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4211	<a href="#t_pointer">pointer</a>
				4212	or integer <a href="#t_vector">vector</a> typed.
				4213	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4214	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4215	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4216	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4217	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4218	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4219	<ol>
				4220	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4221	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4222	</li>
				4223	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4224	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4225	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4226	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4227	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4228	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4229	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4230	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4231	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4232	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4233	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4234	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4235	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4236	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4237	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4238	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4239	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4240	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4241	</ol>
				4242	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4243	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4244	<p>If the operands are integer vectors, then they are compared
				4245	element by element. The result is an <tt>i1</tt> vector with
				4246	the same number of elements as the values being compared.
				4247	Otherwise, the result is an <tt>i1</tt>.
				4248	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4249
				4250	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4251	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4252	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4253	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4254	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4255	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4256	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4257	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4258
				4259	<p>Note that the code generator does not yet support vector types with
				4260	the <tt>icmp</tt> instruction.</p>
				4261
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4262	</div>
				4263
				4264	<!-- _______________________________________________________________________ -->
				4265	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4266	</div>
				4267	<div class="doc_text">
				4268	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4269	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4270	</pre>
				4271	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4272	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4273	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4274	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4275	<p>
				4276	If the operands are floating point scalars, then the result
				4277	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4278	</p>
				4279	<p>If the operands are floating point vectors, then the result type
				4280	is a vector of boolean with the same number of elements as the
				4281	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4282	<h5>Arguments:</h5>
				4283	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4284	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4285	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4286	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4287	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4288	<li><tt>oeq</tt>: ordered and equal</li>
				4289	<li><tt>ogt</tt>: ordered and greater than </li>
				4290	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4291	<li><tt>olt</tt>: ordered and less than </li>
				4292	<li><tt>ole</tt>: ordered and less than or equal</li>
				4293	<li><tt>one</tt>: ordered and not equal</li>
				4294	<li><tt>ord</tt>: ordered (no nans)</li>
				4295	<li><tt>ueq</tt>: unordered or equal</li>
				4296	<li><tt>ugt</tt>: unordered or greater than </li>
				4297	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4298	<li><tt>ult</tt>: unordered or less than </li>
				4299	<li><tt>ule</tt>: unordered or less than or equal</li>
				4300	<li><tt>une</tt>: unordered or not equal</li>
				4301	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4302	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4303	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4304	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4305	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4306	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4307	either a <a href="#t_floating">floating point</a> type
				4308	or a <a href="#t_vector">vector</a> of floating point type.
				4309	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4310	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4311	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4312	according to the condition code given as <tt>cond</tt>.
				4313	If the operands are vectors, then the vectors are compared
				4314	element by element.
				4315	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4316	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4317	<ol>
				4318	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4319	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4320	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4321	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4322	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4323	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4324	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4325	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4326	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4327	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4328	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4329	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4330	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4331	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4332	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4333	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4334	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4335	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4336	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4337	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4338	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4339	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4340	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4341	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4342	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4343	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4344	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4345	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4346	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4347
				4348	<h5>Example:</h5>
				4349	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4350	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4351	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4352	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4353	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4354
				4355	<p>Note that the code generator does not yet support vector types with
				4356	the <tt>fcmp</tt> instruction.</p>
				4357
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4358	</div>
				4359
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4360	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4361	<div class="doc_subsubsection">
				4362	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4363	</div>
				4364	<div class="doc_text">
				4365	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4366	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4367	</pre>
				4368	<h5>Overview:</h5>
				4369	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4370	element-wise comparison of its two integer vector operands.</p>
				4371	<h5>Arguments:</h5>
				4372	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4373	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4374	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4375	<ol>
				4376	<li><tt>eq</tt>: equal</li>
				4377	<li><tt>ne</tt>: not equal </li>
				4378	<li><tt>ugt</tt>: unsigned greater than</li>
				4379	<li><tt>uge</tt>: unsigned greater or equal</li>
				4380	<li><tt>ult</tt>: unsigned less than</li>
				4381	<li><tt>ule</tt>: unsigned less or equal</li>
				4382	<li><tt>sgt</tt>: signed greater than</li>
				4383	<li><tt>sge</tt>: signed greater or equal</li>
				4384	<li><tt>slt</tt>: signed less than</li>
				4385	<li><tt>sle</tt>: signed less or equal</li>
				4386	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4387	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4388	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4389	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4390	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4391	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4392	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4393	identical type as the values being compared. The most significant bit in each
				4394	element is 1 if the element-wise comparison evaluates to true, and is 0
				4395	otherwise. All other bits of the result are undefined. The condition codes
				4396	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4397	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4398
				4399	<h5>Example:</h5>
				4400	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4401	<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>
				4402	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4403	</pre>
				4404	</div>
				4405
				4406	<!-- _______________________________________________________________________ -->
				4407	<div class="doc_subsubsection">
				4408	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4409	</div>
				4410	<div class="doc_text">
				4411	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4412	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4413	<h5>Overview:</h5>
				4414	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4415	element-wise comparison of its two floating point vector operands. The output
				4416	elements have the same width as the input elements.</p>
				4417	<h5>Arguments:</h5>
				4418	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4419	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4420	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4421	<ol>
				4422	<li><tt>false</tt>: no comparison, always returns false</li>
				4423	<li><tt>oeq</tt>: ordered and equal</li>
				4424	<li><tt>ogt</tt>: ordered and greater than </li>
				4425	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4426	<li><tt>olt</tt>: ordered and less than </li>
				4427	<li><tt>ole</tt>: ordered and less than or equal</li>
				4428	<li><tt>one</tt>: ordered and not equal</li>
				4429	<li><tt>ord</tt>: ordered (no nans)</li>
				4430	<li><tt>ueq</tt>: unordered or equal</li>
				4431	<li><tt>ugt</tt>: unordered or greater than </li>
				4432	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4433	<li><tt>ult</tt>: unordered or less than </li>
				4434	<li><tt>ule</tt>: unordered or less than or equal</li>
				4435	<li><tt>une</tt>: unordered or not equal</li>
				4436	<li><tt>uno</tt>: unordered (either nans)</li>
				4437	<li><tt>true</tt>: no comparison, always returns true</li>
				4438	</ol>
				4439	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4440	<a href="#t_floating">floating point</a> typed. They must also be identical
				4441	types.</p>
				4442	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4443	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4444	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4445	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4446	an identical number of elements as the values being compared, and each element
				4447	having identical with to the width of the floating point elements. The most
				4448	significant bit in each element is 1 if the element-wise comparison evaluates to
				4449	true, and is 0 otherwise. All other bits of the result are undefined. The
				4450	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4451	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4452
				4453	<h5>Example:</h5>
				4454	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4455	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4456	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4457
				4458	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4459	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4460	</pre>
				4461	</div>
				4462
				4463	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4464	<div class="doc_subsubsection">
				4465	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4466	</div>
				4467
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4468	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4469
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4470	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4471
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4472	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4473	<h5>Overview:</h5>
				4474	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4475	the SSA graph representing the function.</p>
				4476	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4477
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4478	<p>The type of the incoming values is specified with the first type
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4479	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4480	as arguments, with one pair for each predecessor basic block of the
				4481	current block. Only values of <a href="#t_firstclass">first class</a>
				4482	type may be used as the value arguments to the PHI node. Only labels
				4483	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4484
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4485	<p>There must be no non-phi instructions between the start of a basic
				4486	block and the PHI instructions: i.e. PHI instructions must be first in
				4487	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4488
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4489	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4490
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4491	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4492	specified by the pair corresponding to the predecessor basic block that executed
				4493	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4494
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4495	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4496	<pre>
				4497	Loop: ; Infinite loop that counts from 0 on up...
				4498	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4499	%nextindvar = add i32 %indvar, 1
				4500	br label %Loop
				4501	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4502	</div>
				4503
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4504	<!-- _______________________________________________________________________ -->
				4505	<div class="doc_subsubsection">
				4506	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4507	</div>
				4508
				4509	<div class="doc_text">
				4510
				4511	<h5>Syntax:</h5>
				4512
				4513	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4514	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4515
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4516	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4517	</pre>
				4518
				4519	<h5>Overview:</h5>
				4520
				4521	<p>
				4522	The '<tt>select</tt>' instruction is used to choose one value based on a
				4523	condition, without branching.
				4524	</p>
				4525
				4526
				4527	<h5>Arguments:</h5>
				4528
				4529	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4530	The '<tt>select</tt>' instruction requires an 'i1' value or
				4531	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4532	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4533	type. If the val1/val2 are vectors and
				4534	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4535	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4536	</p>
				4537
				4538	<h5>Semantics:</h5>
				4539
				4540	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4541	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4542	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4543	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4544	<p>
				4545	If the condition is a vector of i1, then the value arguments must
				4546	be vectors of the same size, and the selection is done element
				4547	by element.
				4548	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4549
				4550	<h5>Example:</h5>
				4551
				4552	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4553	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4554	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4555
				4556	<p>Note that the code generator does not yet support conditions
				4557	with vector type.</p>
				4558
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4559	</div>
				4560
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4561
				4562	<!-- _______________________________________________________________________ -->
				4563	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4564	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4565	</div>
				4566
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4567	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4568
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4569	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4570	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4571	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4572	</pre>
				4573
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4574	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4575
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4576	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4577
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4578	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4579
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4580	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4581
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4582	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4583	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4584	<p>The optional "tail" marker indicates whether the callee function accesses
				4585	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4586	function call is eligible for tail call optimization. Note that calls may
				4587	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4588	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4589	</li>
				4590	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4591	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4592	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4593	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4594	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4595
				4596	<li>
				4597	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4598	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4599	and '<tt>inreg</tt>' attributes are valid here.</p>
				4600	</li>
				4601
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4602	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4603	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4604	the type of the return value. Functions that return no value are marked
				4605	<tt><a href="#t_void">void</a></tt>.</p>
				4606	</li>
				4607	<li>
				4608	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4609	value being invoked. The argument types must match the types implied by
				4610	this signature. This type can be omitted if the function is not varargs
				4611	and if the function type does not return a pointer to a function.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4612	</li>
				4613	<li>
				4614	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4615	be invoked. In most cases, this is a direct function invocation, but
				4616	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4617	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4618	</li>
				4619	<li>
				4620	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4621	function signature argument types. All arguments must be of
				4622	<a href="#t_firstclass">first class</a> type. If the function signature
				4623	indicates the function accepts a variable number of arguments, the extra
				4624	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4625	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4626	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4627	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4628	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4629	'<tt>readnone</tt>' attributes are valid here.</p>
				4630	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4631	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4632
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4633	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4634
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4635	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4636	transfer to a specified function, with its incoming arguments bound to
				4637	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4638	instruction in the called function, control flow continues with the
				4639	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4640	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4641
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4642	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4643
				4644	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4645	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4646	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4647	%X = tail call i32 @foo() <i>; yields i32</i>
				4648	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4649	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4650
				4651	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4652	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4653	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4654	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4655	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	cb73d19	2008-10-07 10:03:45 +0000	[diff] [blame]	4656	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4657	</pre>
				4658
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4659	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4660
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4661	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4662	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4663	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4664	</div>
				4665
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4666	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4667
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4668	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4669
				4670	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4671	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4672	</pre>
				4673
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4674	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4675
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4676	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4677	the "variable argument" area of a function call. It is used to implement the
				4678	<tt>va_arg</tt> macro in C.</p>
				4679
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4680	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4681
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4682	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4683	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4684	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4685	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4686
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4687	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4688
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4689	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4690	type from the specified <tt>va_list</tt> and causes the
				4691	<tt>va_list</tt> to point to the next argument. For more information,
				4692	see the variable argument handling <a href="#int_varargs">Intrinsic
				4693	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4694
				4695	<p>It is legal for this instruction to be called in a function which does not
				4696	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4697	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4698
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4699	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4700	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4701	argument.</p>
				4702
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4703	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4704
				4705	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4706
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4707	<p>Note that the code generator does not yet fully support va_arg
				4708	on many targets. Also, it does not currently support va_arg with
				4709	aggregate types on any target.</p>
				4710
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4711	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4712
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4713	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4714	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4715	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4716
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4717	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4718
				4719	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4720	well known names and semantics and are required to follow certain restrictions.
				4721	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4722	language that does not require changing all of the transformations in LLVM when
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	4723	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4724
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4725	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4726	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4727	begin with this prefix. Intrinsic functions must always be external functions:
				4728	you cannot define the body of intrinsic functions. Intrinsic functions may
				4729	only be used in call or invoke instructions: it is illegal to take the address
				4730	of an intrinsic function. Additionally, because intrinsic functions are part
				4731	of the LLVM language, it is required if any are added that they be documented
				4732	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4733
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4734	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4735	a family of functions that perform the same operation but on different data
				4736	types. Because LLVM can represent over 8 million different integer types,
				4737	overloading is used commonly to allow an intrinsic function to operate on any
				4738	integer type. One or more of the argument types or the result type can be
				4739	overloaded to accept any integer type. Argument types may also be defined as
				4740	exactly matching a previous argument's type or the result type. This allows an
				4741	intrinsic function which accepts multiple arguments, but needs all of them to
				4742	be of the same type, to only be overloaded with respect to a single argument or
				4743	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4744
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4745	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4746	encoded into its function name, each preceded by a period. Only those types
				4747	which are overloaded result in a name suffix. Arguments whose type is matched
				4748	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4749	take an integer of any width and returns an integer of exactly the same integer
				4750	width. This leads to a family of functions such as
				4751	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4752	Only one type, the return type, is overloaded, and only one type suffix is
				4753	required. Because the argument's type is matched against the return type, it
				4754	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4755
				4756	<p>To learn how to add an intrinsic function, please see the
				4757	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4758	</p>
				4759
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4760	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4761
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4762	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4763	<div class="doc_subsection">
				4764	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4765	</div>
				4766
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4767	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4768
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4769	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4770	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4771	intrinsic functions. These functions are related to the similarly
				4772	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4773
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4774	<p>All of these functions operate on arguments that use a
				4775	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4776	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4777	transformations should be prepared to handle these functions regardless of
				4778	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4779
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4780	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4781	instruction and the variable argument handling intrinsic functions are
				4782	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4783
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4784	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4785	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4786	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4787	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4788	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4789	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4790	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4791
				4792	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4793	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4794
				4795	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4796	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4797	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4798	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4799	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4800
				4801	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4802	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4803	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4804	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4805
				4806	declare void @llvm.va_start(i8*)
				4807	declare void @llvm.va_copy(i8, i8)
				4808	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4809	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4810	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4811
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4812	</div>
				4813
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4814	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4815	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4816	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4817	</div>
				4818
				4819
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4820	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4821	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4822	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4823	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4824	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4825	<tt>*<arglist></tt> for subsequent use by <tt><a
				4826	href="#i_va_arg">va_arg</a></tt>.</p>
				4827
				4828	<h5>Arguments:</h5>
				4829
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4830	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4831
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4832	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4833
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4834	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4835	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4836	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4837	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4838	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4839	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4840
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4841	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4842
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4843	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4844	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4845	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4846	</div>
				4847
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4848	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4849	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4850	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4851	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4852
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4853	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4854	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4855	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4856
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4857	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4858
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4859	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4860
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4861	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4862
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4863	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4864	macro available in C. In a target-dependent way, it destroys the
				4865	<tt>va_list</tt> element to which the argument points. Calls to <a
				4866	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4867	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4868	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4869
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4870	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4871
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4872	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4873	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4874	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4875	</div>
				4876
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4877	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4878
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4879	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4880
				4881	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4882	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4883	</pre>
				4884
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4885	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4886
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4887	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4888	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4889
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4890	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4891
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4892	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	d0a4c62	2005-06-22 20:38:11 +0000	[diff] [blame]	4893	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4894
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4895
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4896	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4897
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4898	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4899	macro available in C. In a target-dependent way, it copies the source
				4900	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4901	intrinsic is necessary because the <tt><a href="#int_va_start">
				4902	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4903	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4904
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4905	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4906
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4907	<!-- ======================================================================= -->
				4908	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4909	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4910	</div>
				4911
				4912	<div class="doc_text">
				4913
				4914	<p>
				4915	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4916	Collection</a> (GC) requires the implementation and generation of these
				4917	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4918	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4919	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4920	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4921	Front-ends for type-safe garbage collected languages should generate these
				4922	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4923	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4924	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4925
				4926	<p>The garbage collection intrinsics only operate on objects in the generic
				4927	address space (address space zero).</p>
				4928
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4929	</div>
				4930
				4931	<!-- _______________________________________________________________________ -->
				4932	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4933	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4934	</div>
				4935
				4936	<div class="doc_text">
				4937
				4938	<h5>Syntax:</h5>
				4939
				4940	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4941	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4942	</pre>
				4943
				4944	<h5>Overview:</h5>
				4945
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4946	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4947	the code generator, and allows some metadata to be associated with it.</p>
				4948
				4949	<h5>Arguments:</h5>
				4950
				4951	<p>The first argument specifies the address of a stack object that contains the
				4952	root pointer. The second pointer (which must be either a constant or a global
				4953	value address) contains the meta-data to be associated with the root.</p>
				4954
				4955	<h5>Semantics:</h5>
				4956
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4957	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4958	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4959	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4960	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4961	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4962
				4963	</div>
				4964
				4965
				4966	<!-- _______________________________________________________________________ -->
				4967	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4968	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4969	</div>
				4970
				4971	<div class="doc_text">
				4972
				4973	<h5>Syntax:</h5>
				4974
				4975	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4976	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4977	</pre>
				4978
				4979	<h5>Overview:</h5>
				4980
				4981	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4982	locations, allowing garbage collector implementations that require read
				4983	barriers.</p>
				4984
				4985	<h5>Arguments:</h5>
				4986
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4987	<p>The second argument is the address to read from, which should be an address
				4988	allocated from the garbage collector. The first object is a pointer to the
				4989	start of the referenced object, if needed by the language runtime (otherwise
				4990	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4991
				4992	<h5>Semantics:</h5>
				4993
				4994	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4995	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4996	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4997	may only be used in a function which <a href="#gc">specifies a GC
				4998	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4999
				5000	</div>
				5001
				5002
				5003	<!-- _______________________________________________________________________ -->
				5004	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5005	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5006	</div>
				5007
				5008	<div class="doc_text">
				5009
				5010	<h5>Syntax:</h5>
				5011
				5012	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5013	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5014	</pre>
				5015
				5016	<h5>Overview:</h5>
				5017
				5018	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5019	locations, allowing garbage collector implementations that require write
				5020	barriers (such as generational or reference counting collectors).</p>
				5021
				5022	<h5>Arguments:</h5>
				5023
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5024	<p>The first argument is the reference to store, the second is the start of the
				5025	object to store it to, and the third is the address of the field of Obj to
				5026	store to. If the runtime does not require a pointer to the object, Obj may be
				5027	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5028
				5029	<h5>Semantics:</h5>
				5030
				5031	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5032	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5033	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5034	may only be used in a function which <a href="#gc">specifies a GC
				5035	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5036
				5037	</div>
				5038
				5039
				5040
				5041	<!-- ======================================================================= -->
				5042	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5043	<a name="int_codegen">Code Generator Intrinsics</a>
				5044	</div>
				5045
				5046	<div class="doc_text">
				5047	<p>
				5048	These intrinsics are provided by LLVM to expose special features that may only
				5049	be implemented with code generator support.
				5050	</p>
				5051
				5052	</div>
				5053
				5054	<!-- _______________________________________________________________________ -->
				5055	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5056	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5057	</div>
				5058
				5059	<div class="doc_text">
				5060
				5061	<h5>Syntax:</h5>
				5062	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5063	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5064	</pre>
				5065
				5066	<h5>Overview:</h5>
				5067
				5068	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5069	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5070	target-specific value indicating the return address of the current function
				5071	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5072	</p>
				5073
				5074	<h5>Arguments:</h5>
				5075
				5076	<p>
				5077	The argument to this intrinsic indicates which function to return the address
				5078	for. Zero indicates the calling function, one indicates its caller, etc. The
				5079	argument is <b>required</b> to be a constant integer value.
				5080	</p>
				5081
				5082	<h5>Semantics:</h5>
				5083
				5084	<p>
				5085	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5086	the return address of the specified call frame, or zero if it cannot be
				5087	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5088	for arguments other than zero, so it should only be used for debugging purposes.
				5089	</p>
				5090
				5091	<p>
				5092	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5093	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5094	source-language caller.
				5095	</p>
				5096	</div>
				5097
				5098
				5099	<!-- _______________________________________________________________________ -->
				5100	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5101	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5102	</div>
				5103
				5104	<div class="doc_text">
				5105
				5106	<h5>Syntax:</h5>
				5107	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5108	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5109	</pre>
				5110
				5111	<h5>Overview:</h5>
				5112
				5113	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5114	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5115	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5116	</p>
				5117
				5118	<h5>Arguments:</h5>
				5119
				5120	<p>
				5121	The argument to this intrinsic indicates which function to return the frame
				5122	pointer for. Zero indicates the calling function, one indicates its caller,
				5123	etc. The argument is <b>required</b> to be a constant integer value.
				5124	</p>
				5125
				5126	<h5>Semantics:</h5>
				5127
				5128	<p>
				5129	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5130	the frame address of the specified call frame, or zero if it cannot be
				5131	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5132	for arguments other than zero, so it should only be used for debugging purposes.
				5133	</p>
				5134
				5135	<p>
				5136	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5137	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5138	source-language caller.
				5139	</p>
				5140	</div>
				5141
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5142	<!-- _______________________________________________________________________ -->
				5143	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5144	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5145	</div>
				5146
				5147	<div class="doc_text">
				5148
				5149	<h5>Syntax:</h5>
				5150	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5151	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5152	</pre>
				5153
				5154	<h5>Overview:</h5>
				5155
				5156	<p>
				5157	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5158	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5159	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5160	features like scoped automatic variable sized arrays in C99.
				5161	</p>
				5162
				5163	<h5>Semantics:</h5>
				5164
				5165	<p>
				5166	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5167	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5168	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5169	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5170	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5171	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5172	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5173	</p>
				5174
				5175	</div>
				5176
				5177	<!-- _______________________________________________________________________ -->
				5178	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5179	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5180	</div>
				5181
				5182	<div class="doc_text">
				5183
				5184	<h5>Syntax:</h5>
				5185	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5186	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5187	</pre>
				5188
				5189	<h5>Overview:</h5>
				5190
				5191	<p>
				5192	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5193	the function stack to the state it was in when the corresponding <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5194	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5195	useful for implementing language features like scoped automatic variable sized
				5196	arrays in C99.
				5197	</p>
				5198
				5199	<h5>Semantics:</h5>
				5200
				5201	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5202	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5203	</p>
				5204
				5205	</div>
				5206
				5207
				5208	<!-- _______________________________________________________________________ -->
				5209	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5210	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5211	</div>
				5212
				5213	<div class="doc_text">
				5214
				5215	<h5>Syntax:</h5>
				5216	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5217	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5218	</pre>
				5219
				5220	<h5>Overview:</h5>
				5221
				5222
				5223	<p>
				5224	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5225	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5226	no
				5227	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5228	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5229	</p>
				5230
				5231	<h5>Arguments:</h5>
				5232
				5233	<p>
				5234	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5235	determining if the fetch should be for a read (0) or write (1), and
				5236	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5237	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5238	<tt>locality</tt> arguments must be constant integers.
				5239	</p>
				5240
				5241	<h5>Semantics:</h5>
				5242
				5243	<p>
				5244	This intrinsic does not modify the behavior of the program. In particular,
				5245	prefetches cannot trap and do not produce a value. On targets that support this
				5246	intrinsic, the prefetch can provide hints to the processor cache for better
				5247	performance.
				5248	</p>
				5249
				5250	</div>
				5251
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5252	<!-- _______________________________________________________________________ -->
				5253	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5254	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5255	</div>
				5256
				5257	<div class="doc_text">
				5258
				5259	<h5>Syntax:</h5>
				5260	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5261	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5262	</pre>
				5263
				5264	<h5>Overview:</h5>
				5265
				5266
				5267	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5268	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5269	(PC) in a region of
				5270	code to simulators and other tools. The method is target specific, but it is
				5271	expected that the marker will use exported symbols to transmit the PC of the
				5272	marker.
				5273	The marker makes no guarantees that it will remain with any specific instruction
				5274	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b3e7afd	2006-03-24 07:16:10 +0000	[diff] [blame]	5275	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5276	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5277	</p>
				5278
				5279	<h5>Arguments:</h5>
				5280
				5281	<p>
				5282	<tt>id</tt> is a numerical id identifying the marker.
				5283	</p>
				5284
				5285	<h5>Semantics:</h5>
				5286
				5287	<p>
				5288	This intrinsic does not modify the behavior of the program. Backends that do not
				5289	support this intrinisic may ignore it.
				5290	</p>
				5291
				5292	</div>
				5293
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5294	<!-- _______________________________________________________________________ -->
				5295	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5296	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5297	</div>
				5298
				5299	<div class="doc_text">
				5300
				5301	<h5>Syntax:</h5>
				5302	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5303	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5304	</pre>
				5305
				5306	<h5>Overview:</h5>
				5307
				5308
				5309	<p>
				5310	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5311	counter register (or similar low latency, high accuracy clocks) on those targets
				5312	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5313	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5314	should only be used for small timings.
				5315	</p>
				5316
				5317	<h5>Semantics:</h5>
				5318
				5319	<p>
				5320	When directly supported, reading the cycle counter should not modify any memory.
				5321	Implementations are allowed to either return a application specific value or a
				5322	system wide value. On backends without support, this is lowered to a constant 0.
				5323	</p>
				5324
				5325	</div>
				5326
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5327	<!-- ======================================================================= -->
				5328	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5329	<a name="int_libc">Standard C Library Intrinsics</a>
				5330	</div>
				5331
				5332	<div class="doc_text">
				5333	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5334	LLVM provides intrinsics for a few important standard C library functions.
				5335	These intrinsics allow source-language front-ends to pass information about the
				5336	alignment of the pointer arguments to the code generator, providing opportunity
				5337	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5338	</p>
				5339
				5340	</div>
				5341
				5342	<!-- _______________________________________________________________________ -->
				5343	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5344	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5345	</div>
				5346
				5347	<div class="doc_text">
				5348
				5349	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5350	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5351	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5352	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5353	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5354	i8 <len>, i32 <align>)
				5355	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5356	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5357	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5358	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5359	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5360	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5361	</pre>
				5362
				5363	<h5>Overview:</h5>
				5364
				5365	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5366	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5367	location to the destination location.
				5368	</p>
				5369
				5370	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5371	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5372	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5373	</p>
				5374
				5375	<h5>Arguments:</h5>
				5376
				5377	<p>
				5378	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5379	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5380	specifying the number of bytes to copy, and the fourth argument is the alignment
				5381	of the source and destination locations.
				5382	</p>
				5383
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5384	<p>
				5385	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5386	the caller guarantees that both the source and destination pointers are aligned
				5387	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5388	</p>
				5389
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5390	<h5>Semantics:</h5>
				5391
				5392	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5393	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5394	location to the destination location, which are not allowed to overlap. It
				5395	copies "len" bytes of memory over. If the argument is known to be aligned to
				5396	some boundary, this can be specified as the fourth argument, otherwise it should
				5397	be set to 0 or 1.
				5398	</p>
				5399	</div>
				5400
				5401
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5402	<!-- _______________________________________________________________________ -->
				5403	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5404	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5405	</div>
				5406
				5407	<div class="doc_text">
				5408
				5409	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5410	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5411	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5412	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5413	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5414	i8 <len>, i32 <align>)
				5415	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5416	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5417	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5418	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5419	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5420	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5421	</pre>
				5422
				5423	<h5>Overview:</h5>
				5424
				5425	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5426	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5427	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5428	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5429	</p>
				5430
				5431	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5432	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5433	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5434	</p>
				5435
				5436	<h5>Arguments:</h5>
				5437
				5438	<p>
				5439	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5440	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5441	specifying the number of bytes to copy, and the fourth argument is the alignment
				5442	of the source and destination locations.
				5443	</p>
				5444
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5445	<p>
				5446	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5447	the caller guarantees that the source and destination pointers are aligned to
				5448	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5449	</p>
				5450
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5451	<h5>Semantics:</h5>
				5452
				5453	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5454	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5455	location to the destination location, which may overlap. It
				5456	copies "len" bytes of memory over. If the argument is known to be aligned to
				5457	some boundary, this can be specified as the fourth argument, otherwise it should
				5458	be set to 0 or 1.
				5459	</p>
				5460	</div>
				5461
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5462
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5463	<!-- _______________________________________________________________________ -->
				5464	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5465	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5466	</div>
				5467
				5468	<div class="doc_text">
				5469
				5470	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5471	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5472	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5473	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5474	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5475	i8 <len>, i32 <align>)
				5476	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5477	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5478	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5479	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5480	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5481	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5482	</pre>
				5483
				5484	<h5>Overview:</h5>
				5485
				5486	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5487	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5488	byte value.
				5489	</p>
				5490
				5491	<p>
				5492	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5493	does not return a value, and takes an extra alignment argument.
				5494	</p>
				5495
				5496	<h5>Arguments:</h5>
				5497
				5498	<p>
				5499	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5500	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5501	argument specifying the number of bytes to fill, and the fourth argument is the
				5502	known alignment of destination location.
				5503	</p>
				5504
				5505	<p>
				5506	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5507	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5508	</p>
				5509
				5510	<h5>Semantics:</h5>
				5511
				5512	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5513	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5514	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5515	destination location. If the argument is known to be aligned to some boundary,
				5516	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5517	1.
				5518	</p>
				5519	</div>
				5520
				5521
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5522	<!-- _______________________________________________________________________ -->
				5523	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5524	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5525	</div>
				5526
				5527	<div class="doc_text">
				5528
				5529	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5530	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5531	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5532	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5533	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5534	declare float @llvm.sqrt.f32(float %Val)
				5535	declare double @llvm.sqrt.f64(double %Val)
				5536	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5537	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5538	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5539	</pre>
				5540
				5541	<h5>Overview:</h5>
				5542
				5543	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5544	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5545	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5546	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	103e2d7	2008-01-29 07:00:44 +0000	[diff] [blame]	5547	negative numbers other than -0.0 (which allows for better optimization, because
				5548	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5549	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5550	</p>
				5551
				5552	<h5>Arguments:</h5>
				5553
				5554	<p>
				5555	The argument and return value are floating point numbers of the same type.
				5556	</p>
				5557
				5558	<h5>Semantics:</h5>
				5559
				5560	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5561	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5562	floating point number.
				5563	</p>
				5564	</div>
				5565
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5566	<!-- _______________________________________________________________________ -->
				5567	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5568	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5569	</div>
				5570
				5571	<div class="doc_text">
				5572
				5573	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5574	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5575	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5576	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5577	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5578	declare float @llvm.powi.f32(float %Val, i32 %power)
				5579	declare double @llvm.powi.f64(double %Val, i32 %power)
				5580	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5581	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5582	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5583	</pre>
				5584
				5585	<h5>Overview:</h5>
				5586
				5587	<p>
				5588	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5589	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5590	multiplications is not defined. When a vector of floating point type is
				5591	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5592	</p>
				5593
				5594	<h5>Arguments:</h5>
				5595
				5596	<p>
				5597	The second argument is an integer power, and the first is a value to raise to
				5598	that power.
				5599	</p>
				5600
				5601	<h5>Semantics:</h5>
				5602
				5603	<p>
				5604	This function returns the first value raised to the second power with an
				5605	unspecified sequence of rounding operations.</p>
				5606	</div>
				5607
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5608	<!-- _______________________________________________________________________ -->
				5609	<div class="doc_subsubsection">
				5610	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5611	</div>
				5612
				5613	<div class="doc_text">
				5614
				5615	<h5>Syntax:</h5>
				5616	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5617	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5618	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5619	<pre>
				5620	declare float @llvm.sin.f32(float %Val)
				5621	declare double @llvm.sin.f64(double %Val)
				5622	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5623	declare fp128 @llvm.sin.f128(fp128 %Val)
				5624	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5625	</pre>
				5626
				5627	<h5>Overview:</h5>
				5628
				5629	<p>
				5630	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5631	</p>
				5632
				5633	<h5>Arguments:</h5>
				5634
				5635	<p>
				5636	The argument and return value are floating point numbers of the same type.
				5637	</p>
				5638
				5639	<h5>Semantics:</h5>
				5640
				5641	<p>
				5642	This function returns the sine of the specified operand, returning the
				5643	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5644	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5645	</div>
				5646
				5647	<!-- _______________________________________________________________________ -->
				5648	<div class="doc_subsubsection">
				5649	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5650	</div>
				5651
				5652	<div class="doc_text">
				5653
				5654	<h5>Syntax:</h5>
				5655	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5656	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5657	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5658	<pre>
				5659	declare float @llvm.cos.f32(float %Val)
				5660	declare double @llvm.cos.f64(double %Val)
				5661	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5662	declare fp128 @llvm.cos.f128(fp128 %Val)
				5663	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5664	</pre>
				5665
				5666	<h5>Overview:</h5>
				5667
				5668	<p>
				5669	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5670	</p>
				5671
				5672	<h5>Arguments:</h5>
				5673
				5674	<p>
				5675	The argument and return value are floating point numbers of the same type.
				5676	</p>
				5677
				5678	<h5>Semantics:</h5>
				5679
				5680	<p>
				5681	This function returns the cosine of the specified operand, returning the
				5682	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5683	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5684	</div>
				5685
				5686	<!-- _______________________________________________________________________ -->
				5687	<div class="doc_subsubsection">
				5688	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5689	</div>
				5690
				5691	<div class="doc_text">
				5692
				5693	<h5>Syntax:</h5>
				5694	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5695	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5696	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5697	<pre>
				5698	declare float @llvm.pow.f32(float %Val, float %Power)
				5699	declare double @llvm.pow.f64(double %Val, double %Power)
				5700	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5701	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5702	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5703	</pre>
				5704
				5705	<h5>Overview:</h5>
				5706
				5707	<p>
				5708	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5709	specified (positive or negative) power.
				5710	</p>
				5711
				5712	<h5>Arguments:</h5>
				5713
				5714	<p>
				5715	The second argument is a floating point power, and the first is a value to
				5716	raise to that power.
				5717	</p>
				5718
				5719	<h5>Semantics:</h5>
				5720
				5721	<p>
				5722	This function returns the first value raised to the second power,
				5723	returning the
				5724	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5725	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5726	</div>
				5727
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5728
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5729	<!-- ======================================================================= -->
				5730	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5731	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5732	</div>
				5733
				5734	<div class="doc_text">
				5735	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5736	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5737	These allow efficient code generation for some algorithms.
				5738	</p>
				5739
				5740	</div>
				5741
				5742	<!-- _______________________________________________________________________ -->
				5743	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5744	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5745	</div>
				5746
				5747	<div class="doc_text">
				5748
				5749	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5750	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5751	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5752	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5753	declare i16 @llvm.bswap.i16(i16 <id>)
				5754	declare i32 @llvm.bswap.i32(i32 <id>)
				5755	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5756	</pre>
				5757
				5758	<h5>Overview:</h5>
				5759
				5760	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5761	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5762	values with an even number of bytes (positive multiple of 16 bits). These are
				5763	useful for performing operations on data that is not in the target's native
				5764	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5765	</p>
				5766
				5767	<h5>Semantics:</h5>
				5768
				5769	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5770	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5771	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5772	intrinsic returns an i32 value that has the four bytes of the input i32
				5773	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5774	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5775	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5776	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5777	</p>
				5778
				5779	</div>
				5780
				5781	<!-- _______________________________________________________________________ -->
				5782	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5783	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5784	</div>
				5785
				5786	<div class="doc_text">
				5787
				5788	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5789	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5790	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5791	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5792	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5793	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5794	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5795	declare i64 @llvm.ctpop.i64(i64 <src>)
				5796	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5797	</pre>
				5798
				5799	<h5>Overview:</h5>
				5800
				5801	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5802	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5803	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5804	</p>
				5805
				5806	<h5>Arguments:</h5>
				5807
				5808	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5809	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5810	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5811	</p>
				5812
				5813	<h5>Semantics:</h5>
				5814
				5815	<p>
				5816	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5817	</p>
				5818	</div>
				5819
				5820	<!-- _______________________________________________________________________ -->
				5821	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5822	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5823	</div>
				5824
				5825	<div class="doc_text">
				5826
				5827	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5828	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5829	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5830	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5831	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5832	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5833	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5834	declare i64 @llvm.ctlz.i64(i64 <src>)
				5835	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5836	</pre>
				5837
				5838	<h5>Overview:</h5>
				5839
				5840	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5841	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5842	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5843	</p>
				5844
				5845	<h5>Arguments:</h5>
				5846
				5847	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5848	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5849	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5850	</p>
				5851
				5852	<h5>Semantics:</h5>
				5853
				5854	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5855	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5856	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5857	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5858	</p>
				5859	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5860
				5861
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5862
				5863	<!-- _______________________________________________________________________ -->
				5864	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5865	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5866	</div>
				5867
				5868	<div class="doc_text">
				5869
				5870	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5871	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5872	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5873	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5874	declare i8 @llvm.cttz.i8 (i8 <src>)
				5875	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5876	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5877	declare i64 @llvm.cttz.i64(i64 <src>)
				5878	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5879	</pre>
				5880
				5881	<h5>Overview:</h5>
				5882
				5883	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5884	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5885	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5886	</p>
				5887
				5888	<h5>Arguments:</h5>
				5889
				5890	<p>
				5891	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5892	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5893	</p>
				5894
				5895	<h5>Semantics:</h5>
				5896
				5897	<p>
				5898	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5899	in a variable. If the src == 0 then the result is the size in bits of the type
				5900	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5901	</p>
				5902	</div>
				5903
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5904	<!-- _______________________________________________________________________ -->
				5905	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5906	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5907	</div>
				5908
				5909	<div class="doc_text">
				5910
				5911	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5912	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5913	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5914	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5915	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5916	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5917	</pre>
				5918
				5919	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5920	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5921	range of bits from an integer value and returns them in the same bit width as
				5922	the original value.</p>
				5923
				5924	<h5>Arguments:</h5>
				5925	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5926	any bit width but they must have the same bit width. The second and third
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5927	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5928
				5929	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5930	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5931	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5932	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5933	operates in forward mode.</p>
				5934	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5935	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5936	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5937	<ol>
				5938	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5939	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5940	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5941	to determine the number of bits to retain.</li>
				5942	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5943	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5944	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5945	<p>In reverse mode, a similar computation is made except that the bits are
				5946	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5947	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5948	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5949	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5950	</div>
				5951
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5952	<div class="doc_subsubsection">
				5953	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5954	</div>
				5955
				5956	<div class="doc_text">
				5957
				5958	<h5>Syntax:</h5>
				5959	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5960	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5961	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5962	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5963	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5964	</pre>
				5965
				5966	<h5>Overview:</h5>
				5967	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5968	of bits in an integer value with another integer value. It returns the integer
				5969	with the replaced bits.</p>
				5970
				5971	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5972	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				5973	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5974	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5975	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5976	type since they specify only a bit index.</p>
				5977
				5978	<h5>Semantics:</h5>
				5979	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5980	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5981	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5982	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5983
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5984	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5985	truncating it down to the size of the replacement area or zero extending it
				5986	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5987
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5988	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5989	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5990	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5991	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5992
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5993	<p>In reverse mode, a similar computation is made except that the bits are
				5994	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5995	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5996
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5997	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5998
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5999	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6000	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6001	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6002	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6003	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6004	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	6005	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6006
				6007	</div>
				6008
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6009	<!-- ======================================================================= -->
				6010	<div class="doc_subsection">
				6011	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6012	</div>
				6013
				6014	<div class="doc_text">
				6015	<p>
				6016	LLVM provides intrinsics for some arithmetic with overflow operations.
				6017	</p>
				6018
				6019	</div>
				6020
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6021	<!-- _______________________________________________________________________ -->
				6022	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6023	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6024	</div>
				6025
				6026	<div class="doc_text">
				6027
				6028	<h5>Syntax:</h5>
				6029
				6030	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6031	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6032
				6033	<pre>
				6034	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6035	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6036	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6037	</pre>
				6038
				6039	<h5>Overview:</h5>
				6040
				6041	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6042	a signed addition of the two arguments, and indicate whether an overflow
				6043	occurred during the signed summation.</p>
				6044
				6045	<h5>Arguments:</h5>
				6046
				6047	<p>The arguments (%a and %b) and the first element of the result structure may
				6048	be of integer types of any bit width, but they must have the same bit width. The
				6049	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6050	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6051
				6052	<h5>Semantics:</h5>
				6053
				6054	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6055	a signed addition of the two variables. They return a structure — the
				6056	first element of which is the signed summation, and the second element of which
				6057	is a bit specifying if the signed summation resulted in an overflow.</p>
				6058
				6059	<h5>Examples:</h5>
				6060	<pre>
				6061	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6062	%sum = extractvalue {i32, i1} %res, 0
				6063	%obit = extractvalue {i32, i1} %res, 1
				6064	br i1 %obit, label %overflow, label %normal
				6065	</pre>
				6066
				6067	</div>
				6068
				6069	<!-- _______________________________________________________________________ -->
				6070	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6071	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6072	</div>
				6073
				6074	<div class="doc_text">
				6075
				6076	<h5>Syntax:</h5>
				6077
				6078	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6079	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6080
				6081	<pre>
				6082	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6083	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6084	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6085	</pre>
				6086
				6087	<h5>Overview:</h5>
				6088
				6089	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6090	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6091	during the unsigned summation.</p>
				6092
				6093	<h5>Arguments:</h5>
				6094
				6095	<p>The arguments (%a and %b) and the first element of the result structure may
				6096	be of integer types of any bit width, but they must have the same bit width. The
				6097	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6098	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6099
				6100	<h5>Semantics:</h5>
				6101
				6102	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6103	an unsigned addition of the two arguments. They return a structure — the
				6104	first element of which is the sum, and the second element of which is a bit
				6105	specifying if the unsigned summation resulted in a carry.</p>
				6106
				6107	<h5>Examples:</h5>
				6108	<pre>
				6109	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6110	%sum = extractvalue {i32, i1} %res, 0
				6111	%obit = extractvalue {i32, i1} %res, 1
				6112	br i1 %obit, label %carry, label %normal
				6113	</pre>
				6114
				6115	</div>
				6116
				6117	<!-- _______________________________________________________________________ -->
				6118	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6119	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6120	</div>
				6121
				6122	<div class="doc_text">
				6123
				6124	<h5>Syntax:</h5>
				6125
				6126	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6127	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6128
				6129	<pre>
				6130	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6131	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6132	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6133	</pre>
				6134
				6135	<h5>Overview:</h5>
				6136
				6137	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6138	a signed subtraction of the two arguments, and indicate whether an overflow
				6139	occurred during the signed subtraction.</p>
				6140
				6141	<h5>Arguments:</h5>
				6142
				6143	<p>The arguments (%a and %b) and the first element of the result structure may
				6144	be of integer types of any bit width, but they must have the same bit width. The
				6145	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6146	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6147
				6148	<h5>Semantics:</h5>
				6149
				6150	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6151	a signed subtraction of the two arguments. They return a structure — the
				6152	first element of which is the subtraction, and the second element of which is a bit
				6153	specifying if the signed subtraction resulted in an overflow.</p>
				6154
				6155	<h5>Examples:</h5>
				6156	<pre>
				6157	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6158	%sum = extractvalue {i32, i1} %res, 0
				6159	%obit = extractvalue {i32, i1} %res, 1
				6160	br i1 %obit, label %overflow, label %normal
				6161	</pre>
				6162
				6163	</div>
				6164
				6165	<!-- _______________________________________________________________________ -->
				6166	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6167	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6168	</div>
				6169
				6170	<div class="doc_text">
				6171
				6172	<h5>Syntax:</h5>
				6173
				6174	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6175	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6176
				6177	<pre>
				6178	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6179	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6180	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6181	</pre>
				6182
				6183	<h5>Overview:</h5>
				6184
				6185	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6186	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6187	occurred during the unsigned subtraction.</p>
				6188
				6189	<h5>Arguments:</h5>
				6190
				6191	<p>The arguments (%a and %b) and the first element of the result structure may
				6192	be of integer types of any bit width, but they must have the same bit width. The
				6193	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6194	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6195
				6196	<h5>Semantics:</h5>
				6197
				6198	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6199	an unsigned subtraction of the two arguments. They return a structure — the
				6200	first element of which is the subtraction, and the second element of which is a bit
				6201	specifying if the unsigned subtraction resulted in an overflow.</p>
				6202
				6203	<h5>Examples:</h5>
				6204	<pre>
				6205	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6206	%sum = extractvalue {i32, i1} %res, 0
				6207	%obit = extractvalue {i32, i1} %res, 1
				6208	br i1 %obit, label %overflow, label %normal
				6209	</pre>
				6210
				6211	</div>
				6212
				6213	<!-- _______________________________________________________________________ -->
				6214	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6215	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6216	</div>
				6217
				6218	<div class="doc_text">
				6219
				6220	<h5>Syntax:</h5>
				6221
				6222	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6223	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6224
				6225	<pre>
				6226	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6227	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6228	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6229	</pre>
				6230
				6231	<h5>Overview:</h5>
				6232
				6233	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6234	a signed multiplication of the two arguments, and indicate whether an overflow
				6235	occurred during the signed multiplication.</p>
				6236
				6237	<h5>Arguments:</h5>
				6238
				6239	<p>The arguments (%a and %b) and the first element of the result structure may
				6240	be of integer types of any bit width, but they must have the same bit width. The
				6241	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6242	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6243
				6244	<h5>Semantics:</h5>
				6245
				6246	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6247	a signed multiplication of the two arguments. They return a structure —
				6248	the first element of which is the multiplication, and the second element of
				6249	which is a bit specifying if the signed multiplication resulted in an
				6250	overflow.</p>
				6251
				6252	<h5>Examples:</h5>
				6253	<pre>
				6254	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6255	%sum = extractvalue {i32, i1} %res, 0
				6256	%obit = extractvalue {i32, i1} %res, 1
				6257	br i1 %obit, label %overflow, label %normal
				6258	</pre>
				6259
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6260	</div>
				6261
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6262	<!-- _______________________________________________________________________ -->
				6263	<div class="doc_subsubsection">
				6264	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6265	</div>
				6266
				6267	<div class="doc_text">
				6268
				6269	<h5>Syntax:</h5>
				6270
				6271	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6272	on any integer bit width.</p>
				6273
				6274	<pre>
				6275	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6276	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6277	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6278	</pre>
				6279
				6280	<h5>Overview:</h5>
				6281
				6282	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6283	actively being fixed, but it should not currently be used!</i></p>
				6284
				6285	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6286	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6287	occurred during the unsigned multiplication.</p>
				6288
				6289	<h5>Arguments:</h5>
				6290
				6291	<p>The arguments (%a and %b) and the first element of the result structure may
				6292	be of integer types of any bit width, but they must have the same bit width. The
				6293	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6294	and <tt>%b</tt> are the two values that will undergo unsigned
				6295	multiplication.</p>
				6296
				6297	<h5>Semantics:</h5>
				6298
				6299	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6300	an unsigned multiplication of the two arguments. They return a structure —
				6301	the first element of which is the multiplication, and the second element of
				6302	which is a bit specifying if the unsigned multiplication resulted in an
				6303	overflow.</p>
				6304
				6305	<h5>Examples:</h5>
				6306	<pre>
				6307	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6308	%sum = extractvalue {i32, i1} %res, 0
				6309	%obit = extractvalue {i32, i1} %res, 1
				6310	br i1 %obit, label %overflow, label %normal
				6311	</pre>
				6312
				6313	</div>
				6314
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6315	<!-- ======================================================================= -->
				6316	<div class="doc_subsection">
				6317	<a name="int_debugger">Debugger Intrinsics</a>
				6318	</div>
				6319
				6320	<div class="doc_text">
				6321	<p>
				6322	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6323	are described in the <a
				6324	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6325	Debugging</a> document.
				6326	</p>
				6327	</div>
				6328
				6329
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6330	<!-- ======================================================================= -->
				6331	<div class="doc_subsection">
				6332	<a name="int_eh">Exception Handling Intrinsics</a>
				6333	</div>
				6334
				6335	<div class="doc_text">
				6336	<p> The LLVM exception handling intrinsics (which all start with
				6337	<tt>llvm.eh.</tt> prefix), are described in the <a
				6338	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6339	Handling</a> document. </p>
				6340	</div>
				6341
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6342	<!-- ======================================================================= -->
				6343	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6344	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6345	</div>
				6346
				6347	<div class="doc_text">
				6348	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6349	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6350	the <tt>nest</tt> attribute, from a function. The result is a callable
				6351	function pointer lacking the nest parameter - the caller does not need
				6352	to provide a value for it. Instead, the value to use is stored in
				6353	advance in a "trampoline", a block of memory usually allocated
				6354	on the stack, which also contains code to splice the nest value into the
				6355	argument list. This is used to implement the GCC nested function address
				6356	extension.
				6357	</p>
				6358	<p>
				6359	For example, if the function is
				6360	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6361	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6362	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6363	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6364	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6365	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6366	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6367	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6368	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6369	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6370	</div>
				6371
				6372	<!-- _______________________________________________________________________ -->
				6373	<div class="doc_subsubsection">
				6374	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6375	</div>
				6376	<div class="doc_text">
				6377	<h5>Syntax:</h5>
				6378	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6379	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6380	</pre>
				6381	<h5>Overview:</h5>
				6382	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6383	This fills the memory pointed to by <tt>tramp</tt> with code
				6384	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6385	</p>
				6386	<h5>Arguments:</h5>
				6387	<p>
				6388	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6389	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6390	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	c00c2ba	2007-08-22 23:39:54 +0000	[diff] [blame]	6391	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6392	currently provides no portable way of determining them, so a front-end that
				6393	generates this intrinsic needs to have some target-specific knowledge.
				6394	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6395	</p>
				6396	<h5>Semantics:</h5>
				6397	<p>
				6398	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6399	dependent code, turning it into a function. A pointer to this function is
				6400	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6401	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6402	before being called. The new function's signature is the same as that of
				6403	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6404	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6405	of pointer type. Calling the new function is equivalent to calling
				6406	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6407	missing <tt>nest</tt> argument. If, after calling
				6408	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6409	modified, then the effect of any later call to the returned function pointer is
				6410	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6411	</p>
				6412	</div>
				6413
				6414	<!-- ======================================================================= -->
				6415	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6416	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6417	</div>
				6418
				6419	<div class="doc_text">
				6420	<p>
				6421	These intrinsic functions expand the "universal IR" of LLVM to represent
				6422	hardware constructs for atomic operations and memory synchronization. This
				6423	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	6424	is aimed at a low enough level to allow any programming models or APIs
				6425	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6426	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6427	hardware behavior. Just as hardware provides a "universal IR" for source
				6428	languages, it also provides a starting point for developing a "universal"
				6429	atomic operation and synchronization IR.
				6430	</p>
				6431	<p>
				6432	These do <em>not</em> form an API such as high-level threading libraries,
				6433	software transaction memory systems, atomic primitives, and intrinsic
				6434	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6435	application libraries. The hardware interface provided by LLVM should allow
				6436	a clean implementation of all of these APIs and parallel programming models.
				6437	No one model or paradigm should be selected above others unless the hardware
				6438	itself ubiquitously does so.
				6439
				6440	</p>
				6441	</div>
				6442
				6443	<!-- _______________________________________________________________________ -->
				6444	<div class="doc_subsubsection">
				6445	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6446	</div>
				6447	<div class="doc_text">
				6448	<h5>Syntax:</h5>
				6449	<pre>
				6450	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6451	i1 <device> )
				6452
				6453	</pre>
				6454	<h5>Overview:</h5>
				6455	<p>
				6456	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6457	specific pairs of memory access types.
				6458	</p>
				6459	<h5>Arguments:</h5>
				6460	<p>
				6461	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6462	The first four arguments enables a specific barrier as listed below. The fith
				6463	argument specifies that the barrier applies to io or device or uncached memory.
				6464
				6465	</p>
				6466	<ul>
				6467	<li><tt>ll</tt>: load-load barrier</li>
				6468	<li><tt>ls</tt>: load-store barrier</li>
				6469	<li><tt>sl</tt>: store-load barrier</li>
				6470	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6471	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6472	</ul>
				6473	<h5>Semantics:</h5>
				6474	<p>
				6475	This intrinsic causes the system to enforce some ordering constraints upon
				6476	the loads and stores of the program. This barrier does not indicate
				6477	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6478	which they occur. For any of the specified pairs of load and store operations
				6479	(f.ex. load-load, or store-load), all of the first operations preceding the
				6480	barrier will complete before any of the second operations succeeding the
				6481	barrier begin. Specifically the semantics for each pairing is as follows:
				6482	</p>
				6483	<ul>
				6484	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6485	after the barrier begins.</li>
				6486
				6487	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6488	store after the barrier begins.</li>
				6489	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6490	store after the barrier begins.</li>
				6491	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6492	load after the barrier begins.</li>
				6493	</ul>
				6494	<p>
				6495	These semantics are applied with a logical "and" behavior when more than one
				6496	is enabled in a single memory barrier intrinsic.
				6497	</p>
				6498	<p>
				6499	Backends may implement stronger barriers than those requested when they do not
				6500	support as fine grained a barrier as requested. Some architectures do not
				6501	need all types of barriers and on such architectures, these become noops.
				6502	</p>
				6503	<h5>Example:</h5>
				6504	<pre>
				6505	%ptr = malloc i32
				6506	store i32 4, %ptr
				6507
				6508	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6509	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6510	<i>; guarantee the above finishes</i>
				6511	store i32 8, %ptr <i>; before this begins</i>
				6512	</pre>
				6513	</div>
				6514
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6515	<!-- _______________________________________________________________________ -->
				6516	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6517	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6518	</div>
				6519	<div class="doc_text">
				6520	<h5>Syntax:</h5>
				6521	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6522	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6523	any integer bit width and for different address spaces. Not all targets
				6524	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6525
				6526	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6527	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6528	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6529	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6530	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6531
				6532	</pre>
				6533	<h5>Overview:</h5>
				6534	<p>
				6535	This loads a value in memory and compares it to a given value. If they are
				6536	equal, it stores a new value into the memory.
				6537	</p>
				6538	<h5>Arguments:</h5>
				6539	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6540	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6541	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6542	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6543	this integer type. While any bit width integer may be used, targets may only
				6544	lower representations they support in hardware.
				6545
				6546	</p>
				6547	<h5>Semantics:</h5>
				6548	<p>
				6549	This entire intrinsic must be executed atomically. It first loads the value
				6550	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6551	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6552	loaded value is yielded in all cases. This provides the equivalent of an
				6553	atomic compare-and-swap operation within the SSA framework.
				6554	</p>
				6555	<h5>Examples:</h5>
				6556
				6557	<pre>
				6558	%ptr = malloc i32
				6559	store i32 4, %ptr
				6560
				6561	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6562	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6563	<i>; yields {i32}:result1 = 4</i>
				6564	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6565	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6566
				6567	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6568	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6569	<i>; yields {i32}:result2 = 8</i>
				6570	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6571
				6572	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6573	</pre>
				6574	</div>
				6575
				6576	<!-- _______________________________________________________________________ -->
				6577	<div class="doc_subsubsection">
				6578	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6579	</div>
				6580	<div class="doc_text">
				6581	<h5>Syntax:</h5>
				6582
				6583	<p>
				6584	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6585	integer bit width. Not all targets support all bit widths however.</p>
				6586	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6587	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6588	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6589	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6590	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6591
				6592	</pre>
				6593	<h5>Overview:</h5>
				6594	<p>
				6595	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6596	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6597	at <tt>ptr</tt>.
				6598	</p>
				6599	<h5>Arguments:</h5>
				6600
				6601	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6602	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6603	<tt>val</tt> argument and the result must be integers of the same bit width.
				6604	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6605	integer type. The targets may only lower integer representations they
				6606	support.
				6607	</p>
				6608	<h5>Semantics:</h5>
				6609	<p>
				6610	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6611	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6612	equivalent of an atomic swap operation within the SSA framework.
				6613
				6614	</p>
				6615	<h5>Examples:</h5>
				6616	<pre>
				6617	%ptr = malloc i32
				6618	store i32 4, %ptr
				6619
				6620	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6621	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6622	<i>; yields {i32}:result1 = 4</i>
				6623	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6624	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6625
				6626	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6627	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6628	<i>; yields {i32}:result2 = 8</i>
				6629
				6630	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6631	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6632	</pre>
				6633	</div>
				6634
				6635	<!-- _______________________________________________________________________ -->
				6636	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6637	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6638
				6639	</div>
				6640	<div class="doc_text">
				6641	<h5>Syntax:</h5>
				6642	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6643	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6644	integer bit width. Not all targets support all bit widths however.</p>
				6645	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6646	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6647	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6648	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6649	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6650
				6651	</pre>
				6652	<h5>Overview:</h5>
				6653	<p>
				6654	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6655	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6656	</p>
				6657	<h5>Arguments:</h5>
				6658	<p>
				6659
				6660	The intrinsic takes two arguments, the first a pointer to an integer value
				6661	and the second an integer value. The result is also an integer value. These
				6662	integer types can have any bit width, but they must all have the same bit
				6663	width. The targets may only lower integer representations they support.
				6664	</p>
				6665	<h5>Semantics:</h5>
				6666	<p>
				6667	This intrinsic does a series of operations atomically. It first loads the
				6668	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6669	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6670	</p>
				6671
				6672	<h5>Examples:</h5>
				6673	<pre>
				6674	%ptr = malloc i32
				6675	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6676	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6677	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6678	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6679	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6680	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6681	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6682	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6683	</pre>
				6684	</div>
				6685
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6686	<!-- _______________________________________________________________________ -->
				6687	<div class="doc_subsubsection">
				6688	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6689
				6690	</div>
				6691	<div class="doc_text">
				6692	<h5>Syntax:</h5>
				6693	<p>
				6694	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6695	any integer bit width and for different address spaces. Not all targets
				6696	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6697	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6698	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6699	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6700	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6701	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6702
				6703	</pre>
				6704	<h5>Overview:</h5>
				6705	<p>
				6706	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6707	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6708	</p>
				6709	<h5>Arguments:</h5>
				6710	<p>
				6711
				6712	The intrinsic takes two arguments, the first a pointer to an integer value
				6713	and the second an integer value. The result is also an integer value. These
				6714	integer types can have any bit width, but they must all have the same bit
				6715	width. The targets may only lower integer representations they support.
				6716	</p>
				6717	<h5>Semantics:</h5>
				6718	<p>
				6719	This intrinsic does a series of operations atomically. It first loads the
				6720	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6721	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6722	</p>
				6723
				6724	<h5>Examples:</h5>
				6725	<pre>
				6726	%ptr = malloc i32
				6727	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6728	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6729	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6730	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6731	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6732	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6733	<i>; yields {i32}:result3 = 2</i>
				6734	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6735	</pre>
				6736	</div>
				6737
				6738	<!-- _______________________________________________________________________ -->
				6739	<div class="doc_subsubsection">
				6740	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6741	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6742	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6743	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6744
				6745	</div>
				6746	<div class="doc_text">
				6747	<h5>Syntax:</h5>
				6748	<p>
				6749	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6750	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6751	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6752	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6753	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6754	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6755	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6756	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6757	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6758
				6759	</pre>
				6760
				6761	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6762	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6763	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6764	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6765	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6766
				6767	</pre>
				6768
				6769	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6771	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6772	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6773	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6774
				6775	</pre>
				6776
				6777	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6778	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6779	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6780	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6781	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6782
				6783	</pre>
				6784	<h5>Overview:</h5>
				6785	<p>
				6786	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6787	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6788	at <tt>ptr</tt>.
				6789	</p>
				6790	<h5>Arguments:</h5>
				6791	<p>
				6792
				6793	These intrinsics take two arguments, the first a pointer to an integer value
				6794	and the second an integer value. The result is also an integer value. These
				6795	integer types can have any bit width, but they must all have the same bit
				6796	width. The targets may only lower integer representations they support.
				6797	</p>
				6798	<h5>Semantics:</h5>
				6799	<p>
				6800	These intrinsics does a series of operations atomically. They first load the
				6801	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6802	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6803	value stored at <tt>ptr</tt>.
				6804	</p>
				6805
				6806	<h5>Examples:</h5>
				6807	<pre>
				6808	%ptr = malloc i32
				6809	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6810	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6811	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6812	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6813	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6814	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6815	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6816	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6817	<i>; yields {i32}:result3 = FF</i>
				6818	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6819	</pre>
				6820	</div>
				6821
				6822
				6823	<!-- _______________________________________________________________________ -->
				6824	<div class="doc_subsubsection">
				6825	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6826	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6827	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6828	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6829
				6830	</div>
				6831	<div class="doc_text">
				6832	<h5>Syntax:</h5>
				6833	<p>
				6834	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6835	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6836	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6837	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6838	support all bit widths however.</p>
				6839	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6840	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6841	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6842	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6843	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6844
				6845	</pre>
				6846
				6847	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6848	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6849	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6850	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6851	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6852
				6853	</pre>
				6854
				6855	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6856	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6857	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6858	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6859	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6860
				6861	</pre>
				6862
				6863	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6864	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6865	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6866	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6867	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6868
				6869	</pre>
				6870	<h5>Overview:</h5>
				6871	<p>
				6872	These intrinsics takes the signed or unsigned minimum or maximum of
				6873	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6874	original value at <tt>ptr</tt>.
				6875	</p>
				6876	<h5>Arguments:</h5>
				6877	<p>
				6878
				6879	These intrinsics take two arguments, the first a pointer to an integer value
				6880	and the second an integer value. The result is also an integer value. These
				6881	integer types can have any bit width, but they must all have the same bit
				6882	width. The targets may only lower integer representations they support.
				6883	</p>
				6884	<h5>Semantics:</h5>
				6885	<p>
				6886	These intrinsics does a series of operations atomically. They first load the
				6887	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6888	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6889	the original value stored at <tt>ptr</tt>.
				6890	</p>
				6891
				6892	<h5>Examples:</h5>
				6893	<pre>
				6894	%ptr = malloc i32
				6895	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6896	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6897	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6898	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6899	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6900	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6901	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6902	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6903	<i>; yields {i32}:result3 = 8</i>
				6904	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6905	</pre>
				6906	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6907
				6908	<!-- ======================================================================= -->
				6909	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6910	<a name="int_general">General Intrinsics</a>
				6911	</div>
				6912
				6913	<div class="doc_text">
				6914	<p> This class of intrinsics is designed to be generic and has
				6915	no specific purpose. </p>
				6916	</div>
				6917
				6918	<!-- _______________________________________________________________________ -->
				6919	<div class="doc_subsubsection">
				6920	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6921	</div>
				6922
				6923	<div class="doc_text">
				6924
				6925	<h5>Syntax:</h5>
				6926	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6927	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6928	</pre>
				6929
				6930	<h5>Overview:</h5>
				6931
				6932	<p>
				6933	The '<tt>llvm.var.annotation</tt>' intrinsic
				6934	</p>
				6935
				6936	<h5>Arguments:</h5>
				6937
				6938	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6939	The first argument is a pointer to a value, the second is a pointer to a
				6940	global string, the third is a pointer to a global string which is the source
				6941	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6942	</p>
				6943
				6944	<h5>Semantics:</h5>
				6945
				6946	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6947	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6948	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6949	annotations. These have no other defined use, they are ignored by code
				6950	generation and optimization.
				6951	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6952	</div>
				6953
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6954	<!-- _______________________________________________________________________ -->
				6955	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6956	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6957	</div>
				6958
				6959	<div class="doc_text">
				6960
				6961	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6962	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6963	any integer bit width.
				6964	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6965	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6966	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6967	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6968	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6969	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6970	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6971	</pre>
				6972
				6973	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6974
				6975	<p>
				6976	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6977	</p>
				6978
				6979	<h5>Arguments:</h5>
				6980
				6981	<p>
				6982	The first argument is an integer value (result of some expression),
				6983	the second is a pointer to a global string, the third is a pointer to a global
				6984	string which is the source file name, and the last argument is the line number.
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6985	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6986	</p>
				6987
				6988	<h5>Semantics:</h5>
				6989
				6990	<p>
				6991	This intrinsic allows annotations to be put on arbitrary expressions
				6992	with arbitrary strings. This can be useful for special purpose optimizations
				6993	that want to look for these annotations. These have no other defined use, they
				6994	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6995	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6996	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6997
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6998	<!-- _______________________________________________________________________ -->
				6999	<div class="doc_subsubsection">
				7000	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7001	</div>
				7002
				7003	<div class="doc_text">
				7004
				7005	<h5>Syntax:</h5>
				7006	<pre>
				7007	declare void @llvm.trap()
				7008	</pre>
				7009
				7010	<h5>Overview:</h5>
				7011
				7012	<p>
				7013	The '<tt>llvm.trap</tt>' intrinsic
				7014	</p>
				7015
				7016	<h5>Arguments:</h5>
				7017
				7018	<p>
				7019	None
				7020	</p>
				7021
				7022	<h5>Semantics:</h5>
				7023
				7024	<p>
				7025	This intrinsics is lowered to the target dependent trap instruction. If the
				7026	target does not have a trap instruction, this intrinsic will be lowered to the
				7027	call of the abort() function.
				7028	</p>
				7029	</div>
				7030
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7031	<!-- _______________________________________________________________________ -->
				7032	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7033	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7034	</div>
				7035	<div class="doc_text">
				7036	<h5>Syntax:</h5>
				7037	<pre>
				7038	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7039
				7040	</pre>
				7041	<h5>Overview:</h5>
				7042	<p>
				7043	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7044	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7045	it is placed on the stack before local variables.
				7046	</p>
				7047	<h5>Arguments:</h5>
				7048	<p>
				7049	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7050	first argument is the value loaded from the stack guard
				7051	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7052	has enough space to hold the value of the guard.
				7053	</p>
				7054	<h5>Semantics:</h5>
				7055	<p>
				7056	This intrinsic causes the prologue/epilogue inserter to force the position of
				7057	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7058	stack. This is to ensure that if a local variable on the stack is overwritten,
				7059	it will destroy the value of the guard. When the function exits, the guard on
				7060	the stack is checked against the original guard. If they're different, then
				7061	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7062	</p>
				7063	</div>
				7064
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7065	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7066	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7067	<address>
				7068	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7069	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7070	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7071	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7072
				7073	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7074	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7075	Last modified: $Date$
				7076	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7077
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7078	</body>
				7079	</html>