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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	51	<li><a href="#t_function">Function Type</a></li>
				52	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	66	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				67	<li><a href="#undefvalues">Undefined Values</a></li>
				68	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	77	<li><a href="#instref">Instruction Reference</a>
				78	<ol>
				79	<li><a href="#terminators">Terminator Instructions</a>
				80	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				82	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	83	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				84	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	97	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				98	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				99	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	100	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				101	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				102	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	107	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				108	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				109	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	115	<li><a href="#vectorops">Vector Operations</a>
				116	<ol>
				117	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				118	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				119	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	122	<li><a href="#aggregateops">Aggregate Operations</a>
				123	<ol>
				124	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				125	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				126	</ol>
				127	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	130	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				131	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				132	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	133	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				134	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				135	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	139	<ol>
				140	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	145	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				148	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	149	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				150	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	156	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				157	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	159	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	161	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	162	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	164	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	166	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	167	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	168	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				169	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	170	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				171	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				172	<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]	173	</ol>
				174	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				176	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	177	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				178	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				179	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	180	</ol>
				181	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	182	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				183	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	184	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				185	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				186	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				187	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				188	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				189	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				190	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	191	</ol>
				192	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	193	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				194	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	195	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	200	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				202	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	203	</ol>
				204	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	205	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	206	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	207	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	208	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				209	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				210	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	211	</ol>
				212	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	213	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				214	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	215	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	220	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	221	</ol>
				222	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	223	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	224	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	225	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	226	<ol>
				227	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	228	</ol>
				229	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	230	<li><a href="#int_atomics">Atomic intrinsics</a>
				231	<ol>
				232	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				233	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				234	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				235	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				236	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				237	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				238	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				239	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				240	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				241	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				242	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				243	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				244	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				245	</ol>
				246	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	247	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	248	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	250	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	251	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	253	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				255	<li><a href="#int_stackprotector">
				256	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	257	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	258	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	259	</ol>
				260	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	261	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	262
				263	<div class="doc_author">
				264	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				265	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	266	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	268	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	269	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				270	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	272	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	274	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	275	type safety, low-level operations, flexibility, and the capability of
				276	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	representation used throughout all phases of the LLVM compilation
				278	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	279	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	281	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				283	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	285	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	287	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	288	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	289	representation (suitable for fast loading by a Just-In-Time compiler),
				290	and as a human readable assembly language representation. This allows
				291	LLVM to provide a powerful intermediate representation for efficient
				292	compiler transformations and analysis, while providing a natural means
				293	to debug and visualize the transformations. The three different forms
				294	of LLVM are all equivalent. This document describes the human readable
				295	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	297	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	298	while being expressive, typed, and extensible at the same time. It
				299	aims to be a "universal IR" of sorts, by being at a low enough level
				300	that high-level ideas may be cleanly mapped to it (similar to how
				301	microprocessors are "universal IR's", allowing many source languages to
				302	be mapped to them). By providing type information, LLVM can be used as
				303	the target of optimizations: for example, through pointer analysis, it
				304	can be proven that a C automatic variable is never accessed outside of
				305	the current function... allowing it to be promoted to a simple SSA
				306	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	310	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	312
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	313	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<p>It is important to note that this document describes 'well formed'
				316	LLVM assembly language. There is a difference between what the parser
				317	accepts and what is considered 'well formed'. For example, the
				318	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	320	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	322	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	326	<p>...because the definition of <tt>%x</tt> does not dominate all of
				327	its uses. The LLVM infrastructure provides a verification pass that may
				328	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	329	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	330	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	331	by the verifier pass indicate bugs in transformation passes or input to
				332	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	333	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	334
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	335	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	337	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	338	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	341	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	343	<p>LLVM identifiers come in two basic types: global and local. Global
				344	identifiers (functions, global variables) begin with the @ character. Local
				345	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	346	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	347
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	348	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	349	<li>Named values are represented as a string of characters with their prefix.
				350	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				351	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	352	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	353	with quotes. Special characters may be escaped using "\xx" where xx is the
				354	ASCII code for the character in hexadecimal. In this way, any character can
				355	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	356
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	357	<li>Unnamed values are represented as an unsigned numeric value with their
				358	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	360	<li>Constants, which are described in a <a href="#constants">section about
				361	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	362	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	364	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	365	don't need to worry about name clashes with reserved words, and the set of
				366	reserved words may be expanded in the future without penalty. Additionally,
				367	unnamed identifiers allow a compiler to quickly come up with a temporary
				368	variable without having to avoid symbol table conflicts.</p>
				369
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	370	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	371	languages. There are keywords for different opcodes
				372	('<tt><a href="#i_add">add</a></tt>',
				373	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				374	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	375	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	377	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	378
				379	<p>Here is an example of LLVM code to multiply the integer variable
				380	'<tt>%X</tt>' by 8:</p>
				381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	386	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	390	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	394	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	398	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	402	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				403	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				404	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	406	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	408	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				409	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	410
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	411	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	412
				413	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				414	line.</li>
				415
				416	<li>Unnamed temporaries are created when the result of a computation is not
				417	assigned to a named value.</li>
				418
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	419	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	420
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	421	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	423	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424	demonstrating instructions, we will follow an instruction with a comment that
				425	defines the type and name of value produced. Comments are shown in italic
				426	text.</p>
				427
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	428	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	429
				430	<!-- *********************************************************************** -->
				431	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				432	<!-- *********************************************************************** -->
				433
				434	<!-- ======================================================================= -->
				435	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				436	</div>
				437
				438	<div class="doc_text">
				439
				440	<p>LLVM programs are composed of "Module"s, each of which is a
				441	translation unit of the input programs. Each module consists of
				442	functions, global variables, and symbol table entries. Modules may be
				443	combined together with the LLVM linker, which merges function (and
				444	global variable) definitions, resolves forward declarations, and merges
				445	symbol table entries. Here is an example of the "hello world" module:</p>
				446
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	447	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	449	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				450	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	454
				455	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	456	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	457	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	459	href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	460
				461	<i>; Call puts function to write out the string to stdout...</i>
				462	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	463	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	464	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	465	href="#i_ret">ret</a> i32 0<br>}<br>
				466	</pre>
				467	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468
				469	<p>This example is made up of a <a href="#globalvars">global variable</a>
				470	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				471	function, and a <a href="#functionstructure">function definition</a>
				472	for "<tt>main</tt>".</p>
				473
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	474	<p>In general, a module is made up of a list of global values,
				475	where both functions and global variables are global values. Global values are
				476	represented by a pointer to a memory location (in this case, a pointer to an
				477	array of char, and a pointer to a function), and have one of the following <a
				478	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480	</div>
				481
				482	<!-- ======================================================================= -->
				483	<div class="doc_subsection">
				484	<a name="linkage">Linkage Types</a>
				485	</div>
				486
				487	<div class="doc_text">
				488
				489	<p>
				490	All Global Variables and Functions have one of the following types of linkage:
				491	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	492
				493	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	494
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	495	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				496
				497	<dd>Global values with private linkage are only directly accessible by
				498	objects in the current module. In particular, linking code into a module with
				499	an private global value may cause the private to be renamed as necessary to
				500	avoid collisions. Because the symbol is private to the module, all
				501	references can be updated. This doesn't show up in any symbol table in the
				502	object file.
				503	</dd>
				504
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	505	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	507	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	508	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	509	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	510	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	512	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				513	</dt>
				514
				515	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				516	into the object file corresponding to the LLVM module. They exist to
				517	allow inlining and other optimizations to take place given knowledge of the
				518	definition of the global, which is known to be somewhere outside the module.
				519	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				520	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				521	type is only allowed on definitions, not declarations.</dd>
				522
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	525	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				526	the same name when linkage occurs. This is typically used to implement
				527	inline functions, templates, or other code which must be generated in each
				528	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				529	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	532	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				533
				534	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				535	linkage, except that unreferenced <tt>common</tt> globals may not be
				536	discarded. This is used for globals that may be emitted in multiple
				537	translation units, but that are not guaranteed to be emitted into every
				538	translation unit that uses them. One example of this is tentative
				539	definitions in C, such as "<tt>int X;</tt>" at global scope.
				540	</dd>
				541
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	542	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	543
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	544	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				545	that some targets may choose to emit different assembly sequences for them
				546	for target-dependent reasons. This is used for globals that are declared
				547	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	548	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	549
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	550	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	551
				552	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				553	pointer to array type. When two global variables with appending linkage are
				554	linked together, the two global arrays are appended together. This is the
				555	LLVM, typesafe, equivalent of having the system linker append together
				556	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	557	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	558
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	559	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	560
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	561	<dd>The semantics of this linkage follow the ELF object file model: the
				562	symbol is weak until linked, if not linked, the symbol becomes null instead
				563	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	564	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	566	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	567	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	568	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	569	functions with different semantics. Other languages, such as <tt>C++</tt>,
				570	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	571	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	572	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				573	be merged with equivalent globals. These linkage types are otherwise the
				574	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	575	</dd>
				576
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	577	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	578
				579	<dd>If none of the above identifiers are used, the global is externally
				580	visible, meaning that it participates in linkage and can be used to resolve
				581	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	582	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	583	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	584
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	585	<p>
				586	The next two types of linkage are targeted for Microsoft Windows platform
				587	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	588	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	589	</p>
				590
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	591	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	592	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				593
				594	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				595	or variable via a global pointer to a pointer that is set up by the DLL
				596	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	597	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				601
				602	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				603	pointer to a pointer in a DLL, so that it can be referenced with the
				604	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	605	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	606	name.
				607	</dd>
				608
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	609	</dl>
				610
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	611	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	612	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				613	variable and was linked with this one, one of the two would be renamed,
				614	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				615	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	616	outside of the current module.</p>
				617	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	618	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				619	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	620	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				621	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	622	</div>
				623
				624	<!-- ======================================================================= -->
				625	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	626	<a name="callingconv">Calling Conventions</a>
				627	</div>
				628
				629	<div class="doc_text">
				630
				631	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				632	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				633	specified for the call. The calling convention of any pair of dynamic
				634	caller/callee must match, or the behavior of the program is undefined. The
				635	following calling conventions are supported by LLVM, and more may be added in
				636	the future:</p>
				637
				638	<dl>
				639	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				640
				641	<dd>This calling convention (the default if no other calling convention is
				642	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	643	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	644	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	645	</dd>
				646
				647	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				648
				649	<dd>This calling convention attempts to make calls as fast as possible
				650	(e.g. by passing things in registers). This calling convention allows the
				651	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	652	without having to conform to an externally specified ABI (Application Binary
				653	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	654	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				655	supported. This calling convention does not support varargs and requires the
				656	prototype of all callees to exactly match the prototype of the function
				657	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	658	</dd>
				659
				660	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				661
				662	<dd>This calling convention attempts to make code in the caller as efficient
				663	as possible under the assumption that the call is not commonly executed. As
				664	such, these calls often preserve all registers so that the call does not break
				665	any live ranges in the caller side. This calling convention does not support
				666	varargs and requires the prototype of all callees to exactly match the
				667	prototype of the function definition.
				668	</dd>
				669
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	670	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	671
				672	<dd>Any calling convention may be specified by number, allowing
				673	target-specific calling conventions to be used. Target specific calling
				674	conventions start at 64.
				675	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	676	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	677
				678	<p>More calling conventions can be added/defined on an as-needed basis, to
				679	support pascal conventions or any other well-known target-independent
				680	convention.</p>
				681
				682	</div>
				683
				684	<!-- ======================================================================= -->
				685	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	686	<a name="visibility">Visibility Styles</a>
				687	</div>
				688
				689	<div class="doc_text">
				690
				691	<p>
				692	All Global Variables and Functions have one of the following visibility styles:
				693	</p>
				694
				695	<dl>
				696	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				697
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	698	<dd>On targets that use the ELF object file format, default visibility means
				699	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	700	modules and, in shared libraries, means that the declared entity may be
				701	overridden. On Darwin, default visibility means that the declaration is
				702	visible to other modules. Default visibility corresponds to "external
				703	linkage" in the language.
				704	</dd>
				705
				706	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				707
				708	<dd>Two declarations of an object with hidden visibility refer to the same
				709	object if they are in the same shared object. Usually, hidden visibility
				710	indicates that the symbol will not be placed into the dynamic symbol table,
				711	so no other module (executable or shared library) can reference it
				712	directly.
				713	</dd>
				714
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	715	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				716
				717	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				718	the dynamic symbol table, but that references within the defining module will
				719	bind to the local symbol. That is, the symbol cannot be overridden by another
				720	module.
				721	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	722	</dl>
				723
				724	</div>
				725
				726	<!-- ======================================================================= -->
				727	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	728	<a name="namedtypes">Named Types</a>
				729	</div>
				730
				731	<div class="doc_text">
				732
				733	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				734	it easier to read the IR and make the IR more condensed (particularly when
				735	recursive types are involved). An example of a name specification is:
				736	</p>
				737
				738	<div class="doc_code">
				739	<pre>
				740	%mytype = type { %mytype*, i32 }
				741	</pre>
				742	</div>
				743
				744	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				745	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				746	expected with the syntax "%mytype".</p>
				747
				748	<p>Note that type names are aliases for the structural type that they indicate,
				749	and that you can therefore specify multiple names for the same type. This often
				750	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				751	structural typing, the name is not part of the type. When printing out LLVM IR,
				752	the printer will pick <em>one name</em> to render all types of a particular
				753	shape. This means that if you have code where two different source types end up
				754	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				755	unexpected type. This is an important design point and isn't going to
				756	change.</p>
				757
				758	</div>
				759
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	760	<!-- ======================================================================= -->
				761	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	762	<a name="globalvars">Global Variables</a>
				763	</div>
				764
				765	<div class="doc_text">
				766
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	767	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	768	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	769	an explicit section to be placed in, and may have an optional explicit alignment
				770	specified. A variable may be defined as "thread_local", which means that it
				771	will not be shared by threads (each thread will have a separated copy of the
				772	variable). A variable may be defined as a global "constant," which indicates
				773	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	774	optimization, allowing the global data to be placed in the read-only section of
				775	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	776	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	777
				778	<p>
				779	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				780	constant, even if the final definition of the global is not. This capability
				781	can be used to enable slightly better optimization of the program, but requires
				782	the language definition to guarantee that optimizations based on the
				783	'constantness' are valid for the translation units that do not include the
				784	definition.
				785	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	786
				787	<p>As SSA values, global variables define pointer values that are in
				788	scope (i.e. they dominate) all basic blocks in the program. Global
				789	variables always define a pointer to their "content" type because they
				790	describe a region of memory, and all memory objects in LLVM are
				791	accessed through pointers.</p>
				792
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	793	<p>A global variable may be declared to reside in a target-specifc numbered
				794	address space. For targets that support them, address spaces may affect how
				795	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	796	the variable. The default address space is zero. The address space qualifier
				797	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	798
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	799	<p>LLVM allows an explicit section to be specified for globals. If the target
				800	supports it, it will emit globals to the section specified.</p>
				801
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	802	<p>An explicit alignment may be specified for a global. If not present, or if
				803	the alignment is set to zero, the alignment of the global is set by the target
				804	to whatever it feels convenient. If an explicit alignment is specified, the
				805	global is forced to have at least that much alignment. All alignments must be
				806	a power of 2.</p>
				807
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	808	<p>For example, the following defines a global in a numbered address space with
				809	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	810
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	811	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	812	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	813	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	815	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	817	</div>
				818
				819
				820	<!-- ======================================================================= -->
				821	<div class="doc_subsection">
				822	<a name="functionstructure">Functions</a>
				823	</div>
				824
				825	<div class="doc_text">
				826
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	827	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				828	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	829	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	830	<a href="#callingconv">calling convention</a>, a return type, an optional
				831	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				832	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	833	<a href="#paramattrs">parameter attributes</a>), optional
				834	<a href="#fnattrs">function attributes</a>, an optional section,
				835	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	836	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	837
				838	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				839	optional <a href="#linkage">linkage type</a>, an optional
				840	<a href="#visibility">visibility style</a>, an optional
				841	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	842	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	843	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	844	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	845
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	846	<p>A function definition contains a list of basic blocks, forming the CFG
				847	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	848	the function. Each basic block may optionally start with a label (giving the
				849	basic block a symbol table entry), contains a list of instructions, and ends
				850	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				851	function return).</p>
				852
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	853	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	854	executed on entrance to the function, and it is not allowed to have predecessor
				855	basic blocks (i.e. there can not be any branches to the entry block of a
				856	function). Because the block can have no predecessors, it also cannot have any
				857	<a href="#i_phi">PHI nodes</a>.</p>
				858
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	859	<p>LLVM allows an explicit section to be specified for functions. If the target
				860	supports it, it will emit functions to the section specified.</p>
				861
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	862	<p>An explicit alignment may be specified for a function. If not present, or if
				863	the alignment is set to zero, the alignment of the function is set by the target
				864	to whatever it feels convenient. If an explicit alignment is specified, the
				865	function is forced to have at least that much alignment. All alignments must be
				866	a power of 2.</p>
				867
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	868	<h5>Syntax:</h5>
				869
				870	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	871	<tt>
				872	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				873	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				874	<ResultType> @<FunctionName> ([argument list])
				875	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				876	[<a href="#gc">gc</a>] { ... }
				877	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	878	</div>
				879
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	880	</div>
				881
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	882
				883	<!-- ======================================================================= -->
				884	<div class="doc_subsection">
				885	<a name="aliasstructure">Aliases</a>
				886	</div>
				887	<div class="doc_text">
				888	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	889	function, global variable, another alias or bitcast of global value). Aliases
				890	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	891	optional <a href="#visibility">visibility style</a>.</p>
				892
				893	<h5>Syntax:</h5>
				894
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	895	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	896	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	897	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	898	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	899	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	900
				901	</div>
				902
				903
				904
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	905	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	906	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				907	<div class="doc_text">
				908	<p>The return type and each parameter of a function type may have a set of
				909	<i>parameter attributes</i> associated with them. Parameter attributes are
				910	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	911	a function. Parameter attributes are considered to be part of the function,
				912	not of the function type, so functions with different parameter attributes
				913	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	914
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	915	<p>Parameter attributes are simple keywords that follow the type specified. If
				916	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	917	example:</p>
				918
				919	<div class="doc_code">
				920	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	921	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	922	declare i32 @atoi(i8 zeroext)
				923	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	924	</pre>
				925	</div>
				926
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	927	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				928	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	929
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	930	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	931	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	932	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	933	<dd>This indicates to the code generator that the parameter or return value
				934	should be zero-extended to a 32-bit value by the caller (for a parameter)
				935	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	936
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	937	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	938	<dd>This indicates to the code generator that the parameter or return value
				939	should be sign-extended to a 32-bit value by the caller (for a parameter)
				940	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	941
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	942	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	943	<dd>This indicates that this parameter or return value should be treated
				944	in a special target-dependent fashion during while emitting code for a
				945	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	946	to memory, though some targets use it to distinguish between two different
				947	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	948
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	949	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	950	<dd>This indicates that the pointer parameter should really be passed by
				951	value to the function. The attribute implies that a hidden copy of the
				952	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	953	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	954	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	955	value, but is also valid on pointers to scalars. The copy is considered to
				956	belong to the caller not the callee (for example,
				957	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	958	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	959	values. The byval attribute also supports specifying an alignment with the
				960	align attribute. This has a target-specific effect on the code generator
				961	that usually indicates a desired alignment for the synthesized stack
				962	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	963
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	964	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	965	<dd>This indicates that the pointer parameter specifies the address of a
				966	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	967	This pointer must be guaranteed by the caller to be valid: loads and stores
				968	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	969	be applied to the first parameter. This is not a valid attribute for
				970	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	971
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	972	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	973	<dd>This indicates that the pointer does not alias any global or any other
				974	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	975	case. On a function return value, <tt>noalias</tt> additionally indicates
				976	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	977	caller. For further details, please see the discussion of the NoAlias
				978	response in
				979	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				980	analysis</a>.</dd>
				981
				982	<dt><tt>nocapture</tt></dt>
				983	<dd>This indicates that the callee does not make any copies of the pointer
				984	that outlive the callee itself. This is not a valid attribute for return
				985	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	986
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	987	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	988	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	989	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				990	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	991	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	992
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	993	</div>
				994
				995	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	996	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	997	<a name="gc">Garbage Collector Names</a>
				998	</div>
				999
				1000	<div class="doc_text">
				1001	<p>Each function may specify a garbage collector name, which is simply a
				1002	string.</p>
				1003
				1004	<div class="doc_code"><pre
				1005	>define void @f() gc "name" { ...</pre></div>
				1006
				1007	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1008	collector which will cause the compiler to alter its output in order to support
				1009	the named garbage collection algorithm.</p>
				1010	</div>
				1011
				1012	<!-- ======================================================================= -->
				1013	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1014	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1015	</div>
				1016
				1017	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1018
				1019	<p>Function attributes are set to communicate additional information about
				1020	a function. Function attributes are considered to be part of the function,
				1021	not of the function type, so functions with different parameter attributes
				1022	can have the same function type.</p>
				1023
				1024	<p>Function attributes are simple keywords that follow the type specified. If
				1025	multiple attributes are needed, they are space separated. For
				1026	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1027
				1028	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1029	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1030	define void @f() noinline { ... }
				1031	define void @f() alwaysinline { ... }
				1032	define void @f() alwaysinline optsize { ... }
				1033	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1034	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1035	</div>
				1036
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1037	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1038	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1039	<dd>This attribute indicates that the inliner should attempt to inline this
				1040	function into callers whenever possible, ignoring any active inlining size
				1041	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1042
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1043	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1044	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1045	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1046	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1047
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1048	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1049	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	make choices that keep the code size of this function low, and otherwise do
				1051	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1052
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1053	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	<dd>This function attribute indicates that the function never returns normally.
				1055	This produces undefined behavior at runtime if the function ever does
				1056	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1057
				1058	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1059	<dd>This function attribute indicates that the function never returns with an
				1060	unwind or exceptional control flow. If the function does unwind, its runtime
				1061	behavior is undefined.</dd>
				1062
				1063	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1064	<dd>This attribute indicates that the function computes its result (or decides to
				1065	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1066	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1067	registers, etc) visible to caller functions. It does not write through any
				1068	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1069	never changes any state visible to callers. This means that it cannot unwind
				1070	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1071	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1072
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1073	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1074	<dd>This attribute indicates that the function does not write through any
				1075	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1076	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1077	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1078	be set in the caller. A readonly function always returns the same value (or
				1079	unwinds an exception identically) when called with the same set of arguments
				1080	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1081	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1082
				1083	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1084	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1085	protector. It is in the form of a "canary"—a random value placed on the
				1086	stack before the local variables that's checked upon return from the function to
				1087	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1089
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1090	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1091	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1092	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1093
				1094	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1095	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1096	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1097	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1098
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1099	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1100	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1101	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1102	an <tt>sspreq</tt> attribute.</dd>
				1103
				1104	<dt><tt>noredzone</tt></dt>
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1105	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	125473b	2009-06-15 21:18:01 +0000	[diff] [blame]	1106	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1107	</dd>
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1108
				1109	<dt><tt>noimplicitfloat</tt></dt>
				1110	<dd>This attributes disables implicit floating point instructions.</dd>
				1111
Anton Korobeynikov	c5ec8a7	2009-07-17 18:07:26 +0000	[diff] [blame^]	1112	<dt><tt>naked</tt></dt>
				1113	<dd>This attribute disables prologue / epilogue emission for the function</dd>
				1114
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1115	</dl>
				1116
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1117	</div>
				1118
				1119	<!-- ======================================================================= -->
				1120	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1121	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1122	</div>
				1123
				1124	<div class="doc_text">
				1125	<p>
				1126	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1127	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1128	LLVM and treated as a single unit, but may be separated in the .ll file if
				1129	desired. The syntax is very simple:
				1130	</p>
				1131
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1132	<div class="doc_code">
				1133	<pre>
				1134	module asm "inline asm code goes here"
				1135	module asm "more can go here"
				1136	</pre>
				1137	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1138
				1139	<p>The strings can contain any character by escaping non-printable characters.
				1140	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1141	for the number.
				1142	</p>
				1143
				1144	<p>
				1145	The inline asm code is simply printed to the machine code .s file when
				1146	assembly code is generated.
				1147	</p>
				1148	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1149
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1150	<!-- ======================================================================= -->
				1151	<div class="doc_subsection">
				1152	<a name="datalayout">Data Layout</a>
				1153	</div>
				1154
				1155	<div class="doc_text">
				1156	<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]	1157	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1158	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1159	<p>The <i>layout specification</i> consists of a list of specifications
				1160	separated by the minus sign character ('-'). Each specification starts with a
				1161	letter and may include other information after the letter to define some
				1162	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1163	<dl>
				1164	<dt><tt>E</tt></dt>
				1165	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1166	bits with the most significance have the lowest address location.</dd>
				1167	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1168	<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]	1169	the bits with the least significance have the lowest address location.</dd>
				1170	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1172	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1173	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1174	too.</dd>
				1175	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1176	<dd>This specifies the alignment for an integer type of a given bit
				1177	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1178	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1179	<dd>This specifies the alignment for a vector type of a given bit
				1180	<i>size</i>.</dd>
				1181	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1182	<dd>This specifies the alignment for a floating point type of a given bit
				1183	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1184	(double).</dd>
				1185	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1186	<dd>This specifies the alignment for an aggregate type of a given bit
				1187	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1188	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1189	<dd>This specifies the alignment for a stack object of a given bit
				1190	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1191	</dl>
				1192	<p>When constructing the data layout for a given target, LLVM starts with a
				1193	default set of specifications which are then (possibly) overriden by the
				1194	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1195	are given in this list:</p>
				1196	<ul>
				1197	<li><tt>E</tt> - big endian</li>
				1198	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1199	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1200	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1201	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1202	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1203	<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]	1204	alignment of 64-bits</li>
				1205	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1206	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1207	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1208	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1209	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1210	<li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1211	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1212	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1213	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1214	<ol>
				1215	<li>If the type sought is an exact match for one of the specifications, that
				1216	specification is used.</li>
				1217	<li>If no match is found, and the type sought is an integer type, then the
				1218	smallest integer type that is larger than the bitwidth of the sought type is
				1219	used. If none of the specifications are larger than the bitwidth then the the
				1220	largest integer type is used. For example, given the default specifications
				1221	above, the i7 type will use the alignment of i8 (next largest) while both
				1222	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1223	<li>If no match is found, and the type sought is a vector type, then the
				1224	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1225	as a fall back. This happens because <128 x double> can be implemented
				1226	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1227	</ol>
				1228	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1229
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1230	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1231	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1232	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1233
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1234	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1235
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1236	<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]	1237	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1238	optimizations to be performed on the intermediate representation directly,
				1239	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	extra analyses on the side before the transformation. A strong type
				1241	system makes it easier to read the generated code and enables novel
				1242	analyses and transformations that are not feasible to perform on normal
				1243	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1244
				1245	</div>
				1246
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1247	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1248	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1250	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1251	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1253
				1254	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1255	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1256	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1257	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1258	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1259	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1260	</tr>
				1261	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1262	<td><a href="#t_floating">floating point</a></td>
				1263	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1264	</tr>
				1265	<tr>
				1266	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1267	<td><a href="#t_integer">integer</a>,
				1268	<a href="#t_floating">floating point</a>,
				1269	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1270	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1271	<a href="#t_struct">structure</a>,
				1272	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1273	<a href="#t_label">label</a>,
				1274	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1275	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1276	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1277	<tr>
				1278	<td><a href="#t_primitive">primitive</a></td>
				1279	<td><a href="#t_label">label</a>,
				1280	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1281	<a href="#t_floating">floating point</a>,
				1282	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1283	</tr>
				1284	<tr>
				1285	<td><a href="#t_derived">derived</a></td>
				1286	<td><a href="#t_integer">integer</a>,
				1287	<a href="#t_array">array</a>,
				1288	<a href="#t_function">function</a>,
				1289	<a href="#t_pointer">pointer</a>,
				1290	<a href="#t_struct">structure</a>,
				1291	<a href="#t_pstruct">packed structure</a>,
				1292	<a href="#t_vector">vector</a>,
				1293	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1294	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1295	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1296	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1297	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1298
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1299	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1300	most important. Values of these types are the only ones which can be
				1301	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1302	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1303	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1305	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1306	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1307
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1308	<div class="doc_text">
				1309	<p>The primitive types are the fundamental building blocks of the LLVM
				1310	system.</p>
				1311
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1312	</div>
				1313
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1314	<!-- _______________________________________________________________________ -->
				1315	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1316
				1317	<div class="doc_text">
				1318	<table>
				1319	<tbody>
				1320	<tr><th>Type</th><th>Description</th></tr>
				1321	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1322	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1323	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1324	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1325	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1326	</tbody>
				1327	</table>
				1328	</div>
				1329
				1330	<!-- _______________________________________________________________________ -->
				1331	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1332
				1333	<div class="doc_text">
				1334	<h5>Overview:</h5>
				1335	<p>The void type does not represent any value and has no size.</p>
				1336
				1337	<h5>Syntax:</h5>
				1338
				1339	<pre>
				1340	void
				1341	</pre>
				1342	</div>
				1343
				1344	<!-- _______________________________________________________________________ -->
				1345	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1346
				1347	<div class="doc_text">
				1348	<h5>Overview:</h5>
				1349	<p>The label type represents code labels.</p>
				1350
				1351	<h5>Syntax:</h5>
				1352
				1353	<pre>
				1354	label
				1355	</pre>
				1356	</div>
				1357
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1358	<!-- _______________________________________________________________________ -->
				1359	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1360
				1361	<div class="doc_text">
				1362	<h5>Overview:</h5>
				1363	<p>The metadata type represents embedded metadata. The only derived type that
				1364	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1365	takes metadata typed parameters, but not pointer to metadata types.</p>
				1366
				1367	<h5>Syntax:</h5>
				1368
				1369	<pre>
				1370	metadata
				1371	</pre>
				1372	</div>
				1373
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1374
				1375	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1376	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1377
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1378	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1379
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1380	<p>The real power in LLVM comes from the derived types in the system.
				1381	This is what allows a programmer to represent arrays, functions,
				1382	pointers, and other useful types. Note that these derived types may be
				1383	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]	1384
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1385	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1386
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1387	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1388	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1389
				1390	<div class="doc_text">
				1391
				1392	<h5>Overview:</h5>
				1393	<p>The integer type is a very simple derived type that simply specifies an
				1394	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1395	2^23-1 (about 8 million) can be specified.</p>
				1396
				1397	<h5>Syntax:</h5>
				1398
				1399	<pre>
				1400	iN
				1401	</pre>
				1402
				1403	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1404	value.</p>
				1405
				1406	<h5>Examples:</h5>
				1407	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1408	<tr class="layout">
				1409	<td class="left"><tt>i1</tt></td>
				1410	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1411	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1412	<tr class="layout">
				1413	<td class="left"><tt>i32</tt></td>
				1414	<td class="left">a 32-bit integer.</td>
				1415	</tr>
				1416	<tr class="layout">
				1417	<td class="left"><tt>i1942652</tt></td>
				1418	<td class="left">a really big integer of over 1 million bits.</td>
				1419	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1420	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1421
				1422	<p>Note that the code generator does not yet support large integer types
				1423	to be used as function return types. The specific limit on how large a
				1424	return type the code generator can currently handle is target-dependent;
				1425	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1426	targets.</p>
				1427
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1428	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1429
				1430	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1431	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1432
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1433	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1434
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1435	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1436
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1437	<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]	1438	sequentially in memory. The array type requires a size (number of
				1439	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1440
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1441	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1442
				1443	<pre>
				1444	[<# elements> x <elementtype>]
				1445	</pre>
				1446
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1447	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1448	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1449
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1450	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1451	<table class="layout">
				1452	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1453	<td class="left"><tt>[40 x i32]</tt></td>
				1454	<td class="left">Array of 40 32-bit integer values.</td>
				1455	</tr>
				1456	<tr class="layout">
				1457	<td class="left"><tt>[41 x i32]</tt></td>
				1458	<td class="left">Array of 41 32-bit integer values.</td>
				1459	</tr>
				1460	<tr class="layout">
				1461	<td class="left"><tt>[4 x i8]</tt></td>
				1462	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1463	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1464	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1465	<p>Here are some examples of multidimensional arrays:</p>
				1466	<table class="layout">
				1467	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1468	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1469	<td class="left">3x4 array of 32-bit integer values.</td>
				1470	</tr>
				1471	<tr class="layout">
				1472	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1473	<td class="left">12x10 array of single precision floating point values.</td>
				1474	</tr>
				1475	<tr class="layout">
				1476	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1477	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1478	</tr>
				1479	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1480
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1481	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1482	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]	1483	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1484	As a special case, however, zero length arrays are recognized to be variable
				1485	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1486	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1487
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1488	<p>Note that the code generator does not yet support large aggregate types
				1489	to be used as function return types. The specific limit on how large an
				1490	aggregate return type the code generator can currently handle is
				1491	target-dependent, and also dependent on the aggregate element types.</p>
				1492
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1493	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1494
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1495	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1496	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1497	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1498
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1499	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1500
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1501	<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]	1502	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]	1503	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]	1504	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]	1505	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1506
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1507	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1508
				1509	<pre>
				1510	<returntype list> (<parameter list>)
				1511	</pre>
				1512
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1513	<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]	1514	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1515	which indicates that the function takes a variable number of arguments.
				1516	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1517	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1518	'<tt><returntype list></tt>' is a comma-separated list of
				1519	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1520
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1521	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1522	<table class="layout">
				1523	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1524	<td class="left"><tt>i32 (i32)</tt></td>
				1525	<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]	1526	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1527	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1528	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1529	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1530	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1531	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1532	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1533	<tt>float</tt>.
				1534	</td>
				1535	</tr><tr class="layout">
				1536	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1537	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1538	<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]	1539	which returns an integer. This is the signature for <tt>printf</tt> in
				1540	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1541	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1542	</tr><tr class="layout">
				1543	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1544	<td class="left">A function taking an <tt>i32</tt>, returning two
				1545	<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]	1546	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1547	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1548	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1549
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1550	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1551	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1552	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1553	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1554	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1555	<p>The structure type is used to represent a collection of data members
				1556	together in memory. The packing of the field types is defined to match
				1557	the ABI of the underlying processor. The elements of a structure may
				1558	be any type that has a size.</p>
				1559	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1560	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1561	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1562	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1563	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1564	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1565	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1566	<table class="layout">
				1567	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1568	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1569	<td class="left">A triple of three <tt>i32</tt> values</td>
				1570	</tr><tr class="layout">
				1571	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1572	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1573	second element is a <a href="#t_pointer">pointer</a> to a
				1574	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1575	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1576	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1577	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1578
				1579	<p>Note that the code generator does not yet support large aggregate types
				1580	to be used as function return types. The specific limit on how large an
				1581	aggregate return type the code generator can currently handle is
				1582	target-dependent, and also dependent on the aggregate element types.</p>
				1583
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1584	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1585
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1586	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1587	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1588	</div>
				1589	<div class="doc_text">
				1590	<h5>Overview:</h5>
				1591	<p>The packed structure type is used to represent a collection of data members
				1592	together in memory. There is no padding between fields. Further, the alignment
				1593	of a packed structure is 1 byte. The elements of a packed structure may
				1594	be any type that has a size.</p>
				1595	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1596	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1597	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1598	instruction.</p>
				1599	<h5>Syntax:</h5>
				1600	<pre> < { <type list> } > <br></pre>
				1601	<h5>Examples:</h5>
				1602	<table class="layout">
				1603	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1604	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1605	<td class="left">A triple of three <tt>i32</tt> values</td>
				1606	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1607	<td class="left">
				1608	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1609	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1610	second element is a <a href="#t_pointer">pointer</a> to a
				1611	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1612	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1613	</tr>
				1614	</table>
				1615	</div>
				1616
				1617	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1618	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1619	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1620	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1621	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1622	reference to another object, which must live in memory. Pointer types may have
				1623	an optional address space attribute defining the target-specific numbered
				1624	address space where the pointed-to object resides. The default address space is
				1625	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1626
				1627	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	e220e8c	2009-02-08 22:21:28 +0000	[diff] [blame]	1628	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1629
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1630	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1631	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1632	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1633	<table class="layout">
				1634	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1635	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1636	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1637	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1638	</tr>
				1639	<tr class="layout">
				1640	<td class="left"><tt>i32 (i32 ) </tt></td>
				1641	<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]	1642	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]	1643	<tt>i32</tt>.</td>
				1644	</tr>
				1645	<tr class="layout">
				1646	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1647	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1648	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1649	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1650	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1651	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1652
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1653	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1654	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1655	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1656
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1657	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1658
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1659	<p>A vector type is a simple derived type that represents a vector
				1660	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1661	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1662	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1663	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1664	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1665	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1666
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1667	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1668
				1669	<pre>
				1670	< <# elements> x <elementtype> >
				1671	</pre>
				1672
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1673	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1674	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1675
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1676	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1677
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1678	<table class="layout">
				1679	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1680	<td class="left"><tt><4 x i32></tt></td>
				1681	<td class="left">Vector of 4 32-bit integer values.</td>
				1682	</tr>
				1683	<tr class="layout">
				1684	<td class="left"><tt><8 x float></tt></td>
				1685	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1686	</tr>
				1687	<tr class="layout">
				1688	<td class="left"><tt><2 x i64></tt></td>
				1689	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1690	</tr>
				1691	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1692
				1693	<p>Note that the code generator does not yet support large vector types
				1694	to be used as function return types. The specific limit on how large a
				1695	vector return type codegen can currently handle is target-dependent;
				1696	currently it's often a few times longer than a hardware vector register.</p>
				1697
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1698	</div>
				1699
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1700	<!-- _______________________________________________________________________ -->
				1701	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1702	<div class="doc_text">
				1703
				1704	<h5>Overview:</h5>
				1705
				1706	<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]	1707	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]	1708	In LLVM, opaque types can eventually be resolved to any type (not just a
				1709	structure type).</p>
				1710
				1711	<h5>Syntax:</h5>
				1712
				1713	<pre>
				1714	opaque
				1715	</pre>
				1716
				1717	<h5>Examples:</h5>
				1718
				1719	<table class="layout">
				1720	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1721	<td class="left"><tt>opaque</tt></td>
				1722	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1723	</tr>
				1724	</table>
				1725	</div>
				1726
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1727	<!-- ======================================================================= -->
				1728	<div class="doc_subsection">
				1729	<a name="t_uprefs">Type Up-references</a>
				1730	</div>
				1731
				1732	<div class="doc_text">
				1733	<h5>Overview:</h5>
				1734	<p>
				1735	An "up reference" allows you to refer to a lexically enclosing type without
				1736	requiring it to have a name. For instance, a structure declaration may contain a
				1737	pointer to any of the types it is lexically a member of. Example of up
				1738	references (with their equivalent as named type declarations) include:</p>
				1739
				1740	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1741	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1742	{ \2 }* %y = type { %y }*
				1743	\1* %z = type %z*
				1744	</pre>
				1745
				1746	<p>
				1747	An up reference is needed by the asmprinter for printing out cyclic types when
				1748	there is no declared name for a type in the cycle. Because the asmprinter does
				1749	not want to print out an infinite type string, it needs a syntax to handle
				1750	recursive types that have no names (all names are optional in llvm IR).
				1751	</p>
				1752
				1753	<h5>Syntax:</h5>
				1754	<pre>
				1755	\<level>
				1756	</pre>
				1757
				1758	<p>
				1759	The level is the count of the lexical type that is being referred to.
				1760	</p>
				1761
				1762	<h5>Examples:</h5>
				1763
				1764	<table class="layout">
				1765	<tr class="layout">
				1766	<td class="left"><tt>\1*</tt></td>
				1767	<td class="left">Self-referential pointer.</td>
				1768	</tr>
				1769	<tr class="layout">
				1770	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1771	<td class="left">Recursive structure where the upref refers to the out-most
				1772	structure.</td>
				1773	</tr>
				1774	</table>
				1775	</div>
				1776
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1777
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1778	<!-- *********************************************************************** -->
				1779	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1780	<!-- *********************************************************************** -->
				1781
				1782	<div class="doc_text">
				1783
				1784	<p>LLVM has several different basic types of constants. This section describes
				1785	them all and their syntax.</p>
				1786
				1787	</div>
				1788
				1789	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1790	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1791
				1792	<div class="doc_text">
				1793
				1794	<dl>
				1795	<dt><b>Boolean constants</b></dt>
				1796
				1797	<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]	1798	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1799	</dd>
				1800
				1801	<dt><b>Integer constants</b></dt>
				1802
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1803	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1804	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1805	integer types.
				1806	</dd>
				1807
				1808	<dt><b>Floating point constants</b></dt>
				1809
				1810	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1811	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1812	notation (see below). The assembler requires the exact decimal value of
				1813	a floating-point constant. For example, the assembler accepts 1.25 but
				1814	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1815	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]	1816
				1817	<dt><b>Null pointer constants</b></dt>
				1818
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1819	<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]	1820	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1821
				1822	</dl>
				1823
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1824	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1825	of floating point constants. For example, the form '<tt>double
				1826	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1827	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]	1828	(and the only time that they are generated by the disassembler) is when a
				1829	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1830	decimal floating point number in a reasonable number of digits. For example,
				1831	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1832	special values are represented in their IEEE hexadecimal format so that
				1833	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1834	<p>When using the hexadecimal form, constants of types float and double are
				1835	represented using the 16-digit form shown above (which matches the IEEE754
				1836	representation for double); float values must, however, be exactly representable
				1837	as IEE754 single precision.
				1838	Hexadecimal format is always used for long
				1839	double, and there are three forms of long double. The 80-bit
				1840	format used by x86 is represented as <tt>0xK</tt>
				1841	followed by 20 hexadecimal digits.
				1842	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1843	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1844	format is represented
				1845	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1846	target uses this format. Long doubles will only work if they match
				1847	the long double format on your target. All hexadecimal formats are big-endian
				1848	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1849	</div>
				1850
				1851	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1852	<div class="doc_subsection">
				1853	<a name="aggregateconstants"> <!-- old anchor -->
				1854	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1855	</div>
				1856
				1857	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1858	<p>Complex constants are a (potentially recursive) combination of simple
				1859	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1860
				1861	<dl>
				1862	<dt><b>Structure constants</b></dt>
				1863
				1864	<dd>Structure constants are represented with notation similar to structure
				1865	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1866	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1867	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]	1868	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]	1869	types of elements must match those specified by the type.
				1870	</dd>
				1871
				1872	<dt><b>Array constants</b></dt>
				1873
				1874	<dd>Array constants are represented with notation similar to array type
				1875	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1876	(<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]	1877	constants must have <a href="#t_array">array type</a>, and the number and
				1878	types of elements must match those specified by the type.
				1879	</dd>
				1880
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1881	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1882
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1883	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1884	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1885	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1886	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1887	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]	1888	match those specified by the type.
				1889	</dd>
				1890
				1891	<dt><b>Zero initialization</b></dt>
				1892
				1893	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1894	value to zero of <em>any</em> type, including scalar and aggregate types.
				1895	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]	1896	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1897	initializers.
				1898	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1899
				1900	<dt><b>Metadata node</b></dt>
				1901
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1902	<dd>A metadata node is a structure-like constant with
				1903	<a href="#t_metadata">metadata type</a>. For example:
				1904	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1905	that are meant to be interpreted as part of the instruction stream, metadata
				1906	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1907	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1908	</dl>
				1909
				1910	</div>
				1911
				1912	<!-- ======================================================================= -->
				1913	<div class="doc_subsection">
				1914	<a name="globalconstants">Global Variable and Function Addresses</a>
				1915	</div>
				1916
				1917	<div class="doc_text">
				1918
				1919	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1920	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1921	constants. These constants are explicitly referenced when the <a
				1922	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]	1923	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1924	file:</p>
				1925
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1926	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1927	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1928	@X = global i32 17
				1929	@Y = global i32 42
				1930	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1931	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1932	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1933
				1934	</div>
				1935
				1936	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1937	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1938	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1939	<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]	1940	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]	1941	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1942
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1943	<p>Undefined values indicate to the compiler that the program is well defined
				1944	no matter what value is used, giving the compiler more freedom to optimize.
				1945	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1946	</div>
				1947
				1948	<!-- ======================================================================= -->
				1949	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1950	</div>
				1951
				1952	<div class="doc_text">
				1953
				1954	<p>Constant expressions are used to allow expressions involving other constants
				1955	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1956	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]	1957	that does not have side effects (e.g. load and call are not supported). The
				1958	following is the syntax for constant expressions:</p>
				1959
				1960	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1961	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1962	<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]	1963	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1964
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1965	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1966	<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]	1967	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]	1968
				1969	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1970	<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]	1971	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]	1972
				1973	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1974	<dd>Truncate a floating point constant to another floating point type. The
				1975	size of CST must be larger than the size of TYPE. Both types must be
				1976	floating point.</dd>
				1977
				1978	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1979	<dd>Floating point extend a constant to another type. The size of CST must be
				1980	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1981
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1982	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1983	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1984	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1985	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1986	of the same number of elements. If the value won't fit in the integer type,
				1987	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1988
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1989	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1990	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1991	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1992	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1993	of the same number of elements. If the value won't fit in the integer type,
				1994	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1995
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1996	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1997	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1998	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1999	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2000	of the same number of elements. If the value won't fit in the floating point
				2001	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2002
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2003	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2004	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2005	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2006	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2007	of the same number of elements. If the value won't fit in the floating point
				2008	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2009
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2010	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2011	<dd>Convert a pointer typed constant to the corresponding integer constant
				2012	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2013	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2014
				2015	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2016	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2017	pointer type. CST must be of integer type. The CST value is zero extended,
				2018	truncated, or unchanged to make it fit in a pointer size. This one is
				2019	<i>really</i> dangerous!</dd>
				2020
				2021	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2022	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2023	are the same as those for the <a href="#i_bitcast">bitcast
				2024	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2025
				2026	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2027
				2028	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2029	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2030	instruction, the index list may have zero or more indexes, which are required
				2031	to make sense for the type of "CSTPTR".</dd>
				2032
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2033	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2034
				2035	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2036	constants.</dd>
				2037
				2038	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2039	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2040
				2041	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2042	<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]	2043
				2044	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2045
				2046	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2047	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2048
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2049	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2050
				2051	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2052	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2053
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2054
				2055	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2056
				2057	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2058	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2059
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2060	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2061
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2062	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2063	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]	2064	binary</a> operations. The constraints on operands are the same as those for
				2065	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2066	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2067	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2068	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2069
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2070	<!-- ======================================================================= -->
				2071	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2072	</div>
				2073
				2074	<div class="doc_text">
				2075
				2076	<p>Embedded metadata provides a way to attach arbitrary data to the
				2077	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2078	two metadata primitives, strings and nodes. All metadata has the
				2079	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2080	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2081	</p>
				2082
				2083	<p>A metadata string is a string surrounded by double quotes. It can contain
				2084	any character by escaping non-printable characters with "\xx" where "xx" is
				2085	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2086	</p>
				2087
				2088	<p>Metadata nodes are represented with notation similar to structure constants
				2089	(a comma separated list of elements, surrounded by braces and preceeded by an
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2090	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2091	</p>
				2092
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2093	<p>A metadata node will attempt to track changes to the values it holds. In
				2094	the event that a value is deleted, it will be replaced with a typeless
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2095	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2096
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2097	<p>Optimizations may rely on metadata to provide additional information about
				2098	the program that isn't available in the instructions, or that isn't easily
				2099	computable. Similarly, the code generator may expect a certain metadata format
				2100	to be used to express debugging information.</p>
				2101	</div>
				2102
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2103	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2104	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2105	<!-- *********************************************************************** -->
				2106
				2107	<!-- ======================================================================= -->
				2108	<div class="doc_subsection">
				2109	<a name="inlineasm">Inline Assembler Expressions</a>
				2110	</div>
				2111
				2112	<div class="doc_text">
				2113
				2114	<p>
				2115	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2116	Module-Level Inline Assembly</a>) through the use of a special value. This
				2117	value represents the inline assembler as a string (containing the instructions
				2118	to emit), a list of operand constraints (stored as a string), and a flag that
				2119	indicates whether or not the inline asm expression has side effects. An example
				2120	inline assembler expression is:
				2121	</p>
				2122
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2123	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2124	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2125	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2126	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2127	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2128
				2129	<p>
				2130	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2131	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2132	</p>
				2133
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2134	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2135	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2136	%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]	2137	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2138	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2139
				2140	<p>
				2141	Inline asms with side effects not visible in the constraint list must be marked
				2142	as having side effects. This is done through the use of the
				2143	'<tt>sideeffect</tt>' keyword, like so:
				2144	</p>
				2145
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2146	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2147	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2148	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2149	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2150	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2151
				2152	<p>TODO: The format of the asm and constraints string still need to be
				2153	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	4f99335	2008-10-04 18:36:02 +0000	[diff] [blame]	2154	need to be documented). This is probably best done by reference to another
				2155	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2156	</p>
				2157
				2158	</div>
				2159
				2160	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2161	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2162	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2163
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2164	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2165
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2166	<p>The LLVM instruction set consists of several different
				2167	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2168	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2169	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2170	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2171	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2172
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2173	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2174
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2175	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2176	<div class="doc_subsection"> <a name="terminators">Terminator
				2177	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2178
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2179	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2180
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2181	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2182	basic block in a program ends with a "Terminator" instruction, which
				2183	indicates which block should be executed after the current block is
				2184	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2185	value: they produce control flow, not values (the one exception being
				2186	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2187	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2188	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2189	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2190	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2191	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2192	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2193
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2194	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2195
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2196	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2197	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2198	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2199	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2200	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2201	<pre>
				2202	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]	2203	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2205
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2206	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2207
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2208	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2209	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2210	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2211	returns a value and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2212	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2213
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2214	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2215
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2216	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2217	the return value. The type of the return value must be a
				2218	'<a href="#t_firstclass">first class</a>' type.</p>
				2219
				2220	<p>A function is not <a href="#wellformed">well formed</a> if
				2221	it it has a non-void return type and contains a '<tt>ret</tt>'
				2222	instruction with no return value or a return value with a type that
				2223	does not match its type, or if it has a void return type and contains
				2224	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2225
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2226	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2227
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2228	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2229	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]	2230	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2231	the instruction after the call. If the caller was an "<a
				2232	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2233	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2234	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2235	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2236
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2237	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2238
				2239	<pre>
				2240	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2241	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2242	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2244
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2245	<p>Note that the code generator does not yet fully support large
				2246	return values. The specific sizes that are currently supported are
				2247	dependent on the target. For integers, on 32-bit targets the limit
				2248	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2249	For aggregate types, the current limits are dependent on the element
				2250	types; for example targets are often limited to 2 total integer
				2251	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2252
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2253	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2254	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2255	<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]	2256	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2257	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2258	<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]	2259	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2260	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2261	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2262	transfer to a different basic block in the current function. There are
				2263	two forms of this instruction, corresponding to a conditional branch
				2264	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2265	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2266	<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]	2267	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2268	unconditional form of the '<tt>br</tt>' instruction takes a single
				2269	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2271	<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]	2272	argument is evaluated. If the value is <tt>true</tt>, control flows
				2273	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2274	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2275	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2276	<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]	2277	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]	2278	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2279	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2280	<div class="doc_subsubsection">
				2281	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2282	</div>
				2283
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2284	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2285	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2286
				2287	<pre>
				2288	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2289	</pre>
				2290
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2292
				2293	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2294	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2295	instruction, allowing a branch to occur to one of many possible
				2296	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2297
				2298
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2299	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2300
				2301	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2302	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2303	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2304	table is not allowed to contain duplicate constant entries.</p>
				2305
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2306	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2307
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2308	<p>The <tt>switch</tt> instruction specifies a table of values and
				2309	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2310	table is searched for the given value. If the value is found, control flow is
				2311	transfered to the corresponding destination; otherwise, control flow is
				2312	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2313
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2314	<h5>Implementation:</h5>
				2315
				2316	<p>Depending on properties of the target machine and the particular
				2317	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2318	ways. For example, it could be generated as a series of chained conditional
				2319	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2320
				2321	<h5>Example:</h5>
				2322
				2323	<pre>
				2324	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2325	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2326	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2327
				2328	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2329	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2330
				2331	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2332	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2333	i32 1, label %onone
				2334	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2335	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2336	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2337
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2338	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2339	<div class="doc_subsubsection">
				2340	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2341	</div>
				2342
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2343	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2344
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2345	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2346
				2347	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2348	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2349	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2350	</pre>
				2351
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2352	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2353
				2354	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2355	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2356	'<tt>normal</tt>' label or the
				2357	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2358	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2359	"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]	2360	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2361	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2362
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2363	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2364
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2365	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2366
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2367	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2368	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2369	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2370	convention</a> the call should use. If none is specified, the call defaults
				2371	to using C calling conventions.
				2372	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2373
				2374	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2375	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2376	and '<tt>inreg</tt>' attributes are valid here.</li>
				2377
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2378	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2379	function value being invoked. In most cases, this is a direct function
				2380	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2381	an arbitrary pointer to function value.
				2382	</li>
				2383
				2384	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2385	function to be invoked. </li>
				2386
				2387	<li>'<tt>function args</tt>': argument list whose types match the function
				2388	signature argument types. If the function signature indicates the function
				2389	accepts a variable number of arguments, the extra arguments can be
				2390	specified. </li>
				2391
				2392	<li>'<tt>normal label</tt>': the label reached when the called function
				2393	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2394
				2395	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2396	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2397
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2398	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2399	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2400	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2401	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2402
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2403	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2404
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2405	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2406	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2407	difference is that it establishes an association with a label, which is used by
				2408	the runtime library to unwind the stack.</p>
				2409
				2410	<p>This instruction is used in languages with destructors to ensure that proper
				2411	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2412	exception. Additionally, this is important for implementation of
				2413	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2414
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2415	<p>For the purposes of the SSA form, the definition of the value
				2416	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2417	the edge from the current block to the "normal" label. If the callee
				2418	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2419
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2420	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2421	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2422	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2423	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2424	%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]	2425	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2426	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2427	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2428
				2429
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2430	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2431
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2432	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2433	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2434
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2435	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2436
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2437	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2438	<pre>
				2439	unwind
				2440	</pre>
				2441
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2442	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2443
				2444	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2445	at the first callee in the dynamic call stack which used an <a
				2446	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2447	primarily used to implement exception handling.</p>
				2448
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2449	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2450
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2451	<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]	2452	immediately halt. The dynamic call stack is then searched for the first <a
				2453	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2454	execution continues at the "exceptional" destination block specified by the
				2455	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2456	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2457	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2458
				2459	<!-- _______________________________________________________________________ -->
				2460
				2461	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2462	Instruction</a> </div>
				2463
				2464	<div class="doc_text">
				2465
				2466	<h5>Syntax:</h5>
				2467	<pre>
				2468	unreachable
				2469	</pre>
				2470
				2471	<h5>Overview:</h5>
				2472
				2473	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2474	instruction is used to inform the optimizer that a particular portion of the
				2475	code is not reachable. This can be used to indicate that the code after a
				2476	no-return function cannot be reached, and other facts.</p>
				2477
				2478	<h5>Semantics:</h5>
				2479
				2480	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2481	</div>
				2482
				2483
				2484
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2485	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2486	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2487	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2488	<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]	2489	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]	2490	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2491	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]	2492	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2493	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2495	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2496	<div class="doc_subsubsection">
				2497	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2498	</div>
				2499
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2501
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2502	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2503
				2504	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2505	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2506	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2508	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2509
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2510	<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]	2511
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2512	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
				2514	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2515	href="#t_integer">integer</a> or
				2516	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2517	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2519	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2521	<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2522
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2523	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2524	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2525	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2527	<p>Because LLVM integers use a two's complement representation, this
				2528	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2529
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2530	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2531
				2532	<pre>
				2533	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2534	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2535	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2536	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2537	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2538	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2539	</div>
				2540
				2541	<div class="doc_text">
				2542
				2543	<h5>Syntax:</h5>
				2544
				2545	<pre>
				2546	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2547	</pre>
				2548
				2549	<h5>Overview:</h5>
				2550
				2551	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2552
				2553	<h5>Arguments:</h5>
				2554
				2555	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2556	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2557	floating point values. Both arguments must have identical types.</p>
				2558
				2559	<h5>Semantics:</h5>
				2560
				2561	<p>The value produced is the floating point sum of the two operands.</p>
				2562
				2563	<h5>Example:</h5>
				2564
				2565	<pre>
				2566	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2567	</pre>
				2568	</div>
				2569	<!-- _______________________________________________________________________ -->
				2570	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2571	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2572	</div>
				2573
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2574	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2575
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2576	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2577
				2578	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2579	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2580	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2581
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2582	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2584	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2585	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2586
				2587	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2588	'<tt>neg</tt>' instruction present in most other intermediate
				2589	representations.</p>
				2590
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2591	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2592
				2593	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2594	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2595	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2596
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2598
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2599	<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2600
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2601	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2602	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2603	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2605	<p>Because LLVM integers use a two's complement representation, this
				2606	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2607
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2608	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2609	<pre>
				2610	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2611	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2612	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2613	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2616	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2617	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2618	</div>
				2619
				2620	<div class="doc_text">
				2621
				2622	<h5>Syntax:</h5>
				2623
				2624	<pre>
				2625	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2626	</pre>
				2627
				2628	<h5>Overview:</h5>
				2629
				2630	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2631	operands.</p>
				2632
				2633	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2634	'<tt>fneg</tt>' instruction present in most other intermediate
				2635	representations.</p>
				2636
				2637	<h5>Arguments:</h5>
				2638
				2639	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2640	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2641	of floating point values. Both arguments must have identical types.</p>
				2642
				2643	<h5>Semantics:</h5>
				2644
				2645	<p>The value produced is the floating point difference of the two operands.</p>
				2646
				2647	<h5>Example:</h5>
				2648	<pre>
				2649	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2650	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2651	</pre>
				2652	</div>
				2653
				2654	<!-- _______________________________________________________________________ -->
				2655	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2656	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2657	</div>
				2658
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2659	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2660
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2662	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2663	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2664	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2665	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2666	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2667
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2668	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2669
				2670	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2671	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2672	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2673
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2674	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2675
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2676	<p>The value produced is the integer product of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2677
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2678	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2679	the result returned is the mathematical result modulo
				2680	2<sup>n</sup>, where n is the bit width of the result.</p>
				2681	<p>Because LLVM integers use a two's complement representation, and the
				2682	result is the same width as the operands, this instruction returns the
				2683	correct result for both signed and unsigned integers. If a full product
				2684	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2685	should be sign-extended or zero-extended as appropriate to the
				2686	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2687	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2688	<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]	2689	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2690	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2691
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2692	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2693	<div class="doc_subsubsection">
				2694	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2695	</div>
				2696
				2697	<div class="doc_text">
				2698
				2699	<h5>Syntax:</h5>
				2700	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2701	</pre>
				2702	<h5>Overview:</h5>
				2703	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2704	operands.</p>
				2705
				2706	<h5>Arguments:</h5>
				2707
				2708	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2709	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2710	of floating point values. Both arguments must have identical types.</p>
				2711
				2712	<h5>Semantics:</h5>
				2713
				2714	<p>The value produced is the floating point product of the two operands.</p>
				2715
				2716	<h5>Example:</h5>
				2717	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2718	</pre>
				2719	</div>
				2720
				2721	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2722	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2723	</a></div>
				2724	<div class="doc_text">
				2725	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2726	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2727	</pre>
				2728	<h5>Overview:</h5>
				2729	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2730	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2731
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2732	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2733
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2734	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2735	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2736	values. Both arguments must have identical types.</p>
				2737
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2738	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2739
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2740	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2741	<p>Note that unsigned integer division and signed integer division are distinct
				2742	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2743	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2744	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2745	<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]	2746	</pre>
				2747	</div>
				2748	<!-- _______________________________________________________________________ -->
				2749	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2750	</a> </div>
				2751	<div class="doc_text">
				2752	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2753	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2754	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2755	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2756
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2757	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2758
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2759	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2760	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2761
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2762	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2763
				2764	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2765	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2766	values. Both arguments must have identical types.</p>
				2767
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2768	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2769	<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]	2770	<p>Note that signed integer division and unsigned integer division are distinct
				2771	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2772	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2773	undefined behavior; this is a rare case, but can occur, for example,
				2774	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2775	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2776	<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]	2777	</pre>
				2778	</div>
				2779	<!-- _______________________________________________________________________ -->
				2780	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2781	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2782	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2783	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2784	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2785	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2786	</pre>
				2787	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2788
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2789	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2790	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2791
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2792	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2793
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2794	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2795	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2796	of floating point values. Both arguments must have identical types.</p>
				2797
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2798	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2799
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2800	<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]	2801
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2802	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2803
				2804	<pre>
				2805	<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]	2806	</pre>
				2807	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2808
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2809	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2810	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2811	</div>
				2812	<div class="doc_text">
				2813	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2814	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2815	</pre>
				2816	<h5>Overview:</h5>
				2817	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2818	unsigned division of its two arguments.</p>
				2819	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2820	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2821	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2822	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2823	<h5>Semantics:</h5>
				2824	<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]	2825	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2826	<p>Note that unsigned integer remainder and signed integer remainder are
				2827	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2828	<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]	2829	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2830	<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]	2831	</pre>
				2832
				2833	</div>
				2834	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2835	<div class="doc_subsubsection">
				2836	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2837	</div>
				2838
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2839	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2840
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2841	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2842
				2843	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2844	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2845	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2846
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2847	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2848
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2849	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2850	signed division of its two operands. This instruction can also take
				2851	<a href="#t_vector">vector</a> versions of the values in which case
				2852	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2853
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2854	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2855
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2856	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2857	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2858	values. Both arguments must have identical types.</p>
				2859
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2860	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2861
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2862	<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]	2863	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2864	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]	2865	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2866	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]	2867	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]	2868	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2869	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2870	<p>Note that signed integer remainder and unsigned integer remainder are
				2871	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2872	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2873	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2874	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2875	(The remainder doesn't actually overflow, but this rule lets srem be
				2876	implemented using instructions that return both the result of the division
				2877	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2878	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2879	<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]	2880	</pre>
				2881
				2882	</div>
				2883	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2884	<div class="doc_subsubsection">
				2885	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2886
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2887	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2888
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2889	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2890	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2891	</pre>
				2892	<h5>Overview:</h5>
				2893	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2894	division of its two operands.</p>
				2895	<h5>Arguments:</h5>
				2896	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2897	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2898	of floating point values. Both arguments must have identical types.</p>
				2899
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2900	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2901
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2902	<p>This instruction returns the <i>remainder</i> of a division.
				2903	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2904
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2905	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2906
				2907	<pre>
				2908	<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]	2909	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2910	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2911
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2912	<!-- ======================================================================= -->
				2913	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2914	Operations</a> </div>
				2915	<div class="doc_text">
				2916	<p>Bitwise binary operators are used to do various forms of
				2917	bit-twiddling in a program. They are generally very efficient
				2918	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2919	instructions. They require two operands of the same type, execute an operation on them,
				2920	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]	2921	</div>
				2922
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2923	<!-- _______________________________________________________________________ -->
				2924	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2925	Instruction</a> </div>
				2926	<div class="doc_text">
				2927	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2928	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2929	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2930
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2931	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2932
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2933	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2934	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2935
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2936	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2937
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2938	<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]	2939	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]	2940	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2941
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2942	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2943
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2944	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2945	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2946	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2947	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2948	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2949
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2950	<h5>Example:</h5><pre>
				2951	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2952	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2953	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2954	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2955	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2956	</pre>
				2957	</div>
				2958	<!-- _______________________________________________________________________ -->
				2959	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2960	Instruction</a> </div>
				2961	<div class="doc_text">
				2962	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2963	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2964	</pre>
				2965
				2966	<h5>Overview:</h5>
				2967	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2968	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]	2969
				2970	<h5>Arguments:</h5>
				2971	<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]	2972	<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]	2973	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2974
				2975	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2976
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2977	<p>This instruction always performs a logical shift right operation. The most
				2978	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]	2979	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2980	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2981	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2982	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2983
				2984	<h5>Example:</h5>
				2985	<pre>
				2986	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2987	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2988	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2989	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2990	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2991	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2992	</pre>
				2993	</div>
				2994
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2995	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2996	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2997	Instruction</a> </div>
				2998	<div class="doc_text">
				2999
				3000	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3001	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3002	</pre>
				3003
				3004	<h5>Overview:</h5>
				3005	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3006	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]	3007
				3008	<h5>Arguments:</h5>
				3009	<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]	3010	<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]	3011	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3012
				3013	<h5>Semantics:</h5>
				3014	<p>This instruction always performs an arithmetic shift right operation,
				3015	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]	3016	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	3017	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3018	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3019	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3020
				3021	<h5>Example:</h5>
				3022	<pre>
				3023	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3024	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3025	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3026	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3027	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3028	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3029	</pre>
				3030	</div>
				3031
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3032	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3033	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3034	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3035
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3036	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3037
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3038	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3039
				3040	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3041	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3042	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3043
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3044	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3045
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3046	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3047	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3048
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3049	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3050
				3051	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3052	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3053	values. Both arguments must have identical types.</p>
				3054
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3055	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3056	<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]	3057	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3058	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3059	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3060	<tbody>
				3061	<tr>
				3062	<td>In0</td>
				3063	<td>In1</td>
				3064	<td>Out</td>
				3065	</tr>
				3066	<tr>
				3067	<td>0</td>
				3068	<td>0</td>
				3069	<td>0</td>
				3070	</tr>
				3071	<tr>
				3072	<td>0</td>
				3073	<td>1</td>
				3074	<td>0</td>
				3075	</tr>
				3076	<tr>
				3077	<td>1</td>
				3078	<td>0</td>
				3079	<td>0</td>
				3080	</tr>
				3081	<tr>
				3082	<td>1</td>
				3083	<td>1</td>
				3084	<td>1</td>
				3085	</tr>
				3086	</tbody>
				3087	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3088	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3089	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3090	<pre>
				3091	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3092	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3093	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3094	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3095	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3097	<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]	3098	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3100	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3102	<h5>Overview:</h5>
				3103	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3104	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3105	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3106
				3107	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3108	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3109	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3110	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3111	<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]	3112	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3113	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3114	<table border="1" cellspacing="0" cellpadding="4">
				3115	<tbody>
				3116	<tr>
				3117	<td>In0</td>
				3118	<td>In1</td>
				3119	<td>Out</td>
				3120	</tr>
				3121	<tr>
				3122	<td>0</td>
				3123	<td>0</td>
				3124	<td>0</td>
				3125	</tr>
				3126	<tr>
				3127	<td>0</td>
				3128	<td>1</td>
				3129	<td>1</td>
				3130	</tr>
				3131	<tr>
				3132	<td>1</td>
				3133	<td>0</td>
				3134	<td>1</td>
				3135	</tr>
				3136	<tr>
				3137	<td>1</td>
				3138	<td>1</td>
				3139	<td>1</td>
				3140	</tr>
				3141	</tbody>
				3142	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3143	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3144	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3145	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3146	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3147	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3148	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3149	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3151	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3152	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3153	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3154	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3155	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3156	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3158	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3159	or of its two operands. The <tt>xor</tt> is used to implement the
				3160	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3161	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3162	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3163	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3164	values. Both arguments must have identical types.</p>
				3165
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3166	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3167
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3168	<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]	3169	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3170	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3171	<table border="1" cellspacing="0" cellpadding="4">
				3172	<tbody>
				3173	<tr>
				3174	<td>In0</td>
				3175	<td>In1</td>
				3176	<td>Out</td>
				3177	</tr>
				3178	<tr>
				3179	<td>0</td>
				3180	<td>0</td>
				3181	<td>0</td>
				3182	</tr>
				3183	<tr>
				3184	<td>0</td>
				3185	<td>1</td>
				3186	<td>1</td>
				3187	</tr>
				3188	<tr>
				3189	<td>1</td>
				3190	<td>0</td>
				3191	<td>1</td>
				3192	</tr>
				3193	<tr>
				3194	<td>1</td>
				3195	<td>1</td>
				3196	<td>0</td>
				3197	</tr>
				3198	</tbody>
				3199	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3200	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3201	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3202	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3203	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3204	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3205	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3206	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3207	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3208	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3209
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3210	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3211	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3212	<a name="vectorops">Vector Operations</a>
				3213	</div>
				3214
				3215	<div class="doc_text">
				3216
				3217	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3218	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3219	vector-specific operations needed to process vectors effectively. While LLVM
				3220	does directly support these vector operations, many sophisticated algorithms
				3221	will want to use target-specific intrinsics to take full advantage of a specific
				3222	target.</p>
				3223
				3224	</div>
				3225
				3226	<!-- _______________________________________________________________________ -->
				3227	<div class="doc_subsubsection">
				3228	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3229	</div>
				3230
				3231	<div class="doc_text">
				3232
				3233	<h5>Syntax:</h5>
				3234
				3235	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3236	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3237	</pre>
				3238
				3239	<h5>Overview:</h5>
				3240
				3241	<p>
				3242	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3243	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3244	</p>
				3245
				3246
				3247	<h5>Arguments:</h5>
				3248
				3249	<p>
				3250	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3251	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]	3252	an index indicating the position from which to extract the element.
				3253	The index may be a variable.</p>
				3254
				3255	<h5>Semantics:</h5>
				3256
				3257	<p>
				3258	The result is a scalar of the same type as the element type of
				3259	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3260	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3261	results are undefined.
				3262	</p>
				3263
				3264	<h5>Example:</h5>
				3265
				3266	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3267	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3268	</pre>
				3269	</div>
				3270
				3271
				3272	<!-- _______________________________________________________________________ -->
				3273	<div class="doc_subsubsection">
				3274	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3275	</div>
				3276
				3277	<div class="doc_text">
				3278
				3279	<h5>Syntax:</h5>
				3280
				3281	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3282	<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]	3283	</pre>
				3284
				3285	<h5>Overview:</h5>
				3286
				3287	<p>
				3288	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3289	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3290	</p>
				3291
				3292
				3293	<h5>Arguments:</h5>
				3294
				3295	<p>
				3296	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3297	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]	3298	scalar value whose type must equal the element type of the first
				3299	operand. The third operand is an index indicating the position at
				3300	which to insert the value. The index may be a variable.</p>
				3301
				3302	<h5>Semantics:</h5>
				3303
				3304	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3305	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]	3306	element values are those of <tt>val</tt> except at position
				3307	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3308	exceeds the length of <tt>val</tt>, the results are undefined.
				3309	</p>
				3310
				3311	<h5>Example:</h5>
				3312
				3313	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3314	%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]	3315	</pre>
				3316	</div>
				3317
				3318	<!-- _______________________________________________________________________ -->
				3319	<div class="doc_subsubsection">
				3320	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3321	</div>
				3322
				3323	<div class="doc_text">
				3324
				3325	<h5>Syntax:</h5>
				3326
				3327	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3328	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3329	</pre>
				3330
				3331	<h5>Overview:</h5>
				3332
				3333	<p>
				3334	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3335	from two input vectors, returning a vector with the same element type as
				3336	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3337	</p>
				3338
				3339	<h5>Arguments:</h5>
				3340
				3341	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3342	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3343	with types that match each other. The third argument is a shuffle mask whose
				3344	element type is always 'i32'. The result of the instruction is a vector whose
				3345	length is the same as the shuffle mask and whose element type is the same as
				3346	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3347	</p>
				3348
				3349	<p>
				3350	The shuffle mask operand is required to be a constant vector with either
				3351	constant integer or undef values.
				3352	</p>
				3353
				3354	<h5>Semantics:</h5>
				3355
				3356	<p>
				3357	The elements of the two input vectors are numbered from left to right across
				3358	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3359	the result vector, which element of the two input vectors the result element
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3360	gets. The element selector may be undef (meaning "don't care") and the second
				3361	operand may be undef if performing a shuffle from only one vector.
				3362	</p>
				3363
				3364	<h5>Example:</h5>
				3365
				3366	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3367	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3368	<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]	3369	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3370	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3371	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3372	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3373	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3374	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3375	</pre>
				3376	</div>
				3377
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3378
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3379	<!-- ======================================================================= -->
				3380	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3381	<a name="aggregateops">Aggregate Operations</a>
				3382	</div>
				3383
				3384	<div class="doc_text">
				3385
				3386	<p>LLVM supports several instructions for working with aggregate values.
				3387	</p>
				3388
				3389	</div>
				3390
				3391	<!-- _______________________________________________________________________ -->
				3392	<div class="doc_subsubsection">
				3393	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3394	</div>
				3395
				3396	<div class="doc_text">
				3397
				3398	<h5>Syntax:</h5>
				3399
				3400	<pre>
				3401	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3402	</pre>
				3403
				3404	<h5>Overview:</h5>
				3405
				3406	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3407	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3408	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3409	</p>
				3410
				3411
				3412	<h5>Arguments:</h5>
				3413
				3414	<p>
				3415	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3416	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]	3417	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3418	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3419	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3420	</p>
				3421
				3422	<h5>Semantics:</h5>
				3423
				3424	<p>
				3425	The result is the value at the position in the aggregate specified by
				3426	the index operands.
				3427	</p>
				3428
				3429	<h5>Example:</h5>
				3430
				3431	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3432	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3433	</pre>
				3434	</div>
				3435
				3436
				3437	<!-- _______________________________________________________________________ -->
				3438	<div class="doc_subsubsection">
				3439	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3440	</div>
				3441
				3442	<div class="doc_text">
				3443
				3444	<h5>Syntax:</h5>
				3445
				3446	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3447	<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]	3448	</pre>
				3449
				3450	<h5>Overview:</h5>
				3451
				3452	<p>
				3453	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3454	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3455	</p>
				3456
				3457
				3458	<h5>Arguments:</h5>
				3459
				3460	<p>
				3461	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3462	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3463	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3464	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3465	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]	3466	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3467	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3468	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]	3469	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3470	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3471
				3472	<h5>Semantics:</h5>
				3473
				3474	<p>
				3475	The result is an aggregate of the same type as <tt>val</tt>. Its
				3476	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]	3477	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3478	</p>
				3479
				3480	<h5>Example:</h5>
				3481
				3482	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3483	%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]	3484	</pre>
				3485	</div>
				3486
				3487
				3488	<!-- ======================================================================= -->
				3489	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3490	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3491	</div>
				3492
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3493	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3494
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3495	<p>A key design point of an SSA-based representation is how it
				3496	represents memory. In LLVM, no memory locations are in SSA form, which
				3497	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3498	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3499
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3500	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3501
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3502	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3503	<div class="doc_subsubsection">
				3504	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3505	</div>
				3506
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3507	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3508
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3509	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3510
				3511	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3512	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3513	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3514
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3515	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3516
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3517	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3518	heap and returns a pointer to it. The object is always allocated in the generic
				3519	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3520
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3521	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3522
				3523	<p>The '<tt>malloc</tt>' instruction allocates
				3524	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3525	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]	3526	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3527	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3528	If a constant alignment is specified, the value result of the allocation is
				3529	guaranteed to be aligned to at least that boundary. If not specified, or if
				3530	zero, the target can choose to align the allocation on any convenient boundary
				3531	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3532
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3533	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3534
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3535	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3536
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3537	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3538	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3539	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3540
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3541	<h5>Example:</h5>
				3542
				3543	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3544	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3545
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3546	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3547	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3548	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3549	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3550	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3551	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3552
				3553	<p>Note that the code generator does not yet respect the
				3554	alignment value.</p>
				3555
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3556	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3557
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3558	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3559	<div class="doc_subsubsection">
				3560	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3561	</div>
				3562
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3563	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3564
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3565	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3566
				3567	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3568	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3569	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3570
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3571	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3572
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3573	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3574	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3575
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3576	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3577
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3578	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3579	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3580	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3581
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3582	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3583
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3584	<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]	3585	after this instruction executes. If the pointer is null, the operation
				3586	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3587
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3588	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3589
				3590	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3591	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3592	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3593	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3594	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3595
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3596	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3597	<div class="doc_subsubsection">
				3598	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3599	</div>
				3600
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3601	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3602
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3603	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3604
				3605	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3606	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3607	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3608
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3609	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3610
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3611	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3612	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3613	returns to its caller. The object is always allocated in the generic address
				3614	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3615
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3616	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3617
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3618	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3619	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3620	appropriate type to the program. If "NumElements" is specified, it is the
				3621	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3622	If a constant alignment is specified, the value result of the allocation is
				3623	guaranteed to be aligned to at least that boundary. If not specified, or if
				3624	zero, the target can choose to align the allocation on any convenient boundary
				3625	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3626
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3627	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3628
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3629	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3630
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3631	<p>Memory is allocated; a pointer is returned. The operation is undefined if
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3632	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3633	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3634	instruction is commonly used to represent automatic variables that must
				3635	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]	3636	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]	3637	instructions), the memory is reclaimed. Allocating zero bytes
				3638	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3639
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3640	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3641
				3642	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3643	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3644	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3645	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3646	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3647	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3648	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3649
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3650	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3651	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3652	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3653	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3654	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3655	<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]	3656	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3657	<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]	3658	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3659	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3660	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3661	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]	3662	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]	3663	the number or order of execution of this <tt>load</tt> with other
				3664	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3665	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3666	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3667	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3668	(that is, the alignment of the memory address). A value of 0 or an
				3669	omitted "align" argument means that the operation has the preferential
				3670	alignment for the target. It is the responsibility of the code emitter
				3671	to ensure that the alignment information is correct. Overestimating
				3672	the alignment results in an undefined behavior. Underestimating the
				3673	alignment may produce less efficient code. An alignment of 1 is always
				3674	safe.
				3675	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3676	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3677	<p>The location of memory pointed to is loaded. If the value being loaded
				3678	is of scalar type then the number of bytes read does not exceed the minimum
				3679	number of bytes needed to hold all bits of the type. For example, loading an
				3680	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3681	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3682	is undefined if the value was not originally written using a store of the
				3683	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3684	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3685	<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]	3686	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3687	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3688	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3689	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3690	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3691	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3692	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3693	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3694	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3695	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3696	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3697	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3698	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3699	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3700	<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]	3701	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3702	<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]	3703	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]	3704	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3705	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3706	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]	3707	optimizer is not allowed to modify the number or order of execution of
				3708	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3709	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3710	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3711	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3712	(that is, the alignment of the memory address). A value of 0 or an
				3713	omitted "align" argument means that the operation has the preferential
				3714	alignment for the target. It is the responsibility of the code emitter
				3715	to ensure that the alignment information is correct. Overestimating
				3716	the alignment results in an undefined behavior. Underestimating the
				3717	alignment may produce less efficient code. An alignment of 1 is always
				3718	safe.
				3719	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3720	<h5>Semantics:</h5>
				3721	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3722	at the location specified by the '<tt><pointer></tt>' operand.
				3723	If '<tt><value></tt>' is of scalar type then the number of bytes
				3724	written does not exceed the minimum number of bytes needed to hold all
				3725	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3726	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3727	size that is not an integral number of bytes, it is unspecified what
				3728	happens to the extra bits that do not belong to the type, but they will
				3729	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3730	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3731	<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]	3732	store i32 3, i32* %ptr <i>; yields {void}</i>
				3733	%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]	3734	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3735	</div>
				3736
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3737	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3738	<div class="doc_subsubsection">
				3739	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3740	</div>
				3741
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3742	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3743	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3744	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3745	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3746	</pre>
				3747
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3748	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3749
				3750	<p>
				3751	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3752	subelement of an aggregate data structure. It performs address calculation only
				3753	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3754
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3755	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3756
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3757	<p>The first argument is always a pointer, and forms the basis of the
				3758	calculation. The remaining arguments are indices, that indicate which of the
				3759	elements of the aggregate object are indexed. The interpretation of each index
				3760	is dependent on the type being indexed into. The first index always indexes the
				3761	pointer value given as the first argument, the second index indexes a value of
				3762	the type pointed to (not necessarily the value directly pointed to, since the
				3763	first index can be non-zero), etc. The first type indexed into must be a pointer
				3764	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3765	types being indexed into can never be pointers, since that would require loading
				3766	the pointer before continuing calculation.</p>
				3767
				3768	<p>The type of each index argument depends on the type it is indexing into.
				3769	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3770	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	23c70f4	2009-04-27 03:21:00 +0000	[diff] [blame]	3771	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3772
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3773	<p>For example, let's consider a C code fragment and how it gets
				3774	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3775
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3776	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3777	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3778	struct RT {
				3779	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3780	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3781	char C;
				3782	};
				3783	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3784	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3785	double Y;
				3786	struct RT Z;
				3787	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3788
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3789	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3790	return &s[1].Z.B[5][13];
				3791	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3792	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3793	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3794
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3795	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3796
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3797	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3798	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3799	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3800	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3801
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3802	define i32* %foo(%ST* %s) {
				3803	entry:
				3804	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3805	ret i32* %reg
				3806	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3807	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3808	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3809
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3810	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3811
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3812	<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]	3813	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]	3814	}</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]	3815	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3816	i8 }</tt>' type, another structure. The third index indexes into the second
				3817	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]	3818	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3819	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3820	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]	3821
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3822	<p>Note that it is perfectly legal to index partially through a
				3823	structure, returning a pointer to an inner element. Because of this,
				3824	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3825
				3826	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3827	define i32* %foo(%ST* %s) {
				3828	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3829	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3830	%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]	3831	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3832	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3833	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3834	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3835	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3836
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3837	<p>Note that it is undefined to access an array out of bounds: array
				3838	and pointer indexes must always be within the defined bounds of the
				3839	array type when accessed with an instruction that dereferences the
				3840	pointer (e.g. a load or store instruction). The one exception for
				3841	this rule is zero length arrays. These arrays are defined to be
				3842	accessible as variable length arrays, which requires access beyond the
				3843	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3844
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3845	<p>The getelementptr instruction is often confusing. For some more insight
				3846	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3847	FAQ</a>.</p>
				3848
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3849	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3850
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3851	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3852	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3853	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3854	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3855	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3856	<i>; yields i8*:eptr</i>
				3857	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3858	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3859	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3860	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3861	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3862
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3863	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3864	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3865	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3866	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3867	<p>The instructions in this category are the conversion instructions (casting)
				3868	which all take a single operand and a type. They perform various bit conversions
				3869	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3870	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3871
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3872	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3873	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3874	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3875	</div>
				3876	<div class="doc_text">
				3877
				3878	<h5>Syntax:</h5>
				3879	<pre>
				3880	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3881	</pre>
				3882
				3883	<h5>Overview:</h5>
				3884	<p>
				3885	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3886	</p>
				3887
				3888	<h5>Arguments:</h5>
				3889	<p>
				3890	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3891	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]	3892	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]	3893	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3894	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3895
				3896	<h5>Semantics:</h5>
				3897	<p>
				3898	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]	3899	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3900	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3901	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3902
				3903	<h5>Example:</h5>
				3904	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3905	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3906	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3907	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3908	</pre>
				3909	</div>
				3910
				3911	<!-- _______________________________________________________________________ -->
				3912	<div class="doc_subsubsection">
				3913	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3914	</div>
				3915	<div class="doc_text">
				3916
				3917	<h5>Syntax:</h5>
				3918	<pre>
				3919	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3920	</pre>
				3921
				3922	<h5>Overview:</h5>
				3923	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3924	<tt>ty2</tt>.</p>
				3925
				3926
				3927	<h5>Arguments:</h5>
				3928	<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]	3929	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3930	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]	3931	<tt>value</tt> must be smaller than the bit size of the destination type,
				3932	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3933
				3934	<h5>Semantics:</h5>
				3935	<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]	3936	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]	3937
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3938	<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]	3939
				3940	<h5>Example:</h5>
				3941	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3942	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3943	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3944	</pre>
				3945	</div>
				3946
				3947	<!-- _______________________________________________________________________ -->
				3948	<div class="doc_subsubsection">
				3949	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3950	</div>
				3951	<div class="doc_text">
				3952
				3953	<h5>Syntax:</h5>
				3954	<pre>
				3955	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3956	</pre>
				3957
				3958	<h5>Overview:</h5>
				3959	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3960
				3961	<h5>Arguments:</h5>
				3962	<p>
				3963	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]	3964	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3965	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]	3966	<tt>value</tt> must be smaller than the bit size of the destination type,
				3967	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3968
				3969	<h5>Semantics:</h5>
				3970	<p>
				3971	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3972	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]	3973	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3974
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3975	<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]	3976
				3977	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3978	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3979	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3980	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3981	</pre>
				3982	</div>
				3983
				3984	<!-- _______________________________________________________________________ -->
				3985	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3986	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3987	</div>
				3988
				3989	<div class="doc_text">
				3990
				3991	<h5>Syntax:</h5>
				3992
				3993	<pre>
				3994	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3995	</pre>
				3996
				3997	<h5>Overview:</h5>
				3998	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3999	<tt>ty2</tt>.</p>
				4000
				4001
				4002	<h5>Arguments:</h5>
				4003	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4004	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4005	cast it to. The size of <tt>value</tt> must be larger than the size of
				4006	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4007	<i>no-op cast</i>.</p>
				4008
				4009	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4010	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4011	<a href="#t_floating">floating point</a> type to a smaller
				4012	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4013	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4014
				4015	<h5>Example:</h5>
				4016	<pre>
				4017	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4018	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4019	</pre>
				4020	</div>
				4021
				4022	<!-- _______________________________________________________________________ -->
				4023	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4024	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4025	</div>
				4026	<div class="doc_text">
				4027
				4028	<h5>Syntax:</h5>
				4029	<pre>
				4030	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4031	</pre>
				4032
				4033	<h5>Overview:</h5>
				4034	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4035	floating point value.</p>
				4036
				4037	<h5>Arguments:</h5>
				4038	<p>The '<tt>fpext</tt>' instruction takes a
				4039	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4040	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4041	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4042
				4043	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4044	<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]	4045	<a href="#t_floating">floating point</a> type to a larger
				4046	<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]	4047	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]	4048	<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]	4049
				4050	<h5>Example:</h5>
				4051	<pre>
				4052	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4053	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4054	</pre>
				4055	</div>
				4056
				4057	<!-- _______________________________________________________________________ -->
				4058	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4059	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4060	</div>
				4061	<div class="doc_text">
				4062
				4063	<h5>Syntax:</h5>
				4064	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4065	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4066	</pre>
				4067
				4068	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4069	<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]	4070	unsigned integer equivalent of type <tt>ty2</tt>.
				4071	</p>
				4072
				4073	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4074	<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]	4075	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4076	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4077	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4078	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]	4079
				4080	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4081	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4082	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4083	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4084	the results are undefined.</p>
				4085
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4086	<h5>Example:</h5>
				4087	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4088	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4089	%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]	4090	%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]	4091	</pre>
				4092	</div>
				4093
				4094	<!-- _______________________________________________________________________ -->
				4095	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4096	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4097	</div>
				4098	<div class="doc_text">
				4099
				4100	<h5>Syntax:</h5>
				4101	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4102	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4103	</pre>
				4104
				4105	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4106	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4107	<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]	4108	</p>
				4109
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4110	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4111	<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]	4112	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4113	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4114	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4115	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]	4116
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4117	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4118	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4119	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4120	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4121	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4122
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4123	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4124	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4125	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4126	%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]	4127	%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]	4128	</pre>
				4129	</div>
				4130
				4131	<!-- _______________________________________________________________________ -->
				4132	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4133	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4134	</div>
				4135	<div class="doc_text">
				4136
				4137	<h5>Syntax:</h5>
				4138	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4139	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4140	</pre>
				4141
				4142	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4143	<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]	4144	integer and converts that value to the <tt>ty2</tt> type.</p>
				4145
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4146	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4147	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4148	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4149	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4150	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4151	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]	4152
				4153	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4154	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4155	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4156	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]	4157
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4158	<h5>Example:</h5>
				4159	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4160	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4161	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4162	</pre>
				4163	</div>
				4164
				4165	<!-- _______________________________________________________________________ -->
				4166	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4167	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4168	</div>
				4169	<div class="doc_text">
				4170
				4171	<h5>Syntax:</h5>
				4172	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4173	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4174	</pre>
				4175
				4176	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4177	<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]	4178	integer and converts that value to the <tt>ty2</tt> type.</p>
				4179
				4180	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4181	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4182	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4183	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4184	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4185	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]	4186
				4187	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4188	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4189	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4190	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]	4191
				4192	<h5>Example:</h5>
				4193	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4194	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4195	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4196	</pre>
				4197	</div>
				4198
				4199	<!-- _______________________________________________________________________ -->
				4200	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4201	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4202	</div>
				4203	<div class="doc_text">
				4204
				4205	<h5>Syntax:</h5>
				4206	<pre>
				4207	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4208	</pre>
				4209
				4210	<h5>Overview:</h5>
				4211	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4212	the integer type <tt>ty2</tt>.</p>
				4213
				4214	<h5>Arguments:</h5>
				4215	<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]	4216	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4217	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4218
				4219	<h5>Semantics:</h5>
				4220	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4221	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4222	truncating or zero extending that value to the size of the integer type. If
				4223	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4224	<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]	4225	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4226	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4227
				4228	<h5>Example:</h5>
				4229	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4230	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4231	%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]	4232	</pre>
				4233	</div>
				4234
				4235	<!-- _______________________________________________________________________ -->
				4236	<div class="doc_subsubsection">
				4237	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4238	</div>
				4239	<div class="doc_text">
				4240
				4241	<h5>Syntax:</h5>
				4242	<pre>
				4243	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4244	</pre>
				4245
				4246	<h5>Overview:</h5>
				4247	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4248	a pointer type, <tt>ty2</tt>.</p>
				4249
				4250	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4251	<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]	4252	value to cast, and a type to cast it to, which must be a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4253	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4254
				4255	<h5>Semantics:</h5>
				4256	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4257	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4258	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4259	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4260	the size of a pointer then a zero extension is done. If they are the same size,
				4261	nothing is done (<i>no-op cast</i>).</p>
				4262
				4263	<h5>Example:</h5>
				4264	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4265	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4266	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4267	%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]	4268	</pre>
				4269	</div>
				4270
				4271	<!-- _______________________________________________________________________ -->
				4272	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4273	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4274	</div>
				4275	<div class="doc_text">
				4276
				4277	<h5>Syntax:</h5>
				4278	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4279	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4280	</pre>
				4281
				4282	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4283
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4284	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4285	<tt>ty2</tt> without changing any bits.</p>
				4286
				4287	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4288
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4289	<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]	4290	a non-aggregate first class value, and a type to cast it to, which must also be
				4291	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4292	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4293	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]	4294	type is a pointer, the destination type must also be a pointer. This
				4295	instruction supports bitwise conversion of vectors to integers and to vectors
				4296	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4297
				4298	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4299	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4300	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4301	this conversion. The conversion is done as if the <tt>value</tt> had been
				4302	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4303	converted to other pointer types with this instruction. To convert pointers to
				4304	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4305	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4306
				4307	<h5>Example:</h5>
				4308	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4309	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4310	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4311	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4312	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4313	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4314
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4315	<!-- ======================================================================= -->
				4316	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4317	<div class="doc_text">
				4318	<p>The instructions in this category are the "miscellaneous"
				4319	instructions, which defy better classification.</p>
				4320	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4321
				4322	<!-- _______________________________________________________________________ -->
				4323	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4324	</div>
				4325	<div class="doc_text">
				4326	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4327	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4328	</pre>
				4329	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4330	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4331	a vector of boolean values based on comparison
				4332	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4333	<h5>Arguments:</h5>
				4334	<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]	4335	the condition code indicating the kind of comparison to perform. It is not
				4336	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4337	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4338	<ol>
				4339	<li><tt>eq</tt>: equal</li>
				4340	<li><tt>ne</tt>: not equal </li>
				4341	<li><tt>ugt</tt>: unsigned greater than</li>
				4342	<li><tt>uge</tt>: unsigned greater or equal</li>
				4343	<li><tt>ult</tt>: unsigned less than</li>
				4344	<li><tt>ule</tt>: unsigned less or equal</li>
				4345	<li><tt>sgt</tt>: signed greater than</li>
				4346	<li><tt>sge</tt>: signed greater or equal</li>
				4347	<li><tt>slt</tt>: signed less than</li>
				4348	<li><tt>sle</tt>: signed less or equal</li>
				4349	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4350	<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]	4351	<a href="#t_pointer">pointer</a>
				4352	or integer <a href="#t_vector">vector</a> typed.
				4353	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4354	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4355	<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]	4356	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4357	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4358	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4359	<ol>
				4360	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4361	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4362	</li>
				4363	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4364	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4365	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4366	<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]	4367	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4368	<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]	4369	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4370	<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]	4371	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4372	<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]	4373	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4374	<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]	4375	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4376	<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]	4377	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4378	<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]	4379	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4380	<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]	4381	</ol>
				4382	<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]	4383	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4384	<p>If the operands are integer vectors, then they are compared
				4385	element by element. The result is an <tt>i1</tt> vector with
				4386	the same number of elements as the values being compared.
				4387	Otherwise, the result is an <tt>i1</tt>.
				4388	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4389
				4390	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4391	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4392	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4393	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4394	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4395	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4396	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4397	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4398
				4399	<p>Note that the code generator does not yet support vector types with
				4400	the <tt>icmp</tt> instruction.</p>
				4401
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4402	</div>
				4403
				4404	<!-- _______________________________________________________________________ -->
				4405	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4406	</div>
				4407	<div class="doc_text">
				4408	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4409	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4410	</pre>
				4411	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4412	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4413	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4414	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4415	<p>
				4416	If the operands are floating point scalars, then the result
				4417	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4418	</p>
				4419	<p>If the operands are floating point vectors, then the result type
				4420	is a vector of boolean with the same number of elements as the
				4421	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4422	<h5>Arguments:</h5>
				4423	<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]	4424	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4425	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4426	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4427	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4428	<li><tt>oeq</tt>: ordered and equal</li>
				4429	<li><tt>ogt</tt>: ordered and greater than </li>
				4430	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4431	<li><tt>olt</tt>: ordered and less than </li>
				4432	<li><tt>ole</tt>: ordered and less than or equal</li>
				4433	<li><tt>one</tt>: ordered and not equal</li>
				4434	<li><tt>ord</tt>: ordered (no nans)</li>
				4435	<li><tt>ueq</tt>: unordered or equal</li>
				4436	<li><tt>ugt</tt>: unordered or greater than </li>
				4437	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4438	<li><tt>ult</tt>: unordered or less than </li>
				4439	<li><tt>ule</tt>: unordered or less than or equal</li>
				4440	<li><tt>une</tt>: unordered or not equal</li>
				4441	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4442	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4443	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4444	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4445	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4446	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4447	either a <a href="#t_floating">floating point</a> type
				4448	or a <a href="#t_vector">vector</a> of floating point type.
				4449	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4450	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4451	<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]	4452	according to the condition code given as <tt>cond</tt>.
				4453	If the operands are vectors, then the vectors are compared
				4454	element by element.
				4455	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4456	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4457	<ol>
				4458	<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]	4459	<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]	4460	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4461	<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]	4462	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4463	<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]	4464	<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]	4465	<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]	4466	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4467	<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]	4468	<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]	4469	<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]	4470	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4471	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4472	<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]	4473	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4474	<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]	4475	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4476	<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]	4477	<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]	4478	<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]	4479	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4480	<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]	4481	<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]	4482	<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]	4483	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4484	<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]	4485	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4486	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4487
				4488	<h5>Example:</h5>
				4489	<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]	4490	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4491	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4492	<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]	4493	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4494
				4495	<p>Note that the code generator does not yet support vector types with
				4496	the <tt>fcmp</tt> instruction.</p>
				4497
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4498	</div>
				4499
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4500	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4501	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4502	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4503	</div>
				4504
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4505	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4506
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4507	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4508
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4509	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4510	<h5>Overview:</h5>
				4511	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4512	the SSA graph representing the function.</p>
				4513	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4514
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4515	<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]	4516	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4517	as arguments, with one pair for each predecessor basic block of the
				4518	current block. Only values of <a href="#t_firstclass">first class</a>
				4519	type may be used as the value arguments to the PHI node. Only labels
				4520	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4521
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4522	<p>There must be no non-phi instructions between the start of a basic
				4523	block and the PHI instructions: i.e. PHI instructions must be first in
				4524	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4525
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4526	<p>For the purposes of the SSA form, the use of each incoming value is
				4527	deemed to occur on the edge from the corresponding predecessor block
				4528	to the current block (but after any definition of an '<tt>invoke</tt>'
				4529	instruction's return value on the same edge).</p>
				4530
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4531	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4532
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4533	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4534	specified by the pair corresponding to the predecessor basic block that executed
				4535	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4536
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4537	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4538	<pre>
				4539	Loop: ; Infinite loop that counts from 0 on up...
				4540	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4541	%nextindvar = add i32 %indvar, 1
				4542	br label %Loop
				4543	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4544	</div>
				4545
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4546	<!-- _______________________________________________________________________ -->
				4547	<div class="doc_subsubsection">
				4548	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4549	</div>
				4550
				4551	<div class="doc_text">
				4552
				4553	<h5>Syntax:</h5>
				4554
				4555	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4556	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4557
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4558	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4559	</pre>
				4560
				4561	<h5>Overview:</h5>
				4562
				4563	<p>
				4564	The '<tt>select</tt>' instruction is used to choose one value based on a
				4565	condition, without branching.
				4566	</p>
				4567
				4568
				4569	<h5>Arguments:</h5>
				4570
				4571	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4572	The '<tt>select</tt>' instruction requires an 'i1' value or
				4573	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4574	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]	4575	type. If the val1/val2 are vectors and
				4576	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4577	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4578	</p>
				4579
				4580	<h5>Semantics:</h5>
				4581
				4582	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4583	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]	4584	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4585	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4586	<p>
				4587	If the condition is a vector of i1, then the value arguments must
				4588	be vectors of the same size, and the selection is done element
				4589	by element.
				4590	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4591
				4592	<h5>Example:</h5>
				4593
				4594	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4595	%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]	4596	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4597
				4598	<p>Note that the code generator does not yet support conditions
				4599	with vector type.</p>
				4600
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4601	</div>
				4602
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4603
				4604	<!-- _______________________________________________________________________ -->
				4605	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4606	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4607	</div>
				4608
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4609	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4610
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4611	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4612	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4613	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4614	</pre>
				4615
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4616	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4617
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4618	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4619
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4620	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4621
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4622	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4623
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4624	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4625	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4626	<p>The optional "tail" marker indicates whether the callee function accesses
				4627	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]	4628	function call is eligible for tail call optimization. Note that calls may
				4629	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4630	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4631	</li>
				4632	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4633	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4634	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4635	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4636	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4637
				4638	<li>
				4639	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4640	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4641	and '<tt>inreg</tt>' attributes are valid here.</p>
				4642	</li>
				4643
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4644	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4645	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4646	the type of the return value. Functions that return no value are marked
				4647	<tt><a href="#t_void">void</a></tt>.</p>
				4648	</li>
				4649	<li>
				4650	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4651	value being invoked. The argument types must match the types implied by
				4652	this signature. This type can be omitted if the function is not varargs
				4653	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]	4654	</li>
				4655	<li>
				4656	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4657	be invoked. In most cases, this is a direct function invocation, but
				4658	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]	4659	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4660	</li>
				4661	<li>
				4662	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4663	function signature argument types. All arguments must be of
				4664	<a href="#t_firstclass">first class</a> type. If the function signature
				4665	indicates the function accepts a variable number of arguments, the extra
				4666	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4667	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4668	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4669	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4670	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4671	'<tt>readnone</tt>' attributes are valid here.</p>
				4672	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4673	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4674
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4675	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4676
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4677	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4678	transfer to a specified function, with its incoming arguments bound to
				4679	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4680	instruction in the called function, control flow continues with the
				4681	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4682	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4683
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4684	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4685
				4686	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4687	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4688	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4689	%X = tail call i32 @foo() <i>; yields i32</i>
				4690	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4691	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4692
				4693	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4694	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4695	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4696	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4697	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	cb73d19	2008-10-07 10:03:45 +0000	[diff] [blame]	4698	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4699	</pre>
				4700
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4701	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4702
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4703	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4704	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4705	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4706	</div>
				4707
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4708	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4709
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4710	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4711
				4712	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4713	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4714	</pre>
				4715
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4716	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4717
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4718	<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]	4719	the "variable argument" area of a function call. It is used to implement the
				4720	<tt>va_arg</tt> macro in C.</p>
				4721
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4722	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4723
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4724	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4725	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4726	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]	4727	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4728
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4729	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4730
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4731	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4732	type from the specified <tt>va_list</tt> and causes the
				4733	<tt>va_list</tt> to point to the next argument. For more information,
				4734	see the variable argument handling <a href="#int_varargs">Intrinsic
				4735	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4736
				4737	<p>It is legal for this instruction to be called in a function which does not
				4738	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4739	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4740
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4741	<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]	4742	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4743	argument.</p>
				4744
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4745	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4746
				4747	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4748
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4749	<p>Note that the code generator does not yet fully support va_arg
				4750	on many targets. Also, it does not currently support va_arg with
				4751	aggregate types on any target.</p>
				4752
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4753	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4754
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4755	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4756	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4757	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4758
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4759	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4760
				4761	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4762	well known names and semantics and are required to follow certain restrictions.
				4763	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4764	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]	4765	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]	4766
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4767	<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]	4768	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4769	begin with this prefix. Intrinsic functions must always be external functions:
				4770	you cannot define the body of intrinsic functions. Intrinsic functions may
				4771	only be used in call or invoke instructions: it is illegal to take the address
				4772	of an intrinsic function. Additionally, because intrinsic functions are part
				4773	of the LLVM language, it is required if any are added that they be documented
				4774	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4775
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4776	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4777	a family of functions that perform the same operation but on different data
				4778	types. Because LLVM can represent over 8 million different integer types,
				4779	overloading is used commonly to allow an intrinsic function to operate on any
				4780	integer type. One or more of the argument types or the result type can be
				4781	overloaded to accept any integer type. Argument types may also be defined as
				4782	exactly matching a previous argument's type or the result type. This allows an
				4783	intrinsic function which accepts multiple arguments, but needs all of them to
				4784	be of the same type, to only be overloaded with respect to a single argument or
				4785	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4786
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4787	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4788	encoded into its function name, each preceded by a period. Only those types
				4789	which are overloaded result in a name suffix. Arguments whose type is matched
				4790	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4791	take an integer of any width and returns an integer of exactly the same integer
				4792	width. This leads to a family of functions such as
				4793	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4794	Only one type, the return type, is overloaded, and only one type suffix is
				4795	required. Because the argument's type is matched against the return type, it
				4796	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4797
				4798	<p>To learn how to add an intrinsic function, please see the
				4799	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4800	</p>
				4801
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4802	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4803
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4804	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4805	<div class="doc_subsection">
				4806	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4807	</div>
				4808
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4809	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4810
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4811	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4812	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]	4813	intrinsic functions. These functions are related to the similarly
				4814	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4815
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4816	<p>All of these functions operate on arguments that use a
				4817	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4818	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4819	transformations should be prepared to handle these functions regardless of
				4820	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4821
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4822	<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]	4823	instruction and the variable argument handling intrinsic functions are
				4824	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4825
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4826	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4827	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4828	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4829	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4830	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4831	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4832	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4833
				4834	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4835	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4836
				4837	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4838	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4839	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4840	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4841	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4842
				4843	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4844	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4845	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4846	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4847
				4848	declare void @llvm.va_start(i8*)
				4849	declare void @llvm.va_copy(i8, i8)
				4850	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4851	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4852	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4853
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4854	</div>
				4855
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4856	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4857	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4858	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4859	</div>
				4860
				4861
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4862	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4863	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4864	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4865	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4866	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4867	<tt>*<arglist></tt> for subsequent use by <tt><a
				4868	href="#i_va_arg">va_arg</a></tt>.</p>
				4869
				4870	<h5>Arguments:</h5>
				4871
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4872	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4873
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4874	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4875
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4876	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4877	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4878	<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]	4879	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4880	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]	4881	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]	4882
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4883	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4884
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4885	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4886	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4887	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4888	</div>
				4889
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4890	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4891	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4892	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4893	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4894
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4895	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4896	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]	4897	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]	4898
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4899	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4900
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4901	<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]	4902
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4903	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4904
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4905	<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]	4906	macro available in C. In a target-dependent way, it destroys the
				4907	<tt>va_list</tt> element to which the argument points. Calls to <a
				4908	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4909	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4910	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4911
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4912	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4913
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4914	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4915	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4916	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4917	</div>
				4918
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4919	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4920
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4921	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4922
				4923	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4924	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4925	</pre>
				4926
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4927	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4928
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4929	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4930	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4931
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4932	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4933
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4934	<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]	4935	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]	4936
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4937
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4938	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4939
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4940	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4941	macro available in C. In a target-dependent way, it copies the source
				4942	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4943	intrinsic is necessary because the <tt><a href="#int_va_start">
				4944	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4945	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4946
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4947	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4948
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4949	<!-- ======================================================================= -->
				4950	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4951	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4952	</div>
				4953
				4954	<div class="doc_text">
				4955
				4956	<p>
				4957	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4958	Collection</a> (GC) requires the implementation and generation of these
				4959	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4960	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]	4961	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4962	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]	4963	Front-ends for type-safe garbage collected languages should generate these
				4964	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4965	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4966	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4967
				4968	<p>The garbage collection intrinsics only operate on objects in the generic
				4969	address space (address space zero).</p>
				4970
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4971	</div>
				4972
				4973	<!-- _______________________________________________________________________ -->
				4974	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4975	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4976	</div>
				4977
				4978	<div class="doc_text">
				4979
				4980	<h5>Syntax:</h5>
				4981
				4982	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4983	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4984	</pre>
				4985
				4986	<h5>Overview:</h5>
				4987
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4988	<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]	4989	the code generator, and allows some metadata to be associated with it.</p>
				4990
				4991	<h5>Arguments:</h5>
				4992
				4993	<p>The first argument specifies the address of a stack object that contains the
				4994	root pointer. The second pointer (which must be either a constant or a global
				4995	value address) contains the meta-data to be associated with the root.</p>
				4996
				4997	<h5>Semantics:</h5>
				4998
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4999	<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]	5000	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5001	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5002	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5003	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5004
				5005	</div>
				5006
				5007
				5008	<!-- _______________________________________________________________________ -->
				5009	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5010	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5011	</div>
				5012
				5013	<div class="doc_text">
				5014
				5015	<h5>Syntax:</h5>
				5016
				5017	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5018	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5019	</pre>
				5020
				5021	<h5>Overview:</h5>
				5022
				5023	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5024	locations, allowing garbage collector implementations that require read
				5025	barriers.</p>
				5026
				5027	<h5>Arguments:</h5>
				5028
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5029	<p>The second argument is the address to read from, which should be an address
				5030	allocated from the garbage collector. The first object is a pointer to the
				5031	start of the referenced object, if needed by the language runtime (otherwise
				5032	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5033
				5034	<h5>Semantics:</h5>
				5035
				5036	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5037	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5038	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5039	may only be used in a function which <a href="#gc">specifies a GC
				5040	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5041
				5042	</div>
				5043
				5044
				5045	<!-- _______________________________________________________________________ -->
				5046	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5047	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5048	</div>
				5049
				5050	<div class="doc_text">
				5051
				5052	<h5>Syntax:</h5>
				5053
				5054	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5055	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5056	</pre>
				5057
				5058	<h5>Overview:</h5>
				5059
				5060	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5061	locations, allowing garbage collector implementations that require write
				5062	barriers (such as generational or reference counting collectors).</p>
				5063
				5064	<h5>Arguments:</h5>
				5065
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5066	<p>The first argument is the reference to store, the second is the start of the
				5067	object to store it to, and the third is the address of the field of Obj to
				5068	store to. If the runtime does not require a pointer to the object, Obj may be
				5069	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5070
				5071	<h5>Semantics:</h5>
				5072
				5073	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5074	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5075	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5076	may only be used in a function which <a href="#gc">specifies a GC
				5077	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5078
				5079	</div>
				5080
				5081
				5082
				5083	<!-- ======================================================================= -->
				5084	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5085	<a name="int_codegen">Code Generator Intrinsics</a>
				5086	</div>
				5087
				5088	<div class="doc_text">
				5089	<p>
				5090	These intrinsics are provided by LLVM to expose special features that may only
				5091	be implemented with code generator support.
				5092	</p>
				5093
				5094	</div>
				5095
				5096	<!-- _______________________________________________________________________ -->
				5097	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5098	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5099	</div>
				5100
				5101	<div class="doc_text">
				5102
				5103	<h5>Syntax:</h5>
				5104	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5105	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5106	</pre>
				5107
				5108	<h5>Overview:</h5>
				5109
				5110	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5111	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5112	target-specific value indicating the return address of the current function
				5113	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5114	</p>
				5115
				5116	<h5>Arguments:</h5>
				5117
				5118	<p>
				5119	The argument to this intrinsic indicates which function to return the address
				5120	for. Zero indicates the calling function, one indicates its caller, etc. The
				5121	argument is <b>required</b> to be a constant integer value.
				5122	</p>
				5123
				5124	<h5>Semantics:</h5>
				5125
				5126	<p>
				5127	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5128	the return address of the specified call frame, or zero if it cannot be
				5129	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5130	for arguments other than zero, so it should only be used for debugging purposes.
				5131	</p>
				5132
				5133	<p>
				5134	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5135	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]	5136	source-language caller.
				5137	</p>
				5138	</div>
				5139
				5140
				5141	<!-- _______________________________________________________________________ -->
				5142	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5143	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5144	</div>
				5145
				5146	<div class="doc_text">
				5147
				5148	<h5>Syntax:</h5>
				5149	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5150	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5151	</pre>
				5152
				5153	<h5>Overview:</h5>
				5154
				5155	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5156	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5157	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5158	</p>
				5159
				5160	<h5>Arguments:</h5>
				5161
				5162	<p>
				5163	The argument to this intrinsic indicates which function to return the frame
				5164	pointer for. Zero indicates the calling function, one indicates its caller,
				5165	etc. The argument is <b>required</b> to be a constant integer value.
				5166	</p>
				5167
				5168	<h5>Semantics:</h5>
				5169
				5170	<p>
				5171	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5172	the frame address of the specified call frame, or zero if it cannot be
				5173	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5174	for arguments other than zero, so it should only be used for debugging purposes.
				5175	</p>
				5176
				5177	<p>
				5178	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5179	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]	5180	source-language caller.
				5181	</p>
				5182	</div>
				5183
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5184	<!-- _______________________________________________________________________ -->
				5185	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5186	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5187	</div>
				5188
				5189	<div class="doc_text">
				5190
				5191	<h5>Syntax:</h5>
				5192	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5193	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5194	</pre>
				5195
				5196	<h5>Overview:</h5>
				5197
				5198	<p>
				5199	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]	5200	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5201	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5202	features like scoped automatic variable sized arrays in C99.
				5203	</p>
				5204
				5205	<h5>Semantics:</h5>
				5206
				5207	<p>
				5208	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]	5209	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5210	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5211	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5212	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5213	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5214	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5215	</p>
				5216
				5217	</div>
				5218
				5219	<!-- _______________________________________________________________________ -->
				5220	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5221	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5222	</div>
				5223
				5224	<div class="doc_text">
				5225
				5226	<h5>Syntax:</h5>
				5227	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5228	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5229	</pre>
				5230
				5231	<h5>Overview:</h5>
				5232
				5233	<p>
				5234	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5235	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]	5236	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5237	useful for implementing language features like scoped automatic variable sized
				5238	arrays in C99.
				5239	</p>
				5240
				5241	<h5>Semantics:</h5>
				5242
				5243	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5244	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]	5245	</p>
				5246
				5247	</div>
				5248
				5249
				5250	<!-- _______________________________________________________________________ -->
				5251	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5252	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5253	</div>
				5254
				5255	<div class="doc_text">
				5256
				5257	<h5>Syntax:</h5>
				5258	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5259	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5260	</pre>
				5261
				5262	<h5>Overview:</h5>
				5263
				5264
				5265	<p>
				5266	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]	5267	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5268	no
				5269	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5270	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5271	</p>
				5272
				5273	<h5>Arguments:</h5>
				5274
				5275	<p>
				5276	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5277	determining if the fetch should be for a read (0) or write (1), and
				5278	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5279	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]	5280	<tt>locality</tt> arguments must be constant integers.
				5281	</p>
				5282
				5283	<h5>Semantics:</h5>
				5284
				5285	<p>
				5286	This intrinsic does not modify the behavior of the program. In particular,
				5287	prefetches cannot trap and do not produce a value. On targets that support this
				5288	intrinsic, the prefetch can provide hints to the processor cache for better
				5289	performance.
				5290	</p>
				5291
				5292	</div>
				5293
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5294	<!-- _______________________________________________________________________ -->
				5295	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5296	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5297	</div>
				5298
				5299	<div class="doc_text">
				5300
				5301	<h5>Syntax:</h5>
				5302	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5303	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5304	</pre>
				5305
				5306	<h5>Overview:</h5>
				5307
				5308
				5309	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5310	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]	5311	(PC) in a region of
				5312	code to simulators and other tools. The method is target specific, but it is
				5313	expected that the marker will use exported symbols to transmit the PC of the
				5314	marker.
				5315	The marker makes no guarantees that it will remain with any specific instruction
				5316	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]	5317	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5318	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5319	</p>
				5320
				5321	<h5>Arguments:</h5>
				5322
				5323	<p>
				5324	<tt>id</tt> is a numerical id identifying the marker.
				5325	</p>
				5326
				5327	<h5>Semantics:</h5>
				5328
				5329	<p>
				5330	This intrinsic does not modify the behavior of the program. Backends that do not
				5331	support this intrinisic may ignore it.
				5332	</p>
				5333
				5334	</div>
				5335
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5336	<!-- _______________________________________________________________________ -->
				5337	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5338	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5339	</div>
				5340
				5341	<div class="doc_text">
				5342
				5343	<h5>Syntax:</h5>
				5344	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5345	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5346	</pre>
				5347
				5348	<h5>Overview:</h5>
				5349
				5350
				5351	<p>
				5352	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5353	counter register (or similar low latency, high accuracy clocks) on those targets
				5354	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5355	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5356	should only be used for small timings.
				5357	</p>
				5358
				5359	<h5>Semantics:</h5>
				5360
				5361	<p>
				5362	When directly supported, reading the cycle counter should not modify any memory.
				5363	Implementations are allowed to either return a application specific value or a
				5364	system wide value. On backends without support, this is lowered to a constant 0.
				5365	</p>
				5366
				5367	</div>
				5368
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5369	<!-- ======================================================================= -->
				5370	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5371	<a name="int_libc">Standard C Library Intrinsics</a>
				5372	</div>
				5373
				5374	<div class="doc_text">
				5375	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5376	LLVM provides intrinsics for a few important standard C library functions.
				5377	These intrinsics allow source-language front-ends to pass information about the
				5378	alignment of the pointer arguments to the code generator, providing opportunity
				5379	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5380	</p>
				5381
				5382	</div>
				5383
				5384	<!-- _______________________________________________________________________ -->
				5385	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5386	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5387	</div>
				5388
				5389	<div class="doc_text">
				5390
				5391	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5392	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5393	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5394	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5395	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5396	i8 <len>, i32 <align>)
				5397	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5398	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5399	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5400	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5401	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5402	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5403	</pre>
				5404
				5405	<h5>Overview:</h5>
				5406
				5407	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5408	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]	5409	location to the destination location.
				5410	</p>
				5411
				5412	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5413	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5414	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5415	</p>
				5416
				5417	<h5>Arguments:</h5>
				5418
				5419	<p>
				5420	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]	5421	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5422	specifying the number of bytes to copy, and the fourth argument is the alignment
				5423	of the source and destination locations.
				5424	</p>
				5425
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5426	<p>
				5427	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]	5428	the caller guarantees that both the source and destination pointers are aligned
				5429	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5430	</p>
				5431
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5432	<h5>Semantics:</h5>
				5433
				5434	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5435	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]	5436	location to the destination location, which are not allowed to overlap. It
				5437	copies "len" bytes of memory over. If the argument is known to be aligned to
				5438	some boundary, this can be specified as the fourth argument, otherwise it should
				5439	be set to 0 or 1.
				5440	</p>
				5441	</div>
				5442
				5443
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5444	<!-- _______________________________________________________________________ -->
				5445	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5446	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5447	</div>
				5448
				5449	<div class="doc_text">
				5450
				5451	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5452	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5453	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5454	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5455	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5456	i8 <len>, i32 <align>)
				5457	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5458	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5459	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5460	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5461	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5462	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5463	</pre>
				5464
				5465	<h5>Overview:</h5>
				5466
				5467	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5468	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5469	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5470	'<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]	5471	</p>
				5472
				5473	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5474	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5475	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5476	</p>
				5477
				5478	<h5>Arguments:</h5>
				5479
				5480	<p>
				5481	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]	5482	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5483	specifying the number of bytes to copy, and the fourth argument is the alignment
				5484	of the source and destination locations.
				5485	</p>
				5486
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5487	<p>
				5488	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]	5489	the caller guarantees that the source and destination pointers are aligned to
				5490	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5491	</p>
				5492
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5493	<h5>Semantics:</h5>
				5494
				5495	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5496	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]	5497	location to the destination location, which may overlap. It
				5498	copies "len" bytes of memory over. If the argument is known to be aligned to
				5499	some boundary, this can be specified as the fourth argument, otherwise it should
				5500	be set to 0 or 1.
				5501	</p>
				5502	</div>
				5503
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5504
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5505	<!-- _______________________________________________________________________ -->
				5506	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5507	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5508	</div>
				5509
				5510	<div class="doc_text">
				5511
				5512	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5513	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5514	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5515	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5516	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5517	i8 <len>, i32 <align>)
				5518	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5519	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5520	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5521	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5522	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5523	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5524	</pre>
				5525
				5526	<h5>Overview:</h5>
				5527
				5528	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5529	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]	5530	byte value.
				5531	</p>
				5532
				5533	<p>
				5534	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5535	does not return a value, and takes an extra alignment argument.
				5536	</p>
				5537
				5538	<h5>Arguments:</h5>
				5539
				5540	<p>
				5541	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]	5542	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5543	argument specifying the number of bytes to fill, and the fourth argument is the
				5544	known alignment of destination location.
				5545	</p>
				5546
				5547	<p>
				5548	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]	5549	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5550	</p>
				5551
				5552	<h5>Semantics:</h5>
				5553
				5554	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5555	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5556	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5557	destination location. If the argument is known to be aligned to some boundary,
				5558	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5559	1.
				5560	</p>
				5561	</div>
				5562
				5563
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5564	<!-- _______________________________________________________________________ -->
				5565	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5566	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5567	</div>
				5568
				5569	<div class="doc_text">
				5570
				5571	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5572	<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]	5573	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5574	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5575	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5576	declare float @llvm.sqrt.f32(float %Val)
				5577	declare double @llvm.sqrt.f64(double %Val)
				5578	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5579	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5580	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5581	</pre>
				5582
				5583	<h5>Overview:</h5>
				5584
				5585	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5586	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]	5587	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]	5588	<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]	5589	negative numbers other than -0.0 (which allows for better optimization, because
				5590	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5591	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5592	</p>
				5593
				5594	<h5>Arguments:</h5>
				5595
				5596	<p>
				5597	The argument and return value are floating point numbers of the same type.
				5598	</p>
				5599
				5600	<h5>Semantics:</h5>
				5601
				5602	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5603	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]	5604	floating point number.
				5605	</p>
				5606	</div>
				5607
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5608	<!-- _______________________________________________________________________ -->
				5609	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5610	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5611	</div>
				5612
				5613	<div class="doc_text">
				5614
				5615	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5616	<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]	5617	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5618	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5619	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5620	declare float @llvm.powi.f32(float %Val, i32 %power)
				5621	declare double @llvm.powi.f64(double %Val, i32 %power)
				5622	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5623	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5624	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5625	</pre>
				5626
				5627	<h5>Overview:</h5>
				5628
				5629	<p>
				5630	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5631	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5632	multiplications is not defined. When a vector of floating point type is
				5633	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5634	</p>
				5635
				5636	<h5>Arguments:</h5>
				5637
				5638	<p>
				5639	The second argument is an integer power, and the first is a value to raise to
				5640	that power.
				5641	</p>
				5642
				5643	<h5>Semantics:</h5>
				5644
				5645	<p>
				5646	This function returns the first value raised to the second power with an
				5647	unspecified sequence of rounding operations.</p>
				5648	</div>
				5649
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5650	<!-- _______________________________________________________________________ -->
				5651	<div class="doc_subsubsection">
				5652	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5653	</div>
				5654
				5655	<div class="doc_text">
				5656
				5657	<h5>Syntax:</h5>
				5658	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5659	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5660	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5661	<pre>
				5662	declare float @llvm.sin.f32(float %Val)
				5663	declare double @llvm.sin.f64(double %Val)
				5664	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5665	declare fp128 @llvm.sin.f128(fp128 %Val)
				5666	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5667	</pre>
				5668
				5669	<h5>Overview:</h5>
				5670
				5671	<p>
				5672	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5673	</p>
				5674
				5675	<h5>Arguments:</h5>
				5676
				5677	<p>
				5678	The argument and return value are floating point numbers of the same type.
				5679	</p>
				5680
				5681	<h5>Semantics:</h5>
				5682
				5683	<p>
				5684	This function returns the sine of the specified operand, returning the
				5685	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]	5686	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5687	</div>
				5688
				5689	<!-- _______________________________________________________________________ -->
				5690	<div class="doc_subsubsection">
				5691	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5692	</div>
				5693
				5694	<div class="doc_text">
				5695
				5696	<h5>Syntax:</h5>
				5697	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5698	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5699	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5700	<pre>
				5701	declare float @llvm.cos.f32(float %Val)
				5702	declare double @llvm.cos.f64(double %Val)
				5703	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5704	declare fp128 @llvm.cos.f128(fp128 %Val)
				5705	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5706	</pre>
				5707
				5708	<h5>Overview:</h5>
				5709
				5710	<p>
				5711	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5712	</p>
				5713
				5714	<h5>Arguments:</h5>
				5715
				5716	<p>
				5717	The argument and return value are floating point numbers of the same type.
				5718	</p>
				5719
				5720	<h5>Semantics:</h5>
				5721
				5722	<p>
				5723	This function returns the cosine of the specified operand, returning the
				5724	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]	5725	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5726	</div>
				5727
				5728	<!-- _______________________________________________________________________ -->
				5729	<div class="doc_subsubsection">
				5730	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5731	</div>
				5732
				5733	<div class="doc_text">
				5734
				5735	<h5>Syntax:</h5>
				5736	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5737	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5738	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5739	<pre>
				5740	declare float @llvm.pow.f32(float %Val, float %Power)
				5741	declare double @llvm.pow.f64(double %Val, double %Power)
				5742	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5743	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5744	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5745	</pre>
				5746
				5747	<h5>Overview:</h5>
				5748
				5749	<p>
				5750	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5751	specified (positive or negative) power.
				5752	</p>
				5753
				5754	<h5>Arguments:</h5>
				5755
				5756	<p>
				5757	The second argument is a floating point power, and the first is a value to
				5758	raise to that power.
				5759	</p>
				5760
				5761	<h5>Semantics:</h5>
				5762
				5763	<p>
				5764	This function returns the first value raised to the second power,
				5765	returning the
				5766	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]	5767	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5768	</div>
				5769
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5770
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5771	<!-- ======================================================================= -->
				5772	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5773	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5774	</div>
				5775
				5776	<div class="doc_text">
				5777	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5778	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5779	These allow efficient code generation for some algorithms.
				5780	</p>
				5781
				5782	</div>
				5783
				5784	<!-- _______________________________________________________________________ -->
				5785	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5786	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5787	</div>
				5788
				5789	<div class="doc_text">
				5790
				5791	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5792	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5793	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5794	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5795	declare i16 @llvm.bswap.i16(i16 <id>)
				5796	declare i32 @llvm.bswap.i32(i32 <id>)
				5797	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5798	</pre>
				5799
				5800	<h5>Overview:</h5>
				5801
				5802	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5803	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]	5804	values with an even number of bytes (positive multiple of 16 bits). These are
				5805	useful for performing operations on data that is not in the target's native
				5806	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5807	</p>
				5808
				5809	<h5>Semantics:</h5>
				5810
				5811	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5812	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]	5813	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5814	intrinsic returns an i32 value that has the four bytes of the input i32
				5815	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]	5816	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5817	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5818	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5819	</p>
				5820
				5821	</div>
				5822
				5823	<!-- _______________________________________________________________________ -->
				5824	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5825	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5826	</div>
				5827
				5828	<div class="doc_text">
				5829
				5830	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5831	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5832	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5833	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5834	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5835	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5836	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5837	declare i64 @llvm.ctpop.i64(i64 <src>)
				5838	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5839	</pre>
				5840
				5841	<h5>Overview:</h5>
				5842
				5843	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5844	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5845	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5846	</p>
				5847
				5848	<h5>Arguments:</h5>
				5849
				5850	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5851	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]	5852	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5853	</p>
				5854
				5855	<h5>Semantics:</h5>
				5856
				5857	<p>
				5858	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5859	</p>
				5860	</div>
				5861
				5862	<!-- _______________________________________________________________________ -->
				5863	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5864	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5865	</div>
				5866
				5867	<div class="doc_text">
				5868
				5869	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5870	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5871	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5872	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5873	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5874	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5875	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5876	declare i64 @llvm.ctlz.i64(i64 <src>)
				5877	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5878	</pre>
				5879
				5880	<h5>Overview:</h5>
				5881
				5882	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5883	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5884	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5885	</p>
				5886
				5887	<h5>Arguments:</h5>
				5888
				5889	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5890	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]	5891	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5892	</p>
				5893
				5894	<h5>Semantics:</h5>
				5895
				5896	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5897	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5898	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]	5899	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5900	</p>
				5901	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5902
				5903
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5904
				5905	<!-- _______________________________________________________________________ -->
				5906	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5907	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5908	</div>
				5909
				5910	<div class="doc_text">
				5911
				5912	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5913	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5914	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5915	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5916	declare i8 @llvm.cttz.i8 (i8 <src>)
				5917	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5918	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5919	declare i64 @llvm.cttz.i64(i64 <src>)
				5920	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5921	</pre>
				5922
				5923	<h5>Overview:</h5>
				5924
				5925	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5926	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5927	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5928	</p>
				5929
				5930	<h5>Arguments:</h5>
				5931
				5932	<p>
				5933	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]	5934	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5935	</p>
				5936
				5937	<h5>Semantics:</h5>
				5938
				5939	<p>
				5940	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5941	in a variable. If the src == 0 then the result is the size in bits of the type
				5942	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5943	</p>
				5944	</div>
				5945
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5946
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5947	<!-- ======================================================================= -->
				5948	<div class="doc_subsection">
				5949	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5950	</div>
				5951
				5952	<div class="doc_text">
				5953	<p>
				5954	LLVM provides intrinsics for some arithmetic with overflow operations.
				5955	</p>
				5956
				5957	</div>
				5958
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5959	<!-- _______________________________________________________________________ -->
				5960	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5961	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5962	</div>
				5963
				5964	<div class="doc_text">
				5965
				5966	<h5>Syntax:</h5>
				5967
				5968	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5969	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5970
				5971	<pre>
				5972	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5973	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5974	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5975	</pre>
				5976
				5977	<h5>Overview:</h5>
				5978
				5979	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5980	a signed addition of the two arguments, and indicate whether an overflow
				5981	occurred during the signed summation.</p>
				5982
				5983	<h5>Arguments:</h5>
				5984
				5985	<p>The arguments (%a and %b) and the first element of the result structure may
				5986	be of integer types of any bit width, but they must have the same bit width. The
				5987	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				5988	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				5989
				5990	<h5>Semantics:</h5>
				5991
				5992	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5993	a signed addition of the two variables. They return a structure — the
				5994	first element of which is the signed summation, and the second element of which
				5995	is a bit specifying if the signed summation resulted in an overflow.</p>
				5996
				5997	<h5>Examples:</h5>
				5998	<pre>
				5999	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6000	%sum = extractvalue {i32, i1} %res, 0
				6001	%obit = extractvalue {i32, i1} %res, 1
				6002	br i1 %obit, label %overflow, label %normal
				6003	</pre>
				6004
				6005	</div>
				6006
				6007	<!-- _______________________________________________________________________ -->
				6008	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6009	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6010	</div>
				6011
				6012	<div class="doc_text">
				6013
				6014	<h5>Syntax:</h5>
				6015
				6016	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6017	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6018
				6019	<pre>
				6020	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6021	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6022	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6023	</pre>
				6024
				6025	<h5>Overview:</h5>
				6026
				6027	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6028	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6029	during the unsigned summation.</p>
				6030
				6031	<h5>Arguments:</h5>
				6032
				6033	<p>The arguments (%a and %b) and the first element of the result structure may
				6034	be of integer types of any bit width, but they must have the same bit width. The
				6035	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6036	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6037
				6038	<h5>Semantics:</h5>
				6039
				6040	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6041	an unsigned addition of the two arguments. They return a structure — the
				6042	first element of which is the sum, and the second element of which is a bit
				6043	specifying if the unsigned summation resulted in a carry.</p>
				6044
				6045	<h5>Examples:</h5>
				6046	<pre>
				6047	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6048	%sum = extractvalue {i32, i1} %res, 0
				6049	%obit = extractvalue {i32, i1} %res, 1
				6050	br i1 %obit, label %carry, label %normal
				6051	</pre>
				6052
				6053	</div>
				6054
				6055	<!-- _______________________________________________________________________ -->
				6056	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6057	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6058	</div>
				6059
				6060	<div class="doc_text">
				6061
				6062	<h5>Syntax:</h5>
				6063
				6064	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6065	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6066
				6067	<pre>
				6068	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6069	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6070	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6071	</pre>
				6072
				6073	<h5>Overview:</h5>
				6074
				6075	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6076	a signed subtraction of the two arguments, and indicate whether an overflow
				6077	occurred during the signed subtraction.</p>
				6078
				6079	<h5>Arguments:</h5>
				6080
				6081	<p>The arguments (%a and %b) and the first element of the result structure may
				6082	be of integer types of any bit width, but they must have the same bit width. The
				6083	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6084	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6085
				6086	<h5>Semantics:</h5>
				6087
				6088	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6089	a signed subtraction of the two arguments. They return a structure — the
				6090	first element of which is the subtraction, and the second element of which is a bit
				6091	specifying if the signed subtraction resulted in an overflow.</p>
				6092
				6093	<h5>Examples:</h5>
				6094	<pre>
				6095	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6096	%sum = extractvalue {i32, i1} %res, 0
				6097	%obit = extractvalue {i32, i1} %res, 1
				6098	br i1 %obit, label %overflow, label %normal
				6099	</pre>
				6100
				6101	</div>
				6102
				6103	<!-- _______________________________________________________________________ -->
				6104	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6105	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6106	</div>
				6107
				6108	<div class="doc_text">
				6109
				6110	<h5>Syntax:</h5>
				6111
				6112	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6113	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6114
				6115	<pre>
				6116	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6117	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6118	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6119	</pre>
				6120
				6121	<h5>Overview:</h5>
				6122
				6123	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6124	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6125	occurred during the unsigned subtraction.</p>
				6126
				6127	<h5>Arguments:</h5>
				6128
				6129	<p>The arguments (%a and %b) and the first element of the result structure may
				6130	be of integer types of any bit width, but they must have the same bit width. The
				6131	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6132	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6133
				6134	<h5>Semantics:</h5>
				6135
				6136	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6137	an unsigned subtraction of the two arguments. They return a structure — the
				6138	first element of which is the subtraction, and the second element of which is a bit
				6139	specifying if the unsigned subtraction resulted in an overflow.</p>
				6140
				6141	<h5>Examples:</h5>
				6142	<pre>
				6143	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6144	%sum = extractvalue {i32, i1} %res, 0
				6145	%obit = extractvalue {i32, i1} %res, 1
				6146	br i1 %obit, label %overflow, label %normal
				6147	</pre>
				6148
				6149	</div>
				6150
				6151	<!-- _______________________________________________________________________ -->
				6152	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6153	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6154	</div>
				6155
				6156	<div class="doc_text">
				6157
				6158	<h5>Syntax:</h5>
				6159
				6160	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6161	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6162
				6163	<pre>
				6164	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6165	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6166	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6167	</pre>
				6168
				6169	<h5>Overview:</h5>
				6170
				6171	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6172	a signed multiplication of the two arguments, and indicate whether an overflow
				6173	occurred during the signed multiplication.</p>
				6174
				6175	<h5>Arguments:</h5>
				6176
				6177	<p>The arguments (%a and %b) and the first element of the result structure may
				6178	be of integer types of any bit width, but they must have the same bit width. The
				6179	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6180	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6181
				6182	<h5>Semantics:</h5>
				6183
				6184	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6185	a signed multiplication of the two arguments. They return a structure —
				6186	the first element of which is the multiplication, and the second element of
				6187	which is a bit specifying if the signed multiplication resulted in an
				6188	overflow.</p>
				6189
				6190	<h5>Examples:</h5>
				6191	<pre>
				6192	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6193	%sum = extractvalue {i32, i1} %res, 0
				6194	%obit = extractvalue {i32, i1} %res, 1
				6195	br i1 %obit, label %overflow, label %normal
				6196	</pre>
				6197
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6198	</div>
				6199
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6200	<!-- _______________________________________________________________________ -->
				6201	<div class="doc_subsubsection">
				6202	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6203	</div>
				6204
				6205	<div class="doc_text">
				6206
				6207	<h5>Syntax:</h5>
				6208
				6209	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6210	on any integer bit width.</p>
				6211
				6212	<pre>
				6213	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6214	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6215	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6216	</pre>
				6217
				6218	<h5>Overview:</h5>
				6219
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6220	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6221	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6222	occurred during the unsigned multiplication.</p>
				6223
				6224	<h5>Arguments:</h5>
				6225
				6226	<p>The arguments (%a and %b) and the first element of the result structure may
				6227	be of integer types of any bit width, but they must have the same bit width. The
				6228	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6229	and <tt>%b</tt> are the two values that will undergo unsigned
				6230	multiplication.</p>
				6231
				6232	<h5>Semantics:</h5>
				6233
				6234	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6235	an unsigned multiplication of the two arguments. They return a structure —
				6236	the first element of which is the multiplication, and the second element of
				6237	which is a bit specifying if the unsigned multiplication resulted in an
				6238	overflow.</p>
				6239
				6240	<h5>Examples:</h5>
				6241	<pre>
				6242	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6243	%sum = extractvalue {i32, i1} %res, 0
				6244	%obit = extractvalue {i32, i1} %res, 1
				6245	br i1 %obit, label %overflow, label %normal
				6246	</pre>
				6247
				6248	</div>
				6249
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6250	<!-- ======================================================================= -->
				6251	<div class="doc_subsection">
				6252	<a name="int_debugger">Debugger Intrinsics</a>
				6253	</div>
				6254
				6255	<div class="doc_text">
				6256	<p>
				6257	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6258	are described in the <a
				6259	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6260	Debugging</a> document.
				6261	</p>
				6262	</div>
				6263
				6264
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6265	<!-- ======================================================================= -->
				6266	<div class="doc_subsection">
				6267	<a name="int_eh">Exception Handling Intrinsics</a>
				6268	</div>
				6269
				6270	<div class="doc_text">
				6271	<p> The LLVM exception handling intrinsics (which all start with
				6272	<tt>llvm.eh.</tt> prefix), are described in the <a
				6273	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6274	Handling</a> document. </p>
				6275	</div>
				6276
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6277	<!-- ======================================================================= -->
				6278	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6279	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6280	</div>
				6281
				6282	<div class="doc_text">
				6283	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6284	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6285	the <tt>nest</tt> attribute, from a function. The result is a callable
				6286	function pointer lacking the nest parameter - the caller does not need
				6287	to provide a value for it. Instead, the value to use is stored in
				6288	advance in a "trampoline", a block of memory usually allocated
				6289	on the stack, which also contains code to splice the nest value into the
				6290	argument list. This is used to implement the GCC nested function address
				6291	extension.
				6292	</p>
				6293	<p>
				6294	For example, if the function is
				6295	<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]	6296	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]	6297	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6298	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6299	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6300	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6301	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6302	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6303	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6304	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]	6305	</div>
				6306
				6307	<!-- _______________________________________________________________________ -->
				6308	<div class="doc_subsubsection">
				6309	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6310	</div>
				6311	<div class="doc_text">
				6312	<h5>Syntax:</h5>
				6313	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6314	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6315	</pre>
				6316	<h5>Overview:</h5>
				6317	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6318	This fills the memory pointed to by <tt>tramp</tt> with code
				6319	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6320	</p>
				6321	<h5>Arguments:</h5>
				6322	<p>
				6323	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6324	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6325	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]	6326	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6327	currently provides no portable way of determining them, so a front-end that
				6328	generates this intrinsic needs to have some target-specific knowledge.
				6329	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]	6330	</p>
				6331	<h5>Semantics:</h5>
				6332	<p>
				6333	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]	6334	dependent code, turning it into a function. A pointer to this function is
				6335	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6336	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6337	before being called. The new function's signature is the same as that of
				6338	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6339	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6340	of pointer type. Calling the new function is equivalent to calling
				6341	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6342	missing <tt>nest</tt> argument. If, after calling
				6343	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6344	modified, then the effect of any later call to the returned function pointer is
				6345	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6346	</p>
				6347	</div>
				6348
				6349	<!-- ======================================================================= -->
				6350	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6351	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6352	</div>
				6353
				6354	<div class="doc_text">
				6355	<p>
				6356	These intrinsic functions expand the "universal IR" of LLVM to represent
				6357	hardware constructs for atomic operations and memory synchronization. This
				6358	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]	6359	is aimed at a low enough level to allow any programming models or APIs
				6360	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6361	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6362	hardware behavior. Just as hardware provides a "universal IR" for source
				6363	languages, it also provides a starting point for developing a "universal"
				6364	atomic operation and synchronization IR.
				6365	</p>
				6366	<p>
				6367	These do <em>not</em> form an API such as high-level threading libraries,
				6368	software transaction memory systems, atomic primitives, and intrinsic
				6369	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6370	application libraries. The hardware interface provided by LLVM should allow
				6371	a clean implementation of all of these APIs and parallel programming models.
				6372	No one model or paradigm should be selected above others unless the hardware
				6373	itself ubiquitously does so.
				6374
				6375	</p>
				6376	</div>
				6377
				6378	<!-- _______________________________________________________________________ -->
				6379	<div class="doc_subsubsection">
				6380	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6381	</div>
				6382	<div class="doc_text">
				6383	<h5>Syntax:</h5>
				6384	<pre>
				6385	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6386	i1 <device> )
				6387
				6388	</pre>
				6389	<h5>Overview:</h5>
				6390	<p>
				6391	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6392	specific pairs of memory access types.
				6393	</p>
				6394	<h5>Arguments:</h5>
				6395	<p>
				6396	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6397	The first four arguments enables a specific barrier as listed below. The fith
				6398	argument specifies that the barrier applies to io or device or uncached memory.
				6399
				6400	</p>
				6401	<ul>
				6402	<li><tt>ll</tt>: load-load barrier</li>
				6403	<li><tt>ls</tt>: load-store barrier</li>
				6404	<li><tt>sl</tt>: store-load barrier</li>
				6405	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6406	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6407	</ul>
				6408	<h5>Semantics:</h5>
				6409	<p>
				6410	This intrinsic causes the system to enforce some ordering constraints upon
				6411	the loads and stores of the program. This barrier does not indicate
				6412	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6413	which they occur. For any of the specified pairs of load and store operations
				6414	(f.ex. load-load, or store-load), all of the first operations preceding the
				6415	barrier will complete before any of the second operations succeeding the
				6416	barrier begin. Specifically the semantics for each pairing is as follows:
				6417	</p>
				6418	<ul>
				6419	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6420	after the barrier begins.</li>
				6421
				6422	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6423	store after the barrier begins.</li>
				6424	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6425	store after the barrier begins.</li>
				6426	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6427	load after the barrier begins.</li>
				6428	</ul>
				6429	<p>
				6430	These semantics are applied with a logical "and" behavior when more than one
				6431	is enabled in a single memory barrier intrinsic.
				6432	</p>
				6433	<p>
				6434	Backends may implement stronger barriers than those requested when they do not
				6435	support as fine grained a barrier as requested. Some architectures do not
				6436	need all types of barriers and on such architectures, these become noops.
				6437	</p>
				6438	<h5>Example:</h5>
				6439	<pre>
				6440	%ptr = malloc i32
				6441	store i32 4, %ptr
				6442
				6443	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6444	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6445	<i>; guarantee the above finishes</i>
				6446	store i32 8, %ptr <i>; before this begins</i>
				6447	</pre>
				6448	</div>
				6449
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6450	<!-- _______________________________________________________________________ -->
				6451	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6452	<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]	6453	</div>
				6454	<div class="doc_text">
				6455	<h5>Syntax:</h5>
				6456	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6457	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6458	any integer bit width and for different address spaces. Not all targets
				6459	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6460
				6461	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6462	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6463	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6464	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6465	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]	6466
				6467	</pre>
				6468	<h5>Overview:</h5>
				6469	<p>
				6470	This loads a value in memory and compares it to a given value. If they are
				6471	equal, it stores a new value into the memory.
				6472	</p>
				6473	<h5>Arguments:</h5>
				6474	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6475	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]	6476	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6477	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6478	this integer type. While any bit width integer may be used, targets may only
				6479	lower representations they support in hardware.
				6480
				6481	</p>
				6482	<h5>Semantics:</h5>
				6483	<p>
				6484	This entire intrinsic must be executed atomically. It first loads the value
				6485	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6486	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6487	loaded value is yielded in all cases. This provides the equivalent of an
				6488	atomic compare-and-swap operation within the SSA framework.
				6489	</p>
				6490	<h5>Examples:</h5>
				6491
				6492	<pre>
				6493	%ptr = malloc i32
				6494	store i32 4, %ptr
				6495
				6496	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6497	%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]	6498	<i>; yields {i32}:result1 = 4</i>
				6499	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6500	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6501
				6502	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6503	%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]	6504	<i>; yields {i32}:result2 = 8</i>
				6505	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6506
				6507	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6508	</pre>
				6509	</div>
				6510
				6511	<!-- _______________________________________________________________________ -->
				6512	<div class="doc_subsubsection">
				6513	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6514	</div>
				6515	<div class="doc_text">
				6516	<h5>Syntax:</h5>
				6517
				6518	<p>
				6519	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6520	integer bit width. Not all targets support all bit widths however.</p>
				6521	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6522	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6523	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6524	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6525	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6526
				6527	</pre>
				6528	<h5>Overview:</h5>
				6529	<p>
				6530	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6531	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6532	at <tt>ptr</tt>.
				6533	</p>
				6534	<h5>Arguments:</h5>
				6535
				6536	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6537	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6538	<tt>val</tt> argument and the result must be integers of the same bit width.
				6539	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6540	integer type. The targets may only lower integer representations they
				6541	support.
				6542	</p>
				6543	<h5>Semantics:</h5>
				6544	<p>
				6545	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6546	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6547	equivalent of an atomic swap operation within the SSA framework.
				6548
				6549	</p>
				6550	<h5>Examples:</h5>
				6551	<pre>
				6552	%ptr = malloc i32
				6553	store i32 4, %ptr
				6554
				6555	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6556	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6557	<i>; yields {i32}:result1 = 4</i>
				6558	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6559	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6560
				6561	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6562	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6563	<i>; yields {i32}:result2 = 8</i>
				6564
				6565	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6566	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6567	</pre>
				6568	</div>
				6569
				6570	<!-- _______________________________________________________________________ -->
				6571	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6572	<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]	6573
				6574	</div>
				6575	<div class="doc_text">
				6576	<h5>Syntax:</h5>
				6577	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6578	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]	6579	integer bit width. Not all targets support all bit widths however.</p>
				6580	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6581	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6582	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6583	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6584	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6585
				6586	</pre>
				6587	<h5>Overview:</h5>
				6588	<p>
				6589	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6590	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6591	</p>
				6592	<h5>Arguments:</h5>
				6593	<p>
				6594
				6595	The intrinsic takes two arguments, the first a pointer to an integer value
				6596	and the second an integer value. The result is also an integer value. These
				6597	integer types can have any bit width, but they must all have the same bit
				6598	width. The targets may only lower integer representations they support.
				6599	</p>
				6600	<h5>Semantics:</h5>
				6601	<p>
				6602	This intrinsic does a series of operations atomically. It first loads the
				6603	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6604	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6605	</p>
				6606
				6607	<h5>Examples:</h5>
				6608	<pre>
				6609	%ptr = malloc i32
				6610	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6611	%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]	6612	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6613	%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]	6614	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6615	%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]	6616	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6617	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6618	</pre>
				6619	</div>
				6620
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6621	<!-- _______________________________________________________________________ -->
				6622	<div class="doc_subsubsection">
				6623	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6624
				6625	</div>
				6626	<div class="doc_text">
				6627	<h5>Syntax:</h5>
				6628	<p>
				6629	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]	6630	any integer bit width and for different address spaces. Not all targets
				6631	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6632	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6633	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6634	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6635	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6636	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]	6637
				6638	</pre>
				6639	<h5>Overview:</h5>
				6640	<p>
				6641	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6642	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6643	</p>
				6644	<h5>Arguments:</h5>
				6645	<p>
				6646
				6647	The intrinsic takes two arguments, the first a pointer to an integer value
				6648	and the second an integer value. The result is also an integer value. These
				6649	integer types can have any bit width, but they must all have the same bit
				6650	width. The targets may only lower integer representations they support.
				6651	</p>
				6652	<h5>Semantics:</h5>
				6653	<p>
				6654	This intrinsic does a series of operations atomically. It first loads the
				6655	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6656	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6657	</p>
				6658
				6659	<h5>Examples:</h5>
				6660	<pre>
				6661	%ptr = malloc i32
				6662	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6663	%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]	6664	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6665	%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]	6666	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6667	%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]	6668	<i>; yields {i32}:result3 = 2</i>
				6669	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6670	</pre>
				6671	</div>
				6672
				6673	<!-- _______________________________________________________________________ -->
				6674	<div class="doc_subsubsection">
				6675	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6676	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6677	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6678	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6679
				6680	</div>
				6681	<div class="doc_text">
				6682	<h5>Syntax:</h5>
				6683	<p>
				6684	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6685	<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]	6686	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6687	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6688	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6689	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6690	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6691	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6692	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]	6693
				6694	</pre>
				6695
				6696	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6697	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6698	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6699	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6700	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]	6701
				6702	</pre>
				6703
				6704	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6705	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6706	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6707	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6708	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]	6709
				6710	</pre>
				6711
				6712	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6713	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6714	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6715	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6716	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]	6717
				6718	</pre>
				6719	<h5>Overview:</h5>
				6720	<p>
				6721	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6722	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6723	at <tt>ptr</tt>.
				6724	</p>
				6725	<h5>Arguments:</h5>
				6726	<p>
				6727
				6728	These intrinsics take two arguments, the first a pointer to an integer value
				6729	and the second an integer value. The result is also an integer value. These
				6730	integer types can have any bit width, but they must all have the same bit
				6731	width. The targets may only lower integer representations they support.
				6732	</p>
				6733	<h5>Semantics:</h5>
				6734	<p>
				6735	These intrinsics does a series of operations atomically. They first load the
				6736	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6737	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6738	value stored at <tt>ptr</tt>.
				6739	</p>
				6740
				6741	<h5>Examples:</h5>
				6742	<pre>
				6743	%ptr = malloc i32
				6744	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6745	%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]	6746	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6747	%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]	6748	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6749	%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]	6750	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6751	%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]	6752	<i>; yields {i32}:result3 = FF</i>
				6753	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6754	</pre>
				6755	</div>
				6756
				6757
				6758	<!-- _______________________________________________________________________ -->
				6759	<div class="doc_subsubsection">
				6760	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6761	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6762	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6763	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6764
				6765	</div>
				6766	<div class="doc_text">
				6767	<h5>Syntax:</h5>
				6768	<p>
				6769	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6770	<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]	6771	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6772	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6773	support all bit widths however.</p>
				6774	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6775	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6776	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6777	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6778	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]	6779
				6780	</pre>
				6781
				6782	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6783	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6784	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6785	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6786	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]	6787
				6788	</pre>
				6789
				6790	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6791	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6792	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6793	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6794	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]	6795
				6796	</pre>
				6797
				6798	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6799	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6800	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6801	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6802	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]	6803
				6804	</pre>
				6805	<h5>Overview:</h5>
				6806	<p>
				6807	These intrinsics takes the signed or unsigned minimum or maximum of
				6808	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6809	original value at <tt>ptr</tt>.
				6810	</p>
				6811	<h5>Arguments:</h5>
				6812	<p>
				6813
				6814	These intrinsics take two arguments, the first a pointer to an integer value
				6815	and the second an integer value. The result is also an integer value. These
				6816	integer types can have any bit width, but they must all have the same bit
				6817	width. The targets may only lower integer representations they support.
				6818	</p>
				6819	<h5>Semantics:</h5>
				6820	<p>
				6821	These intrinsics does a series of operations atomically. They first load the
				6822	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6823	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6824	the original value stored at <tt>ptr</tt>.
				6825	</p>
				6826
				6827	<h5>Examples:</h5>
				6828	<pre>
				6829	%ptr = malloc i32
				6830	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6831	%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]	6832	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6833	%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]	6834	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6835	%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]	6836	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6837	%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]	6838	<i>; yields {i32}:result3 = 8</i>
				6839	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6840	</pre>
				6841	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6842
				6843	<!-- ======================================================================= -->
				6844	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6845	<a name="int_general">General Intrinsics</a>
				6846	</div>
				6847
				6848	<div class="doc_text">
				6849	<p> This class of intrinsics is designed to be generic and has
				6850	no specific purpose. </p>
				6851	</div>
				6852
				6853	<!-- _______________________________________________________________________ -->
				6854	<div class="doc_subsubsection">
				6855	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6856	</div>
				6857
				6858	<div class="doc_text">
				6859
				6860	<h5>Syntax:</h5>
				6861	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6862	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]	6863	</pre>
				6864
				6865	<h5>Overview:</h5>
				6866
				6867	<p>
				6868	The '<tt>llvm.var.annotation</tt>' intrinsic
				6869	</p>
				6870
				6871	<h5>Arguments:</h5>
				6872
				6873	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6874	The first argument is a pointer to a value, the second is a pointer to a
				6875	global string, the third is a pointer to a global string which is the source
				6876	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6877	</p>
				6878
				6879	<h5>Semantics:</h5>
				6880
				6881	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6882	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6883	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]	6884	annotations. These have no other defined use, they are ignored by code
				6885	generation and optimization.
				6886	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6887	</div>
				6888
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6889	<!-- _______________________________________________________________________ -->
				6890	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6891	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6892	</div>
				6893
				6894	<div class="doc_text">
				6895
				6896	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6897	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6898	any integer bit width.
				6899	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6900	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6901	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6902	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6903	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6904	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6905	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]	6906	</pre>
				6907
				6908	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6909
				6910	<p>
				6911	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6912	</p>
				6913
				6914	<h5>Arguments:</h5>
				6915
				6916	<p>
				6917	The first argument is an integer value (result of some expression),
				6918	the second is a pointer to a global string, the third is a pointer to a global
				6919	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]	6920	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6921	</p>
				6922
				6923	<h5>Semantics:</h5>
				6924
				6925	<p>
				6926	This intrinsic allows annotations to be put on arbitrary expressions
				6927	with arbitrary strings. This can be useful for special purpose optimizations
				6928	that want to look for these annotations. These have no other defined use, they
				6929	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6930	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6931	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6932
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6933	<!-- _______________________________________________________________________ -->
				6934	<div class="doc_subsubsection">
				6935	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6936	</div>
				6937
				6938	<div class="doc_text">
				6939
				6940	<h5>Syntax:</h5>
				6941	<pre>
				6942	declare void @llvm.trap()
				6943	</pre>
				6944
				6945	<h5>Overview:</h5>
				6946
				6947	<p>
				6948	The '<tt>llvm.trap</tt>' intrinsic
				6949	</p>
				6950
				6951	<h5>Arguments:</h5>
				6952
				6953	<p>
				6954	None
				6955	</p>
				6956
				6957	<h5>Semantics:</h5>
				6958
				6959	<p>
				6960	This intrinsics is lowered to the target dependent trap instruction. If the
				6961	target does not have a trap instruction, this intrinsic will be lowered to the
				6962	call of the abort() function.
				6963	</p>
				6964	</div>
				6965
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6966	<!-- _______________________________________________________________________ -->
				6967	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	6968	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6969	</div>
				6970	<div class="doc_text">
				6971	<h5>Syntax:</h5>
				6972	<pre>
				6973	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6974
				6975	</pre>
				6976	<h5>Overview:</h5>
				6977	<p>
				6978	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				6979	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				6980	it is placed on the stack before local variables.
				6981	</p>
				6982	<h5>Arguments:</h5>
				6983	<p>
				6984	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				6985	first argument is the value loaded from the stack guard
				6986	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				6987	has enough space to hold the value of the guard.
				6988	</p>
				6989	<h5>Semantics:</h5>
				6990	<p>
				6991	This intrinsic causes the prologue/epilogue inserter to force the position of
				6992	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				6993	stack. This is to ensure that if a local variable on the stack is overwritten,
				6994	it will destroy the value of the guard. When the function exits, the guard on
				6995	the stack is checked against the original guard. If they're different, then
				6996	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				6997	</p>
				6998	</div>
				6999
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7000	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7001	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7002	<address>
				7003	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7004	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7005	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7006	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7007
				7008	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7009	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7010	Last modified: $Date$
				7011	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7012
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7013	</body>
				7014	</html>