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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	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	25	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	26	<li><a href="#functionstructure">Functions</a></li>
Anton Korobeynikov	c6c98af	2007-04-29 18:02:48 +0000	[diff] [blame]	27	<li><a href="#aliasstructure">Aliases</a>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	28	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	29	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	30	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	31	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	32	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	33	</ol>
				34	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	35	<li><a href="#typesystem">Type System</a>
				36	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	37	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	38	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	39	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	40	<li><a href="#t_floating">Floating Point Types</a></li>
				41	<li><a href="#t_void">Void Type</a></li>
				42	<li><a href="#t_label">Label Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	43	</ol>
				44	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	45	<li><a href="#t_derived">Derived Types</a>
				46	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	47	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	48	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	49	<li><a href="#t_function">Function Type</a></li>
				50	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	51	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	52	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	53	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	54	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	55	</ol>
				56	</li>
				57	</ol>
				58	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	59	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	60	<ol>
				61	<li><a href="#simpleconstants">Simple Constants</a>
				62	<li><a href="#aggregateconstants">Aggregate Constants</a>
				63	<li><a href="#globalconstants">Global Variable and Function Addresses</a>
				64	<li><a href="#undefvalues">Undefined Values</a>
				65	<li><a href="#constantexprs">Constant Expressions</a>
				66	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	67	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	68	<li><a href="#othervalues">Other Values</a>
				69	<ol>
				70	<li><a href="#inlineasm">Inline Assembler Expressions</a>
				71	</ol>
				72	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	73	<li><a href="#instref">Instruction Reference</a>
				74	<ol>
				75	<li><a href="#terminators">Terminator Instructions</a>
				76	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	77	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				78	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	79	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				80	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	82	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	83	</ol>
				84	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	85	<li><a href="#binaryops">Binary Operations</a>
				86	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
				88	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				89	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	90	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				91	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				92	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	93	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				94	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				95	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	96	</ol>
				97	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	98	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				99	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	100	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				101	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				102	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	103	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	104	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	105	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	106	</ol>
				107	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	108	<li><a href="#vectorops">Vector Operations</a>
				109	<ol>
				110	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				111	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				112	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	113	</ol>
				114	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	115	<li><a href="#aggregateops">Aggregate Operations</a>
				116	<ol>
				117	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				118	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				119	</ol>
				120	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	121	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	123	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				124	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				125	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	126	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				127	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				128	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	129	</ol>
				130	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	131	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	132	<ol>
				133	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				134	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				135	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				136	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				137	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	138	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	142	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	144	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	145	</ol>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<li><a href="#otherops">Other Operations</a>
				147	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	148	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				149	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	150	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				151	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	152	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	153	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	154	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	155	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	156	<li><a href="#i_getresult">'<tt>getresult</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	157	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	159	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	161	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	162	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				164	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	165	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				166	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				167	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	168	</ol>
				169	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	170	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				171	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				173	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				174	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	177	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				178	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				180	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				181	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				182	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				183	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				184	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				185	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	186	</ol>
				187	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	188	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				189	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	190	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				191	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				192	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				193	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				194	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	195	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	198	</ol>
				199	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	200	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	201	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	202	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	203	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				204	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				205	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	206	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				207	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	208	</ol>
				209	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	210	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	211	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	212	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	213	<ol>
				214	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	215	</ol>
				216	</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	217	<li><a href="#int_atomics">Atomic intrinsics</a>
				218	<ol>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	219	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	220	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	221	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	222	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				223	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				224	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				225	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				226	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				227	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				228	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				229	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				230	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				231	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	232	</ol>
				233	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	234	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	235	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	236	<li><a href="#int_var_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	237	<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	238	<li><a href="#int_annotation">
Tanya Lattner	91d0b88	2007-09-22 00:01:26 +0000	[diff] [blame]	239	<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	240	<li><a href="#int_trap">
				241	<tt>llvm.trap</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	242	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	243	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	244	</ol>
				245	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	246	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	247
				248	<div class="doc_author">
				249	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				250	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	251	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	252
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	253	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	254	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				255	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	256
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	257	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	258	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	259	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	260	type safety, low-level operations, flexibility, and the capability of
				261	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	262	representation used throughout all phases of the LLVM compilation
				263	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	264	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	265
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	266	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	267	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				268	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	269
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	270	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	272	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	273	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	274	representation (suitable for fast loading by a Just-In-Time compiler),
				275	and as a human readable assembly language representation. This allows
				276	LLVM to provide a powerful intermediate representation for efficient
				277	compiler transformations and analysis, while providing a natural means
				278	to debug and visualize the transformations. The three different forms
				279	of LLVM are all equivalent. This document describes the human readable
				280	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	281
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	282	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	283	while being expressive, typed, and extensible at the same time. It
				284	aims to be a "universal IR" of sorts, by being at a low enough level
				285	that high-level ideas may be cleanly mapped to it (similar to how
				286	microprocessors are "universal IR's", allowing many source languages to
				287	be mapped to them). By providing type information, LLVM can be used as
				288	the target of optimizations: for example, through pointer analysis, it
				289	can be proven that a C automatic variable is never accessed outside of
				290	the current function... allowing it to be promoted to a simple SSA
				291	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	292
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	293	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	294
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	295	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	296	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	297
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	298	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	299
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	300	<p>It is important to note that this document describes 'well formed'
				301	LLVM assembly language. There is a difference between what the parser
				302	accepts and what is considered 'well formed'. For example, the
				303	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	304
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	305	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	306	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	307	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	308	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	309	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<p>...because the definition of <tt>%x</tt> does not dominate all of
				312	its uses. The LLVM infrastructure provides a verification pass that may
				313	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	314	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	315	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	316	by the verifier pass indicate bugs in transformation passes or input to
				317	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	318	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	320	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	322	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	323	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	324	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	326	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	328	<p>LLVM identifiers come in two basic types: global and local. Global
				329	identifiers (functions, global variables) begin with the @ character. Local
				330	identifiers (register names, types) begin with the % character. Additionally,
				331	there are three different formats for identifiers, for different purposes:
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	332
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	333	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	334	<li>Named values are represented as a string of characters with their prefix.
				335	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				336	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	337	Identifiers which require other characters in their names can be surrounded
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	338	with quotes. In this way, anything except a <tt>"</tt> character can
				339	be used in a named value.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	340
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	341	<li>Unnamed values are represented as an unsigned numeric value with their
				342	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	343
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	344	<li>Constants, which are described in a <a href="#constants">section about
				345	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	346	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	347
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	348	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	349	don't need to worry about name clashes with reserved words, and the set of
				350	reserved words may be expanded in the future without penalty. Additionally,
				351	unnamed identifiers allow a compiler to quickly come up with a temporary
				352	variable without having to avoid symbol table conflicts.</p>
				353
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	354	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	355	languages. There are keywords for different opcodes
				356	('<tt><a href="#i_add">add</a></tt>',
				357	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				358	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	359	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	360	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	361	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	362
				363	<p>Here is an example of LLVM code to multiply the integer variable
				364	'<tt>%X</tt>' by 8:</p>
				365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	366	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	368	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	370	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	371	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	372	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	374	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	375
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	376	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	377	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	378	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	379	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	380	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>And the hard 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	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				387	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				388	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	392	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				393	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	394
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	395	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	396
				397	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				398	line.</li>
				399
				400	<li>Unnamed temporaries are created when the result of a computation is not
				401	assigned to a named value.</li>
				402
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	403	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	404
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	405	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	406
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	407	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	408	demonstrating instructions, we will follow an instruction with a comment that
				409	defines the type and name of value produced. Comments are shown in italic
				410	text.</p>
				411
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	412	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	413
				414	<!-- *********************************************************************** -->
				415	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				416	<!-- *********************************************************************** -->
				417
				418	<!-- ======================================================================= -->
				419	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				420	</div>
				421
				422	<div class="doc_text">
				423
				424	<p>LLVM programs are composed of "Module"s, each of which is a
				425	translation unit of the input programs. Each module consists of
				426	functions, global variables, and symbol table entries. Modules may be
				427	combined together with the LLVM linker, which merges function (and
				428	global variable) definitions, resolves forward declarations, and merges
				429	symbol table entries. Here is an example of the "hello world" module:</p>
				430
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	431	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	432	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	433	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				434	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	435
				436	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	437	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	438
				439	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	440	define i32 @main() { <i>; i32()* </i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	441	<i>; Convert [13x i8 ]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	442	%cast210 = <a
Chris Lattner	6c0955b	2007-06-12 17:01:15 +0000	[diff] [blame]	443	href="#i_getelementptr">getelementptr</a> [13 x i8 ]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	444
				445	<i>; Call puts function to write out the string to stdout...</i>
				446	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	447	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	449	href="#i_ret">ret</a> i32 0<br>}<br>
				450	</pre>
				451	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	452
				453	<p>This example is made up of a <a href="#globalvars">global variable</a>
				454	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				455	function, and a <a href="#functionstructure">function definition</a>
				456	for "<tt>main</tt>".</p>
				457
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	458	<p>In general, a module is made up of a list of global values,
				459	where both functions and global variables are global values. Global values are
				460	represented by a pointer to a memory location (in this case, a pointer to an
				461	array of char, and a pointer to a function), and have one of the following <a
				462	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	463
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	464	</div>
				465
				466	<!-- ======================================================================= -->
				467	<div class="doc_subsection">
				468	<a name="linkage">Linkage Types</a>
				469	</div>
				470
				471	<div class="doc_text">
				472
				473	<p>
				474	All Global Variables and Functions have one of the following types of linkage:
				475	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	476
				477	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	479	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480
				481	<dd>Global values with internal linkage are only directly accessible by
				482	objects in the current module. In particular, linking code into a module with
				483	an internal global value may cause the internal to be renamed as necessary to
				484	avoid collisions. Because the symbol is internal to the module, all
				485	references can be updated. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	486	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	487	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	488
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	489	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	490
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	491	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				492	the same name when linkage occurs. This is typically used to implement
				493	inline functions, templates, or other code which must be generated in each
				494	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				495	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	498	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				499
				500	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				501	linkage, except that unreferenced <tt>common</tt> globals may not be
				502	discarded. This is used for globals that may be emitted in multiple
				503	translation units, but that are not guaranteed to be emitted into every
				504	translation unit that uses them. One example of this is tentative
				505	definitions in C, such as "<tt>int X;</tt>" at global scope.
				506	</dd>
				507
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	508	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	509
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	510	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				511	that some targets may choose to emit different assembly sequences for them
				512	for target-dependent reasons. This is used for globals that are declared
				513	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	516	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	517
				518	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				519	pointer to array type. When two global variables with appending linkage are
				520	linked together, the two global arrays are appended together. This is the
				521	LLVM, typesafe, equivalent of having the system linker append together
				522	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	525	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	526	<dd>The semantics of this linkage follow the ELF object file model: the
				527	symbol is weak until linked, if not linked, the symbol becomes null instead
				528	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	529	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	530
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	531	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	532
				533	<dd>If none of the above identifiers are used, the global is externally
				534	visible, meaning that it participates in linkage and can be used to resolve
				535	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	536	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	537	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	538
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	539	<p>
				540	The next two types of linkage are targeted for Microsoft Windows platform
				541	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	542	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	543	</p>
				544
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	545	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				547
				548	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				549	or variable via a global pointer to a pointer that is set up by the DLL
				550	exporting the symbol. On Microsoft Windows targets, the pointer name is
				551	formed by combining <code>_imp__</code> and the function or variable name.
				552	</dd>
				553
				554	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				555
				556	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				557	pointer to a pointer in a DLL, so that it can be referenced with the
				558	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
				559	name is formed by combining <code>_imp__</code> and the function or variable
				560	name.
				561	</dd>
				562
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	563	</dl>
				564
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565	<p><a name="linkage_external"></a>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	566	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				567	variable and was linked with this one, one of the two would be renamed,
				568	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				569	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	570	outside of the current module.</p>
				571	<p>It is illegal for a function <i>declaration</i>
				572	to have any linkage type other than "externally visible", <tt>dllimport</tt>,
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	573	or <tt>extern_weak</tt>.</p>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	574	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt> and <tt>weak</tt>
				575	linkages.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	576	</div>
				577
				578	<!-- ======================================================================= -->
				579	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	580	<a name="callingconv">Calling Conventions</a>
				581	</div>
				582
				583	<div class="doc_text">
				584
				585	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				586	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				587	specified for the call. The calling convention of any pair of dynamic
				588	caller/callee must match, or the behavior of the program is undefined. The
				589	following calling conventions are supported by LLVM, and more may be added in
				590	the future:</p>
				591
				592	<dl>
				593	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				594
				595	<dd>This calling convention (the default if no other calling convention is
				596	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	597	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	598	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	599	</dd>
				600
				601	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				602
				603	<dd>This calling convention attempts to make calls as fast as possible
				604	(e.g. by passing things in registers). This calling convention allows the
				605	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	606	without having to conform to an externally specified ABI (Application Binary
				607	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	608	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				609	supported. This calling convention does not support varargs and requires the
				610	prototype of all callees to exactly match the prototype of the function
				611	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	612	</dd>
				613
				614	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				615
				616	<dd>This calling convention attempts to make code in the caller as efficient
				617	as possible under the assumption that the call is not commonly executed. As
				618	such, these calls often preserve all registers so that the call does not break
				619	any live ranges in the caller side. This calling convention does not support
				620	varargs and requires the prototype of all callees to exactly match the
				621	prototype of the function definition.
				622	</dd>
				623
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	624	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	625
				626	<dd>Any calling convention may be specified by number, allowing
				627	target-specific calling conventions to be used. Target specific calling
				628	conventions start at 64.
				629	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	630	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	631
				632	<p>More calling conventions can be added/defined on an as-needed basis, to
				633	support pascal conventions or any other well-known target-independent
				634	convention.</p>
				635
				636	</div>
				637
				638	<!-- ======================================================================= -->
				639	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	640	<a name="visibility">Visibility Styles</a>
				641	</div>
				642
				643	<div class="doc_text">
				644
				645	<p>
				646	All Global Variables and Functions have one of the following visibility styles:
				647	</p>
				648
				649	<dl>
				650	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				651
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	652	<dd>On targets that use the ELF object file format, default visibility means
				653	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	654	modules and, in shared libraries, means that the declared entity may be
				655	overridden. On Darwin, default visibility means that the declaration is
				656	visible to other modules. Default visibility corresponds to "external
				657	linkage" in the language.
				658	</dd>
				659
				660	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				661
				662	<dd>Two declarations of an object with hidden visibility refer to the same
				663	object if they are in the same shared object. Usually, hidden visibility
				664	indicates that the symbol will not be placed into the dynamic symbol table,
				665	so no other module (executable or shared library) can reference it
				666	directly.
				667	</dd>
				668
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	669	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				670
				671	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				672	the dynamic symbol table, but that references within the defining module will
				673	bind to the local symbol. That is, the symbol cannot be overridden by another
				674	module.
				675	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	676	</dl>
				677
				678	</div>
				679
				680	<!-- ======================================================================= -->
				681	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	682	<a name="globalvars">Global Variables</a>
				683	</div>
				684
				685	<div class="doc_text">
				686
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	687	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	688	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	689	an explicit section to be placed in, and may have an optional explicit alignment
				690	specified. A variable may be defined as "thread_local", which means that it
				691	will not be shared by threads (each thread will have a separated copy of the
				692	variable). A variable may be defined as a global "constant," which indicates
				693	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	694	optimization, allowing the global data to be placed in the read-only section of
				695	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	696	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	697
				698	<p>
				699	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				700	constant, even if the final definition of the global is not. This capability
				701	can be used to enable slightly better optimization of the program, but requires
				702	the language definition to guarantee that optimizations based on the
				703	'constantness' are valid for the translation units that do not include the
				704	definition.
				705	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	706
				707	<p>As SSA values, global variables define pointer values that are in
				708	scope (i.e. they dominate) all basic blocks in the program. Global
				709	variables always define a pointer to their "content" type because they
				710	describe a region of memory, and all memory objects in LLVM are
				711	accessed through pointers.</p>
				712
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	713	<p>A global variable may be declared to reside in a target-specifc numbered
				714	address space. For targets that support them, address spaces may affect how
				715	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	716	the variable. The default address space is zero. The address space qualifier
				717	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	718
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	719	<p>LLVM allows an explicit section to be specified for globals. If the target
				720	supports it, it will emit globals to the section specified.</p>
				721
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	722	<p>An explicit alignment may be specified for a global. If not present, or if
				723	the alignment is set to zero, the alignment of the global is set by the target
				724	to whatever it feels convenient. If an explicit alignment is specified, the
				725	global is forced to have at least that much alignment. All alignments must be
				726	a power of 2.</p>
				727
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	728	<p>For example, the following defines a global in a numbered address space with
				729	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	730
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	731	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	732	<pre>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	733	@G = constant float 1.0 addrspace(5), section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	734	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	735	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	736
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	737	</div>
				738
				739
				740	<!-- ======================================================================= -->
				741	<div class="doc_subsection">
				742	<a name="functionstructure">Functions</a>
				743	</div>
				744
				745	<div class="doc_text">
				746
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	747	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				748	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	749	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	750	<a href="#callingconv">calling convention</a>, a return type, an optional
				751	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				752	name, a (possibly empty) argument list (each with optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	753	<a href="#paramattrs">parameter attributes</a>), an optional section, an
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	754	optional alignment, an optional <a href="#gc">garbage collector name</a>,
				755	an optional <a href="#notes">function notes</a>, an
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	756	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]	757
				758	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				759	optional <a href="#linkage">linkage type</a>, an optional
				760	<a href="#visibility">visibility style</a>, an optional
				761	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	762	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	763	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]	764	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	765
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	766	<p>A function definition contains a list of basic blocks, forming the CFG
				767	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	768	the function. Each basic block may optionally start with a label (giving the
				769	basic block a symbol table entry), contains a list of instructions, and ends
				770	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				771	function return).</p>
				772
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	773	<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]	774	executed on entrance to the function, and it is not allowed to have predecessor
				775	basic blocks (i.e. there can not be any branches to the entry block of a
				776	function). Because the block can have no predecessors, it also cannot have any
				777	<a href="#i_phi">PHI nodes</a>.</p>
				778
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	779	<p>LLVM allows an explicit section to be specified for functions. If the target
				780	supports it, it will emit functions to the section specified.</p>
				781
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	782	<p>An explicit alignment may be specified for a function. If not present, or if
				783	the alignment is set to zero, the alignment of the function is set by the target
				784	to whatever it feels convenient. If an explicit alignment is specified, the
				785	function is forced to have at least that much alignment. All alignments must be
				786	a power of 2.</p>
				787
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	788	</div>
				789
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	790
				791	<!-- ======================================================================= -->
				792	<div class="doc_subsection">
				793	<a name="aliasstructure">Aliases</a>
				794	</div>
				795	<div class="doc_text">
				796	<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]	797	function, global variable, another alias or bitcast of global value). Aliases
				798	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	799	optional <a href="#visibility">visibility style</a>.</p>
				800
				801	<h5>Syntax:</h5>
				802
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	803	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	804	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	805	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	806	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	807	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	808
				809	</div>
				810
				811
				812
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	813	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	814	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				815	<div class="doc_text">
				816	<p>The return type and each parameter of a function type may have a set of
				817	<i>parameter attributes</i> associated with them. Parameter attributes are
				818	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	819	a function. Parameter attributes are considered to be part of the function,
				820	not of the function type, so functions with different parameter attributes
				821	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	822
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	823	<p>Parameter attributes are simple keywords that follow the type specified. If
				824	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	825	example:</p>
				826
				827	<div class="doc_code">
				828	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	829	declare i32 @printf(i8* noalias , ...)
				830	declare i32 @atoi(i8 zeroext*)
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	831	</pre>
				832	</div>
				833
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	834	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				835	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	836
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	837	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	838	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	839	<dt><tt>zeroext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	840	<dd>This indicates that the parameter should be zero extended just before
				841	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	842
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	843	<dt><tt>signext</tt></dt>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	844	<dd>This indicates that the parameter should be sign extended just before
				845	a call to this function.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	846
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	847	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	848	<dd>This indicates that this parameter or return value should be treated
				849	in a special target-dependent fashion during while emitting code for a
				850	function call or return (usually, by putting it in a register as opposed
				851	to memory; in some places it is used to distinguish between two different
				852	kinds of registers). Use of this attribute is target-specific</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	853
				854	<dt><tt>byval</tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	855	<dd>This indicates that the pointer parameter should really be passed by
				856	value to the function. The attribute implies that a hidden copy of the
				857	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]	858	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]	859	pointer arguments. It is generally used to pass structs and arrays by
				860	value, but is also valid on scalars (even though this is silly).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	861
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	862	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	863	<dd>This indicates that the pointer parameter specifies the address of a
				864	structure that is the return value of the function in the source program.
Duncan Sands	b7f0c08	2008-03-17 12:17:41 +0000	[diff] [blame]	865	Loads and stores to the structure are assumed not to trap.
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	866	May only be applied to the first parameter.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	867
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	868	<dt><tt>noalias</tt></dt>
Owen Anderson	117bbd3	2008-02-18 04:09:01 +0000	[diff] [blame]	869	<dd>This indicates that the parameter does not alias any global or any other
				870	parameter. The caller is responsible for ensuring that this is the case,
				871	usually by placing the value in a stack allocation.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	872
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	873	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	874	<dd>This indicates that the pointer parameter can be excised using the
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	875	<a href="#int_trampoline">trampoline intrinsics</a>.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	876	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	877
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	878	</div>
				879
				880	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	881	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	882	<a name="gc">Garbage Collector Names</a>
				883	</div>
				884
				885	<div class="doc_text">
				886	<p>Each function may specify a garbage collector name, which is simply a
				887	string.</p>
				888
				889	<div class="doc_code"><pre
				890	>define void @f() gc "name" { ...</pre></div>
				891
				892	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				893	collector which will cause the compiler to alter its output in order to support
				894	the named garbage collection algorithm.</p>
				895	</div>
				896
				897	<!-- ======================================================================= -->
				898	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	899	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	900	</div>
				901
				902	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	903
				904	<p>Function attributes are set to communicate additional information about
				905	a function. Function attributes are considered to be part of the function,
				906	not of the function type, so functions with different parameter attributes
				907	can have the same function type.</p>
				908
				909	<p>Function attributes are simple keywords that follow the type specified. If
				910	multiple attributes are needed, they are space separated. For
				911	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	912
				913	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	914	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	915	define void @f() noinline { ... }
				916	define void @f() alwaysinline { ... }
				917	define void @f() alwaysinline optsize { ... }
				918	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	919	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	920	</div>
				921
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	922	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	923	<dt><tt>alwaysinline</tt></dt>
				924	<dd>This attribute requests inliner to inline this function irrespective of
				925	inlining size threshold for this function.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	926
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	927	<dt><tt>noinline</tt></dt>
				928	<dd>This attributes requests inliner to never inline this function in any
				929	situation. This attribute may not be used together with <tt>alwaysinline</tt>
				930	attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	931
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	932	<dt><tt>optsize</tt></dt>
				933	<dd>This attribute suggests optimization passes and code generator passes to
				934	make choices that help reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	935
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame^]	936	<dt><tt>noreturn</tt></dt>
				937	<dd>This function attribute indicates that the function never returns. This
				938	indicates to LLVM that every call to this function should be treated as if
				939	an <tt>unreachable</tt> instruction immediately followed the call.</dd>
				940
				941	<dt><tt>nounwind</tt></dt>
				942	<dd>This function attribute indicates that no exceptions unwind out of the
				943	function. Usually this is because the function makes no use of exceptions,
				944	but it may also be that the function catches any exceptions thrown when
				945	executing it.</dd>
				946
				947	<dt><tt>readonly</tt></dt>
				948	<dd>This function attribute indicates that the function has no side-effects
				949	except for producing a return value or throwing an exception. The value
				950	returned must only depend on the function arguments and/or global variables.
				951	It may use values obtained by dereferencing pointers.</dd>
				952	<dt><tt>readnone</tt></dt>
				953	<dd>A <tt>readnone</tt> function has the same restrictions as a <tt>readonly</tt>
				954	function, but in addition it is not allowed to dereference any pointer arguments
				955	or global variables.
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	956	</dl>
				957
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	958	</div>
				959
				960	<!-- ======================================================================= -->
				961	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	962	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	963	</div>
				964
				965	<div class="doc_text">
				966	<p>
				967	Modules may contain "module-level inline asm" blocks, which corresponds to the
				968	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				969	LLVM and treated as a single unit, but may be separated in the .ll file if
				970	desired. The syntax is very simple:
				971	</p>
				972
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	973	<div class="doc_code">
				974	<pre>
				975	module asm "inline asm code goes here"
				976	module asm "more can go here"
				977	</pre>
				978	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	979
				980	<p>The strings can contain any character by escaping non-printable characters.
				981	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				982	for the number.
				983	</p>
				984
				985	<p>
				986	The inline asm code is simply printed to the machine code .s file when
				987	assembly code is generated.
				988	</p>
				989	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	990
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	991	<!-- ======================================================================= -->
				992	<div class="doc_subsection">
				993	<a name="datalayout">Data Layout</a>
				994	</div>
				995
				996	<div class="doc_text">
				997	<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]	998	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				999	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1000	<p>The <i>layout specification</i> consists of a list of specifications
				1001	separated by the minus sign character ('-'). Each specification starts with a
				1002	letter and may include other information after the letter to define some
				1003	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1004	<dl>
				1005	<dt><tt>E</tt></dt>
				1006	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1007	bits with the most significance have the lowest address location.</dd>
				1008	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1009	<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]	1010	the bits with the least significance have the lowest address location.</dd>
				1011	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1012	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1013	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1014	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1015	too.</dd>
				1016	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1017	<dd>This specifies the alignment for an integer type of a given bit
				1018	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1019	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1020	<dd>This specifies the alignment for a vector type of a given bit
				1021	<i>size</i>.</dd>
				1022	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1023	<dd>This specifies the alignment for a floating point type of a given bit
				1024	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1025	(double).</dd>
				1026	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1027	<dd>This specifies the alignment for an aggregate type of a given bit
				1028	<i>size</i>.</dd>
				1029	</dl>
				1030	<p>When constructing the data layout for a given target, LLVM starts with a
				1031	default set of specifications which are then (possibly) overriden by the
				1032	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1033	are given in this list:</p>
				1034	<ul>
				1035	<li><tt>E</tt> - big endian</li>
				1036	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1037	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1038	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1039	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1040	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1041	<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]	1042	alignment of 64-bits</li>
				1043	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1044	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1045	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1046	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1047	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1048	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1049	<p>When LLVM is determining the alignment for a given type, it uses the
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1050	following rules:
				1051	<ol>
				1052	<li>If the type sought is an exact match for one of the specifications, that
				1053	specification is used.</li>
				1054	<li>If no match is found, and the type sought is an integer type, then the
				1055	smallest integer type that is larger than the bitwidth of the sought type is
				1056	used. If none of the specifications are larger than the bitwidth then the the
				1057	largest integer type is used. For example, given the default specifications
				1058	above, the i7 type will use the alignment of i8 (next largest) while both
				1059	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1060	<li>If no match is found, and the type sought is a vector type, then the
				1061	largest vector type that is smaller than the sought vector type will be used
				1062	as a fall back. This happens because <128 x double> can be implemented in
				1063	terms of 64 <2 x double>, for example.</li>
				1064	</ol>
				1065	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1066
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1067	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1068	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1069	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1070
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1071	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1072
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1073	<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]	1074	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1075	optimizations to be performed on the intermediate representation directly,
				1076	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1077	extra analyses on the side before the transformation. A strong type
				1078	system makes it easier to read the generated code and enables novel
				1079	analyses and transformations that are not feasible to perform on normal
				1080	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1081
				1082	</div>
				1083
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1084	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1085	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1086	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1087	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1088	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1089	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1090
				1091	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1092	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1093	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1094	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1095	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1096	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1097	</tr>
				1098	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1099	<td><a href="#t_floating">floating point</a></td>
				1100	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1101	</tr>
				1102	<tr>
				1103	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1104	<td><a href="#t_integer">integer</a>,
				1105	<a href="#t_floating">floating point</a>,
				1106	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1107	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1108	<a href="#t_struct">structure</a>,
				1109	<a href="#t_array">array</a>,
Dan Gohman	ade5faa	2008-05-23 22:50:26 +0000	[diff] [blame]	1110	<a href="#t_label">label</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1111	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1112	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1113	<tr>
				1114	<td><a href="#t_primitive">primitive</a></td>
				1115	<td><a href="#t_label">label</a>,
				1116	<a href="#t_void">void</a>,
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1117	<a href="#t_floating">floating point</a>.</td>
				1118	</tr>
				1119	<tr>
				1120	<td><a href="#t_derived">derived</a></td>
				1121	<td><a href="#t_integer">integer</a>,
				1122	<a href="#t_array">array</a>,
				1123	<a href="#t_function">function</a>,
				1124	<a href="#t_pointer">pointer</a>,
				1125	<a href="#t_struct">structure</a>,
				1126	<a href="#t_pstruct">packed structure</a>,
				1127	<a href="#t_vector">vector</a>,
				1128	<a href="#t_opaque">opaque</a>.
				1129	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1130	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1131	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1132
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1133	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1134	most important. Values of these types are the only ones which can be
				1135	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1136	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1137	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1138
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1139	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1140	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1141
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1142	<div class="doc_text">
				1143	<p>The primitive types are the fundamental building blocks of the LLVM
				1144	system.</p>
				1145
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1146	</div>
				1147
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1148	<!-- _______________________________________________________________________ -->
				1149	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1150
				1151	<div class="doc_text">
				1152	<table>
				1153	<tbody>
				1154	<tr><th>Type</th><th>Description</th></tr>
				1155	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1156	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1157	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1158	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1159	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1160	</tbody>
				1161	</table>
				1162	</div>
				1163
				1164	<!-- _______________________________________________________________________ -->
				1165	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1166
				1167	<div class="doc_text">
				1168	<h5>Overview:</h5>
				1169	<p>The void type does not represent any value and has no size.</p>
				1170
				1171	<h5>Syntax:</h5>
				1172
				1173	<pre>
				1174	void
				1175	</pre>
				1176	</div>
				1177
				1178	<!-- _______________________________________________________________________ -->
				1179	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1180
				1181	<div class="doc_text">
				1182	<h5>Overview:</h5>
				1183	<p>The label type represents code labels.</p>
				1184
				1185	<h5>Syntax:</h5>
				1186
				1187	<pre>
				1188	label
				1189	</pre>
				1190	</div>
				1191
				1192
				1193	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1194	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1195
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1196	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1197
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1198	<p>The real power in LLVM comes from the derived types in the system.
				1199	This is what allows a programmer to represent arrays, functions,
				1200	pointers, and other useful types. Note that these derived types may be
				1201	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]	1202
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1203	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1204
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1205	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1206	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1207
				1208	<div class="doc_text">
				1209
				1210	<h5>Overview:</h5>
				1211	<p>The integer type is a very simple derived type that simply specifies an
				1212	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1213	2^23-1 (about 8 million) can be specified.</p>
				1214
				1215	<h5>Syntax:</h5>
				1216
				1217	<pre>
				1218	iN
				1219	</pre>
				1220
				1221	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1222	value.</p>
				1223
				1224	<h5>Examples:</h5>
				1225	<table class="layout">
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1226	<tbody>
				1227	<tr>
				1228	<td><tt>i1</tt></td>
				1229	<td>a single-bit integer.</td>
				1230	</tr><tr>
				1231	<td><tt>i32</tt></td>
				1232	<td>a 32-bit integer.</td>
				1233	</tr><tr>
				1234	<td><tt>i1942652</tt></td>
				1235	<td>a really big integer of over 1 million bits.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1236	</tr>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	1237	</tbody>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1238	</table>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1239	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1240
				1241	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1242	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1243
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1244	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1245
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1246	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1247
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1248	<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]	1249	sequentially in memory. The array type requires a size (number of
				1250	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1251
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1252	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1253
				1254	<pre>
				1255	[<# elements> x <elementtype>]
				1256	</pre>
				1257
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1258	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1259	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1260
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1261	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1262	<table class="layout">
				1263	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1264	<td class="left"><tt>[40 x i32]</tt></td>
				1265	<td class="left">Array of 40 32-bit integer values.</td>
				1266	</tr>
				1267	<tr class="layout">
				1268	<td class="left"><tt>[41 x i32]</tt></td>
				1269	<td class="left">Array of 41 32-bit integer values.</td>
				1270	</tr>
				1271	<tr class="layout">
				1272	<td class="left"><tt>[4 x i8]</tt></td>
				1273	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1274	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1275	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1276	<p>Here are some examples of multidimensional arrays:</p>
				1277	<table class="layout">
				1278	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1279	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1280	<td class="left">3x4 array of 32-bit integer values.</td>
				1281	</tr>
				1282	<tr class="layout">
				1283	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1284	<td class="left">12x10 array of single precision floating point values.</td>
				1285	</tr>
				1286	<tr class="layout">
				1287	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1288	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1289	</tr>
				1290	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1291
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1292	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1293	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]	1294	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1295	As a special case, however, zero length arrays are recognized to be variable
				1296	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1297	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1298
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1299	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1300
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1301	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1302	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1303	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1305	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1306
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1307	<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]	1308	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]	1309	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]	1310	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]	1311	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1312
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1313	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1314
				1315	<pre>
				1316	<returntype list> (<parameter list>)
				1317	</pre>
				1318
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1319	<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]	1320	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1321	which indicates that the function takes a variable number of arguments.
				1322	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1323	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1324	'<tt><returntype list></tt>' is a comma-separated list of
				1325	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1326
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1327	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1328	<table class="layout">
				1329	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1330	<td class="left"><tt>i32 (i32)</tt></td>
				1331	<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]	1332	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1333	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1334	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1335	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1336	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1337	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1338	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1339	<tt>float</tt>.
				1340	</td>
				1341	</tr><tr class="layout">
				1342	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1343	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1344	<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]	1345	which returns an integer. This is the signature for <tt>printf</tt> in
				1346	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1347	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1348	</tr><tr class="layout">
				1349	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Devang Patel	3a5bff8	2008-03-24 18:10:52 +0000	[diff] [blame]	1350	<td class="left">A function taking an <tt>i32></tt>, returning two
				1351	<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]	1352	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1353	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1354	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1355
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1356	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1357	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1358	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1359	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1360	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1361	<p>The structure type is used to represent a collection of data members
				1362	together in memory. The packing of the field types is defined to match
				1363	the ABI of the underlying processor. The elements of a structure may
				1364	be any type that has a size.</p>
				1365	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1366	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1367	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1368	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1369	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1370	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1371	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1372	<table class="layout">
				1373	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1374	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1375	<td class="left">A triple of three <tt>i32</tt> values</td>
				1376	</tr><tr class="layout">
				1377	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1378	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1379	second element is a <a href="#t_pointer">pointer</a> to a
				1380	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1381	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1382	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1383	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1384	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1385
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1386	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1387	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1388	</div>
				1389	<div class="doc_text">
				1390	<h5>Overview:</h5>
				1391	<p>The packed structure type is used to represent a collection of data members
				1392	together in memory. There is no padding between fields. Further, the alignment
				1393	of a packed structure is 1 byte. The elements of a packed structure may
				1394	be any type that has a size.</p>
				1395	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1396	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1397	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1398	instruction.</p>
				1399	<h5>Syntax:</h5>
				1400	<pre> < { <type list> } > <br></pre>
				1401	<h5>Examples:</h5>
				1402	<table class="layout">
				1403	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1404	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1405	<td class="left">A triple of three <tt>i32</tt> values</td>
				1406	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1407	<td class="left">
				1408	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1409	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1410	second element is a <a href="#t_pointer">pointer</a> to a
				1411	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1412	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1413	</tr>
				1414	</table>
				1415	</div>
				1416
				1417	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1418	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1419	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1420	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1421	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1422	reference to another object, which must live in memory. Pointer types may have
				1423	an optional address space attribute defining the target-specific numbered
				1424	address space where the pointed-to object resides. The default address space is
				1425	zero.</p>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1426	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1427	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1428	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	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>[4x i32]*</tt></td>
				1432	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1433	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1434	</tr>
				1435	<tr class="layout">
				1436	<td class="left"><tt>i32 (i32 ) </tt></td>
				1437	<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]	1438	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]	1439	<tt>i32</tt>.</td>
				1440	</tr>
				1441	<tr class="layout">
				1442	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1443	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1444	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1445	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1446	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1447	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1448
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1449	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1450	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1451	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1452
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1453	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1454
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1455	<p>A vector type is a simple derived type that represents a vector
				1456	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1457	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1458	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1459	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1460	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1461	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1462
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1463	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1464
				1465	<pre>
				1466	< <# elements> x <elementtype> >
				1467	</pre>
				1468
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1469	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1470	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1471
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1472	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1473
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1474	<table class="layout">
				1475	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1476	<td class="left"><tt><4 x i32></tt></td>
				1477	<td class="left">Vector of 4 32-bit integer values.</td>
				1478	</tr>
				1479	<tr class="layout">
				1480	<td class="left"><tt><8 x float></tt></td>
				1481	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1482	</tr>
				1483	<tr class="layout">
				1484	<td class="left"><tt><2 x i64></tt></td>
				1485	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1486	</tr>
				1487	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1488	</div>
				1489
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1490	<!-- _______________________________________________________________________ -->
				1491	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1492	<div class="doc_text">
				1493
				1494	<h5>Overview:</h5>
				1495
				1496	<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]	1497	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]	1498	In LLVM, opaque types can eventually be resolved to any type (not just a
				1499	structure type).</p>
				1500
				1501	<h5>Syntax:</h5>
				1502
				1503	<pre>
				1504	opaque
				1505	</pre>
				1506
				1507	<h5>Examples:</h5>
				1508
				1509	<table class="layout">
				1510	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1511	<td class="left"><tt>opaque</tt></td>
				1512	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1513	</tr>
				1514	</table>
				1515	</div>
				1516
				1517
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1518	<!-- *********************************************************************** -->
				1519	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1520	<!-- *********************************************************************** -->
				1521
				1522	<div class="doc_text">
				1523
				1524	<p>LLVM has several different basic types of constants. This section describes
				1525	them all and their syntax.</p>
				1526
				1527	</div>
				1528
				1529	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1530	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1531
				1532	<div class="doc_text">
				1533
				1534	<dl>
				1535	<dt><b>Boolean constants</b></dt>
				1536
				1537	<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]	1538	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1539	</dd>
				1540
				1541	<dt><b>Integer constants</b></dt>
				1542
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1543	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1544	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1545	integer types.
				1546	</dd>
				1547
				1548	<dt><b>Floating point constants</b></dt>
				1549
				1550	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1551	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1552	notation (see below). The assembler requires the exact decimal value of
				1553	a floating-point constant. For example, the assembler accepts 1.25 but
				1554	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1555	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]	1556
				1557	<dt><b>Null pointer constants</b></dt>
				1558
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1559	<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]	1560	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1561
				1562	</dl>
				1563
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1564	<p>The one non-intuitive notation for constants is the optional hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1565	of floating point constants. For example, the form '<tt>double
				1566	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1567	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]	1568	(and the only time that they are generated by the disassembler) is when a
				1569	floating point constant must be emitted but it cannot be represented as a
				1570	decimal floating point number. For example, NaN's, infinities, and other
				1571	special values are represented in their IEEE hexadecimal format so that
				1572	assembly and disassembly do not cause any bits to change in the constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1573
				1574	</div>
				1575
				1576	<!-- ======================================================================= -->
				1577	<div class="doc_subsection"><a name="aggregateconstants">Aggregate Constants</a>
				1578	</div>
				1579
				1580	<div class="doc_text">
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1581	<p>Aggregate constants arise from aggregation of simple constants
				1582	and smaller aggregate constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1583
				1584	<dl>
				1585	<dt><b>Structure constants</b></dt>
				1586
				1587	<dd>Structure constants are represented with notation similar to structure
				1588	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1589	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1590	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]	1591	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]	1592	types of elements must match those specified by the type.
				1593	</dd>
				1594
				1595	<dt><b>Array constants</b></dt>
				1596
				1597	<dd>Array constants are represented with notation similar to array type
				1598	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1599	(<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]	1600	constants must have <a href="#t_array">array type</a>, and the number and
				1601	types of elements must match those specified by the type.
				1602	</dd>
				1603
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1604	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1605
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1606	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1607	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1608	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1609	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1610	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]	1611	match those specified by the type.
				1612	</dd>
				1613
				1614	<dt><b>Zero initialization</b></dt>
				1615
				1616	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1617	value to zero of <em>any</em> type, including scalar and aggregate types.
				1618	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]	1619	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1620	initializers.
				1621	</dd>
				1622	</dl>
				1623
				1624	</div>
				1625
				1626	<!-- ======================================================================= -->
				1627	<div class="doc_subsection">
				1628	<a name="globalconstants">Global Variable and Function Addresses</a>
				1629	</div>
				1630
				1631	<div class="doc_text">
				1632
				1633	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1634	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1635	constants. These constants are explicitly referenced when the <a
				1636	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]	1637	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1638	file:</p>
				1639
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1640	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1641	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1642	@X = global i32 17
				1643	@Y = global i32 42
				1644	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1645	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1646	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1647
				1648	</div>
				1649
				1650	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1651	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1652	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1653	<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]	1654	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]	1655	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1656
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1657	<p>Undefined values indicate to the compiler that the program is well defined
				1658	no matter what value is used, giving the compiler more freedom to optimize.
				1659	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1660	</div>
				1661
				1662	<!-- ======================================================================= -->
				1663	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1664	</div>
				1665
				1666	<div class="doc_text">
				1667
				1668	<p>Constant expressions are used to allow expressions involving other constants
				1669	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1670	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]	1671	that does not have side effects (e.g. load and call are not supported). The
				1672	following is the syntax for constant expressions:</p>
				1673
				1674	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1675	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1676	<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]	1677	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1678
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1679	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1680	<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]	1681	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]	1682
				1683	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1684	<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]	1685	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]	1686
				1687	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1688	<dd>Truncate a floating point constant to another floating point type. The
				1689	size of CST must be larger than the size of TYPE. Both types must be
				1690	floating point.</dd>
				1691
				1692	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1693	<dd>Floating point extend a constant to another type. The size of CST must be
				1694	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1695
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1696	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1697	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1698	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1699	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1700	of the same number of elements. If the value won't fit in the integer type,
				1701	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1702
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1703	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1704	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1705	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1706	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1707	of the same number of elements. If the value won't fit in the integer type,
				1708	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1709
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1710	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1711	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1712	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1713	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1714	of the same number of elements. If the value won't fit in the floating point
				1715	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1716
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1717	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1718	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1719	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1720	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1721	of the same number of elements. If the value won't fit in the floating point
				1722	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1723
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1724	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1725	<dd>Convert a pointer typed constant to the corresponding integer constant
				1726	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1727	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1728
				1729	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				1730	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				1731	pointer type. CST must be of integer type. The CST value is zero extended,
				1732	truncated, or unchanged to make it fit in a pointer size. This one is
				1733	<i>really</i> dangerous!</dd>
				1734
				1735	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1736	<dd>Convert a constant, CST, to another TYPE. The size of CST and TYPE must be
				1737	identical (same number of bits). The conversion is done as if the CST value
				1738	was stored to memory and read back as TYPE. In other words, no bits change
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	1739	with this operator, just the type. This can be used for conversion of
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1740	vector types to any other type, as long as they have the same bit width. For
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	1741	pointers it is only valid to cast to another pointer type. It is not valid
				1742	to bitcast to or from an aggregate type.
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1743	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1744
				1745	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				1746
				1747	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				1748	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				1749	instruction, the index list may have zero or more indexes, which are required
				1750	to make sense for the type of "CSTPTR".</dd>
				1751
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1752	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				1753
				1754	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1755	constants.</dd>
				1756
				1757	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				1758	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				1759
				1760	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1761	<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]	1762
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	1763	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				1764	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				1765
				1766	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				1767	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				1768
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	1769	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				1770
				1771	<dd>Perform the <a href="#i_extractelement">extractelement
				1772	operation</a> on constants.
				1773
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1774	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				1775
				1776	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1777	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	1778
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1779
				1780	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				1781
				1782	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	1783	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	1784
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1785	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				1786
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1787	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				1788	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]	1789	binary</a> operations. The constraints on operands are the same as those for
				1790	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1791	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1792	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1793	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	1794
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1795	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1796	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				1797	<!-- *********************************************************************** -->
				1798
				1799	<!-- ======================================================================= -->
				1800	<div class="doc_subsection">
				1801	<a name="inlineasm">Inline Assembler Expressions</a>
				1802	</div>
				1803
				1804	<div class="doc_text">
				1805
				1806	<p>
				1807	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				1808	Module-Level Inline Assembly</a>) through the use of a special value. This
				1809	value represents the inline assembler as a string (containing the instructions
				1810	to emit), a list of operand constraints (stored as a string), and a flag that
				1811	indicates whether or not the inline asm expression has side effects. An example
				1812	inline assembler expression is:
				1813	</p>
				1814
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1815	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1816	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1817	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1818	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1819	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1820
				1821	<p>
				1822	Inline assembler expressions may <b>only</b> be used as the callee operand of
				1823	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				1824	</p>
				1825
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1826	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1827	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1828	%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]	1829	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1830	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1831
				1832	<p>
				1833	Inline asms with side effects not visible in the constraint list must be marked
				1834	as having side effects. This is done through the use of the
				1835	'<tt>sideeffect</tt>' keyword, like so:
				1836	</p>
				1837
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1838	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1839	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1840	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1841	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1842	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	1843
				1844	<p>TODO: The format of the asm and constraints string still need to be
				1845	documented here. Constraints on what can be done (e.g. duplication, moving, etc
				1846	need to be documented).
				1847	</p>
				1848
				1849	</div>
				1850
				1851	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1852	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				1853	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1854
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1855	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1856
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1857	<p>The LLVM instruction set consists of several different
				1858	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1859	instructions</a>, <a href="#binaryops">binary instructions</a>,
				1860	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1861	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				1862	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1863
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1864	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1865
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1866	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1867	<div class="doc_subsection"> <a name="terminators">Terminator
				1868	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1869
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1870	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1871
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1872	<p>As mentioned <a href="#functionstructure">previously</a>, every
				1873	basic block in a program ends with a "Terminator" instruction, which
				1874	indicates which block should be executed after the current block is
				1875	finished. These terminator instructions typically yield a '<tt>void</tt>'
				1876	value: they produce control flow, not values (the one exception being
				1877	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1878	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1879	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				1880	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	1881	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				1882	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				1883	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1884
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1885	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1886
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1887	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1888	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				1889	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1890	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1891	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1892	<pre> 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]	1893	ret void <i>; Return from void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1894	ret <type> <value>, <type> <value> <i>; Return two values from a non-void function </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1895	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1896
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1897	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1898
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1899	<p>The '<tt>ret</tt>' instruction is used to return control flow (and a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1900	value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	1901	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1902	returns value(s) and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1903	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1904
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1905	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1906
				1907	<p>The '<tt>ret</tt>' instruction may return zero, one or multiple values.
				1908	The type of each return value must be a '<a href="#t_firstclass">first
				1909	class</a>' type. Note that a function is not <a href="#wellformed">well
				1910	formed</a> if there exists a '<tt>ret</tt>' instruction inside of the
				1911	function that returns values that do not match the return type of the
				1912	function.</p>
				1913
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1914	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1915
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1916	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				1917	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]	1918	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1919	the instruction after the call. If the caller was an "<a
				1920	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1921	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1922	returns a value, that value shall set the call or invoke instruction's
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1923	return value. If the instruction returns multiple values then these
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	1924	values can only be accessed through a '<a href="#i_getresult"><tt>getresult</tt>
				1925	</a>' instruction.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1926
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1927	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1928
				1929	<pre>
				1930	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1931	ret void <i>; Return from a void function</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1932	ret i32 4, i8 2 <i>; Return two values 4 and 2 </i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1933	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1934	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1935	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1936	<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]	1937	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1938	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1939	<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]	1940	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1941	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1942	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				1943	transfer to a different basic block in the current function. There are
				1944	two forms of this instruction, corresponding to a conditional branch
				1945	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1946	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1947	<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]	1948	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1949	unconditional form of the '<tt>br</tt>' instruction takes a single
				1950	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1951	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1952	<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]	1953	argument is evaluated. If the value is <tt>true</tt>, control flows
				1954	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				1955	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1956	<h5>Example:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1957	<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]	1958	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]	1959	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1960	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1961	<div class="doc_subsubsection">
				1962	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				1963	</div>
				1964
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1965	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1966	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1967
				1968	<pre>
				1969	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				1970	</pre>
				1971
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1972	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1973
				1974	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				1975	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1976	instruction, allowing a branch to occur to one of many possible
				1977	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1978
				1979
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1980	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1981
				1982	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				1983	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				1984	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				1985	table is not allowed to contain duplicate constant entries.</p>
				1986
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1987	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1988
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1989	<p>The <tt>switch</tt> instruction specifies a table of values and
				1990	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1991	table is searched for the given value. If the value is found, control flow is
				1992	transfered to the corresponding destination; otherwise, control flow is
				1993	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1994
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	1995	<h5>Implementation:</h5>
				1996
				1997	<p>Depending on properties of the target machine and the particular
				1998	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	1999	ways. For example, it could be generated as a series of chained conditional
				2000	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2001
				2002	<h5>Example:</h5>
				2003
				2004	<pre>
				2005	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2006	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2007	switch i32 %Val, label %truedest [i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2008
				2009	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2010	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2011
				2012	<i>; Implement a jump table:</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2013	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2014	i32 1, label %onone
				2015	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2016	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2017	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2018
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2019	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2020	<div class="doc_subsubsection">
				2021	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2022	</div>
				2023
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2024	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2025
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2026	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2027
				2028	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2029	<result> = invoke [<a href="#callingconv">cconv</a>] <ptr to function ty> <function ptr val>(<function args>)
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2030	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2031	</pre>
				2032
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2033	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2034
				2035	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2036	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2037	'<tt>normal</tt>' label or the
				2038	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2039	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2040	"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]	2041	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	2042	continued at the dynamically nearest "exception" label. If the callee function
Devang Patel	0dbb4a1	2008-03-11 05:51:59 +0000	[diff] [blame]	2043	returns multiple values then individual return values are only accessible through
				2044	a '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2045
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2046	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2047
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2048	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2049
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2050	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2051	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2052	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2053	convention</a> the call should use. If none is specified, the call defaults
				2054	to using C calling conventions.
				2055	</li>
				2056	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2057	function value being invoked. In most cases, this is a direct function
				2058	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2059	an arbitrary pointer to function value.
				2060	</li>
				2061
				2062	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2063	function to be invoked. </li>
				2064
				2065	<li>'<tt>function args</tt>': argument list whose types match the function
				2066	signature argument types. If the function signature indicates the function
				2067	accepts a variable number of arguments, the extra arguments can be
				2068	specified. </li>
				2069
				2070	<li>'<tt>normal label</tt>': the label reached when the called function
				2071	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2072
				2073	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2074	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2075
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2076	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2077
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2078	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2079
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2080	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2081	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2082	difference is that it establishes an association with a label, which is used by
				2083	the runtime library to unwind the stack.</p>
				2084
				2085	<p>This instruction is used in languages with destructors to ensure that proper
				2086	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2087	exception. Additionally, this is important for implementation of
				2088	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2089
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2090	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2091	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2092	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2093	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2094	%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]	2095	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2096	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2097	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2098
				2099
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2100	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2101
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2102	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2103	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2104
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2105	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2106
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2107	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2108	<pre>
				2109	unwind
				2110	</pre>
				2111
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2112	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2113
				2114	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2115	at the first callee in the dynamic call stack which used an <a
				2116	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2117	primarily used to implement exception handling.</p>
				2118
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2119	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2120
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2121	<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]	2122	immediately halt. The dynamic call stack is then searched for the first <a
				2123	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2124	execution continues at the "exceptional" destination block specified by the
				2125	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2126	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2127	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2128
				2129	<!-- _______________________________________________________________________ -->
				2130
				2131	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2132	Instruction</a> </div>
				2133
				2134	<div class="doc_text">
				2135
				2136	<h5>Syntax:</h5>
				2137	<pre>
				2138	unreachable
				2139	</pre>
				2140
				2141	<h5>Overview:</h5>
				2142
				2143	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2144	instruction is used to inform the optimizer that a particular portion of the
				2145	code is not reachable. This can be used to indicate that the code after a
				2146	no-return function cannot be reached, and other facts.</p>
				2147
				2148	<h5>Semantics:</h5>
				2149
				2150	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2151	</div>
				2152
				2153
				2154
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2155	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2156	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2157	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2158	<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]	2159	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]	2160	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2161	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]	2162	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2163	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2164	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2165	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2166	<div class="doc_subsubsection">
				2167	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2168	</div>
				2169
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2171
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2172	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2173
				2174	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2175	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2176	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2177
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2178	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2179
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2180	<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]	2181
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2183
				2184	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2185	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2186	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2187	types.</p>
				2188
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2189	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2190
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2191	<p>The value produced is the integer or floating point sum of the two
				2192	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2193
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2194	<p>If an integer sum has unsigned overflow, the result returned is the
				2195	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2196	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2197
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2198	<p>Because LLVM integers use a two's complement representation, this
				2199	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2200
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2202
				2203	<pre>
				2204	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2206	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2208	<div class="doc_subsubsection">
				2209	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2210	</div>
				2211
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2212	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2213
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2214	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2215
				2216	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2217	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2218	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2219
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2220	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2221
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2222	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2223	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2224
				2225	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2226	'<tt>neg</tt>' instruction present in most other intermediate
				2227	representations.</p>
				2228
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2230
				2231	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2232	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2233	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2234	types.</p>
				2235
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2236	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2237
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2238	<p>The value produced is the integer or floating point difference of
				2239	the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2240
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2241	<p>If an integer difference has unsigned overflow, the result returned is the
				2242	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2243	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2244
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2245	<p>Because LLVM integers use a two's complement representation, this
				2246	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2247
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2248	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2249	<pre>
				2250	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2251	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2252	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2253	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2254
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2255	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2256	<div class="doc_subsubsection">
				2257	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2258	</div>
				2259
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2260	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2261
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2262	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2263	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2265	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2266	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2267	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2268
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2269	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2270
				2271	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2272	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2273	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2274	types.</p>
				2275
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2277
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2278	<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]	2279	two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2280
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2281	<p>If the result of an integer multiplication has unsigned overflow,
				2282	the result returned is the mathematical result modulo
				2283	2<sup>n</sup>, where n is the bit width of the result.</p>
				2284	<p>Because LLVM integers use a two's complement representation, and the
				2285	result is the same width as the operands, this instruction returns the
				2286	correct result for both signed and unsigned integers. If a full product
				2287	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2288	should be sign-extended or zero-extended as appropriate to the
				2289	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2290	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2291	<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]	2292	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2293	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2294
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2295	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2296	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2297	</a></div>
				2298	<div class="doc_text">
				2299	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2300	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2301	</pre>
				2302	<h5>Overview:</h5>
				2303	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2304	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2305
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2306	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2307
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2308	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2309	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2310	values. Both arguments must have identical types.</p>
				2311
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2312	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2313
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2314	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2315	<p>Note that unsigned integer division and signed integer division are distinct
				2316	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2317	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2318	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2319	<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]	2320	</pre>
				2321	</div>
				2322	<!-- _______________________________________________________________________ -->
				2323	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2324	</a> </div>
				2325	<div class="doc_text">
				2326	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2327	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2328	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2329	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2330
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2331	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2332
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2333	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2334	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2335
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2336	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2337
				2338	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2339	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2340	values. Both arguments must have identical types.</p>
				2341
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2342	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2343	<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]	2344	<p>Note that signed integer division and unsigned integer division are distinct
				2345	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2346	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2347	undefined behavior; this is a rare case, but can occur, for example,
				2348	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2349	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2350	<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]	2351	</pre>
				2352	</div>
				2353	<!-- _______________________________________________________________________ -->
				2354	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2355	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2356	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2357	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2358	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2359	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2360	</pre>
				2361	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2362
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2363	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2364	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2365
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2366	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2367
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2368	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2369	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2370	of floating point values. Both arguments must have identical types.</p>
				2371
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2372	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2373
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2374	<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]	2375
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2376	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2377
				2378	<pre>
				2379	<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]	2380	</pre>
				2381	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2382
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2383	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2384	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2385	</div>
				2386	<div class="doc_text">
				2387	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2388	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2389	</pre>
				2390	<h5>Overview:</h5>
				2391	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2392	unsigned division of its two arguments.</p>
				2393	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2394	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2395	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2396	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2397	<h5>Semantics:</h5>
				2398	<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]	2399	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2400	<p>Note that unsigned integer remainder and signed integer remainder are
				2401	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2402	<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]	2403	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2404	<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]	2405	</pre>
				2406
				2407	</div>
				2408	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2409	<div class="doc_subsubsection">
				2410	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2411	</div>
				2412
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2413	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2414
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2415	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2416
				2417	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2418	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2419	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2420
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2421	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2422
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2423	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2424	signed division of its two operands. This instruction can also take
				2425	<a href="#t_vector">vector</a> versions of the values in which case
				2426	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2427
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2428	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2429
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2430	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2431	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2432	values. Both arguments must have identical types.</p>
				2433
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2434	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2435
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2436	<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]	2437	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2438	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]	2439	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2440	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]	2441	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]	2442	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2443	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2444	<p>Note that signed integer remainder and unsigned integer remainder are
				2445	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2446	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2447	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2448	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2449	(The remainder doesn't actually overflow, but this rule lets srem be
				2450	implemented using instructions that return both the result of the division
				2451	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2452	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2453	<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]	2454	</pre>
				2455
				2456	</div>
				2457	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2458	<div class="doc_subsubsection">
				2459	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2460
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2461	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2462
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2463	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2464	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2465	</pre>
				2466	<h5>Overview:</h5>
				2467	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2468	division of its two operands.</p>
				2469	<h5>Arguments:</h5>
				2470	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2471	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2472	of floating point values. Both arguments must have identical types.</p>
				2473
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2474	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2475
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2476	<p>This instruction returns the <i>remainder</i> of a division.
				2477	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2478
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2479	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2480
				2481	<pre>
				2482	<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]	2483	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2484	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2485
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2486	<!-- ======================================================================= -->
				2487	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2488	Operations</a> </div>
				2489	<div class="doc_text">
				2490	<p>Bitwise binary operators are used to do various forms of
				2491	bit-twiddling in a program. They are generally very efficient
				2492	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2493	instructions. They require two operands of the same type, execute an operation on them,
				2494	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]	2495	</div>
				2496
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2497	<!-- _______________________________________________________________________ -->
				2498	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2499	Instruction</a> </div>
				2500	<div class="doc_text">
				2501	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2502	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2503	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2504
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2505	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2506
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2507	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2508	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2509
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2510	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2511
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2512	<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]	2513	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]	2514	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2515
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2516	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2517
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2518	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2519	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
				2520	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2521
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2522	<h5>Example:</h5><pre>
				2523	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2524	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2525	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2526	<result> = shl i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2527	</pre>
				2528	</div>
				2529	<!-- _______________________________________________________________________ -->
				2530	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2531	Instruction</a> </div>
				2532	<div class="doc_text">
				2533	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2534	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2535	</pre>
				2536
				2537	<h5>Overview:</h5>
				2538	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2539	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]	2540
				2541	<h5>Arguments:</h5>
				2542	<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]	2543	<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]	2544	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2545
				2546	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2547
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2548	<p>This instruction always performs a logical shift right operation. The most
				2549	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]	2550	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
				2551	the number of bits in <tt>op1</tt>, the result is undefined.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2552
				2553	<h5>Example:</h5>
				2554	<pre>
				2555	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2556	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2557	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2558	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2559	<result> = lshr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2560	</pre>
				2561	</div>
				2562
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2563	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2564	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2565	Instruction</a> </div>
				2566	<div class="doc_text">
				2567
				2568	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2569	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2570	</pre>
				2571
				2572	<h5>Overview:</h5>
				2573	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2574	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]	2575
				2576	<h5>Arguments:</h5>
				2577	<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]	2578	<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]	2579	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2580
				2581	<h5>Semantics:</h5>
				2582	<p>This instruction always performs an arithmetic shift right operation,
				2583	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]	2584	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
				2585	larger than the number of bits in <tt>op1</tt>, the result is undefined.
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2586	</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2587
				2588	<h5>Example:</h5>
				2589	<pre>
				2590	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2591	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2592	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2593	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2594	<result> = ashr i32 1, 32 <i>; undefined</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2595	</pre>
				2596	</div>
				2597
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2598	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2599	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2600	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2602	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2603
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2604	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
				2606	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2607	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2608	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2609
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2610	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2612	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2613	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2615	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2616
				2617	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2618	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2619	values. Both arguments must have identical types.</p>
				2620
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2621	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2622	<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]	2623	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2624	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2625	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2626	<tbody>
				2627	<tr>
				2628	<td>In0</td>
				2629	<td>In1</td>
				2630	<td>Out</td>
				2631	</tr>
				2632	<tr>
				2633	<td>0</td>
				2634	<td>0</td>
				2635	<td>0</td>
				2636	</tr>
				2637	<tr>
				2638	<td>0</td>
				2639	<td>1</td>
				2640	<td>0</td>
				2641	</tr>
				2642	<tr>
				2643	<td>1</td>
				2644	<td>0</td>
				2645	<td>0</td>
				2646	</tr>
				2647	<tr>
				2648	<td>1</td>
				2649	<td>1</td>
				2650	<td>1</td>
				2651	</tr>
				2652	</tbody>
				2653	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2654	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2655	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2656	<pre>
				2657	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2658	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2659	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2660	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2661	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2663	<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]	2664	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2666	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2667	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2668	<h5>Overview:</h5>
				2669	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2670	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2672
				2673	<p>The two arguments to the '<tt>or</tt>' instruction must be
				2674	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2675	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2676	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2677	<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]	2678	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2679	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2680	<table border="1" cellspacing="0" cellpadding="4">
				2681	<tbody>
				2682	<tr>
				2683	<td>In0</td>
				2684	<td>In1</td>
				2685	<td>Out</td>
				2686	</tr>
				2687	<tr>
				2688	<td>0</td>
				2689	<td>0</td>
				2690	<td>0</td>
				2691	</tr>
				2692	<tr>
				2693	<td>0</td>
				2694	<td>1</td>
				2695	<td>1</td>
				2696	</tr>
				2697	<tr>
				2698	<td>1</td>
				2699	<td>0</td>
				2700	<td>1</td>
				2701	</tr>
				2702	<tr>
				2703	<td>1</td>
				2704	<td>1</td>
				2705	<td>1</td>
				2706	</tr>
				2707	</tbody>
				2708	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2709	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2710	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2711	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				2712	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				2713	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2714	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2715	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2716	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2717	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				2718	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2719	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2720	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2721	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2722	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2723	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2724	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				2725	or of its two operands. The <tt>xor</tt> is used to implement the
				2726	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2727	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2728	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				2729	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2730	values. Both arguments must have identical types.</p>
				2731
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2732	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2733
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2734	<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]	2735	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	2736	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2737	<table border="1" cellspacing="0" cellpadding="4">
				2738	<tbody>
				2739	<tr>
				2740	<td>In0</td>
				2741	<td>In1</td>
				2742	<td>Out</td>
				2743	</tr>
				2744	<tr>
				2745	<td>0</td>
				2746	<td>0</td>
				2747	<td>0</td>
				2748	</tr>
				2749	<tr>
				2750	<td>0</td>
				2751	<td>1</td>
				2752	<td>1</td>
				2753	</tr>
				2754	<tr>
				2755	<td>1</td>
				2756	<td>0</td>
				2757	<td>1</td>
				2758	</tr>
				2759	<tr>
				2760	<td>1</td>
				2761	<td>1</td>
				2762	<td>0</td>
				2763	</tr>
				2764	</tbody>
				2765	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	2766	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2767	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2768	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2769	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				2770	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				2771	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				2772	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2773	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2774	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2775
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2776	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	2777	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2778	<a name="vectorops">Vector Operations</a>
				2779	</div>
				2780
				2781	<div class="doc_text">
				2782
				2783	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2784	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2785	vector-specific operations needed to process vectors effectively. While LLVM
				2786	does directly support these vector operations, many sophisticated algorithms
				2787	will want to use target-specific intrinsics to take full advantage of a specific
				2788	target.</p>
				2789
				2790	</div>
				2791
				2792	<!-- _______________________________________________________________________ -->
				2793	<div class="doc_subsubsection">
				2794	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				2795	</div>
				2796
				2797	<div class="doc_text">
				2798
				2799	<h5>Syntax:</h5>
				2800
				2801	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2802	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2803	</pre>
				2804
				2805	<h5>Overview:</h5>
				2806
				2807	<p>
				2808	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2809	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2810	</p>
				2811
				2812
				2813	<h5>Arguments:</h5>
				2814
				2815	<p>
				2816	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2817	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]	2818	an index indicating the position from which to extract the element.
				2819	The index may be a variable.</p>
				2820
				2821	<h5>Semantics:</h5>
				2822
				2823	<p>
				2824	The result is a scalar of the same type as the element type of
				2825	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				2826	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				2827	results are undefined.
				2828	</p>
				2829
				2830	<h5>Example:</h5>
				2831
				2832	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2833	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2834	</pre>
				2835	</div>
				2836
				2837
				2838	<!-- _______________________________________________________________________ -->
				2839	<div class="doc_subsubsection">
				2840	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				2841	</div>
				2842
				2843	<div class="doc_text">
				2844
				2845	<h5>Syntax:</h5>
				2846
				2847	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	2848	<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]	2849	</pre>
				2850
				2851	<h5>Overview:</h5>
				2852
				2853	<p>
				2854	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2855	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2856	</p>
				2857
				2858
				2859	<h5>Arguments:</h5>
				2860
				2861	<p>
				2862	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2863	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]	2864	scalar value whose type must equal the element type of the first
				2865	operand. The third operand is an index indicating the position at
				2866	which to insert the value. The index may be a variable.</p>
				2867
				2868	<h5>Semantics:</h5>
				2869
				2870	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2871	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]	2872	element values are those of <tt>val</tt> except at position
				2873	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				2874	exceeds the length of <tt>val</tt>, the results are undefined.
				2875	</p>
				2876
				2877	<h5>Example:</h5>
				2878
				2879	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2880	%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]	2881	</pre>
				2882	</div>
				2883
				2884	<!-- _______________________________________________________________________ -->
				2885	<div class="doc_subsubsection">
				2886	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				2887	</div>
				2888
				2889	<div class="doc_text">
				2890
				2891	<h5>Syntax:</h5>
				2892
				2893	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2894	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <n x i32> <mask> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2895	</pre>
				2896
				2897	<h5>Overview:</h5>
				2898
				2899	<p>
				2900	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
				2901	from two input vectors, returning a vector of the same type.
				2902	</p>
				2903
				2904	<h5>Arguments:</h5>
				2905
				2906	<p>
				2907	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				2908	with types that match each other and types that match the result of the
				2909	instruction. The third argument is a shuffle mask, which has the same number
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2910	of elements as the other vector type, but whose element type is always 'i32'.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2911	</p>
				2912
				2913	<p>
				2914	The shuffle mask operand is required to be a constant vector with either
				2915	constant integer or undef values.
				2916	</p>
				2917
				2918	<h5>Semantics:</h5>
				2919
				2920	<p>
				2921	The elements of the two input vectors are numbered from left to right across
				2922	both of the vectors. The shuffle mask operand specifies, for each element of
				2923	the result vector, which element of the two input registers the result element
				2924	gets. The element selector may be undef (meaning "don't care") and the second
				2925	operand may be undef if performing a shuffle from only one vector.
				2926	</p>
				2927
				2928	<h5>Example:</h5>
				2929
				2930	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2931	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2932	<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]	2933	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				2934	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2935	</pre>
				2936	</div>
				2937
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	2938
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	2939	<!-- ======================================================================= -->
				2940	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2941	<a name="aggregateops">Aggregate Operations</a>
				2942	</div>
				2943
				2944	<div class="doc_text">
				2945
				2946	<p>LLVM supports several instructions for working with aggregate values.
				2947	</p>
				2948
				2949	</div>
				2950
				2951	<!-- _______________________________________________________________________ -->
				2952	<div class="doc_subsubsection">
				2953	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				2954	</div>
				2955
				2956	<div class="doc_text">
				2957
				2958	<h5>Syntax:</h5>
				2959
				2960	<pre>
				2961	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				2962	</pre>
				2963
				2964	<h5>Overview:</h5>
				2965
				2966	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	2967	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				2968	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2969	</p>
				2970
				2971
				2972	<h5>Arguments:</h5>
				2973
				2974	<p>
				2975	The first operand of an '<tt>extractvalue</tt>' instruction is a
				2976	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]	2977	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2978	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2979	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				2980	</p>
				2981
				2982	<h5>Semantics:</h5>
				2983
				2984	<p>
				2985	The result is the value at the position in the aggregate specified by
				2986	the index operands.
				2987	</p>
				2988
				2989	<h5>Example:</h5>
				2990
				2991	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	2992	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	2993	</pre>
				2994	</div>
				2995
				2996
				2997	<!-- _______________________________________________________________________ -->
				2998	<div class="doc_subsubsection">
				2999	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3000	</div>
				3001
				3002	<div class="doc_text">
				3003
				3004	<h5>Syntax:</h5>
				3005
				3006	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3007	<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]	3008	</pre>
				3009
				3010	<h5>Overview:</h5>
				3011
				3012	<p>
				3013	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3014	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3015	</p>
				3016
				3017
				3018	<h5>Arguments:</h5>
				3019
				3020	<p>
				3021	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3022	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3023	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3024	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3025	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]	3026	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3027	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3028	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]	3029	by the indices.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3030
				3031	<h5>Semantics:</h5>
				3032
				3033	<p>
				3034	The result is an aggregate of the same type as <tt>val</tt>. Its
				3035	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]	3036	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3037	</p>
				3038
				3039	<h5>Example:</h5>
				3040
				3041	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3042	%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]	3043	</pre>
				3044	</div>
				3045
				3046
				3047	<!-- ======================================================================= -->
				3048	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3049	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3050	</div>
				3051
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3052	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3053
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3054	<p>A key design point of an SSA-based representation is how it
				3055	represents memory. In LLVM, no memory locations are in SSA form, which
				3056	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3057	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3058
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3059	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3060
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3061	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3062	<div class="doc_subsubsection">
				3063	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3064	</div>
				3065
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3066	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3067
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3068	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3069
				3070	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3071	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3072	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3073
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3074	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3075
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3076	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3077	heap and returns a pointer to it. The object is always allocated in the generic
				3078	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3079
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3080	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3081
				3082	<p>The '<tt>malloc</tt>' instruction allocates
				3083	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3084	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]	3085	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3086	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3087	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]	3088	be aligned to at least that boundary. If not specified, or if zero, the target can
				3089	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3090
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3091	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3092
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3094
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3095	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3096	a pointer is returned. The result of a zero byte allocattion is undefined. The
				3097	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3098
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3099	<h5>Example:</h5>
				3100
				3101	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3102	%array = malloc [4 x i8 ] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3103
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3104	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3105	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3106	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3107	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3108	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3109	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3110	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3111
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3113	<div class="doc_subsubsection">
				3114	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3115	</div>
				3116
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3117	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3118
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3119	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3120
				3121	<pre>
				3122	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3123	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3124
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3125	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3126
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3127	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3128	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3129
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3130	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3131
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3132	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3133	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3134	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3135
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3136	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3137
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3138	<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]	3139	after this instruction executes. If the pointer is null, the operation
				3140	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3141
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3142	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3143
				3144	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3145	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
				3146	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3147	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3148	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3149
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3151	<div class="doc_subsubsection">
				3152	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3153	</div>
				3154
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3155	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3156
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3158
				3159	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3160	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3161	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3162
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3164
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3165	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3166	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3167	returns to its caller. The object is always allocated in the generic address
				3168	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3169
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3170	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3171
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3172	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3173	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3174	appropriate type to the program. If "NumElements" is specified, it is the
				3175	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3176	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]	3177	to be aligned to at least that boundary. If not specified, or if zero, the target
				3178	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3179
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3180	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3181
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3182	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3183
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3184	<p>Memory is allocated; a pointer is returned. The operation is undefiend if
				3185	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3186	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3187	instruction is commonly used to represent automatic variables that must
				3188	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]	3189	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]	3190	instructions), the memory is reclaimed. Allocating zero bytes
				3191	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3192
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3193	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3194
				3195	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3196	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3197	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3198	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3199	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3200	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3201	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3202
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3203	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3204	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3205	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3206	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3207	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3208	<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]	3209	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3210	<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]	3211	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3212	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3213	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3214	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]	3215	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]	3216	the number or order of execution of this <tt>load</tt> with other
				3217	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3218	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3219	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3220	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3221	(that is, the alignment of the memory address). A value of 0 or an
				3222	omitted "align" argument means that the operation has the preferential
				3223	alignment for the target. It is the responsibility of the code emitter
				3224	to ensure that the alignment information is correct. Overestimating
				3225	the alignment results in an undefined behavior. Underestimating the
				3226	alignment may produce less efficient code. An alignment of 1 is always
				3227	safe.
				3228	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3229	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3230	<p>The location of memory pointed to is loaded.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3231	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3232	<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]	3233	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3234	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3235	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3236	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3237	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3238	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3239	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3240	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3241	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3242	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3243	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3244	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3245	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3246	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3247	<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]	3248	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3249	<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]	3250	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]	3251	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3252	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3253	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]	3254	optimizer is not allowed to modify the number or order of execution of
				3255	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3256	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3257	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3258	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3259	(that is, the alignment of the memory address). A value of 0 or an
				3260	omitted "align" argument means that the operation has the preferential
				3261	alignment for the target. It is the responsibility of the code emitter
				3262	to ensure that the alignment information is correct. Overestimating
				3263	the alignment results in an undefined behavior. Underestimating the
				3264	alignment may produce less efficient code. An alignment of 1 is always
				3265	safe.
				3266	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3267	<h5>Semantics:</h5>
				3268	<p>The contents of memory are updated to contain '<tt><value></tt>'
				3269	at the location specified by the '<tt><pointer></tt>' operand.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3270	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3271	<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]	3272	store i32 3, i32* %ptr <i>; yields {void}</i>
				3273	%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]	3274	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3275	</div>
				3276
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3277	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3278	<div class="doc_subsubsection">
				3279	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3280	</div>
				3281
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3282	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3283	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3284	<pre>
				3285	<result> = getelementptr <ty>* <ptrval>{, <ty> <idx>}*
				3286	</pre>
				3287
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3288	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3289
				3290	<p>
				3291	The '<tt>getelementptr</tt>' instruction is used to get the address of a
				3292	subelement of an aggregate data structure.</p>
				3293
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3294	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3295
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3296	<p>This instruction takes a list of integer operands that indicate what
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3297	elements of the aggregate object to index to. The actual types of the arguments
				3298	provided depend on the type of the first pointer argument. The
				3299	'<tt>getelementptr</tt>' instruction is used to index down through the type
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	3300	levels of a structure or to a specific index in an array. When indexing into a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3301	structure, only <tt>i32</tt> integer constants are allowed. When indexing
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3302	into an array or pointer, only integers of 32 or 64 bits are allowed; 32-bit
				3303	values will be sign extended to 64-bits if required.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3304
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3305	<p>For example, let's consider a C code fragment and how it gets
				3306	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3307
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3308	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3309	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3310	struct RT {
				3311	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3312	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3313	char C;
				3314	};
				3315	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3316	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3317	double Y;
				3318	struct RT Z;
				3319	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3320
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3321	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3322	return &s[1].Z.B[5][13];
				3323	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3324	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3325	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3326
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3327	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3328
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3329	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3330	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3331	%RT = type { i8 , [10 x [20 x i32]], i8 }
				3332	%ST = type { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3333
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3334	define i32* %foo(%ST* %s) {
				3335	entry:
				3336	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3337	ret i32* %reg
				3338	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3339	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3340	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3341
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3342	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3343
				3344	<p>The index types specified for the '<tt>getelementptr</tt>' instruction depend
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3345	on the pointer type that is being indexed into. <a href="#t_pointer">Pointer</a>
Reid Spencer	85f5b5b	2006-12-04 21:29:24 +0000	[diff] [blame]	3346	and <a href="#t_array">array</a> types can use a 32-bit or 64-bit
Reid Spencer	42ddd84	2006-12-03 16:53:48 +0000	[diff] [blame]	3347	<a href="#t_integer">integer</a> type but the value will always be sign extended
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3348	to 64-bits. <a href="#t_struct">Structure</a> and <a href="#t_pstruct">packed
				3349	structure</a> types require <tt>i32</tt> <b>constants</b>.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3350
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3351	<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]	3352	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]	3353	}</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]	3354	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3355	i8 }</tt>' type, another structure. The third index indexes into the second
				3356	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]	3357	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3358	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3359	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]	3360
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3361	<p>Note that it is perfectly legal to index partially through a
				3362	structure, returning a pointer to an inner element. Because of this,
				3363	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3364
				3365	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3366	define i32* %foo(%ST* %s) {
				3367	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3368	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3369	%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]	3370	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3371	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3372	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3373	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3374	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3375
				3376	<p>Note that it is undefined to access an array out of bounds: array and
				3377	pointer indexes must always be within the defined bounds of the array type.
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	3378	The one exception for this rule is zero length arrays. These arrays are
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3379	defined to be accessible as variable length arrays, which requires access
				3380	beyond the zero'th element.</p>
				3381
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3382	<p>The getelementptr instruction is often confusing. For some more insight
				3383	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3384	FAQ</a>.</p>
				3385
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3386	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3387
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3388	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3389	<i>; yields [12 x i8]*:aptr</i>
				3390	%aptr = getelementptr {i32, [12 x i8]}* %sptr, i64 0, i32 1
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3391	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3392	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3393
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3394	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3395	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3396	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3397	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3398	<p>The instructions in this category are the conversion instructions (casting)
				3399	which all take a single operand and a type. They perform various bit conversions
				3400	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3401	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3402
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3403	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3404	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3405	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3406	</div>
				3407	<div class="doc_text">
				3408
				3409	<h5>Syntax:</h5>
				3410	<pre>
				3411	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3412	</pre>
				3413
				3414	<h5>Overview:</h5>
				3415	<p>
				3416	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3417	</p>
				3418
				3419	<h5>Arguments:</h5>
				3420	<p>
				3421	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3422	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]	3423	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]	3424	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3425	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3426
				3427	<h5>Semantics:</h5>
				3428	<p>
				3429	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]	3430	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3431	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3432	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3433
				3434	<h5>Example:</h5>
				3435	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3436	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3437	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3438	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3439	</pre>
				3440	</div>
				3441
				3442	<!-- _______________________________________________________________________ -->
				3443	<div class="doc_subsubsection">
				3444	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3445	</div>
				3446	<div class="doc_text">
				3447
				3448	<h5>Syntax:</h5>
				3449	<pre>
				3450	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3451	</pre>
				3452
				3453	<h5>Overview:</h5>
				3454	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3455	<tt>ty2</tt>.</p>
				3456
				3457
				3458	<h5>Arguments:</h5>
				3459	<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]	3460	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3461	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]	3462	<tt>value</tt> must be smaller than the bit size of the destination type,
				3463	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3464
				3465	<h5>Semantics:</h5>
				3466	<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]	3467	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]	3468
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3469	<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]	3470
				3471	<h5>Example:</h5>
				3472	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3473	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3474	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3475	</pre>
				3476	</div>
				3477
				3478	<!-- _______________________________________________________________________ -->
				3479	<div class="doc_subsubsection">
				3480	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3481	</div>
				3482	<div class="doc_text">
				3483
				3484	<h5>Syntax:</h5>
				3485	<pre>
				3486	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3487	</pre>
				3488
				3489	<h5>Overview:</h5>
				3490	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3491
				3492	<h5>Arguments:</h5>
				3493	<p>
				3494	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]	3495	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3496	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]	3497	<tt>value</tt> must be smaller than the bit size of the destination type,
				3498	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3499
				3500	<h5>Semantics:</h5>
				3501	<p>
				3502	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3503	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]	3504	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3505
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3506	<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]	3507
				3508	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3509	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3510	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3511	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3512	</pre>
				3513	</div>
				3514
				3515	<!-- _______________________________________________________________________ -->
				3516	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3517	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3518	</div>
				3519
				3520	<div class="doc_text">
				3521
				3522	<h5>Syntax:</h5>
				3523
				3524	<pre>
				3525	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3526	</pre>
				3527
				3528	<h5>Overview:</h5>
				3529	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3530	<tt>ty2</tt>.</p>
				3531
				3532
				3533	<h5>Arguments:</h5>
				3534	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3535	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3536	cast it to. The size of <tt>value</tt> must be larger than the size of
				3537	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3538	<i>no-op cast</i>.</p>
				3539
				3540	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3541	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3542	<a href="#t_floating">floating point</a> type to a smaller
				3543	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3544	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3545
				3546	<h5>Example:</h5>
				3547	<pre>
				3548	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3549	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3550	</pre>
				3551	</div>
				3552
				3553	<!-- _______________________________________________________________________ -->
				3554	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3555	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3556	</div>
				3557	<div class="doc_text">
				3558
				3559	<h5>Syntax:</h5>
				3560	<pre>
				3561	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3562	</pre>
				3563
				3564	<h5>Overview:</h5>
				3565	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3566	floating point value.</p>
				3567
				3568	<h5>Arguments:</h5>
				3569	<p>The '<tt>fpext</tt>' instruction takes a
				3570	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3571	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3572	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3573
				3574	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3575	<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]	3576	<a href="#t_floating">floating point</a> type to a larger
				3577	<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]	3578	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]	3579	<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]	3580
				3581	<h5>Example:</h5>
				3582	<pre>
				3583	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3584	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3585	</pre>
				3586	</div>
				3587
				3588	<!-- _______________________________________________________________________ -->
				3589	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	3590	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3591	</div>
				3592	<div class="doc_text">
				3593
				3594	<h5>Syntax:</h5>
				3595	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3596	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3597	</pre>
				3598
				3599	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3600	<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]	3601	unsigned integer equivalent of type <tt>ty2</tt>.
				3602	</p>
				3603
				3604	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3605	<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]	3606	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3607	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3608	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3609	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]	3610
				3611	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3612	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3613	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3614	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3615	the results are undefined.</p>
				3616
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3617	<h5>Example:</h5>
				3618	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	3619	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3620	%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]	3621	%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]	3622	</pre>
				3623	</div>
				3624
				3625	<!-- _______________________________________________________________________ -->
				3626	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3627	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3628	</div>
				3629	<div class="doc_text">
				3630
				3631	<h5>Syntax:</h5>
				3632	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3633	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3634	</pre>
				3635
				3636	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3637	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3638	<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]	3639	</p>
				3640
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3641	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3642	<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]	3643	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3644	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3645	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3646	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]	3647
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3648	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3649	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3650	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3651	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				3652	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3653
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3654	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3655	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3656	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	3657	%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]	3658	%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]	3659	</pre>
				3660	</div>
				3661
				3662	<!-- _______________________________________________________________________ -->
				3663	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3664	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3665	</div>
				3666	<div class="doc_text">
				3667
				3668	<h5>Syntax:</h5>
				3669	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3670	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3671	</pre>
				3672
				3673	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3674	<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]	3675	integer and converts that value to the <tt>ty2</tt> type.</p>
				3676
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3677	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3678	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				3679	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3680	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3681	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3682	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]	3683
				3684	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3685	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3686	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3687	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]	3688
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3689	<h5>Example:</h5>
				3690	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3691	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3692	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3693	</pre>
				3694	</div>
				3695
				3696	<!-- _______________________________________________________________________ -->
				3697	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3698	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3699	</div>
				3700	<div class="doc_text">
				3701
				3702	<h5>Syntax:</h5>
				3703	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3704	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3705	</pre>
				3706
				3707	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3708	<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]	3709	integer and converts that value to the <tt>ty2</tt> type.</p>
				3710
				3711	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	3712	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				3713	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				3714	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				3715	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				3716	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]	3717
				3718	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3719	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3720	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	3721	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]	3722
				3723	<h5>Example:</h5>
				3724	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3725	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3726	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3727	</pre>
				3728	</div>
				3729
				3730	<!-- _______________________________________________________________________ -->
				3731	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3732	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				3733	</div>
				3734	<div class="doc_text">
				3735
				3736	<h5>Syntax:</h5>
				3737	<pre>
				3738	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				3739	</pre>
				3740
				3741	<h5>Overview:</h5>
				3742	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				3743	the integer type <tt>ty2</tt>.</p>
				3744
				3745	<h5>Arguments:</h5>
				3746	<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]	3747	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3748	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.
				3749
				3750	<h5>Semantics:</h5>
				3751	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				3752	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				3753	truncating or zero extending that value to the size of the integer type. If
				3754	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				3755	<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]	3756	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				3757	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3758
				3759	<h5>Example:</h5>
				3760	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3761	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				3762	%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]	3763	</pre>
				3764	</div>
				3765
				3766	<!-- _______________________________________________________________________ -->
				3767	<div class="doc_subsubsection">
				3768	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				3769	</div>
				3770	<div class="doc_text">
				3771
				3772	<h5>Syntax:</h5>
				3773	<pre>
				3774	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				3775	</pre>
				3776
				3777	<h5>Overview:</h5>
				3778	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				3779	a pointer type, <tt>ty2</tt>.</p>
				3780
				3781	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	3782	<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]	3783	value to cast, and a type to cast it to, which must be a
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	3784	<a href="#t_pointer">pointer</a> type.
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3785
				3786	<h5>Semantics:</h5>
				3787	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				3788	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				3789	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				3790	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				3791	the size of a pointer then a zero extension is done. If they are the same size,
				3792	nothing is done (<i>no-op cast</i>).</p>
				3793
				3794	<h5>Example:</h5>
				3795	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3796	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				3797	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				3798	%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]	3799	</pre>
				3800	</div>
				3801
				3802	<!-- _______________________________________________________________________ -->
				3803	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3804	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3805	</div>
				3806	<div class="doc_text">
				3807
				3808	<h5>Syntax:</h5>
				3809	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3810	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3811	</pre>
				3812
				3813	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3814
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3815	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3816	<tt>ty2</tt> without changing any bits.</p>
				3817
				3818	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3819
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3820	<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]	3821	a non-aggregate first class value, and a type to cast it to, which must also be
				3822	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				3823	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	3824	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]	3825	type is a pointer, the destination type must also be a pointer. This
				3826	instruction supports bitwise conversion of vectors to integers and to vectors
				3827	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3828
				3829	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	3830	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	3831	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				3832	this conversion. The conversion is done as if the <tt>value</tt> had been
				3833	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				3834	converted to other pointer types with this instruction. To convert pointers to
				3835	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				3836	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3837
				3838	<h5>Example:</h5>
				3839	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3840	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3841	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
				3842	%Z = bitcast <2xint> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	3843	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3844	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3845
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3846	<!-- ======================================================================= -->
				3847	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				3848	<div class="doc_text">
				3849	<p>The instructions in this category are the "miscellaneous"
				3850	instructions, which defy better classification.</p>
				3851	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3852
				3853	<!-- _______________________________________________________________________ -->
				3854	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				3855	</div>
				3856	<div class="doc_text">
				3857	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3858	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3859	</pre>
				3860	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3861	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				3862	a vector of boolean values based on comparison
				3863	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3864	<h5>Arguments:</h5>
				3865	<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]	3866	the condition code indicating the kind of comparison to perform. It is not
				3867	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3868	<ol>
				3869	<li><tt>eq</tt>: equal</li>
				3870	<li><tt>ne</tt>: not equal </li>
				3871	<li><tt>ugt</tt>: unsigned greater than</li>
				3872	<li><tt>uge</tt>: unsigned greater or equal</li>
				3873	<li><tt>ult</tt>: unsigned less than</li>
				3874	<li><tt>ule</tt>: unsigned less or equal</li>
				3875	<li><tt>sgt</tt>: signed greater than</li>
				3876	<li><tt>sge</tt>: signed greater or equal</li>
				3877	<li><tt>slt</tt>: signed less than</li>
				3878	<li><tt>sle</tt>: signed less or equal</li>
				3879	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3880	<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]	3881	<a href="#t_pointer">pointer</a>
				3882	or integer <a href="#t_vector">vector</a> typed.
				3883	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3884	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3885	<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]	3886	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3887	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3888	<ol>
				3889	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				3890	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3891	</li>
				3892	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
				3893	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				3894	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3895	<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]	3896	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3897	<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]	3898	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3899	<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]	3900	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3901	<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]	3902	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3903	<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]	3904	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3905	<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]	3906	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3907	<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]	3908	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3909	<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]	3910	</ol>
				3911	<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]	3912	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3913	<p>If the operands are integer vectors, then they are compared
				3914	element by element. The result is an <tt>i1</tt> vector with
				3915	the same number of elements as the values being compared.
				3916	Otherwise, the result is an <tt>i1</tt>.
				3917	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3918
				3919	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3920	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				3921	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				3922	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				3923	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				3924	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				3925	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3926	</pre>
				3927	</div>
				3928
				3929	<!-- _______________________________________________________________________ -->
				3930	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				3931	</div>
				3932	<div class="doc_text">
				3933	<h5>Syntax:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3934	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1&gt}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3935	</pre>
				3936	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3937	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				3938	or vector of boolean values based on comparison
				3939	of its operands.
				3940	<p>
				3941	If the operands are floating point scalars, then the result
				3942	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				3943	</p>
				3944	<p>If the operands are floating point vectors, then the result type
				3945	is a vector of boolean with the same number of elements as the
				3946	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3947	<h5>Arguments:</h5>
				3948	<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]	3949	the condition code indicating the kind of comparison to perform. It is not
				3950	a value, just a keyword. The possible condition code are:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3951	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3952	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3953	<li><tt>oeq</tt>: ordered and equal</li>
				3954	<li><tt>ogt</tt>: ordered and greater than </li>
				3955	<li><tt>oge</tt>: ordered and greater than or equal</li>
				3956	<li><tt>olt</tt>: ordered and less than </li>
				3957	<li><tt>ole</tt>: ordered and less than or equal</li>
				3958	<li><tt>one</tt>: ordered and not equal</li>
				3959	<li><tt>ord</tt>: ordered (no nans)</li>
				3960	<li><tt>ueq</tt>: unordered or equal</li>
				3961	<li><tt>ugt</tt>: unordered or greater than </li>
				3962	<li><tt>uge</tt>: unordered or greater than or equal</li>
				3963	<li><tt>ult</tt>: unordered or less than </li>
				3964	<li><tt>ule</tt>: unordered or less than or equal</li>
				3965	<li><tt>une</tt>: unordered or not equal</li>
				3966	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3967	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3968	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	3969	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	3970	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	3971	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				3972	either a <a href="#t_floating">floating point</a> type
				3973	or a <a href="#t_vector">vector</a> of floating point type.
				3974	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3975	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3976	<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]	3977	according to the condition code given as <tt>cond</tt>.
				3978	If the operands are vectors, then the vectors are compared
				3979	element by element.
				3980	Each comparison performed
				3981	always yields an <a href="#t_primitive">i1</a> result, as follows:
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	3982	<ol>
				3983	<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]	3984	<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]	3985	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3986	<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]	3987	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3988	<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]	3989	<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]	3990	<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]	3991	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3992	<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]	3993	<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]	3994	<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]	3995	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3996	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				3997	<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]	3998	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	3999	<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]	4000	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4001	<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]	4002	<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]	4003	<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]	4004	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4005	<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]	4006	<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]	4007	<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]	4008	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4009	<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]	4010	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4011	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4012
				4013	<h5>Example:</h5>
				4014	<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]	4015	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4016	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4017	<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]	4018	</pre>
				4019	</div>
				4020
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4021	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4022	<div class="doc_subsubsection">
				4023	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4024	</div>
				4025	<div class="doc_text">
				4026	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4027	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4028	</pre>
				4029	<h5>Overview:</h5>
				4030	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4031	element-wise comparison of its two integer vector operands.</p>
				4032	<h5>Arguments:</h5>
				4033	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4034	the condition code indicating the kind of comparison to perform. It is not
				4035	a value, just a keyword. The possible condition code are:
				4036	<ol>
				4037	<li><tt>eq</tt>: equal</li>
				4038	<li><tt>ne</tt>: not equal </li>
				4039	<li><tt>ugt</tt>: unsigned greater than</li>
				4040	<li><tt>uge</tt>: unsigned greater or equal</li>
				4041	<li><tt>ult</tt>: unsigned less than</li>
				4042	<li><tt>ule</tt>: unsigned less or equal</li>
				4043	<li><tt>sgt</tt>: signed greater than</li>
				4044	<li><tt>sge</tt>: signed greater or equal</li>
				4045	<li><tt>slt</tt>: signed less than</li>
				4046	<li><tt>sle</tt>: signed less or equal</li>
				4047	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4048	<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]	4049	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4050	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4051	<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]	4052	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4053	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4054	identical type as the values being compared. The most significant bit in each
				4055	element is 1 if the element-wise comparison evaluates to true, and is 0
				4056	otherwise. All other bits of the result are undefined. The condition codes
				4057	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
				4058	instruction</a>.
				4059
				4060	<h5>Example:</h5>
				4061	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4062	<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>
				4063	<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]	4064	</pre>
				4065	</div>
				4066
				4067	<!-- _______________________________________________________________________ -->
				4068	<div class="doc_subsubsection">
				4069	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4070	</div>
				4071	<div class="doc_text">
				4072	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4073	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4074	<h5>Overview:</h5>
				4075	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4076	element-wise comparison of its two floating point vector operands. The output
				4077	elements have the same width as the input elements.</p>
				4078	<h5>Arguments:</h5>
				4079	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4080	the condition code indicating the kind of comparison to perform. It is not
				4081	a value, just a keyword. The possible condition code are:
				4082	<ol>
				4083	<li><tt>false</tt>: no comparison, always returns false</li>
				4084	<li><tt>oeq</tt>: ordered and equal</li>
				4085	<li><tt>ogt</tt>: ordered and greater than </li>
				4086	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4087	<li><tt>olt</tt>: ordered and less than </li>
				4088	<li><tt>ole</tt>: ordered and less than or equal</li>
				4089	<li><tt>one</tt>: ordered and not equal</li>
				4090	<li><tt>ord</tt>: ordered (no nans)</li>
				4091	<li><tt>ueq</tt>: unordered or equal</li>
				4092	<li><tt>ugt</tt>: unordered or greater than </li>
				4093	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4094	<li><tt>ult</tt>: unordered or less than </li>
				4095	<li><tt>ule</tt>: unordered or less than or equal</li>
				4096	<li><tt>une</tt>: unordered or not equal</li>
				4097	<li><tt>uno</tt>: unordered (either nans)</li>
				4098	<li><tt>true</tt>: no comparison, always returns true</li>
				4099	</ol>
				4100	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4101	<a href="#t_floating">floating point</a> typed. They must also be identical
				4102	types.</p>
				4103	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4104	<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]	4105	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4106	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4107	an identical number of elements as the values being compared, and each element
				4108	having identical with to the width of the floating point elements. The most
				4109	significant bit in each element is 1 if the element-wise comparison evaluates to
				4110	true, and is 0 otherwise. All other bits of the result are undefined. The
				4111	condition codes are evaluated identically to the
				4112	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.
				4113
				4114	<h5>Example:</h5>
				4115	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4116	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 > <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4117	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2> <i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4118	</pre>
				4119	</div>
				4120
				4121	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4122	<div class="doc_subsubsection">
				4123	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4124	</div>
				4125
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4126	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4127
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4128	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4129
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4130	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4131	<h5>Overview:</h5>
				4132	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4133	the SSA graph representing the function.</p>
				4134	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4135
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4136	<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]	4137	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4138	as arguments, with one pair for each predecessor basic block of the
				4139	current block. Only values of <a href="#t_firstclass">first class</a>
				4140	type may be used as the value arguments to the PHI node. Only labels
				4141	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4142
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4143	<p>There must be no non-phi instructions between the start of a basic
				4144	block and the PHI instructions: i.e. PHI instructions must be first in
				4145	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4146
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4147	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4148
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4149	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4150	specified by the pair corresponding to the predecessor basic block that executed
				4151	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4152
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4153	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4154	<pre>
				4155	Loop: ; Infinite loop that counts from 0 on up...
				4156	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4157	%nextindvar = add i32 %indvar, 1
				4158	br label %Loop
				4159	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4160	</div>
				4161
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4162	<!-- _______________________________________________________________________ -->
				4163	<div class="doc_subsubsection">
				4164	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4165	</div>
				4166
				4167	<div class="doc_text">
				4168
				4169	<h5>Syntax:</h5>
				4170
				4171	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4172	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4173
				4174	<i>selty</i> is either i1 or {<N x i1&gt}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4175	</pre>
				4176
				4177	<h5>Overview:</h5>
				4178
				4179	<p>
				4180	The '<tt>select</tt>' instruction is used to choose one value based on a
				4181	condition, without branching.
				4182	</p>
				4183
				4184
				4185	<h5>Arguments:</h5>
				4186
				4187	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4188	The '<tt>select</tt>' instruction requires an 'i1' value or
				4189	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4190	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]	4191	type. If the val1/val2 are vectors and
				4192	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4193	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4194	</p>
				4195
				4196	<h5>Semantics:</h5>
				4197
				4198	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4199	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]	4200	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4201	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4202	<p>
				4203	If the condition is a vector of i1, then the value arguments must
				4204	be vectors of the same size, and the selection is done element
				4205	by element.
				4206	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4207
				4208	<h5>Example:</h5>
				4209
				4210	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4211	%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]	4212	</pre>
				4213	</div>
				4214
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4215
				4216	<!-- _______________________________________________________________________ -->
				4217	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4218	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4219	</div>
				4220
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4221	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4222
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4223	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4224	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4225	<result> = [tail] call [<a href="#callingconv">cconv</a>] <ty> [<fnty>*] <fnptrval>(<param list>)
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4226	</pre>
				4227
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4228	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4229
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4230	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4231
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4232	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4233
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4234	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4235
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4236	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4237	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4238	<p>The optional "tail" marker indicates whether the callee function accesses
				4239	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]	4240	function call is eligible for tail call optimization. Note that calls may
				4241	be marked "tail" even if they do not occur before a <a
				4242	href="#i_ret"><tt>ret</tt></a> instruction.
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4243	</li>
				4244	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4245	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4246	convention</a> the call should use. If none is specified, the call defaults
				4247	to using C calling conventions.
				4248	</li>
				4249	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4250	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4251	the type of the return value. Functions that return no value are marked
				4252	<tt><a href="#t_void">void</a></tt>.</p>
				4253	</li>
				4254	<li>
				4255	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4256	value being invoked. The argument types must match the types implied by
				4257	this signature. This type can be omitted if the function is not varargs
				4258	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]	4259	</li>
				4260	<li>
				4261	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4262	be invoked. In most cases, this is a direct function invocation, but
				4263	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]	4264	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4265	</li>
				4266	<li>
				4267	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4268	function signature argument types. All arguments must be of
				4269	<a href="#t_firstclass">first class</a> type. If the function signature
				4270	indicates the function accepts a variable number of arguments, the extra
				4271	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4272	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4273	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4274
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4275	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4276
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4277	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4278	transfer to a specified function, with its incoming arguments bound to
				4279	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4280	instruction in the called function, control flow continues with the
				4281	instruction after the function call, and the return value of the
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4282	function is bound to the result argument. If the callee returns multiple
				4283	values then the return values of the function are only accessible through
				4284	the '<tt><a href="#i_getresult">getresult</a></tt>' instruction.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4285
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4286	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4287
				4288	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4289	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4290	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4291	%X = tail call i32 @foo() <i>; yields i32</i>
				4292	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4293	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4294
				4295	%struct.A = type { i32, i8 }
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4296	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
				4297	%gr = getresult %struct.A %r, 0 <i>; yields i32</i>
				4298	%gr1 = getresult %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4299	</pre>
				4300
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4301	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4302
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4303	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4304	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4305	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4306	</div>
				4307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4308	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4309
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4310	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4311
				4312	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4313	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4314	</pre>
				4315
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4316	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4317
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4318	<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]	4319	the "variable argument" area of a function call. It is used to implement the
				4320	<tt>va_arg</tt> macro in C.</p>
				4321
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4322	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4323
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4324	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4325	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4326	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]	4327	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4328
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4329	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4330
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4331	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4332	type from the specified <tt>va_list</tt> and causes the
				4333	<tt>va_list</tt> to point to the next argument. For more information,
				4334	see the variable argument handling <a href="#int_varargs">Intrinsic
				4335	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4336
				4337	<p>It is legal for this instruction to be called in a function which does not
				4338	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4339	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4340
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4341	<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]	4342	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4343	argument.</p>
				4344
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4345	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4346
				4347	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4348
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4349	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4350
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4351	<!-- _______________________________________________________________________ -->
				4352	<div class="doc_subsubsection">
				4353	<a name="i_getresult">'<tt>getresult</tt>' Instruction</a>
				4354	</div>
				4355
				4356	<div class="doc_text">
				4357
				4358	<h5>Syntax:</h5>
				4359	<pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4360	<resultval> = getresult <type> <retval>, <index>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4361	</pre>
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4362
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4363	<h5>Overview:</h5>
				4364
				4365	<p> The '<tt>getresult</tt>' instruction is used to extract individual values
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4366	from a '<tt><a href="#i_call">call</a></tt>'
				4367	or '<tt><a href="#i_invoke">invoke</a></tt>' instruction that returns multiple
				4368	results.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4369
				4370	<h5>Arguments:</h5>
				4371
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4372	<p>The '<tt>getresult</tt>' instruction takes a call or invoke value as its
Chris Lattner	1c406d7	2008-04-23 04:06:52 +0000	[diff] [blame]	4373	first argument, or an undef value. The value must have <a
				4374	href="#t_struct">structure type</a>. The second argument is a constant
				4375	unsigned index value which must be in range for the number of values returned
				4376	by the call.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4377
				4378	<h5>Semantics:</h5>
				4379
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4380	<p>The '<tt>getresult</tt>' instruction extracts the element identified by
				4381	'<tt>index</tt>' from the aggregate value.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4382
				4383	<h5>Example:</h5>
				4384
				4385	<pre>
				4386	%struct.A = type { i32, i8 }
				4387
				4388	%r = call %struct.A @foo()
Chris Lattner	45c5e8b	2008-03-21 17:20:51 +0000	[diff] [blame]	4389	%gr = getresult %struct.A %r, 0 <i>; yields i32:%gr</i>
				4390	%gr1 = getresult %struct.A %r, 1 <i>; yields i8:%gr1</i>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4391	add i32 %gr, 42
				4392	add i8 %gr1, 41
				4393	</pre>
				4394
				4395	</div>
				4396
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4397	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4398	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4399	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4400
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4401	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4402
				4403	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4404	well known names and semantics and are required to follow certain restrictions.
				4405	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4406	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]	4407	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]	4408
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4409	<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]	4410	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4411	begin with this prefix. Intrinsic functions must always be external functions:
				4412	you cannot define the body of intrinsic functions. Intrinsic functions may
				4413	only be used in call or invoke instructions: it is illegal to take the address
				4414	of an intrinsic function. Additionally, because intrinsic functions are part
				4415	of the LLVM language, it is required if any are added that they be documented
				4416	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4417
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4418	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4419	a family of functions that perform the same operation but on different data
				4420	types. Because LLVM can represent over 8 million different integer types,
				4421	overloading is used commonly to allow an intrinsic function to operate on any
				4422	integer type. One or more of the argument types or the result type can be
				4423	overloaded to accept any integer type. Argument types may also be defined as
				4424	exactly matching a previous argument's type or the result type. This allows an
				4425	intrinsic function which accepts multiple arguments, but needs all of them to
				4426	be of the same type, to only be overloaded with respect to a single argument or
				4427	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4428
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4429	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4430	encoded into its function name, each preceded by a period. Only those types
				4431	which are overloaded result in a name suffix. Arguments whose type is matched
				4432	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4433	take an integer of any width and returns an integer of exactly the same integer
				4434	width. This leads to a family of functions such as
				4435	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4436	Only one type, the return type, is overloaded, and only one type suffix is
				4437	required. Because the argument's type is matched against the return type, it
				4438	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4439
				4440	<p>To learn how to add an intrinsic function, please see the
				4441	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4442	</p>
				4443
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4444	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4445
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4446	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4447	<div class="doc_subsection">
				4448	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4449	</div>
				4450
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4451	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4452
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4453	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4454	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]	4455	intrinsic functions. These functions are related to the similarly
				4456	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4457
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4458	<p>All of these functions operate on arguments that use a
				4459	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4460	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4461	transformations should be prepared to handle these functions regardless of
				4462	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4463
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4464	<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]	4465	instruction and the variable argument handling intrinsic functions are
				4466	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4467
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4468	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4469	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4470	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4471	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4472	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4473	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4474	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4475
				4476	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4477	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4478
				4479	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4480	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4481	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4482	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4483	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4484
				4485	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4486	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4487	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4488	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4489
				4490	declare void @llvm.va_start(i8*)
				4491	declare void @llvm.va_copy(i8, i8)
				4492	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4493	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4494	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4495
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4496	</div>
				4497
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4498	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4499	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4500	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4501	</div>
				4502
				4503
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4504	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4505	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4506	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4507	<h5>Overview:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4508	<P>The '<tt>llvm.va_start</tt>' intrinsic initializes
				4509	<tt>*<arglist></tt> for subsequent use by <tt><a
				4510	href="#i_va_arg">va_arg</a></tt>.</p>
				4511
				4512	<h5>Arguments:</h5>
				4513
				4514	<P>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
				4515
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4516	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4517
				4518	<P>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
				4519	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4520	<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]	4521	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4522	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]	4523	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]	4524
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4525	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4526
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4527	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4528	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4529	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4530	</div>
				4531
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4532	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4533	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4534	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4535	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4536
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4537	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4538	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]	4539	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]	4540
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4541	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4542
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4543	<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]	4544
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4545	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4546
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4547	<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]	4548	macro available in C. In a target-dependent way, it destroys the
				4549	<tt>va_list</tt> element to which the argument points. Calls to <a
				4550	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4551	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4552	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4553
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4554	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4555
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4556	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4557	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4558	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4559	</div>
				4560
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4561	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4562
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4563	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4564
				4565	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4566	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4567	</pre>
				4568
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4569	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4570
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4571	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4572	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4573
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4574	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4575
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4576	<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]	4577	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]	4578
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4579
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4580	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4581
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4582	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4583	macro available in C. In a target-dependent way, it copies the source
				4584	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4585	intrinsic is necessary because the <tt><a href="#int_va_start">
				4586	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4587	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4588
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4589	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4590
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4591	<!-- ======================================================================= -->
				4592	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4593	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4594	</div>
				4595
				4596	<div class="doc_text">
				4597
				4598	<p>
				4599	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4600	Collection</a> (GC) requires the implementation and generation of these
				4601	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4602	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]	4603	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4604	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]	4605	Front-ends for type-safe garbage collected languages should generate these
				4606	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4607	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4608	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4609
				4610	<p>The garbage collection intrinsics only operate on objects in the generic
				4611	address space (address space zero).</p>
				4612
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4613	</div>
				4614
				4615	<!-- _______________________________________________________________________ -->
				4616	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4617	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4618	</div>
				4619
				4620	<div class="doc_text">
				4621
				4622	<h5>Syntax:</h5>
				4623
				4624	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4625	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4626	</pre>
				4627
				4628	<h5>Overview:</h5>
				4629
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4630	<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]	4631	the code generator, and allows some metadata to be associated with it.</p>
				4632
				4633	<h5>Arguments:</h5>
				4634
				4635	<p>The first argument specifies the address of a stack object that contains the
				4636	root pointer. The second pointer (which must be either a constant or a global
				4637	value address) contains the meta-data to be associated with the root.</p>
				4638
				4639	<h5>Semantics:</h5>
				4640
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4641	<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]	4642	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4643	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4644	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4645	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4646
				4647	</div>
				4648
				4649
				4650	<!-- _______________________________________________________________________ -->
				4651	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4652	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4653	</div>
				4654
				4655	<div class="doc_text">
				4656
				4657	<h5>Syntax:</h5>
				4658
				4659	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4660	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4661	</pre>
				4662
				4663	<h5>Overview:</h5>
				4664
				4665	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				4666	locations, allowing garbage collector implementations that require read
				4667	barriers.</p>
				4668
				4669	<h5>Arguments:</h5>
				4670
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4671	<p>The second argument is the address to read from, which should be an address
				4672	allocated from the garbage collector. The first object is a pointer to the
				4673	start of the referenced object, if needed by the language runtime (otherwise
				4674	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4675
				4676	<h5>Semantics:</h5>
				4677
				4678	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				4679	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4680	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				4681	may only be used in a function which <a href="#gc">specifies a GC
				4682	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4683
				4684	</div>
				4685
				4686
				4687	<!-- _______________________________________________________________________ -->
				4688	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4689	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4690	</div>
				4691
				4692	<div class="doc_text">
				4693
				4694	<h5>Syntax:</h5>
				4695
				4696	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4697	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4698	</pre>
				4699
				4700	<h5>Overview:</h5>
				4701
				4702	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				4703	locations, allowing garbage collector implementations that require write
				4704	barriers (such as generational or reference counting collectors).</p>
				4705
				4706	<h5>Arguments:</h5>
				4707
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	4708	<p>The first argument is the reference to store, the second is the start of the
				4709	object to store it to, and the third is the address of the field of Obj to
				4710	store to. If the runtime does not require a pointer to the object, Obj may be
				4711	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4712
				4713	<h5>Semantics:</h5>
				4714
				4715	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				4716	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4717	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				4718	may only be used in a function which <a href="#gc">specifies a GC
				4719	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4720
				4721	</div>
				4722
				4723
				4724
				4725	<!-- ======================================================================= -->
				4726	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4727	<a name="int_codegen">Code Generator Intrinsics</a>
				4728	</div>
				4729
				4730	<div class="doc_text">
				4731	<p>
				4732	These intrinsics are provided by LLVM to expose special features that may only
				4733	be implemented with code generator support.
				4734	</p>
				4735
				4736	</div>
				4737
				4738	<!-- _______________________________________________________________________ -->
				4739	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4740	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4741	</div>
				4742
				4743	<div class="doc_text">
				4744
				4745	<h5>Syntax:</h5>
				4746	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4747	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4748	</pre>
				4749
				4750	<h5>Overview:</h5>
				4751
				4752	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4753	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				4754	target-specific value indicating the return address of the current function
				4755	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4756	</p>
				4757
				4758	<h5>Arguments:</h5>
				4759
				4760	<p>
				4761	The argument to this intrinsic indicates which function to return the address
				4762	for. Zero indicates the calling function, one indicates its caller, etc. The
				4763	argument is <b>required</b> to be a constant integer value.
				4764	</p>
				4765
				4766	<h5>Semantics:</h5>
				4767
				4768	<p>
				4769	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				4770	the return address of the specified call frame, or zero if it cannot be
				4771	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4772	for arguments other than zero, so it should only be used for debugging purposes.
				4773	</p>
				4774
				4775	<p>
				4776	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4777	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]	4778	source-language caller.
				4779	</p>
				4780	</div>
				4781
				4782
				4783	<!-- _______________________________________________________________________ -->
				4784	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4785	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4786	</div>
				4787
				4788	<div class="doc_text">
				4789
				4790	<h5>Syntax:</h5>
				4791	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4792	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4793	</pre>
				4794
				4795	<h5>Overview:</h5>
				4796
				4797	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	4798	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				4799	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	4800	</p>
				4801
				4802	<h5>Arguments:</h5>
				4803
				4804	<p>
				4805	The argument to this intrinsic indicates which function to return the frame
				4806	pointer for. Zero indicates the calling function, one indicates its caller,
				4807	etc. The argument is <b>required</b> to be a constant integer value.
				4808	</p>
				4809
				4810	<h5>Semantics:</h5>
				4811
				4812	<p>
				4813	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				4814	the frame address of the specified call frame, or zero if it cannot be
				4815	identified. The value returned by this intrinsic is likely to be incorrect or 0
				4816	for arguments other than zero, so it should only be used for debugging purposes.
				4817	</p>
				4818
				4819	<p>
				4820	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	4821	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]	4822	source-language caller.
				4823	</p>
				4824	</div>
				4825
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4826	<!-- _______________________________________________________________________ -->
				4827	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4828	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4829	</div>
				4830
				4831	<div class="doc_text">
				4832
				4833	<h5>Syntax:</h5>
				4834	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4835	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4836	</pre>
				4837
				4838	<h5>Overview:</h5>
				4839
				4840	<p>
				4841	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]	4842	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4843	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				4844	features like scoped automatic variable sized arrays in C99.
				4845	</p>
				4846
				4847	<h5>Semantics:</h5>
				4848
				4849	<p>
				4850	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]	4851	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4852	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				4853	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				4854	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				4855	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				4856	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				4857	</p>
				4858
				4859	</div>
				4860
				4861	<!-- _______________________________________________________________________ -->
				4862	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4863	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4864	</div>
				4865
				4866	<div class="doc_text">
				4867
				4868	<h5>Syntax:</h5>
				4869	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4870	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4871	</pre>
				4872
				4873	<h5>Overview:</h5>
				4874
				4875	<p>
				4876	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				4877	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]	4878	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	4879	useful for implementing language features like scoped automatic variable sized
				4880	arrays in C99.
				4881	</p>
				4882
				4883	<h5>Semantics:</h5>
				4884
				4885	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4886	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]	4887	</p>
				4888
				4889	</div>
				4890
				4891
				4892	<!-- _______________________________________________________________________ -->
				4893	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4894	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4895	</div>
				4896
				4897	<div class="doc_text">
				4898
				4899	<h5>Syntax:</h5>
				4900	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4901	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4902	</pre>
				4903
				4904	<h5>Overview:</h5>
				4905
				4906
				4907	<p>
				4908	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]	4909	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				4910	no
				4911	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	4912	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	4913	</p>
				4914
				4915	<h5>Arguments:</h5>
				4916
				4917	<p>
				4918	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				4919	determining if the fetch should be for a read (0) or write (1), and
				4920	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	4921	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]	4922	<tt>locality</tt> arguments must be constant integers.
				4923	</p>
				4924
				4925	<h5>Semantics:</h5>
				4926
				4927	<p>
				4928	This intrinsic does not modify the behavior of the program. In particular,
				4929	prefetches cannot trap and do not produce a value. On targets that support this
				4930	intrinsic, the prefetch can provide hints to the processor cache for better
				4931	performance.
				4932	</p>
				4933
				4934	</div>
				4935
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4936	<!-- _______________________________________________________________________ -->
				4937	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4938	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4939	</div>
				4940
				4941	<div class="doc_text">
				4942
				4943	<h5>Syntax:</h5>
				4944	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4945	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4946	</pre>
				4947
				4948	<h5>Overview:</h5>
				4949
				4950
				4951	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4952	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]	4953	(PC) in a region of
				4954	code to simulators and other tools. The method is target specific, but it is
				4955	expected that the marker will use exported symbols to transmit the PC of the
				4956	marker.
				4957	The marker makes no guarantees that it will remain with any specific instruction
				4958	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]	4959	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4960	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	4961	</p>
				4962
				4963	<h5>Arguments:</h5>
				4964
				4965	<p>
				4966	<tt>id</tt> is a numerical id identifying the marker.
				4967	</p>
				4968
				4969	<h5>Semantics:</h5>
				4970
				4971	<p>
				4972	This intrinsic does not modify the behavior of the program. Backends that do not
				4973	support this intrinisic may ignore it.
				4974	</p>
				4975
				4976	</div>
				4977
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4978	<!-- _______________________________________________________________________ -->
				4979	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4980	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4981	</div>
				4982
				4983	<div class="doc_text">
				4984
				4985	<h5>Syntax:</h5>
				4986	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4987	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	4988	</pre>
				4989
				4990	<h5>Overview:</h5>
				4991
				4992
				4993	<p>
				4994	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				4995	counter register (or similar low latency, high accuracy clocks) on those targets
				4996	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				4997	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				4998	should only be used for small timings.
				4999	</p>
				5000
				5001	<h5>Semantics:</h5>
				5002
				5003	<p>
				5004	When directly supported, reading the cycle counter should not modify any memory.
				5005	Implementations are allowed to either return a application specific value or a
				5006	system wide value. On backends without support, this is lowered to a constant 0.
				5007	</p>
				5008
				5009	</div>
				5010
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5011	<!-- ======================================================================= -->
				5012	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5013	<a name="int_libc">Standard C Library Intrinsics</a>
				5014	</div>
				5015
				5016	<div class="doc_text">
				5017	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5018	LLVM provides intrinsics for a few important standard C library functions.
				5019	These intrinsics allow source-language front-ends to pass information about the
				5020	alignment of the pointer arguments to the code generator, providing opportunity
				5021	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5022	</p>
				5023
				5024	</div>
				5025
				5026	<!-- _______________________________________________________________________ -->
				5027	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5028	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5029	</div>
				5030
				5031	<div class="doc_text">
				5032
				5033	<h5>Syntax:</h5>
				5034	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5035	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5036	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5037	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5038	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5039	</pre>
				5040
				5041	<h5>Overview:</h5>
				5042
				5043	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5044	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]	5045	location to the destination location.
				5046	</p>
				5047
				5048	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5049	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5050	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5051	</p>
				5052
				5053	<h5>Arguments:</h5>
				5054
				5055	<p>
				5056	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]	5057	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5058	specifying the number of bytes to copy, and the fourth argument is the alignment
				5059	of the source and destination locations.
				5060	</p>
				5061
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5062	<p>
				5063	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]	5064	the caller guarantees that both the source and destination pointers are aligned
				5065	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5066	</p>
				5067
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5068	<h5>Semantics:</h5>
				5069
				5070	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5071	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]	5072	location to the destination location, which are not allowed to overlap. It
				5073	copies "len" bytes of memory over. If the argument is known to be aligned to
				5074	some boundary, this can be specified as the fourth argument, otherwise it should
				5075	be set to 0 or 1.
				5076	</p>
				5077	</div>
				5078
				5079
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5080	<!-- _______________________________________________________________________ -->
				5081	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5082	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5083	</div>
				5084
				5085	<div class="doc_text">
				5086
				5087	<h5>Syntax:</h5>
				5088	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5089	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5090	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5091	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5092	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5093	</pre>
				5094
				5095	<h5>Overview:</h5>
				5096
				5097	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5098	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5099	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5100	'<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]	5101	</p>
				5102
				5103	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5104	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5105	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5106	</p>
				5107
				5108	<h5>Arguments:</h5>
				5109
				5110	<p>
				5111	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]	5112	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5113	specifying the number of bytes to copy, and the fourth argument is the alignment
				5114	of the source and destination locations.
				5115	</p>
				5116
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5117	<p>
				5118	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]	5119	the caller guarantees that the source and destination pointers are aligned to
				5120	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5121	</p>
				5122
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5123	<h5>Semantics:</h5>
				5124
				5125	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5126	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]	5127	location to the destination location, which may overlap. It
				5128	copies "len" bytes of memory over. If the argument is known to be aligned to
				5129	some boundary, this can be specified as the fourth argument, otherwise it should
				5130	be set to 0 or 1.
				5131	</p>
				5132	</div>
				5133
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5134
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5135	<!-- _______________________________________________________________________ -->
				5136	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5137	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5138	</div>
				5139
				5140	<div class="doc_text">
				5141
				5142	<h5>Syntax:</h5>
				5143	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5144	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5145	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5146	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5147	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5148	</pre>
				5149
				5150	<h5>Overview:</h5>
				5151
				5152	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5153	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]	5154	byte value.
				5155	</p>
				5156
				5157	<p>
				5158	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5159	does not return a value, and takes an extra alignment argument.
				5160	</p>
				5161
				5162	<h5>Arguments:</h5>
				5163
				5164	<p>
				5165	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]	5166	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5167	argument specifying the number of bytes to fill, and the fourth argument is the
				5168	known alignment of destination location.
				5169	</p>
				5170
				5171	<p>
				5172	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]	5173	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5174	</p>
				5175
				5176	<h5>Semantics:</h5>
				5177
				5178	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5179	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5180	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5181	destination location. If the argument is known to be aligned to some boundary,
				5182	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5183	1.
				5184	</p>
				5185	</div>
				5186
				5187
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5188	<!-- _______________________________________________________________________ -->
				5189	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5190	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5191	</div>
				5192
				5193	<div class="doc_text">
				5194
				5195	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5196	<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]	5197	floating point or vector of floating point type. Not all targets support all
				5198	types however.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5199	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5200	declare float @llvm.sqrt.f32(float %Val)
				5201	declare double @llvm.sqrt.f64(double %Val)
				5202	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5203	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5204	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5205	</pre>
				5206
				5207	<h5>Overview:</h5>
				5208
				5209	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5210	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]	5211	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]	5212	<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]	5213	negative numbers other than -0.0 (which allows for better optimization, because
				5214	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5215	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5216	</p>
				5217
				5218	<h5>Arguments:</h5>
				5219
				5220	<p>
				5221	The argument and return value are floating point numbers of the same type.
				5222	</p>
				5223
				5224	<h5>Semantics:</h5>
				5225
				5226	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5227	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]	5228	floating point number.
				5229	</p>
				5230	</div>
				5231
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5232	<!-- _______________________________________________________________________ -->
				5233	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5234	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5235	</div>
				5236
				5237	<div class="doc_text">
				5238
				5239	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5240	<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]	5241	floating point or vector of floating point type. Not all targets support all
				5242	types however.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5243	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5244	declare float @llvm.powi.f32(float %Val, i32 %power)
				5245	declare double @llvm.powi.f64(double %Val, i32 %power)
				5246	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5247	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5248	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5249	</pre>
				5250
				5251	<h5>Overview:</h5>
				5252
				5253	<p>
				5254	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5255	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5256	multiplications is not defined. When a vector of floating point type is
				5257	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5258	</p>
				5259
				5260	<h5>Arguments:</h5>
				5261
				5262	<p>
				5263	The second argument is an integer power, and the first is a value to raise to
				5264	that power.
				5265	</p>
				5266
				5267	<h5>Semantics:</h5>
				5268
				5269	<p>
				5270	This function returns the first value raised to the second power with an
				5271	unspecified sequence of rounding operations.</p>
				5272	</div>
				5273
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5274	<!-- _______________________________________________________________________ -->
				5275	<div class="doc_subsubsection">
				5276	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5277	</div>
				5278
				5279	<div class="doc_text">
				5280
				5281	<h5>Syntax:</h5>
				5282	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5283	floating point or vector of floating point type. Not all targets support all
				5284	types however.
				5285	<pre>
				5286	declare float @llvm.sin.f32(float %Val)
				5287	declare double @llvm.sin.f64(double %Val)
				5288	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5289	declare fp128 @llvm.sin.f128(fp128 %Val)
				5290	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5291	</pre>
				5292
				5293	<h5>Overview:</h5>
				5294
				5295	<p>
				5296	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5297	</p>
				5298
				5299	<h5>Arguments:</h5>
				5300
				5301	<p>
				5302	The argument and return value are floating point numbers of the same type.
				5303	</p>
				5304
				5305	<h5>Semantics:</h5>
				5306
				5307	<p>
				5308	This function returns the sine of the specified operand, returning the
				5309	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]	5310	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5311	</div>
				5312
				5313	<!-- _______________________________________________________________________ -->
				5314	<div class="doc_subsubsection">
				5315	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5316	</div>
				5317
				5318	<div class="doc_text">
				5319
				5320	<h5>Syntax:</h5>
				5321	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5322	floating point or vector of floating point type. Not all targets support all
				5323	types however.
				5324	<pre>
				5325	declare float @llvm.cos.f32(float %Val)
				5326	declare double @llvm.cos.f64(double %Val)
				5327	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5328	declare fp128 @llvm.cos.f128(fp128 %Val)
				5329	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5330	</pre>
				5331
				5332	<h5>Overview:</h5>
				5333
				5334	<p>
				5335	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5336	</p>
				5337
				5338	<h5>Arguments:</h5>
				5339
				5340	<p>
				5341	The argument and return value are floating point numbers of the same type.
				5342	</p>
				5343
				5344	<h5>Semantics:</h5>
				5345
				5346	<p>
				5347	This function returns the cosine of the specified operand, returning the
				5348	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]	5349	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5350	</div>
				5351
				5352	<!-- _______________________________________________________________________ -->
				5353	<div class="doc_subsubsection">
				5354	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5355	</div>
				5356
				5357	<div class="doc_text">
				5358
				5359	<h5>Syntax:</h5>
				5360	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5361	floating point or vector of floating point type. Not all targets support all
				5362	types however.
				5363	<pre>
				5364	declare float @llvm.pow.f32(float %Val, float %Power)
				5365	declare double @llvm.pow.f64(double %Val, double %Power)
				5366	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5367	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5368	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5369	</pre>
				5370
				5371	<h5>Overview:</h5>
				5372
				5373	<p>
				5374	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5375	specified (positive or negative) power.
				5376	</p>
				5377
				5378	<h5>Arguments:</h5>
				5379
				5380	<p>
				5381	The second argument is a floating point power, and the first is a value to
				5382	raise to that power.
				5383	</p>
				5384
				5385	<h5>Semantics:</h5>
				5386
				5387	<p>
				5388	This function returns the first value raised to the second power,
				5389	returning the
				5390	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]	5391	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5392	</div>
				5393
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5394
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5395	<!-- ======================================================================= -->
				5396	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5397	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5398	</div>
				5399
				5400	<div class="doc_text">
				5401	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5402	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5403	These allow efficient code generation for some algorithms.
				5404	</p>
				5405
				5406	</div>
				5407
				5408	<!-- _______________________________________________________________________ -->
				5409	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5410	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5411	</div>
				5412
				5413	<div class="doc_text">
				5414
				5415	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5416	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5417	type that is an even number of bytes (i.e. BitWidth % 16 == 0).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5418	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5419	declare i16 @llvm.bswap.i16(i16 <id>)
				5420	declare i32 @llvm.bswap.i32(i32 <id>)
				5421	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5422	</pre>
				5423
				5424	<h5>Overview:</h5>
				5425
				5426	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5427	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]	5428	values with an even number of bytes (positive multiple of 16 bits). These are
				5429	useful for performing operations on data that is not in the target's native
				5430	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5431	</p>
				5432
				5433	<h5>Semantics:</h5>
				5434
				5435	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5436	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]	5437	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5438	intrinsic returns an i32 value that has the four bytes of the input i32
				5439	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]	5440	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5441	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5442	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5443	</p>
				5444
				5445	</div>
				5446
				5447	<!-- _______________________________________________________________________ -->
				5448	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5449	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5450	</div>
				5451
				5452	<div class="doc_text">
				5453
				5454	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5455	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
				5456	width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5457	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5458	declare i8 @llvm.ctpop.i8 (i8 <src>)
				5459	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5460	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5461	declare i64 @llvm.ctpop.i64(i64 <src>)
				5462	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5463	</pre>
				5464
				5465	<h5>Overview:</h5>
				5466
				5467	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5468	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5469	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5470	</p>
				5471
				5472	<h5>Arguments:</h5>
				5473
				5474	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5475	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]	5476	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5477	</p>
				5478
				5479	<h5>Semantics:</h5>
				5480
				5481	<p>
				5482	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5483	</p>
				5484	</div>
				5485
				5486	<!-- _______________________________________________________________________ -->
				5487	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5488	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5489	</div>
				5490
				5491	<div class="doc_text">
				5492
				5493	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5494	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
				5495	integer bit width. Not all targets support all bit widths however.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5496	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5497	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5498	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5499	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5500	declare i64 @llvm.ctlz.i64(i64 <src>)
				5501	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5502	</pre>
				5503
				5504	<h5>Overview:</h5>
				5505
				5506	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5507	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5508	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5509	</p>
				5510
				5511	<h5>Arguments:</h5>
				5512
				5513	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5514	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]	5515	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5516	</p>
				5517
				5518	<h5>Semantics:</h5>
				5519
				5520	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5521	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5522	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]	5523	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5524	</p>
				5525	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5526
				5527
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5528
				5529	<!-- _______________________________________________________________________ -->
				5530	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5531	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5532	</div>
				5533
				5534	<div class="doc_text">
				5535
				5536	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5537	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
				5538	integer bit width. Not all targets support all bit widths however.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5539	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5540	declare i8 @llvm.cttz.i8 (i8 <src>)
				5541	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5542	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5543	declare i64 @llvm.cttz.i64(i64 <src>)
				5544	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5545	</pre>
				5546
				5547	<h5>Overview:</h5>
				5548
				5549	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5550	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5551	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5552	</p>
				5553
				5554	<h5>Arguments:</h5>
				5555
				5556	<p>
				5557	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]	5558	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5559	</p>
				5560
				5561	<h5>Semantics:</h5>
				5562
				5563	<p>
				5564	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5565	in a variable. If the src == 0 then the result is the size in bits of the type
				5566	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5567	</p>
				5568	</div>
				5569
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	5570	<!-- _______________________________________________________________________ -->
				5571	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5572	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5573	</div>
				5574
				5575	<div class="doc_text">
				5576
				5577	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5578	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5579	on any integer bit width.
				5580	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5581	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5582	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5583	</pre>
				5584
				5585	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5586	<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]	5587	range of bits from an integer value and returns them in the same bit width as
				5588	the original value.</p>
				5589
				5590	<h5>Arguments:</h5>
				5591	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5592	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]	5593	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]	5594
				5595	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	5596	<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]	5597	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5598	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5599	operates in forward mode.</p>
				5600	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5601	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]	5602	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5603	<ol>
				5604	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5605	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5606	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5607	to determine the number of bits to retain.</li>
				5608	<li>A mask of the retained bits is created by shifting a -1 value.</li>
				5609	<li>The mask is ANDed with <tt>%val</tt> to produce the result.
				5610	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	5611	<p>In reverse mode, a similar computation is made except that the bits are
				5612	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5613	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5614	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5615	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	5616	</div>
				5617
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5618	<div class="doc_subsubsection">
				5619	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5620	</div>
				5621
				5622	<div class="doc_text">
				5623
				5624	<h5>Syntax:</h5>
				5625	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
				5626	on any integer bit width.
				5627	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5628	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5629	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]	5630	</pre>
				5631
				5632	<h5>Overview:</h5>
				5633	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				5634	of bits in an integer value with another integer value. It returns the integer
				5635	with the replaced bits.</p>
				5636
				5637	<h5>Arguments:</h5>
				5638	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5639	any bit width but they must have the same bit width. <tt>%val</tt> is the value
				5640	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				5641	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				5642	type since they specify only a bit index.</p>
				5643
				5644	<h5>Semantics:</h5>
				5645	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				5646	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				5647	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				5648	operates in forward mode.</p>
				5649	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				5650	truncating it down to the size of the replacement area or zero extending it
				5651	up to that size.</p>
				5652	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				5653	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				5654	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
				5655	to the <tt>%hi</tt>th bit.
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5656	<p>In reverse mode, a similar computation is made except that the bits are
				5657	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
				5658	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5659	<h5>Examples:</h5>
				5660	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5661	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	5662	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				5663	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				5664	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	5665	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	5666	</pre>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	5667	</div>
				5668
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5669	<!-- ======================================================================= -->
				5670	<div class="doc_subsection">
				5671	<a name="int_debugger">Debugger Intrinsics</a>
				5672	</div>
				5673
				5674	<div class="doc_text">
				5675	<p>
				5676	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				5677	are described in the <a
				5678	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				5679	Debugging</a> document.
				5680	</p>
				5681	</div>
				5682
				5683
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	5684	<!-- ======================================================================= -->
				5685	<div class="doc_subsection">
				5686	<a name="int_eh">Exception Handling Intrinsics</a>
				5687	</div>
				5688
				5689	<div class="doc_text">
				5690	<p> The LLVM exception handling intrinsics (which all start with
				5691	<tt>llvm.eh.</tt> prefix), are described in the <a
				5692	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				5693	Handling</a> document. </p>
				5694	</div>
				5695
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	5696	<!-- ======================================================================= -->
				5697	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5698	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5699	</div>
				5700
				5701	<div class="doc_text">
				5702	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5703	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5704	the <tt>nest</tt> attribute, from a function. The result is a callable
				5705	function pointer lacking the nest parameter - the caller does not need
				5706	to provide a value for it. Instead, the value to use is stored in
				5707	advance in a "trampoline", a block of memory usually allocated
				5708	on the stack, which also contains code to splice the nest value into the
				5709	argument list. This is used to implement the GCC nested function address
				5710	extension.
				5711	</p>
				5712	<p>
				5713	For example, if the function is
				5714	<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]	5715	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]	5716	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5717	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				5718	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				5719	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				5720	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5721	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	5722	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				5723	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]	5724	</div>
				5725
				5726	<!-- _______________________________________________________________________ -->
				5727	<div class="doc_subsubsection">
				5728	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				5729	</div>
				5730	<div class="doc_text">
				5731	<h5>Syntax:</h5>
				5732	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5733	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5734	</pre>
				5735	<h5>Overview:</h5>
				5736	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5737	This fills the memory pointed to by <tt>tramp</tt> with code
				5738	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5739	</p>
				5740	<h5>Arguments:</h5>
				5741	<p>
				5742	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				5743	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				5744	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]	5745	intrinsic. Note that the size and the alignment are target-specific - LLVM
				5746	currently provides no portable way of determining them, so a front-end that
				5747	generates this intrinsic needs to have some target-specific knowledge.
				5748	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]	5749	</p>
				5750	<h5>Semantics:</h5>
				5751	<p>
				5752	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]	5753	dependent code, turning it into a function. A pointer to this function is
				5754	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5755	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	5756	before being called. The new function's signature is the same as that of
				5757	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				5758	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				5759	of pointer type. Calling the new function is equivalent to calling
				5760	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				5761	missing <tt>nest</tt> argument. If, after calling
				5762	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				5763	modified, then the effect of any later call to the returned function pointer is
				5764	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	5765	</p>
				5766	</div>
				5767
				5768	<!-- ======================================================================= -->
				5769	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5770	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				5771	</div>
				5772
				5773	<div class="doc_text">
				5774	<p>
				5775	These intrinsic functions expand the "universal IR" of LLVM to represent
				5776	hardware constructs for atomic operations and memory synchronization. This
				5777	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]	5778	is aimed at a low enough level to allow any programming models or APIs
				5779	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	5780	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				5781	hardware behavior. Just as hardware provides a "universal IR" for source
				5782	languages, it also provides a starting point for developing a "universal"
				5783	atomic operation and synchronization IR.
				5784	</p>
				5785	<p>
				5786	These do <em>not</em> form an API such as high-level threading libraries,
				5787	software transaction memory systems, atomic primitives, and intrinsic
				5788	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				5789	application libraries. The hardware interface provided by LLVM should allow
				5790	a clean implementation of all of these APIs and parallel programming models.
				5791	No one model or paradigm should be selected above others unless the hardware
				5792	itself ubiquitously does so.
				5793
				5794	</p>
				5795	</div>
				5796
				5797	<!-- _______________________________________________________________________ -->
				5798	<div class="doc_subsubsection">
				5799	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				5800	</div>
				5801	<div class="doc_text">
				5802	<h5>Syntax:</h5>
				5803	<pre>
				5804	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				5805	i1 <device> )
				5806
				5807	</pre>
				5808	<h5>Overview:</h5>
				5809	<p>
				5810	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				5811	specific pairs of memory access types.
				5812	</p>
				5813	<h5>Arguments:</h5>
				5814	<p>
				5815	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				5816	The first four arguments enables a specific barrier as listed below. The fith
				5817	argument specifies that the barrier applies to io or device or uncached memory.
				5818
				5819	</p>
				5820	<ul>
				5821	<li><tt>ll</tt>: load-load barrier</li>
				5822	<li><tt>ls</tt>: load-store barrier</li>
				5823	<li><tt>sl</tt>: store-load barrier</li>
				5824	<li><tt>ss</tt>: store-store barrier</li>
				5825	<li><tt>device</tt>: barrier applies to device and uncached memory also.
				5826	</ul>
				5827	<h5>Semantics:</h5>
				5828	<p>
				5829	This intrinsic causes the system to enforce some ordering constraints upon
				5830	the loads and stores of the program. This barrier does not indicate
				5831	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				5832	which they occur. For any of the specified pairs of load and store operations
				5833	(f.ex. load-load, or store-load), all of the first operations preceding the
				5834	barrier will complete before any of the second operations succeeding the
				5835	barrier begin. Specifically the semantics for each pairing is as follows:
				5836	</p>
				5837	<ul>
				5838	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				5839	after the barrier begins.</li>
				5840
				5841	<li><tt>ls</tt>: All loads before the barrier must complete before any
				5842	store after the barrier begins.</li>
				5843	<li><tt>ss</tt>: All stores before the barrier must complete before any
				5844	store after the barrier begins.</li>
				5845	<li><tt>sl</tt>: All stores before the barrier must complete before any
				5846	load after the barrier begins.</li>
				5847	</ul>
				5848	<p>
				5849	These semantics are applied with a logical "and" behavior when more than one
				5850	is enabled in a single memory barrier intrinsic.
				5851	</p>
				5852	<p>
				5853	Backends may implement stronger barriers than those requested when they do not
				5854	support as fine grained a barrier as requested. Some architectures do not
				5855	need all types of barriers and on such architectures, these become noops.
				5856	</p>
				5857	<h5>Example:</h5>
				5858	<pre>
				5859	%ptr = malloc i32
				5860	store i32 4, %ptr
				5861
				5862	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				5863	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				5864	<i>; guarantee the above finishes</i>
				5865	store i32 8, %ptr <i>; before this begins</i>
				5866	</pre>
				5867	</div>
				5868
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5869	<!-- _______________________________________________________________________ -->
				5870	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5871	<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]	5872	</div>
				5873	<div class="doc_text">
				5874	<h5>Syntax:</h5>
				5875	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5876	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				5877	any integer bit width and for different address spaces. Not all targets
				5878	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5879
				5880	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5881	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				5882	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				5883	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				5884	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]	5885
				5886	</pre>
				5887	<h5>Overview:</h5>
				5888	<p>
				5889	This loads a value in memory and compares it to a given value. If they are
				5890	equal, it stores a new value into the memory.
				5891	</p>
				5892	<h5>Arguments:</h5>
				5893	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5894	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]	5895	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				5896	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				5897	this integer type. While any bit width integer may be used, targets may only
				5898	lower representations they support in hardware.
				5899
				5900	</p>
				5901	<h5>Semantics:</h5>
				5902	<p>
				5903	This entire intrinsic must be executed atomically. It first loads the value
				5904	in memory pointed to by <tt>ptr</tt> and compares it with the value
				5905	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				5906	loaded value is yielded in all cases. This provides the equivalent of an
				5907	atomic compare-and-swap operation within the SSA framework.
				5908	</p>
				5909	<h5>Examples:</h5>
				5910
				5911	<pre>
				5912	%ptr = malloc i32
				5913	store i32 4, %ptr
				5914
				5915	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5916	%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]	5917	<i>; yields {i32}:result1 = 4</i>
				5918	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5919	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5920
				5921	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5922	%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]	5923	<i>; yields {i32}:result2 = 8</i>
				5924	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				5925
				5926	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				5927	</pre>
				5928	</div>
				5929
				5930	<!-- _______________________________________________________________________ -->
				5931	<div class="doc_subsubsection">
				5932	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				5933	</div>
				5934	<div class="doc_text">
				5935	<h5>Syntax:</h5>
				5936
				5937	<p>
				5938	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				5939	integer bit width. Not all targets support all bit widths however.</p>
				5940	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5941	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				5942	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				5943	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				5944	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5945
				5946	</pre>
				5947	<h5>Overview:</h5>
				5948	<p>
				5949	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				5950	the value from memory. It then stores the value in <tt>val</tt> in the memory
				5951	at <tt>ptr</tt>.
				5952	</p>
				5953	<h5>Arguments:</h5>
				5954
				5955	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5956	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5957	<tt>val</tt> argument and the result must be integers of the same bit width.
				5958	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				5959	integer type. The targets may only lower integer representations they
				5960	support.
				5961	</p>
				5962	<h5>Semantics:</h5>
				5963	<p>
				5964	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				5965	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				5966	equivalent of an atomic swap operation within the SSA framework.
				5967
				5968	</p>
				5969	<h5>Examples:</h5>
				5970	<pre>
				5971	%ptr = malloc i32
				5972	store i32 4, %ptr
				5973
				5974	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5975	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5976	<i>; yields {i32}:result1 = 4</i>
				5977	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				5978	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				5979
				5980	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	5981	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	5982	<i>; yields {i32}:result2 = 8</i>
				5983
				5984	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				5985	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				5986	</pre>
				5987	</div>
				5988
				5989	<!-- _______________________________________________________________________ -->
				5990	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5991	<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]	5992
				5993	</div>
				5994	<div class="doc_text">
				5995	<h5>Syntax:</h5>
				5996	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	5997	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]	5998	integer bit width. Not all targets support all bit widths however.</p>
				5999	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6000	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6001	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6002	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6003	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6004
				6005	</pre>
				6006	<h5>Overview:</h5>
				6007	<p>
				6008	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6009	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6010	</p>
				6011	<h5>Arguments:</h5>
				6012	<p>
				6013
				6014	The intrinsic takes two arguments, the first a pointer to an integer value
				6015	and the second an integer value. The result is also an integer value. These
				6016	integer types can have any bit width, but they must all have the same bit
				6017	width. The targets may only lower integer representations they support.
				6018	</p>
				6019	<h5>Semantics:</h5>
				6020	<p>
				6021	This intrinsic does a series of operations atomically. It first loads the
				6022	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6023	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6024	</p>
				6025
				6026	<h5>Examples:</h5>
				6027	<pre>
				6028	%ptr = malloc i32
				6029	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6030	%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]	6031	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6032	%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]	6033	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6034	%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]	6035	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6036	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6037	</pre>
				6038	</div>
				6039
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6040	<!-- _______________________________________________________________________ -->
				6041	<div class="doc_subsubsection">
				6042	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6043
				6044	</div>
				6045	<div class="doc_text">
				6046	<h5>Syntax:</h5>
				6047	<p>
				6048	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]	6049	any integer bit width and for different address spaces. Not all targets
				6050	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6051	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6052	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6053	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6054	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6055	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]	6056
				6057	</pre>
				6058	<h5>Overview:</h5>
				6059	<p>
				6060	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6061	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6062	</p>
				6063	<h5>Arguments:</h5>
				6064	<p>
				6065
				6066	The intrinsic takes two arguments, the first a pointer to an integer value
				6067	and the second an integer value. The result is also an integer value. These
				6068	integer types can have any bit width, but they must all have the same bit
				6069	width. The targets may only lower integer representations they support.
				6070	</p>
				6071	<h5>Semantics:</h5>
				6072	<p>
				6073	This intrinsic does a series of operations atomically. It first loads the
				6074	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6075	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6076	</p>
				6077
				6078	<h5>Examples:</h5>
				6079	<pre>
				6080	%ptr = malloc i32
				6081	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6082	%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]	6083	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6084	%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]	6085	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6086	%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]	6087	<i>; yields {i32}:result3 = 2</i>
				6088	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6089	</pre>
				6090	</div>
				6091
				6092	<!-- _______________________________________________________________________ -->
				6093	<div class="doc_subsubsection">
				6094	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6095	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6096	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6097	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6098
				6099	</div>
				6100	<div class="doc_text">
				6101	<h5>Syntax:</h5>
				6102	<p>
				6103	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6104	<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]	6105	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6106	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6107	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6108	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6109	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6110	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6111	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]	6112
				6113	</pre>
				6114
				6115	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6116	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6117	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6118	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6119	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]	6120
				6121	</pre>
				6122
				6123	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6124	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6125	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6126	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6127	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]	6128
				6129	</pre>
				6130
				6131	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6132	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6133	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6134	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6135	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]	6136
				6137	</pre>
				6138	<h5>Overview:</h5>
				6139	<p>
				6140	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6141	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6142	at <tt>ptr</tt>.
				6143	</p>
				6144	<h5>Arguments:</h5>
				6145	<p>
				6146
				6147	These intrinsics take two arguments, the first a pointer to an integer value
				6148	and the second an integer value. The result is also an integer value. These
				6149	integer types can have any bit width, but they must all have the same bit
				6150	width. The targets may only lower integer representations they support.
				6151	</p>
				6152	<h5>Semantics:</h5>
				6153	<p>
				6154	These intrinsics does a series of operations atomically. They first load the
				6155	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6156	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6157	value stored at <tt>ptr</tt>.
				6158	</p>
				6159
				6160	<h5>Examples:</h5>
				6161	<pre>
				6162	%ptr = malloc i32
				6163	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6164	%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]	6165	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6166	%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]	6167	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6168	%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]	6169	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6170	%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]	6171	<i>; yields {i32}:result3 = FF</i>
				6172	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6173	</pre>
				6174	</div>
				6175
				6176
				6177	<!-- _______________________________________________________________________ -->
				6178	<div class="doc_subsubsection">
				6179	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6180	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6181	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6182	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6183
				6184	</div>
				6185	<div class="doc_text">
				6186	<h5>Syntax:</h5>
				6187	<p>
				6188	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6189	<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]	6190	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6191	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6192	support all bit widths however.</p>
				6193	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6194	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6195	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6196	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6197	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]	6198
				6199	</pre>
				6200
				6201	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6202	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6203	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6204	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6205	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]	6206
				6207	</pre>
				6208
				6209	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6210	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6211	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6212	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6213	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]	6214
				6215	</pre>
				6216
				6217	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6218	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6219	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6220	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6221	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]	6222
				6223	</pre>
				6224	<h5>Overview:</h5>
				6225	<p>
				6226	These intrinsics takes the signed or unsigned minimum or maximum of
				6227	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6228	original value at <tt>ptr</tt>.
				6229	</p>
				6230	<h5>Arguments:</h5>
				6231	<p>
				6232
				6233	These intrinsics take two arguments, the first a pointer to an integer value
				6234	and the second an integer value. The result is also an integer value. These
				6235	integer types can have any bit width, but they must all have the same bit
				6236	width. The targets may only lower integer representations they support.
				6237	</p>
				6238	<h5>Semantics:</h5>
				6239	<p>
				6240	These intrinsics does a series of operations atomically. They first load the
				6241	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6242	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6243	the original value stored at <tt>ptr</tt>.
				6244	</p>
				6245
				6246	<h5>Examples:</h5>
				6247	<pre>
				6248	%ptr = malloc i32
				6249	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6250	%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]	6251	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6252	%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]	6253	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6254	%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]	6255	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6256	%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]	6257	<i>; yields {i32}:result3 = 8</i>
				6258	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6259	</pre>
				6260	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6261
				6262	<!-- ======================================================================= -->
				6263	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6264	<a name="int_general">General Intrinsics</a>
				6265	</div>
				6266
				6267	<div class="doc_text">
				6268	<p> This class of intrinsics is designed to be generic and has
				6269	no specific purpose. </p>
				6270	</div>
				6271
				6272	<!-- _______________________________________________________________________ -->
				6273	<div class="doc_subsubsection">
				6274	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6275	</div>
				6276
				6277	<div class="doc_text">
				6278
				6279	<h5>Syntax:</h5>
				6280	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6281	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]	6282	</pre>
				6283
				6284	<h5>Overview:</h5>
				6285
				6286	<p>
				6287	The '<tt>llvm.var.annotation</tt>' intrinsic
				6288	</p>
				6289
				6290	<h5>Arguments:</h5>
				6291
				6292	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6293	The first argument is a pointer to a value, the second is a pointer to a
				6294	global string, the third is a pointer to a global string which is the source
				6295	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6296	</p>
				6297
				6298	<h5>Semantics:</h5>
				6299
				6300	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6301	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6302	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]	6303	annotations. These have no other defined use, they are ignored by code
				6304	generation and optimization.
				6305	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6306	</div>
				6307
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6308	<!-- _______________________________________________________________________ -->
				6309	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6310	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6311	</div>
				6312
				6313	<div class="doc_text">
				6314
				6315	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6316	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6317	any integer bit width.
				6318	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6319	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6320	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6321	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6322	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6323	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6324	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]	6325	</pre>
				6326
				6327	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6328
				6329	<p>
				6330	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6331	</p>
				6332
				6333	<h5>Arguments:</h5>
				6334
				6335	<p>
				6336	The first argument is an integer value (result of some expression),
				6337	the second is a pointer to a global string, the third is a pointer to a global
				6338	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]	6339	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6340	</p>
				6341
				6342	<h5>Semantics:</h5>
				6343
				6344	<p>
				6345	This intrinsic allows annotations to be put on arbitrary expressions
				6346	with arbitrary strings. This can be useful for special purpose optimizations
				6347	that want to look for these annotations. These have no other defined use, they
				6348	are ignored by code generation and optimization.
				6349	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6350
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6351	<!-- _______________________________________________________________________ -->
				6352	<div class="doc_subsubsection">
				6353	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6354	</div>
				6355
				6356	<div class="doc_text">
				6357
				6358	<h5>Syntax:</h5>
				6359	<pre>
				6360	declare void @llvm.trap()
				6361	</pre>
				6362
				6363	<h5>Overview:</h5>
				6364
				6365	<p>
				6366	The '<tt>llvm.trap</tt>' intrinsic
				6367	</p>
				6368
				6369	<h5>Arguments:</h5>
				6370
				6371	<p>
				6372	None
				6373	</p>
				6374
				6375	<h5>Semantics:</h5>
				6376
				6377	<p>
				6378	This intrinsics is lowered to the target dependent trap instruction. If the
				6379	target does not have a trap instruction, this intrinsic will be lowered to the
				6380	call of the abort() function.
				6381	</p>
				6382	</div>
				6383
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6384	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6385	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6386	<address>
				6387	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
				6388	src="http://jigsaw.w3.org/css-validator/images/vcss" alt="Valid CSS!"></a>
				6389	<a href="http://validator.w3.org/check/referer"><img
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6390	src="http://www.w3.org/Icons/valid-html401" alt="Valid HTML 4.01!"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6391
				6392	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	6393	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6394	Last modified: $Date$
				6395	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	6396
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	6397	</body>
				6398	</html>