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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>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	158	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				159	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	161	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	163	<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]	164	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	166	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	168	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	169	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	170	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				171	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				173	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				174	<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]	175	</ol>
				176	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	177	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				178	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				180	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				181	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	182	</ol>
				183	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	184	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				185	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	186	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				187	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				188	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				189	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				190	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				191	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				192	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	193	</ol>
				194	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	195	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				196	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	197	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	202	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				203	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				204	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	205	</ol>
				206	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	207	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	208	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	209	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	210	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				211	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				212	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	213	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				214	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	215	</ol>
				216	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	217	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				218	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	219	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				220	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				221	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				222	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				223	<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]	224	<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]	225	</ol>
				226	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	227	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	228	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	229	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	230	<ol>
				231	<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]	232	</ol>
				233	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	234	<li><a href="#int_atomics">Atomic intrinsics</a>
				235	<ol>
				236	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				237	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				238	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				239	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				240	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				241	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				242	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				243	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				244	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				245	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				246	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				247	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				248	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				249	</ol>
				250	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	251	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	252	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	253	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	255	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	256	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	257	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	258	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				259	<li><a href="#int_stackprotector">
				260	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	261	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	262	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	263	</ol>
				264	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	265	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	266
				267	<div class="doc_author">
				268	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				269	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	270	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	272	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				274	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	275
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	276	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	278	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	279	type safety, low-level operations, flexibility, and the capability of
				280	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	281	representation used throughout all phases of the LLVM compilation
				282	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				287	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	289	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	290
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	291	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	292	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]	293	representation (suitable for fast loading by a Just-In-Time compiler),
				294	and as a human readable assembly language representation. This allows
				295	LLVM to provide a powerful intermediate representation for efficient
				296	compiler transformations and analysis, while providing a natural means
				297	to debug and visualize the transformations. The three different forms
				298	of LLVM are all equivalent. This document describes the human readable
				299	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	300
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	301	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	302	while being expressive, typed, and extensible at the same time. It
				303	aims to be a "universal IR" of sorts, by being at a low enough level
				304	that high-level ideas may be cleanly mapped to it (similar to how
				305	microprocessors are "universal IR's", allowing many source languages to
				306	be mapped to them). By providing type information, LLVM can be used as
				307	the target of optimizations: for example, through pointer analysis, it
				308	can be proven that a C automatic variable is never accessed outside of
				309	the current function... allowing it to be promoted to a simple SSA
				310	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	312	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	316
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	317	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	319	<p>It is important to note that this document describes 'well formed'
				320	LLVM assembly language. There is a difference between what the parser
				321	accepts and what is considered 'well formed'. For example, the
				322	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	326	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	328	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	329
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	330	<p>...because the definition of <tt>%x</tt> does not dominate all of
				331	its uses. The LLVM infrastructure provides a verification pass that may
				332	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]	333	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	334	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	335	by the verifier pass indicate bugs in transformation passes or input to
				336	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	337	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	338
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	339	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	341	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	342	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	343	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	344
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	345	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<p>LLVM identifiers come in two basic types: global and local. Global
				348	identifiers (functions, global variables) begin with the @ character. Local
				349	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	350	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	351
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	352	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	353	<li>Named values are represented as a string of characters with their prefix.
				354	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				355	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]	356	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	357	with quotes. Special characters may be escaped using "\xx" where xx is the
				358	ASCII code for the character in hexadecimal. In this way, any character can
				359	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	361	<li>Unnamed values are represented as an unsigned numeric value with their
				362	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	364	<li>Constants, which are described in a <a href="#constants">section about
				365	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	366	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	368	<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]	369	don't need to worry about name clashes with reserved words, and the set of
				370	reserved words may be expanded in the future without penalty. Additionally,
				371	unnamed identifiers allow a compiler to quickly come up with a temporary
				372	variable without having to avoid symbol table conflicts.</p>
				373
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	374	<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]	375	languages. There are keywords for different opcodes
				376	('<tt><a href="#i_add">add</a></tt>',
				377	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				378	'<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]	379	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]	380	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	381	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382
				383	<p>Here is an example of LLVM code to multiply the integer variable
				384	'<tt>%X</tt>' by 8:</p>
				385
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	386	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	394	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	398	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	404	<div class="doc_code">
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	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				407	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				408	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	409	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	410	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	412	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				413	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	414
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	415	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	416
				417	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				418	line.</li>
				419
				420	<li>Unnamed temporaries are created when the result of a computation is not
				421	assigned to a named value.</li>
				422
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	423	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	425	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	426
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	427	<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]	428	demonstrating instructions, we will follow an instruction with a comment that
				429	defines the type and name of value produced. Comments are shown in italic
				430	text.</p>
				431
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	432	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	433
				434	<!-- *********************************************************************** -->
				435	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				436	<!-- *********************************************************************** -->
				437
				438	<!-- ======================================================================= -->
				439	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				440	</div>
				441
				442	<div class="doc_text">
				443
				444	<p>LLVM programs are composed of "Module"s, each of which is a
				445	translation unit of the input programs. Each module consists of
				446	functions, global variables, and symbol table entries. Modules may be
				447	combined together with the LLVM linker, which merges function (and
				448	global variable) definitions, resolves forward declarations, and merges
				449	symbol table entries. Here is an example of the "hello world" module:</p>
				450
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	451	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	452	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				454	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]	455
				456	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	457	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458
				459	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	460	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	461	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	462	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	463	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]	464
				465	<i>; Call puts function to write out the string to stdout...</i>
				466	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	467	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	469	href="#i_ret">ret</a> i32 0<br>}<br>
				470	</pre>
				471	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	472
				473	<p>This example is made up of a <a href="#globalvars">global variable</a>
				474	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				475	function, and a <a href="#functionstructure">function definition</a>
				476	for "<tt>main</tt>".</p>
				477
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478	<p>In general, a module is made up of a list of global values,
				479	where both functions and global variables are global values. Global values are
				480	represented by a pointer to a memory location (in this case, a pointer to an
				481	array of char, and a pointer to a function), and have one of the following <a
				482	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	483
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	484	</div>
				485
				486	<!-- ======================================================================= -->
				487	<div class="doc_subsection">
				488	<a name="linkage">Linkage Types</a>
				489	</div>
				490
				491	<div class="doc_text">
				492
				493	<p>
				494	All Global Variables and Functions have one of the following types of linkage:
				495	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496
				497	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	498
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	499	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				500
				501	<dd>Global values with private linkage are only directly accessible by
				502	objects in the current module. In particular, linking code into a module with
				503	an private global value may cause the private to be renamed as necessary to
				504	avoid collisions. Because the symbol is private to the module, all
				505	references can be updated. This doesn't show up in any symbol table in the
				506	object file.
				507	</dd>
				508
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	511	<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]	512	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]	513	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	516	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				517	</dt>
				518
				519	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				520	into the object file corresponding to the LLVM module. They exist to
				521	allow inlining and other optimizations to take place given knowledge of the
				522	definition of the global, which is known to be somewhere outside the module.
				523	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				524	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				525	type is only allowed on definitions, not declarations.</dd>
				526
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	527	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	528
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	529	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				530	the same name when linkage occurs. This is typically used to implement
				531	inline functions, templates, or other code which must be generated in each
				532	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				533	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	534	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	535
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	536	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				537
				538	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				539	linkage, except that unreferenced <tt>common</tt> globals may not be
				540	discarded. This is used for globals that may be emitted in multiple
				541	translation units, but that are not guaranteed to be emitted into every
				542	translation unit that uses them. One example of this is tentative
				543	definitions in C, such as "<tt>int X;</tt>" at global scope.
				544	</dd>
				545
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	547
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	548	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				549	that some targets may choose to emit different assembly sequences for them
				550	for target-dependent reasons. This is used for globals that are declared
				551	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	552	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	553
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	555
				556	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				557	pointer to array type. When two global variables with appending linkage are
				558	linked together, the two global arrays are appended together. This is the
				559	LLVM, typesafe, equivalent of having the system linker append together
				560	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	561	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	562
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	563	<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]	564
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	565	<dd>The semantics of this linkage follow the ELF object file model: the
				566	symbol is weak until linked, if not linked, the symbol becomes null instead
				567	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	568	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	569
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	570	<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]	571	<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]	572	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	573	functions with different semantics. Other languages, such as <tt>C++</tt>,
				574	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	575	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	576	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				577	be merged with equivalent globals. These linkage types are otherwise the
				578	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	579	</dd>
				580
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	581	<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]	582
				583	<dd>If none of the above identifiers are used, the global is externally
				584	visible, meaning that it participates in linkage and can be used to resolve
				585	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	586	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	587	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	588
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	589	<p>
				590	The next two types of linkage are targeted for Microsoft Windows platform
				591	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	592	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	593	</p>
				594
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	595	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	596	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				597
				598	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				599	or variable via a global pointer to a pointer that is set up by the DLL
				600	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	601	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	602	</dd>
				603
				604	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				605
				606	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				607	pointer to a pointer in a DLL, so that it can be referenced with the
				608	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	609	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]	610	name.
				611	</dd>
				612
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	613	</dl>
				614
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	615	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	616	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				617	variable and was linked with this one, one of the two would be renamed,
				618	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				619	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	620	outside of the current module.</p>
				621	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	622	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				623	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	624	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				625	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	630	<a name="callingconv">Calling Conventions</a>
				631	</div>
				632
				633	<div class="doc_text">
				634
				635	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				636	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				637	specified for the call. The calling convention of any pair of dynamic
				638	caller/callee must match, or the behavior of the program is undefined. The
				639	following calling conventions are supported by LLVM, and more may be added in
				640	the future:</p>
				641
				642	<dl>
				643	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				644
				645	<dd>This calling convention (the default if no other calling convention is
				646	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	647	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	648	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	649	</dd>
				650
				651	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				652
				653	<dd>This calling convention attempts to make calls as fast as possible
				654	(e.g. by passing things in registers). This calling convention allows the
				655	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]	656	without having to conform to an externally specified ABI (Application Binary
				657	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	658	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				659	supported. This calling convention does not support varargs and requires the
				660	prototype of all callees to exactly match the prototype of the function
				661	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	662	</dd>
				663
				664	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				665
				666	<dd>This calling convention attempts to make code in the caller as efficient
				667	as possible under the assumption that the call is not commonly executed. As
				668	such, these calls often preserve all registers so that the call does not break
				669	any live ranges in the caller side. This calling convention does not support
				670	varargs and requires the prototype of all callees to exactly match the
				671	prototype of the function definition.
				672	</dd>
				673
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	674	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	675
				676	<dd>Any calling convention may be specified by number, allowing
				677	target-specific calling conventions to be used. Target specific calling
				678	conventions start at 64.
				679	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	680	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	681
				682	<p>More calling conventions can be added/defined on an as-needed basis, to
				683	support pascal conventions or any other well-known target-independent
				684	convention.</p>
				685
				686	</div>
				687
				688	<!-- ======================================================================= -->
				689	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	690	<a name="visibility">Visibility Styles</a>
				691	</div>
				692
				693	<div class="doc_text">
				694
				695	<p>
				696	All Global Variables and Functions have one of the following visibility styles:
				697	</p>
				698
				699	<dl>
				700	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				701
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	702	<dd>On targets that use the ELF object file format, default visibility means
				703	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	704	modules and, in shared libraries, means that the declared entity may be
				705	overridden. On Darwin, default visibility means that the declaration is
				706	visible to other modules. Default visibility corresponds to "external
				707	linkage" in the language.
				708	</dd>
				709
				710	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				711
				712	<dd>Two declarations of an object with hidden visibility refer to the same
				713	object if they are in the same shared object. Usually, hidden visibility
				714	indicates that the symbol will not be placed into the dynamic symbol table,
				715	so no other module (executable or shared library) can reference it
				716	directly.
				717	</dd>
				718
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	719	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				720
				721	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				722	the dynamic symbol table, but that references within the defining module will
				723	bind to the local symbol. That is, the symbol cannot be overridden by another
				724	module.
				725	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	726	</dl>
				727
				728	</div>
				729
				730	<!-- ======================================================================= -->
				731	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	732	<a name="namedtypes">Named Types</a>
				733	</div>
				734
				735	<div class="doc_text">
				736
				737	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				738	it easier to read the IR and make the IR more condensed (particularly when
				739	recursive types are involved). An example of a name specification is:
				740	</p>
				741
				742	<div class="doc_code">
				743	<pre>
				744	%mytype = type { %mytype*, i32 }
				745	</pre>
				746	</div>
				747
				748	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				749	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				750	expected with the syntax "%mytype".</p>
				751
				752	<p>Note that type names are aliases for the structural type that they indicate,
				753	and that you can therefore specify multiple names for the same type. This often
				754	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				755	structural typing, the name is not part of the type. When printing out LLVM IR,
				756	the printer will pick <em>one name</em> to render all types of a particular
				757	shape. This means that if you have code where two different source types end up
				758	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				759	unexpected type. This is an important design point and isn't going to
				760	change.</p>
				761
				762	</div>
				763
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	764	<!-- ======================================================================= -->
				765	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	766	<a name="globalvars">Global Variables</a>
				767	</div>
				768
				769	<div class="doc_text">
				770
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	771	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	772	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	773	an explicit section to be placed in, and may have an optional explicit alignment
				774	specified. A variable may be defined as "thread_local", which means that it
				775	will not be shared by threads (each thread will have a separated copy of the
				776	variable). A variable may be defined as a global "constant," which indicates
				777	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]	778	optimization, allowing the global data to be placed in the read-only section of
				779	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	780	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]	781
				782	<p>
				783	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				784	constant, even if the final definition of the global is not. This capability
				785	can be used to enable slightly better optimization of the program, but requires
				786	the language definition to guarantee that optimizations based on the
				787	'constantness' are valid for the translation units that do not include the
				788	definition.
				789	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	790
				791	<p>As SSA values, global variables define pointer values that are in
				792	scope (i.e. they dominate) all basic blocks in the program. Global
				793	variables always define a pointer to their "content" type because they
				794	describe a region of memory, and all memory objects in LLVM are
				795	accessed through pointers.</p>
				796
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	797	<p>A global variable may be declared to reside in a target-specifc numbered
				798	address space. For targets that support them, address spaces may affect how
				799	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	800	the variable. The default address space is zero. The address space qualifier
				801	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	802
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	803	<p>LLVM allows an explicit section to be specified for globals. If the target
				804	supports it, it will emit globals to the section specified.</p>
				805
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	806	<p>An explicit alignment may be specified for a global. If not present, or if
				807	the alignment is set to zero, the alignment of the global is set by the target
				808	to whatever it feels convenient. If an explicit alignment is specified, the
				809	global is forced to have at least that much alignment. All alignments must be
				810	a power of 2.</p>
				811
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	812	<p>For example, the following defines a global in a numbered address space with
				813	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	815	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	817	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	818	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	819	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	820
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	821	</div>
				822
				823
				824	<!-- ======================================================================= -->
				825	<div class="doc_subsection">
				826	<a name="functionstructure">Functions</a>
				827	</div>
				828
				829	<div class="doc_text">
				830
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				832	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	833	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	834	<a href="#callingconv">calling convention</a>, a return type, an optional
				835	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				836	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	837	<a href="#paramattrs">parameter attributes</a>), optional
				838	<a href="#fnattrs">function attributes</a>, an optional section,
				839	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	840	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]	841
				842	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				843	optional <a href="#linkage">linkage type</a>, an optional
				844	<a href="#visibility">visibility style</a>, an optional
				845	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	846	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	847	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]	848	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	849
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	850	<p>A function definition contains a list of basic blocks, forming the CFG
				851	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	852	the function. Each basic block may optionally start with a label (giving the
				853	basic block a symbol table entry), contains a list of instructions, and ends
				854	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				855	function return).</p>
				856
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	857	<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]	858	executed on entrance to the function, and it is not allowed to have predecessor
				859	basic blocks (i.e. there can not be any branches to the entry block of a
				860	function). Because the block can have no predecessors, it also cannot have any
				861	<a href="#i_phi">PHI nodes</a>.</p>
				862
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	863	<p>LLVM allows an explicit section to be specified for functions. If the target
				864	supports it, it will emit functions to the section specified.</p>
				865
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	866	<p>An explicit alignment may be specified for a function. If not present, or if
				867	the alignment is set to zero, the alignment of the function is set by the target
				868	to whatever it feels convenient. If an explicit alignment is specified, the
				869	function is forced to have at least that much alignment. All alignments must be
				870	a power of 2.</p>
				871
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	872	<h5>Syntax:</h5>
				873
				874	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	875	<tt>
				876	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				877	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				878	<ResultType> @<FunctionName> ([argument list])
				879	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				880	[<a href="#gc">gc</a>] { ... }
				881	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	882	</div>
				883
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	884	</div>
				885
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	886
				887	<!-- ======================================================================= -->
				888	<div class="doc_subsection">
				889	<a name="aliasstructure">Aliases</a>
				890	</div>
				891	<div class="doc_text">
				892	<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]	893	function, global variable, another alias or bitcast of global value). Aliases
				894	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	895	optional <a href="#visibility">visibility style</a>.</p>
				896
				897	<h5>Syntax:</h5>
				898
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	899	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	900	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	901	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	902	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	903	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	904
				905	</div>
				906
				907
				908
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	909	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	910	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				911	<div class="doc_text">
				912	<p>The return type and each parameter of a function type may have a set of
				913	<i>parameter attributes</i> associated with them. Parameter attributes are
				914	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	915	a function. Parameter attributes are considered to be part of the function,
				916	not of the function type, so functions with different parameter attributes
				917	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	918
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	919	<p>Parameter attributes are simple keywords that follow the type specified. If
				920	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	921	example:</p>
				922
				923	<div class="doc_code">
				924	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	925	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	926	declare i32 @atoi(i8 zeroext)
				927	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	928	</pre>
				929	</div>
				930
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	931	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				932	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	933
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	934	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	935	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	936	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	937	<dd>This indicates to the code generator that the parameter or return value
				938	should be zero-extended to a 32-bit value by the caller (for a parameter)
				939	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	940
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	941	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	942	<dd>This indicates to the code generator that the parameter or return value
				943	should be sign-extended to a 32-bit value by the caller (for a parameter)
				944	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	945
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	946	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	947	<dd>This indicates that this parameter or return value should be treated
				948	in a special target-dependent fashion during while emitting code for a
				949	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]	950	to memory, though some targets use it to distinguish between two different
				951	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	952
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	953	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	954	<dd>This indicates that the pointer parameter should really be passed by
				955	value to the function. The attribute implies that a hidden copy of the
				956	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]	957	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]	958	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	959	value, but is also valid on pointers to scalars. The copy is considered to
				960	belong to the caller not the callee (for example,
				961	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	962	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	963	values. The byval attribute also supports specifying an alignment with the
				964	align attribute. This has a target-specific effect on the code generator
				965	that usually indicates a desired alignment for the synthesized stack
				966	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	967
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	968	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	969	<dd>This indicates that the pointer parameter specifies the address of a
				970	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]	971	This pointer must be guaranteed by the caller to be valid: loads and stores
				972	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]	973	be applied to the first parameter. This is not a valid attribute for
				974	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	975
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	976	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	977	<dd>This indicates that the pointer does not alias any global or any other
				978	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	979	case. On a function return value, <tt>noalias</tt> additionally indicates
				980	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	981	caller. For further details, please see the discussion of the NoAlias
				982	response in
				983	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				984	analysis</a>.</dd>
				985
				986	<dt><tt>nocapture</tt></dt>
				987	<dd>This indicates that the callee does not make any copies of the pointer
				988	that outlive the callee itself. This is not a valid attribute for return
				989	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	990
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	991	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	992	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	993	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				994	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	995	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	996
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	997	</div>
				998
				999	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1000	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	1001	<a name="gc">Garbage Collector Names</a>
				1002	</div>
				1003
				1004	<div class="doc_text">
				1005	<p>Each function may specify a garbage collector name, which is simply a
				1006	string.</p>
				1007
				1008	<div class="doc_code"><pre
				1009	>define void @f() gc "name" { ...</pre></div>
				1010
				1011	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1012	collector which will cause the compiler to alter its output in order to support
				1013	the named garbage collection algorithm.</p>
				1014	</div>
				1015
				1016	<!-- ======================================================================= -->
				1017	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1018	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1019	</div>
				1020
				1021	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1022
				1023	<p>Function attributes are set to communicate additional information about
				1024	a function. Function attributes are considered to be part of the function,
				1025	not of the function type, so functions with different parameter attributes
				1026	can have the same function type.</p>
				1027
				1028	<p>Function attributes are simple keywords that follow the type specified. If
				1029	multiple attributes are needed, they are space separated. For
				1030	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1031
				1032	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1033	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1034	define void @f() noinline { ... }
				1035	define void @f() alwaysinline { ... }
				1036	define void @f() alwaysinline optsize { ... }
				1037	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1039	</div>
				1040
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1041	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1042	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1043	<dd>This attribute indicates that the inliner should attempt to inline this
				1044	function into callers whenever possible, ignoring any active inlining size
				1045	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1046
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1047	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1049	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1051
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1052	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1053	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	make choices that keep the code size of this function low, and otherwise do
				1055	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1056
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1057	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1058	<dd>This function attribute indicates that the function never returns normally.
				1059	This produces undefined behavior at runtime if the function ever does
				1060	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1061
				1062	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1063	<dd>This function attribute indicates that the function never returns with an
				1064	unwind or exceptional control flow. If the function does unwind, its runtime
				1065	behavior is undefined.</dd>
				1066
				1067	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1068	<dd>This attribute indicates that the function computes its result (or decides to
				1069	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1070	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1071	registers, etc) visible to caller functions. It does not write through any
				1072	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1073	never changes any state visible to callers. This means that it cannot unwind
				1074	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1075	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1076
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1077	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1078	<dd>This attribute indicates that the function does not write through any
				1079	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1080	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1081	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1082	be set in the caller. A readonly function always returns the same value (or
				1083	unwinds an exception identically) when called with the same set of arguments
				1084	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1085	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
				1087	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1089	protector. It is in the form of a "canary"—a random value placed on the
				1090	stack before the local variables that's checked upon return from the function to
				1091	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]	1092	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1093
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1094	<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]	1095	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]	1096	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1097
				1098	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1099	<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]	1100	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]	1101	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1102
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1103	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]	1104	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1105	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1106	an <tt>sspreq</tt> attribute.</dd>
				1107
				1108	<dt><tt>noredzone</tt></dt>
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1109	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	125473b	2009-06-15 21:18:01 +0000	[diff] [blame^]	1110	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1111	</dd>
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1112
				1113	<dt><tt>noimplicitfloat</tt></dt>
				1114	<dd>This attributes disables implicit floating point instructions.</dd>
				1115
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1116	</dl>
				1117
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1118	</div>
				1119
				1120	<!-- ======================================================================= -->
				1121	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1122	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1123	</div>
				1124
				1125	<div class="doc_text">
				1126	<p>
				1127	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1128	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1129	LLVM and treated as a single unit, but may be separated in the .ll file if
				1130	desired. The syntax is very simple:
				1131	</p>
				1132
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1133	<div class="doc_code">
				1134	<pre>
				1135	module asm "inline asm code goes here"
				1136	module asm "more can go here"
				1137	</pre>
				1138	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1139
				1140	<p>The strings can contain any character by escaping non-printable characters.
				1141	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1142	for the number.
				1143	</p>
				1144
				1145	<p>
				1146	The inline asm code is simply printed to the machine code .s file when
				1147	assembly code is generated.
				1148	</p>
				1149	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1150
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1151	<!-- ======================================================================= -->
				1152	<div class="doc_subsection">
				1153	<a name="datalayout">Data Layout</a>
				1154	</div>
				1155
				1156	<div class="doc_text">
				1157	<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]	1158	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1159	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1160	<p>The <i>layout specification</i> consists of a list of specifications
				1161	separated by the minus sign character ('-'). Each specification starts with a
				1162	letter and may include other information after the letter to define some
				1163	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1164	<dl>
				1165	<dt><tt>E</tt></dt>
				1166	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1167	bits with the most significance have the lowest address location.</dd>
				1168	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1169	<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]	1170	the bits with the least significance have the lowest address location.</dd>
				1171	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1172	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1173	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1174	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1175	too.</dd>
				1176	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1177	<dd>This specifies the alignment for an integer type of a given bit
				1178	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1179	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1180	<dd>This specifies the alignment for a vector type of a given bit
				1181	<i>size</i>.</dd>
				1182	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1183	<dd>This specifies the alignment for a floating point type of a given bit
				1184	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1185	(double).</dd>
				1186	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1187	<dd>This specifies the alignment for an aggregate type of a given bit
				1188	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1189	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1190	<dd>This specifies the alignment for a stack object of a given bit
				1191	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1192	</dl>
				1193	<p>When constructing the data layout for a given target, LLVM starts with a
				1194	default set of specifications which are then (possibly) overriden by the
				1195	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1196	are given in this list:</p>
				1197	<ul>
				1198	<li><tt>E</tt> - big endian</li>
				1199	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1200	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1201	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1202	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1203	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1204	<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]	1205	alignment of 64-bits</li>
				1206	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1207	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1208	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1209	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1210	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1211	<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]	1212	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1213	<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]	1214	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1215	<ol>
				1216	<li>If the type sought is an exact match for one of the specifications, that
				1217	specification is used.</li>
				1218	<li>If no match is found, and the type sought is an integer type, then the
				1219	smallest integer type that is larger than the bitwidth of the sought type is
				1220	used. If none of the specifications are larger than the bitwidth then the the
				1221	largest integer type is used. For example, given the default specifications
				1222	above, the i7 type will use the alignment of i8 (next largest) while both
				1223	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1224	<li>If no match is found, and the type sought is a vector type, then the
				1225	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]	1226	as a fall back. This happens because <128 x double> can be implemented
				1227	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1228	</ol>
				1229	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1230
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1231	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1232	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1233	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1234
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1236
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1237	<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]	1238	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1239	optimizations to be performed on the intermediate representation directly,
				1240	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	extra analyses on the side before the transformation. A strong type
				1242	system makes it easier to read the generated code and enables novel
				1243	analyses and transformations that are not feasible to perform on normal
				1244	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1245
				1246	</div>
				1247
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1248	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1249	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1250	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1251	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1252	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1253	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1254
				1255	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1257	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1258	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1259	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1260	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1261	</tr>
				1262	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1263	<td><a href="#t_floating">floating point</a></td>
				1264	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1265	</tr>
				1266	<tr>
				1267	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1268	<td><a href="#t_integer">integer</a>,
				1269	<a href="#t_floating">floating point</a>,
				1270	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1271	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1272	<a href="#t_struct">structure</a>,
				1273	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1274	<a href="#t_label">label</a>,
				1275	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1276	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1277	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1278	<tr>
				1279	<td><a href="#t_primitive">primitive</a></td>
				1280	<td><a href="#t_label">label</a>,
				1281	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1282	<a href="#t_floating">floating point</a>,
				1283	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1284	</tr>
				1285	<tr>
				1286	<td><a href="#t_derived">derived</a></td>
				1287	<td><a href="#t_integer">integer</a>,
				1288	<a href="#t_array">array</a>,
				1289	<a href="#t_function">function</a>,
				1290	<a href="#t_pointer">pointer</a>,
				1291	<a href="#t_struct">structure</a>,
				1292	<a href="#t_pstruct">packed structure</a>,
				1293	<a href="#t_vector">vector</a>,
				1294	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1295	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1296	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1297	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1298	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1299
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1300	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1301	most important. Values of these types are the only ones which can be
				1302	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1303	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1304	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1305
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1306	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1307	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1308
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1309	<div class="doc_text">
				1310	<p>The primitive types are the fundamental building blocks of the LLVM
				1311	system.</p>
				1312
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1313	</div>
				1314
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1315	<!-- _______________________________________________________________________ -->
				1316	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1317
				1318	<div class="doc_text">
				1319	<table>
				1320	<tbody>
				1321	<tr><th>Type</th><th>Description</th></tr>
				1322	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1323	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1324	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1325	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1326	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1327	</tbody>
				1328	</table>
				1329	</div>
				1330
				1331	<!-- _______________________________________________________________________ -->
				1332	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1333
				1334	<div class="doc_text">
				1335	<h5>Overview:</h5>
				1336	<p>The void type does not represent any value and has no size.</p>
				1337
				1338	<h5>Syntax:</h5>
				1339
				1340	<pre>
				1341	void
				1342	</pre>
				1343	</div>
				1344
				1345	<!-- _______________________________________________________________________ -->
				1346	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1347
				1348	<div class="doc_text">
				1349	<h5>Overview:</h5>
				1350	<p>The label type represents code labels.</p>
				1351
				1352	<h5>Syntax:</h5>
				1353
				1354	<pre>
				1355	label
				1356	</pre>
				1357	</div>
				1358
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1359	<!-- _______________________________________________________________________ -->
				1360	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1361
				1362	<div class="doc_text">
				1363	<h5>Overview:</h5>
				1364	<p>The metadata type represents embedded metadata. The only derived type that
				1365	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1366	takes metadata typed parameters, but not pointer to metadata types.</p>
				1367
				1368	<h5>Syntax:</h5>
				1369
				1370	<pre>
				1371	metadata
				1372	</pre>
				1373	</div>
				1374
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1375
				1376	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1377	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1378
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1379	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1380
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1381	<p>The real power in LLVM comes from the derived types in the system.
				1382	This is what allows a programmer to represent arrays, functions,
				1383	pointers, and other useful types. Note that these derived types may be
				1384	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]	1385
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1386	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1387
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1388	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1389	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1390
				1391	<div class="doc_text">
				1392
				1393	<h5>Overview:</h5>
				1394	<p>The integer type is a very simple derived type that simply specifies an
				1395	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1396	2^23-1 (about 8 million) can be specified.</p>
				1397
				1398	<h5>Syntax:</h5>
				1399
				1400	<pre>
				1401	iN
				1402	</pre>
				1403
				1404	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1405	value.</p>
				1406
				1407	<h5>Examples:</h5>
				1408	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1409	<tr class="layout">
				1410	<td class="left"><tt>i1</tt></td>
				1411	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1412	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1413	<tr class="layout">
				1414	<td class="left"><tt>i32</tt></td>
				1415	<td class="left">a 32-bit integer.</td>
				1416	</tr>
				1417	<tr class="layout">
				1418	<td class="left"><tt>i1942652</tt></td>
				1419	<td class="left">a really big integer of over 1 million bits.</td>
				1420	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1421	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1422
				1423	<p>Note that the code generator does not yet support large integer types
				1424	to be used as function return types. The specific limit on how large a
				1425	return type the code generator can currently handle is target-dependent;
				1426	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1427	targets.</p>
				1428
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1429	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1430
				1431	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1432	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1433
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1434	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1435
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1436	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1437
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1438	<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]	1439	sequentially in memory. The array type requires a size (number of
				1440	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1441
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1442	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1443
				1444	<pre>
				1445	[<# elements> x <elementtype>]
				1446	</pre>
				1447
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1448	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1449	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1450
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1451	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1452	<table class="layout">
				1453	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1454	<td class="left"><tt>[40 x i32]</tt></td>
				1455	<td class="left">Array of 40 32-bit integer values.</td>
				1456	</tr>
				1457	<tr class="layout">
				1458	<td class="left"><tt>[41 x i32]</tt></td>
				1459	<td class="left">Array of 41 32-bit integer values.</td>
				1460	</tr>
				1461	<tr class="layout">
				1462	<td class="left"><tt>[4 x i8]</tt></td>
				1463	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1464	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1465	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1466	<p>Here are some examples of multidimensional arrays:</p>
				1467	<table class="layout">
				1468	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1469	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1470	<td class="left">3x4 array of 32-bit integer values.</td>
				1471	</tr>
				1472	<tr class="layout">
				1473	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1474	<td class="left">12x10 array of single precision floating point values.</td>
				1475	</tr>
				1476	<tr class="layout">
				1477	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1478	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1479	</tr>
				1480	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1481
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1482	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1483	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]	1484	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1485	As a special case, however, zero length arrays are recognized to be variable
				1486	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1487	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1488
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1489	<p>Note that the code generator does not yet support large aggregate types
				1490	to be used as function return types. The specific limit on how large an
				1491	aggregate return type the code generator can currently handle is
				1492	target-dependent, and also dependent on the aggregate element types.</p>
				1493
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1494	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1495
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1496	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1497	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1498	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1499
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1500	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1501
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1502	<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]	1503	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]	1504	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]	1505	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]	1506	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1508	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1509
				1510	<pre>
				1511	<returntype list> (<parameter list>)
				1512	</pre>
				1513
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1514	<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]	1515	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1516	which indicates that the function takes a variable number of arguments.
				1517	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1518	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1519	'<tt><returntype list></tt>' is a comma-separated list of
				1520	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1521
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1522	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1523	<table class="layout">
				1524	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1525	<td class="left"><tt>i32 (i32)</tt></td>
				1526	<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]	1527	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1528	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1529	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1530	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1531	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1532	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1533	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1534	<tt>float</tt>.
				1535	</td>
				1536	</tr><tr class="layout">
				1537	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1538	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1539	<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]	1540	which returns an integer. This is the signature for <tt>printf</tt> in
				1541	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1542	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1543	</tr><tr class="layout">
				1544	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1545	<td class="left">A function taking an <tt>i32</tt>, returning two
				1546	<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]	1547	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1548	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1549	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1550
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1551	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1552	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1553	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1554	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1555	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1556	<p>The structure type is used to represent a collection of data members
				1557	together in memory. The packing of the field types is defined to match
				1558	the ABI of the underlying processor. The elements of a structure may
				1559	be any type that has a size.</p>
				1560	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1561	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1562	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1563	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1564	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1565	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1566	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1567	<table class="layout">
				1568	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1569	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1570	<td class="left">A triple of three <tt>i32</tt> values</td>
				1571	</tr><tr class="layout">
				1572	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1573	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1574	second element is a <a href="#t_pointer">pointer</a> to a
				1575	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1576	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1577	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1578	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1579
				1580	<p>Note that the code generator does not yet support large aggregate types
				1581	to be used as function return types. The specific limit on how large an
				1582	aggregate return type the code generator can currently handle is
				1583	target-dependent, and also dependent on the aggregate element types.</p>
				1584
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1585	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1586
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1587	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1588	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1589	</div>
				1590	<div class="doc_text">
				1591	<h5>Overview:</h5>
				1592	<p>The packed structure type is used to represent a collection of data members
				1593	together in memory. There is no padding between fields. Further, the alignment
				1594	of a packed structure is 1 byte. The elements of a packed structure may
				1595	be any type that has a size.</p>
				1596	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1597	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1598	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1599	instruction.</p>
				1600	<h5>Syntax:</h5>
				1601	<pre> < { <type list> } > <br></pre>
				1602	<h5>Examples:</h5>
				1603	<table class="layout">
				1604	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1605	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1606	<td class="left">A triple of three <tt>i32</tt> values</td>
				1607	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1608	<td class="left">
				1609	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1610	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1611	second element is a <a href="#t_pointer">pointer</a> to a
				1612	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1613	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1614	</tr>
				1615	</table>
				1616	</div>
				1617
				1618	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1619	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1620	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1621	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1622	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1623	reference to another object, which must live in memory. Pointer types may have
				1624	an optional address space attribute defining the target-specific numbered
				1625	address space where the pointed-to object resides. The default address space is
				1626	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1627
				1628	<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]	1629	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]	1630
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1631	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1632	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1633	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1634	<table class="layout">
				1635	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1636	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1637	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1638	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1639	</tr>
				1640	<tr class="layout">
				1641	<td class="left"><tt>i32 (i32 ) </tt></td>
				1642	<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]	1643	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]	1644	<tt>i32</tt>.</td>
				1645	</tr>
				1646	<tr class="layout">
				1647	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1648	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1649	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1650	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1651	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1652	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1653
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1654	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1655	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1656	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1657
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1658	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1659
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1660	<p>A vector type is a simple derived type that represents a vector
				1661	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1662	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1663	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1664	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1665	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1666	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1667
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1668	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1669
				1670	<pre>
				1671	< <# elements> x <elementtype> >
				1672	</pre>
				1673
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1674	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1675	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1676
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1677	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1678
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1679	<table class="layout">
				1680	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1681	<td class="left"><tt><4 x i32></tt></td>
				1682	<td class="left">Vector of 4 32-bit integer values.</td>
				1683	</tr>
				1684	<tr class="layout">
				1685	<td class="left"><tt><8 x float></tt></td>
				1686	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1687	</tr>
				1688	<tr class="layout">
				1689	<td class="left"><tt><2 x i64></tt></td>
				1690	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1691	</tr>
				1692	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1693
				1694	<p>Note that the code generator does not yet support large vector types
				1695	to be used as function return types. The specific limit on how large a
				1696	vector return type codegen can currently handle is target-dependent;
				1697	currently it's often a few times longer than a hardware vector register.</p>
				1698
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1699	</div>
				1700
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1701	<!-- _______________________________________________________________________ -->
				1702	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1703	<div class="doc_text">
				1704
				1705	<h5>Overview:</h5>
				1706
				1707	<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]	1708	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]	1709	In LLVM, opaque types can eventually be resolved to any type (not just a
				1710	structure type).</p>
				1711
				1712	<h5>Syntax:</h5>
				1713
				1714	<pre>
				1715	opaque
				1716	</pre>
				1717
				1718	<h5>Examples:</h5>
				1719
				1720	<table class="layout">
				1721	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1722	<td class="left"><tt>opaque</tt></td>
				1723	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1724	</tr>
				1725	</table>
				1726	</div>
				1727
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1728	<!-- ======================================================================= -->
				1729	<div class="doc_subsection">
				1730	<a name="t_uprefs">Type Up-references</a>
				1731	</div>
				1732
				1733	<div class="doc_text">
				1734	<h5>Overview:</h5>
				1735	<p>
				1736	An "up reference" allows you to refer to a lexically enclosing type without
				1737	requiring it to have a name. For instance, a structure declaration may contain a
				1738	pointer to any of the types it is lexically a member of. Example of up
				1739	references (with their equivalent as named type declarations) include:</p>
				1740
				1741	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1742	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1743	{ \2 }* %y = type { %y }*
				1744	\1* %z = type %z*
				1745	</pre>
				1746
				1747	<p>
				1748	An up reference is needed by the asmprinter for printing out cyclic types when
				1749	there is no declared name for a type in the cycle. Because the asmprinter does
				1750	not want to print out an infinite type string, it needs a syntax to handle
				1751	recursive types that have no names (all names are optional in llvm IR).
				1752	</p>
				1753
				1754	<h5>Syntax:</h5>
				1755	<pre>
				1756	\<level>
				1757	</pre>
				1758
				1759	<p>
				1760	The level is the count of the lexical type that is being referred to.
				1761	</p>
				1762
				1763	<h5>Examples:</h5>
				1764
				1765	<table class="layout">
				1766	<tr class="layout">
				1767	<td class="left"><tt>\1*</tt></td>
				1768	<td class="left">Self-referential pointer.</td>
				1769	</tr>
				1770	<tr class="layout">
				1771	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1772	<td class="left">Recursive structure where the upref refers to the out-most
				1773	structure.</td>
				1774	</tr>
				1775	</table>
				1776	</div>
				1777
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1778
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1779	<!-- *********************************************************************** -->
				1780	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1781	<!-- *********************************************************************** -->
				1782
				1783	<div class="doc_text">
				1784
				1785	<p>LLVM has several different basic types of constants. This section describes
				1786	them all and their syntax.</p>
				1787
				1788	</div>
				1789
				1790	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1791	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1792
				1793	<div class="doc_text">
				1794
				1795	<dl>
				1796	<dt><b>Boolean constants</b></dt>
				1797
				1798	<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]	1799	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1800	</dd>
				1801
				1802	<dt><b>Integer constants</b></dt>
				1803
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1804	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1805	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1806	integer types.
				1807	</dd>
				1808
				1809	<dt><b>Floating point constants</b></dt>
				1810
				1811	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1812	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1813	notation (see below). The assembler requires the exact decimal value of
				1814	a floating-point constant. For example, the assembler accepts 1.25 but
				1815	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1816	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]	1817
				1818	<dt><b>Null pointer constants</b></dt>
				1819
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1820	<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]	1821	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1822
				1823	</dl>
				1824
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1825	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1826	of floating point constants. For example, the form '<tt>double
				1827	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1828	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]	1829	(and the only time that they are generated by the disassembler) is when a
				1830	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]	1831	decimal floating point number in a reasonable number of digits. For example,
				1832	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1833	special values are represented in their IEEE hexadecimal format so that
				1834	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]	1835	<p>When using the hexadecimal form, constants of types float and double are
				1836	represented using the 16-digit form shown above (which matches the IEEE754
				1837	representation for double); float values must, however, be exactly representable
				1838	as IEE754 single precision.
				1839	Hexadecimal format is always used for long
				1840	double, and there are three forms of long double. The 80-bit
				1841	format used by x86 is represented as <tt>0xK</tt>
				1842	followed by 20 hexadecimal digits.
				1843	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1844	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1845	format is represented
				1846	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1847	target uses this format. Long doubles will only work if they match
				1848	the long double format on your target. All hexadecimal formats are big-endian
				1849	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1850	</div>
				1851
				1852	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1853	<div class="doc_subsection">
				1854	<a name="aggregateconstants"> <!-- old anchor -->
				1855	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1856	</div>
				1857
				1858	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1859	<p>Complex constants are a (potentially recursive) combination of simple
				1860	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1861
				1862	<dl>
				1863	<dt><b>Structure constants</b></dt>
				1864
				1865	<dd>Structure constants are represented with notation similar to structure
				1866	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1867	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1868	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]	1869	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]	1870	types of elements must match those specified by the type.
				1871	</dd>
				1872
				1873	<dt><b>Array constants</b></dt>
				1874
				1875	<dd>Array constants are represented with notation similar to array type
				1876	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1877	(<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]	1878	constants must have <a href="#t_array">array type</a>, and the number and
				1879	types of elements must match those specified by the type.
				1880	</dd>
				1881
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1882	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1883
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1884	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1885	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1886	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1887	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1888	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]	1889	match those specified by the type.
				1890	</dd>
				1891
				1892	<dt><b>Zero initialization</b></dt>
				1893
				1894	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1895	value to zero of <em>any</em> type, including scalar and aggregate types.
				1896	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]	1897	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1898	initializers.
				1899	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1900
				1901	<dt><b>Metadata node</b></dt>
				1902
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1903	<dd>A metadata node is a structure-like constant with
				1904	<a href="#t_metadata">metadata type</a>. For example:
				1905	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1906	that are meant to be interpreted as part of the instruction stream, metadata
				1907	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1908	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1909	</dl>
				1910
				1911	</div>
				1912
				1913	<!-- ======================================================================= -->
				1914	<div class="doc_subsection">
				1915	<a name="globalconstants">Global Variable and Function Addresses</a>
				1916	</div>
				1917
				1918	<div class="doc_text">
				1919
				1920	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1921	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1922	constants. These constants are explicitly referenced when the <a
				1923	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]	1924	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1925	file:</p>
				1926
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1927	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1928	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1929	@X = global i32 17
				1930	@Y = global i32 42
				1931	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1932	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1933	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1934
				1935	</div>
				1936
				1937	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1938	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1939	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1940	<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]	1941	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]	1942	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1943
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1944	<p>Undefined values indicate to the compiler that the program is well defined
				1945	no matter what value is used, giving the compiler more freedom to optimize.
				1946	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1947	</div>
				1948
				1949	<!-- ======================================================================= -->
				1950	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1951	</div>
				1952
				1953	<div class="doc_text">
				1954
				1955	<p>Constant expressions are used to allow expressions involving other constants
				1956	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1957	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]	1958	that does not have side effects (e.g. load and call are not supported). The
				1959	following is the syntax for constant expressions:</p>
				1960
				1961	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1962	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1963	<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]	1964	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1965
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1966	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1967	<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]	1968	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]	1969
				1970	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1971	<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]	1972	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]	1973
				1974	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1975	<dd>Truncate a floating point constant to another floating point type. The
				1976	size of CST must be larger than the size of TYPE. Both types must be
				1977	floating point.</dd>
				1978
				1979	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1980	<dd>Floating point extend a constant to another type. The size of CST must be
				1981	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1982
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1983	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1984	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1985	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1986	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1987	of the same number of elements. If the value won't fit in the integer type,
				1988	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1989
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1990	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1991	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1992	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1993	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1994	of the same number of elements. If the value won't fit in the integer type,
				1995	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1996
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1997	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1998	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1999	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2000	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2001	of the same number of elements. If the value won't fit in the floating point
				2002	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2003
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2004	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2005	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2006	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2007	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2008	of the same number of elements. If the value won't fit in the floating point
				2009	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2010
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2011	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2012	<dd>Convert a pointer typed constant to the corresponding integer constant
				2013	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2014	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2015
				2016	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2017	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2018	pointer type. CST must be of integer type. The CST value is zero extended,
				2019	truncated, or unchanged to make it fit in a pointer size. This one is
				2020	<i>really</i> dangerous!</dd>
				2021
				2022	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2023	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2024	are the same as those for the <a href="#i_bitcast">bitcast
				2025	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2026
				2027	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2028
				2029	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2030	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2031	instruction, the index list may have zero or more indexes, which are required
				2032	to make sense for the type of "CSTPTR".</dd>
				2033
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2034	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2035
				2036	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2037	constants.</dd>
				2038
				2039	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2040	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2041
				2042	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2043	<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]	2044
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	2045	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2046	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2047
				2048	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2049	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2050
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2051	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2052
				2053	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2054	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2055
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2056	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2057
				2058	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2059	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2060
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2061
				2062	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2063
				2064	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2065	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2066
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2067	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2068
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2069	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2070	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]	2071	binary</a> operations. The constraints on operands are the same as those for
				2072	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2073	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2074	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2075	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2076
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2077	<!-- ======================================================================= -->
				2078	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2079	</div>
				2080
				2081	<div class="doc_text">
				2082
				2083	<p>Embedded metadata provides a way to attach arbitrary data to the
				2084	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2085	two metadata primitives, strings and nodes. All metadata has the
				2086	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2087	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2088	</p>
				2089
				2090	<p>A metadata string is a string surrounded by double quotes. It can contain
				2091	any character by escaping non-printable characters with "\xx" where "xx" is
				2092	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2093	</p>
				2094
				2095	<p>Metadata nodes are represented with notation similar to structure constants
				2096	(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]	2097	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2098	</p>
				2099
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2100	<p>A metadata node will attempt to track changes to the values it holds. In
				2101	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]	2102	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2103
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2104	<p>Optimizations may rely on metadata to provide additional information about
				2105	the program that isn't available in the instructions, or that isn't easily
				2106	computable. Similarly, the code generator may expect a certain metadata format
				2107	to be used to express debugging information.</p>
				2108	</div>
				2109
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2110	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2111	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2112	<!-- *********************************************************************** -->
				2113
				2114	<!-- ======================================================================= -->
				2115	<div class="doc_subsection">
				2116	<a name="inlineasm">Inline Assembler Expressions</a>
				2117	</div>
				2118
				2119	<div class="doc_text">
				2120
				2121	<p>
				2122	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2123	Module-Level Inline Assembly</a>) through the use of a special value. This
				2124	value represents the inline assembler as a string (containing the instructions
				2125	to emit), a list of operand constraints (stored as a string), and a flag that
				2126	indicates whether or not the inline asm expression has side effects. An example
				2127	inline assembler expression is:
				2128	</p>
				2129
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2130	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2131	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2132	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2133	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2134	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2135
				2136	<p>
				2137	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2138	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2139	</p>
				2140
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2141	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2142	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2143	%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]	2144	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2145	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2146
				2147	<p>
				2148	Inline asms with side effects not visible in the constraint list must be marked
				2149	as having side effects. This is done through the use of the
				2150	'<tt>sideeffect</tt>' keyword, like so:
				2151	</p>
				2152
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2153	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2154	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2155	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2156	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2157	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2158
				2159	<p>TODO: The format of the asm and constraints string still need to be
				2160	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]	2161	need to be documented). This is probably best done by reference to another
				2162	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2163	</p>
				2164
				2165	</div>
				2166
				2167	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2168	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2169	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2170
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2171	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2172
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2173	<p>The LLVM instruction set consists of several different
				2174	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2175	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2176	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2177	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2178	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2179
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2180	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2181
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2183	<div class="doc_subsection"> <a name="terminators">Terminator
				2184	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2185
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2186	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2187
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2188	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2189	basic block in a program ends with a "Terminator" instruction, which
				2190	indicates which block should be executed after the current block is
				2191	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2192	value: they produce control flow, not values (the one exception being
				2193	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2194	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2196	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2197	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2198	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2199	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2200
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2201	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2202
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2204	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2205	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2206	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2208	<pre>
				2209	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]	2210	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2211	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2212
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2214
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2215	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2216	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2217	<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]	2218	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]	2219	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2220
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2222
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2223	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2224	the return value. The type of the return value must be a
				2225	'<a href="#t_firstclass">first class</a>' type.</p>
				2226
				2227	<p>A function is not <a href="#wellformed">well formed</a> if
				2228	it it has a non-void return type and contains a '<tt>ret</tt>'
				2229	instruction with no return value or a return value with a type that
				2230	does not match its type, or if it has a void return type and contains
				2231	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2232
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2233	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2234
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2235	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2236	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]	2237	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2238	the instruction after the call. If the caller was an "<a
				2239	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2240	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2241	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]	2242	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2243
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2244	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2245
				2246	<pre>
				2247	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2248	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2249	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]	2250	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2251
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2252	<p>Note that the code generator does not yet fully support large
				2253	return values. The specific sizes that are currently supported are
				2254	dependent on the target. For integers, on 32-bit targets the limit
				2255	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2256	For aggregate types, the current limits are dependent on the element
				2257	types; for example targets are often limited to 2 total integer
				2258	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2259
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2260	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2262	<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]	2263	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2265	<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]	2266	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2267	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2268	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2269	transfer to a different basic block in the current function. There are
				2270	two forms of this instruction, corresponding to a conditional branch
				2271	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2272	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2273	<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]	2274	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2275	unconditional form of the '<tt>br</tt>' instruction takes a single
				2276	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2278	<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]	2279	argument is evaluated. If the value is <tt>true</tt>, control flows
				2280	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2281	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2283	<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]	2284	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]	2285	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2286	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2287	<div class="doc_subsubsection">
				2288	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2289	</div>
				2290
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2291	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2292	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2293
				2294	<pre>
				2295	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2296	</pre>
				2297
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2299
				2300	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2301	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2302	instruction, allowing a branch to occur to one of many possible
				2303	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2304
				2305
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2306	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2307
				2308	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2309	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2310	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2311	table is not allowed to contain duplicate constant entries.</p>
				2312
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2313	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2315	<p>The <tt>switch</tt> instruction specifies a table of values and
				2316	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2317	table is searched for the given value. If the value is found, control flow is
				2318	transfered to the corresponding destination; otherwise, control flow is
				2319	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2320
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2321	<h5>Implementation:</h5>
				2322
				2323	<p>Depending on properties of the target machine and the particular
				2324	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2325	ways. For example, it could be generated as a series of chained conditional
				2326	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2327
				2328	<h5>Example:</h5>
				2329
				2330	<pre>
				2331	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2332	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2333	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2334
				2335	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2336	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2337
				2338	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2339	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2340	i32 1, label %onone
				2341	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2342	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2343	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2346	<div class="doc_subsubsection">
				2347	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2348	</div>
				2349
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2350	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2351
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2352	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2353
				2354	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2355	<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]	2356	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2357	</pre>
				2358
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2359	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2360
				2361	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2362	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2363	'<tt>normal</tt>' label or the
				2364	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2365	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2366	"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]	2367	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2368	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2369
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2370	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2371
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2372	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2373
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2374	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2375	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2376	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2377	convention</a> the call should use. If none is specified, the call defaults
				2378	to using C calling conventions.
				2379	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2380
				2381	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2382	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2383	and '<tt>inreg</tt>' attributes are valid here.</li>
				2384
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2385	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2386	function value being invoked. In most cases, this is a direct function
				2387	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2388	an arbitrary pointer to function value.
				2389	</li>
				2390
				2391	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2392	function to be invoked. </li>
				2393
				2394	<li>'<tt>function args</tt>': argument list whose types match the function
				2395	signature argument types. If the function signature indicates the function
				2396	accepts a variable number of arguments, the extra arguments can be
				2397	specified. </li>
				2398
				2399	<li>'<tt>normal label</tt>': the label reached when the called function
				2400	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2401
				2402	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2403	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2404
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2405	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2406	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2407	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2408	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2409
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2410	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2411
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2412	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2413	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2414	difference is that it establishes an association with a label, which is used by
				2415	the runtime library to unwind the stack.</p>
				2416
				2417	<p>This instruction is used in languages with destructors to ensure that proper
				2418	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2419	exception. Additionally, this is important for implementation of
				2420	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2421
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2422	<p>For the purposes of the SSA form, the definition of the value
				2423	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2424	the edge from the current block to the "normal" label. If the callee
				2425	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2426
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2427	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2428	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2429	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2430	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2431	%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]	2432	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2433	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2434	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2435
				2436
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2437	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2438
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2439	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2440	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2441
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2442	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2443
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2444	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2445	<pre>
				2446	unwind
				2447	</pre>
				2448
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2449	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2450
				2451	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2452	at the first callee in the dynamic call stack which used an <a
				2453	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2454	primarily used to implement exception handling.</p>
				2455
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2456	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2457
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2458	<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]	2459	immediately halt. The dynamic call stack is then searched for the first <a
				2460	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2461	execution continues at the "exceptional" destination block specified by the
				2462	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2463	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2464	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2465
				2466	<!-- _______________________________________________________________________ -->
				2467
				2468	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2469	Instruction</a> </div>
				2470
				2471	<div class="doc_text">
				2472
				2473	<h5>Syntax:</h5>
				2474	<pre>
				2475	unreachable
				2476	</pre>
				2477
				2478	<h5>Overview:</h5>
				2479
				2480	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2481	instruction is used to inform the optimizer that a particular portion of the
				2482	code is not reachable. This can be used to indicate that the code after a
				2483	no-return function cannot be reached, and other facts.</p>
				2484
				2485	<h5>Semantics:</h5>
				2486
				2487	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2488	</div>
				2489
				2490
				2491
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2493	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2495	<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]	2496	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]	2497	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2498	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]	2499	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2502	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2503	<div class="doc_subsubsection">
				2504	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2505	</div>
				2506
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2507	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
				2511	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2512	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2513	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2515	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2516
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2517	<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]	2518
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2519	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
				2521	<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]	2522	href="#t_integer">integer</a> or
				2523	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2524	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2525
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2526	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2527
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2528	<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]	2529
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2530	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2531	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2532	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2534	<p>Because LLVM integers use a two's complement representation, this
				2535	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2537	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2538
				2539	<pre>
				2540	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2542	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2543	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2544	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2545	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2546	</div>
				2547
				2548	<div class="doc_text">
				2549
				2550	<h5>Syntax:</h5>
				2551
				2552	<pre>
				2553	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2554	</pre>
				2555
				2556	<h5>Overview:</h5>
				2557
				2558	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2559
				2560	<h5>Arguments:</h5>
				2561
				2562	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2563	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2564	floating point values. Both arguments must have identical types.</p>
				2565
				2566	<h5>Semantics:</h5>
				2567
				2568	<p>The value produced is the floating point sum of the two operands.</p>
				2569
				2570	<h5>Example:</h5>
				2571
				2572	<pre>
				2573	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2574	</pre>
				2575	</div>
				2576	<!-- _______________________________________________________________________ -->
				2577	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2578	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2579	</div>
				2580
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2581	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2582
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2583	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2584
				2585	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2586	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2587	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2588
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2589	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2591	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2592	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
				2594	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2595	'<tt>neg</tt>' instruction present in most other intermediate
				2596	representations.</p>
				2597
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2598	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2599
				2600	<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]	2601	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2602	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2603
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2604	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2606	<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]	2607
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2608	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2609	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2610	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2612	<p>Because LLVM integers use a two's complement representation, this
				2613	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2615	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2616	<pre>
				2617	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2618	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2619	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2620	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2622	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2623	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2624	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2625	</div>
				2626
				2627	<div class="doc_text">
				2628
				2629	<h5>Syntax:</h5>
				2630
				2631	<pre>
				2632	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2633	</pre>
				2634
				2635	<h5>Overview:</h5>
				2636
				2637	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2638	operands.</p>
				2639
				2640	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2641	'<tt>fneg</tt>' instruction present in most other intermediate
				2642	representations.</p>
				2643
				2644	<h5>Arguments:</h5>
				2645
				2646	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2647	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2648	of floating point values. Both arguments must have identical types.</p>
				2649
				2650	<h5>Semantics:</h5>
				2651
				2652	<p>The value produced is the floating point difference of the two operands.</p>
				2653
				2654	<h5>Example:</h5>
				2655	<pre>
				2656	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2657	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2658	</pre>
				2659	</div>
				2660
				2661	<!-- _______________________________________________________________________ -->
				2662	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2663	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2664	</div>
				2665
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2666	<div class="doc_text">
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>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2669	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2673	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2674
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2676
				2677	<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]	2678	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2679	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2680
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2681	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2682
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2683	<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]	2684
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2685	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2686	the result returned is the mathematical result modulo
				2687	2<sup>n</sup>, where n is the bit width of the result.</p>
				2688	<p>Because LLVM integers use a two's complement representation, and the
				2689	result is the same width as the operands, this instruction returns the
				2690	correct result for both signed and unsigned integers. If a full product
				2691	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2692	should be sign-extended or zero-extended as appropriate to the
				2693	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2694	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2695	<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]	2696	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2697	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2698
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2699	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2700	<div class="doc_subsubsection">
				2701	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2702	</div>
				2703
				2704	<div class="doc_text">
				2705
				2706	<h5>Syntax:</h5>
				2707	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2708	</pre>
				2709	<h5>Overview:</h5>
				2710	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2711	operands.</p>
				2712
				2713	<h5>Arguments:</h5>
				2714
				2715	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2716	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2717	of floating point values. Both arguments must have identical types.</p>
				2718
				2719	<h5>Semantics:</h5>
				2720
				2721	<p>The value produced is the floating point product of the two operands.</p>
				2722
				2723	<h5>Example:</h5>
				2724	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2725	</pre>
				2726	</div>
				2727
				2728	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2729	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2730	</a></div>
				2731	<div class="doc_text">
				2732	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2733	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2734	</pre>
				2735	<h5>Overview:</h5>
				2736	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2737	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2738
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2739	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2740
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2741	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2742	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2743	values. Both arguments must have identical types.</p>
				2744
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2745	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2746
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2747	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2748	<p>Note that unsigned integer division and signed integer division are distinct
				2749	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2750	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2751	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2752	<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]	2753	</pre>
				2754	</div>
				2755	<!-- _______________________________________________________________________ -->
				2756	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2757	</a> </div>
				2758	<div class="doc_text">
				2759	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2760	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2761	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2762	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2763
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2764	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2765
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2766	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2767	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2768
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2769	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2770
				2771	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2772	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2773	values. Both arguments must have identical types.</p>
				2774
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2775	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2776	<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]	2777	<p>Note that signed integer division and unsigned integer division are distinct
				2778	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2779	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2780	undefined behavior; this is a rare case, but can occur, for example,
				2781	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2782	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2783	<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]	2784	</pre>
				2785	</div>
				2786	<!-- _______________________________________________________________________ -->
				2787	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2788	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2789	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2790	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2791	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2792	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2793	</pre>
				2794	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2795
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2796	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2797	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2798
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2799	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2800
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2801	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2802	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2803	of floating point values. Both arguments must have identical types.</p>
				2804
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2805	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2806
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2807	<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]	2808
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2809	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2810
				2811	<pre>
				2812	<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]	2813	</pre>
				2814	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2815
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2816	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2817	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2818	</div>
				2819	<div class="doc_text">
				2820	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2821	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2822	</pre>
				2823	<h5>Overview:</h5>
				2824	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2825	unsigned division of its two arguments.</p>
				2826	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2827	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2828	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2829	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2830	<h5>Semantics:</h5>
				2831	<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]	2832	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2833	<p>Note that unsigned integer remainder and signed integer remainder are
				2834	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2835	<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]	2836	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2837	<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]	2838	</pre>
				2839
				2840	</div>
				2841	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2842	<div class="doc_subsubsection">
				2843	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2844	</div>
				2845
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2846	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2847
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2848	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2849
				2850	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2851	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2852	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2853
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2854	<h5>Overview:</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 '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2857	signed division of its two operands. This instruction can also take
				2858	<a href="#t_vector">vector</a> versions of the values in which case
				2859	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2860
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2861	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2862
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2863	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2864	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2865	values. Both arguments must have identical types.</p>
				2866
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2867	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2868
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2869	<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]	2870	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2871	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]	2872	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2873	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]	2874	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]	2875	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2876	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2877	<p>Note that signed integer remainder and unsigned integer remainder are
				2878	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2879	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2880	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2881	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2882	(The remainder doesn't actually overflow, but this rule lets srem be
				2883	implemented using instructions that return both the result of the division
				2884	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2885	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2886	<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]	2887	</pre>
				2888
				2889	</div>
				2890	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2891	<div class="doc_subsubsection">
				2892	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2893
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2894	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2895
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2896	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2897	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2898	</pre>
				2899	<h5>Overview:</h5>
				2900	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2901	division of its two operands.</p>
				2902	<h5>Arguments:</h5>
				2903	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2904	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2905	of floating point values. Both arguments must have identical types.</p>
				2906
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2907	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2908
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2909	<p>This instruction returns the <i>remainder</i> of a division.
				2910	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2911
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2912	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2913
				2914	<pre>
				2915	<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]	2916	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2917	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2918
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2919	<!-- ======================================================================= -->
				2920	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2921	Operations</a> </div>
				2922	<div class="doc_text">
				2923	<p>Bitwise binary operators are used to do various forms of
				2924	bit-twiddling in a program. They are generally very efficient
				2925	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2926	instructions. They require two operands of the same type, execute an operation on them,
				2927	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]	2928	</div>
				2929
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	<!-- _______________________________________________________________________ -->
				2931	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2932	Instruction</a> </div>
				2933	<div class="doc_text">
				2934	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2935	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2936	</pre>
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	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2939
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2940	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2941	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2942
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2943	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2944
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2945	<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]	2946	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]	2947	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2948
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2949	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2950
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2951	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2952	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]	2953	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2954	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2955	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2956
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2957	<h5>Example:</h5><pre>
				2958	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2959	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2960	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2961	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2962	<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]	2963	</pre>
				2964	</div>
				2965	<!-- _______________________________________________________________________ -->
				2966	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2967	Instruction</a> </div>
				2968	<div class="doc_text">
				2969	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2970	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2971	</pre>
				2972
				2973	<h5>Overview:</h5>
				2974	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2975	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]	2976
				2977	<h5>Arguments:</h5>
				2978	<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]	2979	<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]	2980	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2981
				2982	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2983
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2984	<p>This instruction always performs a logical shift right operation. The most
				2985	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]	2986	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]	2987	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2988	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2989	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2990
				2991	<h5>Example:</h5>
				2992	<pre>
				2993	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2994	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2995	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2996	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2997	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2998	<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]	2999	</pre>
				3000	</div>
				3001
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	3002	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3003	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				3004	Instruction</a> </div>
				3005	<div class="doc_text">
				3006
				3007	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3008	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3009	</pre>
				3010
				3011	<h5>Overview:</h5>
				3012	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3013	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]	3014
				3015	<h5>Arguments:</h5>
				3016	<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]	3017	<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]	3018	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3019
				3020	<h5>Semantics:</h5>
				3021	<p>This instruction always performs an arithmetic shift right operation,
				3022	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]	3023	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]	3024	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3025	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3026	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3027
				3028	<h5>Example:</h5>
				3029	<pre>
				3030	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3031	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3032	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3033	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3034	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3035	<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]	3036	</pre>
				3037	</div>
				3038
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3039	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3040	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3041	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3042
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3043	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3044
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3045	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3046
				3047	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3048	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3049	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3050
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3051	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3052
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3053	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3054	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3055
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3056	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3057
				3058	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3059	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3060	values. Both arguments must have identical types.</p>
				3061
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3062	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3063	<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]	3064	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3065	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3066	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3067	<tbody>
				3068	<tr>
				3069	<td>In0</td>
				3070	<td>In1</td>
				3071	<td>Out</td>
				3072	</tr>
				3073	<tr>
				3074	<td>0</td>
				3075	<td>0</td>
				3076	<td>0</td>
				3077	</tr>
				3078	<tr>
				3079	<td>0</td>
				3080	<td>1</td>
				3081	<td>0</td>
				3082	</tr>
				3083	<tr>
				3084	<td>1</td>
				3085	<td>0</td>
				3086	<td>0</td>
				3087	</tr>
				3088	<tr>
				3089	<td>1</td>
				3090	<td>1</td>
				3091	<td>1</td>
				3092	</tr>
				3093	</tbody>
				3094	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3095	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3097	<pre>
				3098	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3099	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3100	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3102	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3103	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3104	<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]	3105	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3107	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3108	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3109	<h5>Overview:</h5>
				3110	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3111	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3113
				3114	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3115	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3116	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3117	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3118	<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]	3119	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3120	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3121	<table border="1" cellspacing="0" cellpadding="4">
				3122	<tbody>
				3123	<tr>
				3124	<td>In0</td>
				3125	<td>In1</td>
				3126	<td>Out</td>
				3127	</tr>
				3128	<tr>
				3129	<td>0</td>
				3130	<td>0</td>
				3131	<td>0</td>
				3132	</tr>
				3133	<tr>
				3134	<td>0</td>
				3135	<td>1</td>
				3136	<td>1</td>
				3137	</tr>
				3138	<tr>
				3139	<td>1</td>
				3140	<td>0</td>
				3141	<td>1</td>
				3142	</tr>
				3143	<tr>
				3144	<td>1</td>
				3145	<td>1</td>
				3146	<td>1</td>
				3147	</tr>
				3148	</tbody>
				3149	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3150	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3152	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3153	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3154	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3156	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3158	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3159	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3160	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3161	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3162	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3164	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3165	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3166	or of its two operands. The <tt>xor</tt> is used to implement the
				3167	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3168	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3169	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3170	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3171	values. Both arguments must have identical types.</p>
				3172
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3173	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3174
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3175	<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]	3176	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3177	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3178	<table border="1" cellspacing="0" cellpadding="4">
				3179	<tbody>
				3180	<tr>
				3181	<td>In0</td>
				3182	<td>In1</td>
				3183	<td>Out</td>
				3184	</tr>
				3185	<tr>
				3186	<td>0</td>
				3187	<td>0</td>
				3188	<td>0</td>
				3189	</tr>
				3190	<tr>
				3191	<td>0</td>
				3192	<td>1</td>
				3193	<td>1</td>
				3194	</tr>
				3195	<tr>
				3196	<td>1</td>
				3197	<td>0</td>
				3198	<td>1</td>
				3199	</tr>
				3200	<tr>
				3201	<td>1</td>
				3202	<td>1</td>
				3203	<td>0</td>
				3204	</tr>
				3205	</tbody>
				3206	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3207	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3208	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3210	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3211	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3212	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3213	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3214	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3215	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3216
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3217	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3218	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3219	<a name="vectorops">Vector Operations</a>
				3220	</div>
				3221
				3222	<div class="doc_text">
				3223
				3224	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3225	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3226	vector-specific operations needed to process vectors effectively. While LLVM
				3227	does directly support these vector operations, many sophisticated algorithms
				3228	will want to use target-specific intrinsics to take full advantage of a specific
				3229	target.</p>
				3230
				3231	</div>
				3232
				3233	<!-- _______________________________________________________________________ -->
				3234	<div class="doc_subsubsection">
				3235	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3236	</div>
				3237
				3238	<div class="doc_text">
				3239
				3240	<h5>Syntax:</h5>
				3241
				3242	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3243	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3244	</pre>
				3245
				3246	<h5>Overview:</h5>
				3247
				3248	<p>
				3249	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3250	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3251	</p>
				3252
				3253
				3254	<h5>Arguments:</h5>
				3255
				3256	<p>
				3257	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3258	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]	3259	an index indicating the position from which to extract the element.
				3260	The index may be a variable.</p>
				3261
				3262	<h5>Semantics:</h5>
				3263
				3264	<p>
				3265	The result is a scalar of the same type as the element type of
				3266	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3267	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3268	results are undefined.
				3269	</p>
				3270
				3271	<h5>Example:</h5>
				3272
				3273	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3274	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3275	</pre>
				3276	</div>
				3277
				3278
				3279	<!-- _______________________________________________________________________ -->
				3280	<div class="doc_subsubsection">
				3281	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3282	</div>
				3283
				3284	<div class="doc_text">
				3285
				3286	<h5>Syntax:</h5>
				3287
				3288	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3289	<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]	3290	</pre>
				3291
				3292	<h5>Overview:</h5>
				3293
				3294	<p>
				3295	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3296	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3297	</p>
				3298
				3299
				3300	<h5>Arguments:</h5>
				3301
				3302	<p>
				3303	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3304	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]	3305	scalar value whose type must equal the element type of the first
				3306	operand. The third operand is an index indicating the position at
				3307	which to insert the value. The index may be a variable.</p>
				3308
				3309	<h5>Semantics:</h5>
				3310
				3311	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3312	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]	3313	element values are those of <tt>val</tt> except at position
				3314	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3315	exceeds the length of <tt>val</tt>, the results are undefined.
				3316	</p>
				3317
				3318	<h5>Example:</h5>
				3319
				3320	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3321	%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]	3322	</pre>
				3323	</div>
				3324
				3325	<!-- _______________________________________________________________________ -->
				3326	<div class="doc_subsubsection">
				3327	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3328	</div>
				3329
				3330	<div class="doc_text">
				3331
				3332	<h5>Syntax:</h5>
				3333
				3334	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3335	<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]	3336	</pre>
				3337
				3338	<h5>Overview:</h5>
				3339
				3340	<p>
				3341	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3342	from two input vectors, returning a vector with the same element type as
				3343	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3344	</p>
				3345
				3346	<h5>Arguments:</h5>
				3347
				3348	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3349	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3350	with types that match each other. The third argument is a shuffle mask whose
				3351	element type is always 'i32'. The result of the instruction is a vector whose
				3352	length is the same as the shuffle mask and whose element type is the same as
				3353	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3354	</p>
				3355
				3356	<p>
				3357	The shuffle mask operand is required to be a constant vector with either
				3358	constant integer or undef values.
				3359	</p>
				3360
				3361	<h5>Semantics:</h5>
				3362
				3363	<p>
				3364	The elements of the two input vectors are numbered from left to right across
				3365	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]	3366	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]	3367	gets. The element selector may be undef (meaning "don't care") and the second
				3368	operand may be undef if performing a shuffle from only one vector.
				3369	</p>
				3370
				3371	<h5>Example:</h5>
				3372
				3373	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3374	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3375	<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]	3376	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3377	<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]	3378	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3379	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3380	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3381	<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]	3382	</pre>
				3383	</div>
				3384
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3385
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3386	<!-- ======================================================================= -->
				3387	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3388	<a name="aggregateops">Aggregate Operations</a>
				3389	</div>
				3390
				3391	<div class="doc_text">
				3392
				3393	<p>LLVM supports several instructions for working with aggregate values.
				3394	</p>
				3395
				3396	</div>
				3397
				3398	<!-- _______________________________________________________________________ -->
				3399	<div class="doc_subsubsection">
				3400	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3401	</div>
				3402
				3403	<div class="doc_text">
				3404
				3405	<h5>Syntax:</h5>
				3406
				3407	<pre>
				3408	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3409	</pre>
				3410
				3411	<h5>Overview:</h5>
				3412
				3413	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3414	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3415	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3416	</p>
				3417
				3418
				3419	<h5>Arguments:</h5>
				3420
				3421	<p>
				3422	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3423	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]	3424	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3425	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3426	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3427	</p>
				3428
				3429	<h5>Semantics:</h5>
				3430
				3431	<p>
				3432	The result is the value at the position in the aggregate specified by
				3433	the index operands.
				3434	</p>
				3435
				3436	<h5>Example:</h5>
				3437
				3438	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3439	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3440	</pre>
				3441	</div>
				3442
				3443
				3444	<!-- _______________________________________________________________________ -->
				3445	<div class="doc_subsubsection">
				3446	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3447	</div>
				3448
				3449	<div class="doc_text">
				3450
				3451	<h5>Syntax:</h5>
				3452
				3453	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3454	<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]	3455	</pre>
				3456
				3457	<h5>Overview:</h5>
				3458
				3459	<p>
				3460	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3461	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3462	</p>
				3463
				3464
				3465	<h5>Arguments:</h5>
				3466
				3467	<p>
				3468	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3469	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3470	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3471	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3472	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]	3473	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3474	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3475	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]	3476	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3477	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3478
				3479	<h5>Semantics:</h5>
				3480
				3481	<p>
				3482	The result is an aggregate of the same type as <tt>val</tt>. Its
				3483	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]	3484	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3485	</p>
				3486
				3487	<h5>Example:</h5>
				3488
				3489	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3490	%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]	3491	</pre>
				3492	</div>
				3493
				3494
				3495	<!-- ======================================================================= -->
				3496	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3497	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3498	</div>
				3499
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3500	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3501
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3502	<p>A key design point of an SSA-based representation is how it
				3503	represents memory. In LLVM, no memory locations are in SSA form, which
				3504	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3505	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3506
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3507	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3510	<div class="doc_subsubsection">
				3511	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3512	</div>
				3513
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3514	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3515
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3516	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3517
				3518	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3519	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3520	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3521
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3522	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3523
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3524	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3525	heap and returns a pointer to it. The object is always allocated in the generic
				3526	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3527
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3528	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3529
				3530	<p>The '<tt>malloc</tt>' instruction allocates
				3531	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3532	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]	3533	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3534	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3535	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3536	be aligned to at least that boundary. If not specified, or if zero, the target can
				3537	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3538
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3539	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3540
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3541	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3542
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3543	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3544	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]	3545	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3546
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3547	<h5>Example:</h5>
				3548
				3549	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3550	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3551
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3552	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3553	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3554	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3555	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3556	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3557	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3558
				3559	<p>Note that the code generator does not yet respect the
				3560	alignment value.</p>
				3561
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3562	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3563
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3564	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3565	<div class="doc_subsubsection">
				3566	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3567	</div>
				3568
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3569	<div class="doc_text">
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>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3572
				3573	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3574	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3575	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3576
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3577	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3578
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3579	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3580	memory heap to be reallocated in the future.</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>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3583
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3584	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3585	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3586	instruction.</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>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3589
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3590	<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]	3591	after this instruction executes. If the pointer is null, the operation
				3592	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3593
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3594	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3595
				3596	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3597	%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]	3598	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3599	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3600	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3601
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3602	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3603	<div class="doc_subsubsection">
				3604	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3605	</div>
				3606
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3607	<div class="doc_text">
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>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3610
				3611	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3612	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3613	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3614
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3615	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3616
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3617	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3618	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3619	returns to its caller. The object is always allocated in the generic address
				3620	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3621
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3622	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3623
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3624	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3625	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3626	appropriate type to the program. If "NumElements" is specified, it is the
				3627	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3628	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3629	to be aligned to at least that boundary. If not specified, or if zero, the target
				3630	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3631
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3632	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3633
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3634	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3635
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3636	<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]	3637	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3638	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3639	instruction is commonly used to represent automatic variables that must
				3640	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]	3641	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]	3642	instructions), the memory is reclaimed. Allocating zero bytes
				3643	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3644
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3645	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3646
				3647	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3648	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3649	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3650	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3651	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3652	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3653	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3654
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3655	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3656	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3657	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3658	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3659	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3660	<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]	3661	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3662	<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]	3663	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3664	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3665	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3666	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]	3667	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]	3668	the number or order of execution of this <tt>load</tt> with other
				3669	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3670	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3671	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3672	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3673	(that is, the alignment of the memory address). A value of 0 or an
				3674	omitted "align" argument means that the operation has the preferential
				3675	alignment for the target. It is the responsibility of the code emitter
				3676	to ensure that the alignment information is correct. Overestimating
				3677	the alignment results in an undefined behavior. Underestimating the
				3678	alignment may produce less efficient code. An alignment of 1 is always
				3679	safe.
				3680	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3681	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3682	<p>The location of memory pointed to is loaded. If the value being loaded
				3683	is of scalar type then the number of bytes read does not exceed the minimum
				3684	number of bytes needed to hold all bits of the type. For example, loading an
				3685	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3686	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3687	is undefined if the value was not originally written using a store of the
				3688	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3689	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3690	<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]	3691	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3692	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3693	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3694	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3695	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3696	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3697	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3698	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3699	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3700	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3701	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3702	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3703	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3704	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3705	<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]	3706	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3707	<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]	3708	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]	3709	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3710	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3711	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]	3712	optimizer is not allowed to modify the number or order of execution of
				3713	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3714	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3715	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3716	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3717	(that is, the alignment of the memory address). A value of 0 or an
				3718	omitted "align" argument means that the operation has the preferential
				3719	alignment for the target. It is the responsibility of the code emitter
				3720	to ensure that the alignment information is correct. Overestimating
				3721	the alignment results in an undefined behavior. Underestimating the
				3722	alignment may produce less efficient code. An alignment of 1 is always
				3723	safe.
				3724	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3725	<h5>Semantics:</h5>
				3726	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3727	at the location specified by the '<tt><pointer></tt>' operand.
				3728	If '<tt><value></tt>' is of scalar type then the number of bytes
				3729	written does not exceed the minimum number of bytes needed to hold all
				3730	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3731	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3732	size that is not an integral number of bytes, it is unspecified what
				3733	happens to the extra bits that do not belong to the type, but they will
				3734	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3735	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3736	<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]	3737	store i32 3, i32* %ptr <i>; yields {void}</i>
				3738	%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]	3739	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3740	</div>
				3741
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3742	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3743	<div class="doc_subsubsection">
				3744	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3745	</div>
				3746
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3747	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3748	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3749	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3750	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3751	</pre>
				3752
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3753	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3754
				3755	<p>
				3756	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]	3757	subelement of an aggregate data structure. It performs address calculation only
				3758	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3759
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3760	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3761
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3762	<p>The first argument is always a pointer, and forms the basis of the
				3763	calculation. The remaining arguments are indices, that indicate which of the
				3764	elements of the aggregate object are indexed. The interpretation of each index
				3765	is dependent on the type being indexed into. The first index always indexes the
				3766	pointer value given as the first argument, the second index indexes a value of
				3767	the type pointed to (not necessarily the value directly pointed to, since the
				3768	first index can be non-zero), etc. The first type indexed into must be a pointer
				3769	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3770	types being indexed into can never be pointers, since that would require loading
				3771	the pointer before continuing calculation.</p>
				3772
				3773	<p>The type of each index argument depends on the type it is indexing into.
				3774	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3775	<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]	3776	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3777
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3778	<p>For example, let's consider a C code fragment and how it gets
				3779	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3780
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3781	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3782	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3783	struct RT {
				3784	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3785	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3786	char C;
				3787	};
				3788	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3789	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3790	double Y;
				3791	struct RT Z;
				3792	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3793
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3794	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3795	return &s[1].Z.B[5][13];
				3796	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3797	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3798	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3799
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3800	<p>The LLVM code generated by the GCC frontend is:</p>
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	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3803	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3804	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3805	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3806
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3807	define i32* %foo(%ST* %s) {
				3808	entry:
				3809	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3810	ret i32* %reg
				3811	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3812	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3813	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3814
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3815	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3816
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3817	<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]	3818	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]	3819	}</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]	3820	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3821	i8 }</tt>' type, another structure. The third index indexes into the second
				3822	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]	3823	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3824	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3825	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]	3826
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3827	<p>Note that it is perfectly legal to index partially through a
				3828	structure, returning a pointer to an inner element. Because of this,
				3829	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3830
				3831	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3832	define i32* %foo(%ST* %s) {
				3833	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3834	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3835	%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]	3836	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3837	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3838	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3839	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3840	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3841
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3842	<p>Note that it is undefined to access an array out of bounds: array
				3843	and pointer indexes must always be within the defined bounds of the
				3844	array type when accessed with an instruction that dereferences the
				3845	pointer (e.g. a load or store instruction). The one exception for
				3846	this rule is zero length arrays. These arrays are defined to be
				3847	accessible as variable length arrays, which requires access beyond the
				3848	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3849
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3850	<p>The getelementptr instruction is often confusing. For some more insight
				3851	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3852	FAQ</a>.</p>
				3853
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3854	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3855
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3856	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3857	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3858	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3859	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3860	%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]	3861	<i>; yields i8*:eptr</i>
				3862	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3863	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3864	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3865	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3866	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3867
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3868	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3869	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3870	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3871	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3872	<p>The instructions in this category are the conversion instructions (casting)
				3873	which all take a single operand and a type. They perform various bit conversions
				3874	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3875	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3876
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3877	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3878	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3879	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3880	</div>
				3881	<div class="doc_text">
				3882
				3883	<h5>Syntax:</h5>
				3884	<pre>
				3885	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3886	</pre>
				3887
				3888	<h5>Overview:</h5>
				3889	<p>
				3890	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3891	</p>
				3892
				3893	<h5>Arguments:</h5>
				3894	<p>
				3895	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3896	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]	3897	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]	3898	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3899	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3900
				3901	<h5>Semantics:</h5>
				3902	<p>
				3903	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]	3904	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3905	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3906	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3907
				3908	<h5>Example:</h5>
				3909	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3910	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3911	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3912	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3913	</pre>
				3914	</div>
				3915
				3916	<!-- _______________________________________________________________________ -->
				3917	<div class="doc_subsubsection">
				3918	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3919	</div>
				3920	<div class="doc_text">
				3921
				3922	<h5>Syntax:</h5>
				3923	<pre>
				3924	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3925	</pre>
				3926
				3927	<h5>Overview:</h5>
				3928	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3929	<tt>ty2</tt>.</p>
				3930
				3931
				3932	<h5>Arguments:</h5>
				3933	<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]	3934	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3935	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]	3936	<tt>value</tt> must be smaller than the bit size of the destination type,
				3937	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3938
				3939	<h5>Semantics:</h5>
				3940	<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]	3941	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]	3942
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3943	<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]	3944
				3945	<h5>Example:</h5>
				3946	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3947	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3948	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3949	</pre>
				3950	</div>
				3951
				3952	<!-- _______________________________________________________________________ -->
				3953	<div class="doc_subsubsection">
				3954	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3955	</div>
				3956	<div class="doc_text">
				3957
				3958	<h5>Syntax:</h5>
				3959	<pre>
				3960	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3961	</pre>
				3962
				3963	<h5>Overview:</h5>
				3964	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3965
				3966	<h5>Arguments:</h5>
				3967	<p>
				3968	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]	3969	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3970	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]	3971	<tt>value</tt> must be smaller than the bit size of the destination type,
				3972	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3973
				3974	<h5>Semantics:</h5>
				3975	<p>
				3976	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3977	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]	3978	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3979
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3980	<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]	3981
				3982	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3983	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3984	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3985	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3986	</pre>
				3987	</div>
				3988
				3989	<!-- _______________________________________________________________________ -->
				3990	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3991	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3992	</div>
				3993
				3994	<div class="doc_text">
				3995
				3996	<h5>Syntax:</h5>
				3997
				3998	<pre>
				3999	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				4000	</pre>
				4001
				4002	<h5>Overview:</h5>
				4003	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				4004	<tt>ty2</tt>.</p>
				4005
				4006
				4007	<h5>Arguments:</h5>
				4008	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4009	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4010	cast it to. The size of <tt>value</tt> must be larger than the size of
				4011	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4012	<i>no-op cast</i>.</p>
				4013
				4014	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4015	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4016	<a href="#t_floating">floating point</a> type to a smaller
				4017	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4018	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4019
				4020	<h5>Example:</h5>
				4021	<pre>
				4022	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4023	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4024	</pre>
				4025	</div>
				4026
				4027	<!-- _______________________________________________________________________ -->
				4028	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4029	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4030	</div>
				4031	<div class="doc_text">
				4032
				4033	<h5>Syntax:</h5>
				4034	<pre>
				4035	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4036	</pre>
				4037
				4038	<h5>Overview:</h5>
				4039	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4040	floating point value.</p>
				4041
				4042	<h5>Arguments:</h5>
				4043	<p>The '<tt>fpext</tt>' instruction takes a
				4044	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4045	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4046	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4047
				4048	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4049	<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]	4050	<a href="#t_floating">floating point</a> type to a larger
				4051	<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]	4052	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]	4053	<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]	4054
				4055	<h5>Example:</h5>
				4056	<pre>
				4057	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4058	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4059	</pre>
				4060	</div>
				4061
				4062	<!-- _______________________________________________________________________ -->
				4063	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4064	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4065	</div>
				4066	<div class="doc_text">
				4067
				4068	<h5>Syntax:</h5>
				4069	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4070	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4071	</pre>
				4072
				4073	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4074	<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]	4075	unsigned integer equivalent of type <tt>ty2</tt>.
				4076	</p>
				4077
				4078	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4079	<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]	4080	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4081	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4082	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4083	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]	4084
				4085	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4086	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4087	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4088	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4089	the results are undefined.</p>
				4090
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4091	<h5>Example:</h5>
				4092	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4093	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4094	%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]	4095	%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]	4096	</pre>
				4097	</div>
				4098
				4099	<!-- _______________________________________________________________________ -->
				4100	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4101	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4102	</div>
				4103	<div class="doc_text">
				4104
				4105	<h5>Syntax:</h5>
				4106	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4107	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4108	</pre>
				4109
				4110	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4111	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4112	<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]	4113	</p>
				4114
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4115	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4116	<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]	4117	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4118	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4119	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4120	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]	4121
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4122	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4123	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4124	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4125	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4126	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4127
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4128	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4129	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4130	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4131	%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]	4132	%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]	4133	</pre>
				4134	</div>
				4135
				4136	<!-- _______________________________________________________________________ -->
				4137	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4138	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4139	</div>
				4140	<div class="doc_text">
				4141
				4142	<h5>Syntax:</h5>
				4143	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4144	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4145	</pre>
				4146
				4147	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4148	<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]	4149	integer and converts that value to the <tt>ty2</tt> type.</p>
				4150
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4151	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4152	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4153	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4154	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4155	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4156	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]	4157
				4158	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4159	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4160	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4161	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]	4162
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4163	<h5>Example:</h5>
				4164	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4165	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4166	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4167	</pre>
				4168	</div>
				4169
				4170	<!-- _______________________________________________________________________ -->
				4171	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4172	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4173	</div>
				4174	<div class="doc_text">
				4175
				4176	<h5>Syntax:</h5>
				4177	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4178	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4179	</pre>
				4180
				4181	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4182	<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]	4183	integer and converts that value to the <tt>ty2</tt> type.</p>
				4184
				4185	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4186	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4187	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4188	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4189	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4190	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]	4191
				4192	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4193	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4194	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4195	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]	4196
				4197	<h5>Example:</h5>
				4198	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4199	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4200	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4201	</pre>
				4202	</div>
				4203
				4204	<!-- _______________________________________________________________________ -->
				4205	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4206	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4207	</div>
				4208	<div class="doc_text">
				4209
				4210	<h5>Syntax:</h5>
				4211	<pre>
				4212	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4213	</pre>
				4214
				4215	<h5>Overview:</h5>
				4216	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4217	the integer type <tt>ty2</tt>.</p>
				4218
				4219	<h5>Arguments:</h5>
				4220	<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]	4221	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]	4222	<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]	4223
				4224	<h5>Semantics:</h5>
				4225	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4226	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4227	truncating or zero extending that value to the size of the integer type. If
				4228	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4229	<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]	4230	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4231	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4232
				4233	<h5>Example:</h5>
				4234	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4235	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4236	%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]	4237	</pre>
				4238	</div>
				4239
				4240	<!-- _______________________________________________________________________ -->
				4241	<div class="doc_subsubsection">
				4242	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4243	</div>
				4244	<div class="doc_text">
				4245
				4246	<h5>Syntax:</h5>
				4247	<pre>
				4248	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4249	</pre>
				4250
				4251	<h5>Overview:</h5>
				4252	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4253	a pointer type, <tt>ty2</tt>.</p>
				4254
				4255	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4256	<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]	4257	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]	4258	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4259
				4260	<h5>Semantics:</h5>
				4261	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4262	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4263	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4264	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4265	the size of a pointer then a zero extension is done. If they are the same size,
				4266	nothing is done (<i>no-op cast</i>).</p>
				4267
				4268	<h5>Example:</h5>
				4269	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4270	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4271	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4272	%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]	4273	</pre>
				4274	</div>
				4275
				4276	<!-- _______________________________________________________________________ -->
				4277	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4278	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4279	</div>
				4280	<div class="doc_text">
				4281
				4282	<h5>Syntax:</h5>
				4283	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4284	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4285	</pre>
				4286
				4287	<h5>Overview:</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 converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4290	<tt>ty2</tt> without changing any bits.</p>
				4291
				4292	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4293
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4294	<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]	4295	a non-aggregate first class value, and a type to cast it to, which must also be
				4296	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4297	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4298	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]	4299	type is a pointer, the destination type must also be a pointer. This
				4300	instruction supports bitwise conversion of vectors to integers and to vectors
				4301	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4302
				4303	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4304	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4305	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4306	this conversion. The conversion is done as if the <tt>value</tt> had been
				4307	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4308	converted to other pointer types with this instruction. To convert pointers to
				4309	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4310	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4311
				4312	<h5>Example:</h5>
				4313	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4314	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4315	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4316	%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]	4317	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4318	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4319
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4320	<!-- ======================================================================= -->
				4321	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4322	<div class="doc_text">
				4323	<p>The instructions in this category are the "miscellaneous"
				4324	instructions, which defy better classification.</p>
				4325	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4326
				4327	<!-- _______________________________________________________________________ -->
				4328	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4329	</div>
				4330	<div class="doc_text">
				4331	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4332	<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]	4333	</pre>
				4334	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4335	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4336	a vector of boolean values based on comparison
				4337	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4338	<h5>Arguments:</h5>
				4339	<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]	4340	the condition code indicating the kind of comparison to perform. It is not
				4341	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4342	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4343	<ol>
				4344	<li><tt>eq</tt>: equal</li>
				4345	<li><tt>ne</tt>: not equal </li>
				4346	<li><tt>ugt</tt>: unsigned greater than</li>
				4347	<li><tt>uge</tt>: unsigned greater or equal</li>
				4348	<li><tt>ult</tt>: unsigned less than</li>
				4349	<li><tt>ule</tt>: unsigned less or equal</li>
				4350	<li><tt>sgt</tt>: signed greater than</li>
				4351	<li><tt>sge</tt>: signed greater or equal</li>
				4352	<li><tt>slt</tt>: signed less than</li>
				4353	<li><tt>sle</tt>: signed less or equal</li>
				4354	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4355	<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]	4356	<a href="#t_pointer">pointer</a>
				4357	or integer <a href="#t_vector">vector</a> typed.
				4358	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4359	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4360	<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]	4361	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4362	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]	4363	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4364	<ol>
				4365	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4366	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4367	</li>
				4368	<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]	4369	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4370	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4371	<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]	4372	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4373	<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]	4374	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4375	<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]	4376	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4377	<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]	4378	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4379	<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]	4380	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4381	<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]	4382	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4383	<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]	4384	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4385	<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]	4386	</ol>
				4387	<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]	4388	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4389	<p>If the operands are integer vectors, then they are compared
				4390	element by element. The result is an <tt>i1</tt> vector with
				4391	the same number of elements as the values being compared.
				4392	Otherwise, the result is an <tt>i1</tt>.
				4393	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4394
				4395	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4396	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4397	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4398	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4399	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4400	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4401	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4402	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4403
				4404	<p>Note that the code generator does not yet support vector types with
				4405	the <tt>icmp</tt> instruction.</p>
				4406
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4407	</div>
				4408
				4409	<!-- _______________________________________________________________________ -->
				4410	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4411	</div>
				4412	<div class="doc_text">
				4413	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4414	<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]	4415	</pre>
				4416	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4417	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4418	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4419	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4420	<p>
				4421	If the operands are floating point scalars, then the result
				4422	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4423	</p>
				4424	<p>If the operands are floating point vectors, then the result type
				4425	is a vector of boolean with the same number of elements as the
				4426	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4427	<h5>Arguments:</h5>
				4428	<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]	4429	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]	4430	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4431	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4432	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4433	<li><tt>oeq</tt>: ordered and equal</li>
				4434	<li><tt>ogt</tt>: ordered and greater than </li>
				4435	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4436	<li><tt>olt</tt>: ordered and less than </li>
				4437	<li><tt>ole</tt>: ordered and less than or equal</li>
				4438	<li><tt>one</tt>: ordered and not equal</li>
				4439	<li><tt>ord</tt>: ordered (no nans)</li>
				4440	<li><tt>ueq</tt>: unordered or equal</li>
				4441	<li><tt>ugt</tt>: unordered or greater than </li>
				4442	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4443	<li><tt>ult</tt>: unordered or less than </li>
				4444	<li><tt>ule</tt>: unordered or less than or equal</li>
				4445	<li><tt>une</tt>: unordered or not equal</li>
				4446	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4447	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4448	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4449	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4450	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4451	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4452	either a <a href="#t_floating">floating point</a> type
				4453	or a <a href="#t_vector">vector</a> of floating point type.
				4454	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4455	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4456	<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]	4457	according to the condition code given as <tt>cond</tt>.
				4458	If the operands are vectors, then the vectors are compared
				4459	element by element.
				4460	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4461	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]	4462	<ol>
				4463	<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]	4464	<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]	4465	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4466	<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]	4467	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4468	<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]	4469	<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]	4470	<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]	4471	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4472	<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]	4473	<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]	4474	<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]	4475	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4476	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4477	<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]	4478	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4479	<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]	4480	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4481	<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]	4482	<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]	4483	<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]	4484	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4485	<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]	4486	<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]	4487	<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]	4488	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4489	<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]	4490	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4491	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4492
				4493	<h5>Example:</h5>
				4494	<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]	4495	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4496	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4497	<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]	4498	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4499
				4500	<p>Note that the code generator does not yet support vector types with
				4501	the <tt>fcmp</tt> instruction.</p>
				4502
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4503	</div>
				4504
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4505	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4506	<div class="doc_subsubsection">
				4507	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4508	</div>
				4509	<div class="doc_text">
				4510	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4511	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4512	</pre>
				4513	<h5>Overview:</h5>
				4514	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4515	element-wise comparison of its two integer vector operands.</p>
				4516	<h5>Arguments:</h5>
				4517	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4518	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]	4519	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4520	<ol>
				4521	<li><tt>eq</tt>: equal</li>
				4522	<li><tt>ne</tt>: not equal </li>
				4523	<li><tt>ugt</tt>: unsigned greater than</li>
				4524	<li><tt>uge</tt>: unsigned greater or equal</li>
				4525	<li><tt>ult</tt>: unsigned less than</li>
				4526	<li><tt>ule</tt>: unsigned less or equal</li>
				4527	<li><tt>sgt</tt>: signed greater than</li>
				4528	<li><tt>sge</tt>: signed greater or equal</li>
				4529	<li><tt>slt</tt>: signed less than</li>
				4530	<li><tt>sle</tt>: signed less or equal</li>
				4531	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4532	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4533	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4534	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4535	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4536	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4537	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4538	identical type as the values being compared. The most significant bit in each
				4539	element is 1 if the element-wise comparison evaluates to true, and is 0
				4540	otherwise. All other bits of the result are undefined. The condition codes
				4541	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4542	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4543
				4544	<h5>Example:</h5>
				4545	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4546	<result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4547	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4548	</pre>
				4549	</div>
				4550
				4551	<!-- _______________________________________________________________________ -->
				4552	<div class="doc_subsubsection">
				4553	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4554	</div>
				4555	<div class="doc_text">
				4556	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4557	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4558	<h5>Overview:</h5>
				4559	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4560	element-wise comparison of its two floating point vector operands. The output
				4561	elements have the same width as the input elements.</p>
				4562	<h5>Arguments:</h5>
				4563	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4564	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]	4565	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4566	<ol>
				4567	<li><tt>false</tt>: no comparison, always returns false</li>
				4568	<li><tt>oeq</tt>: ordered and equal</li>
				4569	<li><tt>ogt</tt>: ordered and greater than </li>
				4570	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4571	<li><tt>olt</tt>: ordered and less than </li>
				4572	<li><tt>ole</tt>: ordered and less than or equal</li>
				4573	<li><tt>one</tt>: ordered and not equal</li>
				4574	<li><tt>ord</tt>: ordered (no nans)</li>
				4575	<li><tt>ueq</tt>: unordered or equal</li>
				4576	<li><tt>ugt</tt>: unordered or greater than </li>
				4577	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4578	<li><tt>ult</tt>: unordered or less than </li>
				4579	<li><tt>ule</tt>: unordered or less than or equal</li>
				4580	<li><tt>une</tt>: unordered or not equal</li>
				4581	<li><tt>uno</tt>: unordered (either nans)</li>
				4582	<li><tt>true</tt>: no comparison, always returns true</li>
				4583	</ol>
				4584	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4585	<a href="#t_floating">floating point</a> typed. They must also be identical
				4586	types.</p>
				4587	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4588	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4589	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4590	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4591	an identical number of elements as the values being compared, and each element
				4592	having identical with to the width of the floating point elements. The most
				4593	significant bit in each element is 1 if the element-wise comparison evaluates to
				4594	true, and is 0 otherwise. All other bits of the result are undefined. The
				4595	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4596	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4597
				4598	<h5>Example:</h5>
				4599	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4600	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4601	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4602
				4603	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4604	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4605	</pre>
				4606	</div>
				4607
				4608	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4609	<div class="doc_subsubsection">
				4610	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4611	</div>
				4612
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4613	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4614
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4615	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4616
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4617	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4618	<h5>Overview:</h5>
				4619	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4620	the SSA graph representing the function.</p>
				4621	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4622
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4623	<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]	4624	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4625	as arguments, with one pair for each predecessor basic block of the
				4626	current block. Only values of <a href="#t_firstclass">first class</a>
				4627	type may be used as the value arguments to the PHI node. Only labels
				4628	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4629
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4630	<p>There must be no non-phi instructions between the start of a basic
				4631	block and the PHI instructions: i.e. PHI instructions must be first in
				4632	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4633
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4634	<p>For the purposes of the SSA form, the use of each incoming value is
				4635	deemed to occur on the edge from the corresponding predecessor block
				4636	to the current block (but after any definition of an '<tt>invoke</tt>'
				4637	instruction's return value on the same edge).</p>
				4638
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4639	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4640
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4641	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4642	specified by the pair corresponding to the predecessor basic block that executed
				4643	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4644
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4645	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4646	<pre>
				4647	Loop: ; Infinite loop that counts from 0 on up...
				4648	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4649	%nextindvar = add i32 %indvar, 1
				4650	br label %Loop
				4651	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4652	</div>
				4653
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4654	<!-- _______________________________________________________________________ -->
				4655	<div class="doc_subsubsection">
				4656	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4657	</div>
				4658
				4659	<div class="doc_text">
				4660
				4661	<h5>Syntax:</h5>
				4662
				4663	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4664	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4665
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4666	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4667	</pre>
				4668
				4669	<h5>Overview:</h5>
				4670
				4671	<p>
				4672	The '<tt>select</tt>' instruction is used to choose one value based on a
				4673	condition, without branching.
				4674	</p>
				4675
				4676
				4677	<h5>Arguments:</h5>
				4678
				4679	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4680	The '<tt>select</tt>' instruction requires an 'i1' value or
				4681	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4682	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]	4683	type. If the val1/val2 are vectors and
				4684	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4685	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4686	</p>
				4687
				4688	<h5>Semantics:</h5>
				4689
				4690	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4691	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]	4692	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4693	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4694	<p>
				4695	If the condition is a vector of i1, then the value arguments must
				4696	be vectors of the same size, and the selection is done element
				4697	by element.
				4698	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4699
				4700	<h5>Example:</h5>
				4701
				4702	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4703	%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]	4704	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4705
				4706	<p>Note that the code generator does not yet support conditions
				4707	with vector type.</p>
				4708
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4709	</div>
				4710
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4711
				4712	<!-- _______________________________________________________________________ -->
				4713	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4714	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4715	</div>
				4716
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4717	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4718
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4719	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4720	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4721	<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]	4722	</pre>
				4723
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4724	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4725
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4726	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4727
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4728	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4729
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4730	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4731
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4732	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4733	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4734	<p>The optional "tail" marker indicates whether the callee function accesses
				4735	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]	4736	function call is eligible for tail call optimization. Note that calls may
				4737	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4738	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4739	</li>
				4740	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4741	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4742	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]	4743	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4744	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4745
				4746	<li>
				4747	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4748	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4749	and '<tt>inreg</tt>' attributes are valid here.</p>
				4750	</li>
				4751
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4752	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4753	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4754	the type of the return value. Functions that return no value are marked
				4755	<tt><a href="#t_void">void</a></tt>.</p>
				4756	</li>
				4757	<li>
				4758	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4759	value being invoked. The argument types must match the types implied by
				4760	this signature. This type can be omitted if the function is not varargs
				4761	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]	4762	</li>
				4763	<li>
				4764	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4765	be invoked. In most cases, this is a direct function invocation, but
				4766	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]	4767	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4768	</li>
				4769	<li>
				4770	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4771	function signature argument types. All arguments must be of
				4772	<a href="#t_firstclass">first class</a> type. If the function signature
				4773	indicates the function accepts a variable number of arguments, the extra
				4774	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4775	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4776	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4777	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4778	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4779	'<tt>readnone</tt>' attributes are valid here.</p>
				4780	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4781	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4782
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4783	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4784
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4785	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4786	transfer to a specified function, with its incoming arguments bound to
				4787	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4788	instruction in the called function, control flow continues with the
				4789	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4790	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4791
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4792	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4793
				4794	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4795	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4796	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4797	%X = tail call i32 @foo() <i>; yields i32</i>
				4798	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4799	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4800
				4801	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4802	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4803	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4804	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4805	%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]	4806	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4807	</pre>
				4808
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4809	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4810
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4811	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4812	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4813	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4814	</div>
				4815
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4816	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4817
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4818	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4819
				4820	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4821	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4822	</pre>
				4823
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4824	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4825
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4826	<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]	4827	the "variable argument" area of a function call. It is used to implement the
				4828	<tt>va_arg</tt> macro in C.</p>
				4829
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4830	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4831
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4832	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4833	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4834	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]	4835	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4836
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4837	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4838
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4839	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4840	type from the specified <tt>va_list</tt> and causes the
				4841	<tt>va_list</tt> to point to the next argument. For more information,
				4842	see the variable argument handling <a href="#int_varargs">Intrinsic
				4843	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4844
				4845	<p>It is legal for this instruction to be called in a function which does not
				4846	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4847	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4848
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4849	<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]	4850	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4851	argument.</p>
				4852
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4853	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4854
				4855	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4856
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4857	<p>Note that the code generator does not yet fully support va_arg
				4858	on many targets. Also, it does not currently support va_arg with
				4859	aggregate types on any target.</p>
				4860
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4861	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4862
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4863	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4864	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4865	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4866
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4867	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4868
				4869	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4870	well known names and semantics and are required to follow certain restrictions.
				4871	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4872	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]	4873	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]	4874
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4875	<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]	4876	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4877	begin with this prefix. Intrinsic functions must always be external functions:
				4878	you cannot define the body of intrinsic functions. Intrinsic functions may
				4879	only be used in call or invoke instructions: it is illegal to take the address
				4880	of an intrinsic function. Additionally, because intrinsic functions are part
				4881	of the LLVM language, it is required if any are added that they be documented
				4882	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4883
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4884	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4885	a family of functions that perform the same operation but on different data
				4886	types. Because LLVM can represent over 8 million different integer types,
				4887	overloading is used commonly to allow an intrinsic function to operate on any
				4888	integer type. One or more of the argument types or the result type can be
				4889	overloaded to accept any integer type. Argument types may also be defined as
				4890	exactly matching a previous argument's type or the result type. This allows an
				4891	intrinsic function which accepts multiple arguments, but needs all of them to
				4892	be of the same type, to only be overloaded with respect to a single argument or
				4893	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4894
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4895	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4896	encoded into its function name, each preceded by a period. Only those types
				4897	which are overloaded result in a name suffix. Arguments whose type is matched
				4898	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4899	take an integer of any width and returns an integer of exactly the same integer
				4900	width. This leads to a family of functions such as
				4901	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4902	Only one type, the return type, is overloaded, and only one type suffix is
				4903	required. Because the argument's type is matched against the return type, it
				4904	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4905
				4906	<p>To learn how to add an intrinsic function, please see the
				4907	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4908	</p>
				4909
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4910	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4911
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4912	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4913	<div class="doc_subsection">
				4914	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4915	</div>
				4916
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4917	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4918
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4919	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4920	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]	4921	intrinsic functions. These functions are related to the similarly
				4922	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4923
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4924	<p>All of these functions operate on arguments that use a
				4925	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4926	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4927	transformations should be prepared to handle these functions regardless of
				4928	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4929
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4930	<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]	4931	instruction and the variable argument handling intrinsic functions are
				4932	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4933
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4934	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4935	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4936	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4937	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4938	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4939	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4940	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4941
				4942	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4943	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4944
				4945	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4946	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4947	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4948	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4949	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4950
				4951	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4952	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4953	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4954	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4955
				4956	declare void @llvm.va_start(i8*)
				4957	declare void @llvm.va_copy(i8, i8)
				4958	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4959	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4960	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4961
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4962	</div>
				4963
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4964	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4965	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4966	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4967	</div>
				4968
				4969
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4970	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4971	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4972	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4973	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4974	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4975	<tt>*<arglist></tt> for subsequent use by <tt><a
				4976	href="#i_va_arg">va_arg</a></tt>.</p>
				4977
				4978	<h5>Arguments:</h5>
				4979
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4980	<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]	4981
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4982	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4983
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4984	<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]	4985	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4986	<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]	4987	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4988	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]	4989	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]	4990
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4991	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4992
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4993	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4994	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4995	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4996	</div>
				4997
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4998	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4999	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5000	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5001	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5002
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5003	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5004	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]	5005	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]	5006
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5007	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5008
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5009	<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]	5010
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5011	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5012
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5013	<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]	5014	macro available in C. In a target-dependent way, it destroys the
				5015	<tt>va_list</tt> element to which the argument points. Calls to <a
				5016	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				5017	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				5018	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5019
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5020	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5021
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5022	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5023	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5024	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5025	</div>
				5026
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5027	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5028
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5029	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5030
				5031	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5032	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5033	</pre>
				5034
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5035	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5036
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5037	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				5038	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5039
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5040	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5041
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	5042	<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]	5043	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]	5044
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5045
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5046	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5047
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5048	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				5049	macro available in C. In a target-dependent way, it copies the source
				5050	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				5051	intrinsic is necessary because the <tt><a href="#int_va_start">
				5052	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				5053	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5054
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5055	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5056
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5057	<!-- ======================================================================= -->
				5058	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5059	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				5060	</div>
				5061
				5062	<div class="doc_text">
				5063
				5064	<p>
				5065	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5066	Collection</a> (GC) requires the implementation and generation of these
				5067	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5068	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]	5069	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5070	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]	5071	Front-ends for type-safe garbage collected languages should generate these
				5072	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				5073	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				5074	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	5075
				5076	<p>The garbage collection intrinsics only operate on objects in the generic
				5077	address space (address space zero).</p>
				5078
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5079	</div>
				5080
				5081	<!-- _______________________________________________________________________ -->
				5082	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5083	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5084	</div>
				5085
				5086	<div class="doc_text">
				5087
				5088	<h5>Syntax:</h5>
				5089
				5090	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5091	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5092	</pre>
				5093
				5094	<h5>Overview:</h5>
				5095
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	5096	<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]	5097	the code generator, and allows some metadata to be associated with it.</p>
				5098
				5099	<h5>Arguments:</h5>
				5100
				5101	<p>The first argument specifies the address of a stack object that contains the
				5102	root pointer. The second pointer (which must be either a constant or a global
				5103	value address) contains the meta-data to be associated with the root.</p>
				5104
				5105	<h5>Semantics:</h5>
				5106
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	5107	<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]	5108	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5109	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5110	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5111	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5112
				5113	</div>
				5114
				5115
				5116	<!-- _______________________________________________________________________ -->
				5117	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5118	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5119	</div>
				5120
				5121	<div class="doc_text">
				5122
				5123	<h5>Syntax:</h5>
				5124
				5125	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5126	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5127	</pre>
				5128
				5129	<h5>Overview:</h5>
				5130
				5131	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5132	locations, allowing garbage collector implementations that require read
				5133	barriers.</p>
				5134
				5135	<h5>Arguments:</h5>
				5136
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5137	<p>The second argument is the address to read from, which should be an address
				5138	allocated from the garbage collector. The first object is a pointer to the
				5139	start of the referenced object, if needed by the language runtime (otherwise
				5140	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5141
				5142	<h5>Semantics:</h5>
				5143
				5144	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5145	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5146	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5147	may only be used in a function which <a href="#gc">specifies a GC
				5148	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5149
				5150	</div>
				5151
				5152
				5153	<!-- _______________________________________________________________________ -->
				5154	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5155	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5156	</div>
				5157
				5158	<div class="doc_text">
				5159
				5160	<h5>Syntax:</h5>
				5161
				5162	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5163	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5164	</pre>
				5165
				5166	<h5>Overview:</h5>
				5167
				5168	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5169	locations, allowing garbage collector implementations that require write
				5170	barriers (such as generational or reference counting collectors).</p>
				5171
				5172	<h5>Arguments:</h5>
				5173
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5174	<p>The first argument is the reference to store, the second is the start of the
				5175	object to store it to, and the third is the address of the field of Obj to
				5176	store to. If the runtime does not require a pointer to the object, Obj may be
				5177	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5178
				5179	<h5>Semantics:</h5>
				5180
				5181	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5182	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5183	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5184	may only be used in a function which <a href="#gc">specifies a GC
				5185	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5186
				5187	</div>
				5188
				5189
				5190
				5191	<!-- ======================================================================= -->
				5192	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5193	<a name="int_codegen">Code Generator Intrinsics</a>
				5194	</div>
				5195
				5196	<div class="doc_text">
				5197	<p>
				5198	These intrinsics are provided by LLVM to expose special features that may only
				5199	be implemented with code generator support.
				5200	</p>
				5201
				5202	</div>
				5203
				5204	<!-- _______________________________________________________________________ -->
				5205	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5206	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5207	</div>
				5208
				5209	<div class="doc_text">
				5210
				5211	<h5>Syntax:</h5>
				5212	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5213	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5214	</pre>
				5215
				5216	<h5>Overview:</h5>
				5217
				5218	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5219	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5220	target-specific value indicating the return address of the current function
				5221	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5222	</p>
				5223
				5224	<h5>Arguments:</h5>
				5225
				5226	<p>
				5227	The argument to this intrinsic indicates which function to return the address
				5228	for. Zero indicates the calling function, one indicates its caller, etc. The
				5229	argument is <b>required</b> to be a constant integer value.
				5230	</p>
				5231
				5232	<h5>Semantics:</h5>
				5233
				5234	<p>
				5235	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5236	the return address of the specified call frame, or zero if it cannot be
				5237	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5238	for arguments other than zero, so it should only be used for debugging purposes.
				5239	</p>
				5240
				5241	<p>
				5242	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5243	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]	5244	source-language caller.
				5245	</p>
				5246	</div>
				5247
				5248
				5249	<!-- _______________________________________________________________________ -->
				5250	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5251	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5252	</div>
				5253
				5254	<div class="doc_text">
				5255
				5256	<h5>Syntax:</h5>
				5257	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5258	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5259	</pre>
				5260
				5261	<h5>Overview:</h5>
				5262
				5263	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5264	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5265	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5266	</p>
				5267
				5268	<h5>Arguments:</h5>
				5269
				5270	<p>
				5271	The argument to this intrinsic indicates which function to return the frame
				5272	pointer for. Zero indicates the calling function, one indicates its caller,
				5273	etc. The argument is <b>required</b> to be a constant integer value.
				5274	</p>
				5275
				5276	<h5>Semantics:</h5>
				5277
				5278	<p>
				5279	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5280	the frame address of the specified call frame, or zero if it cannot be
				5281	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5282	for arguments other than zero, so it should only be used for debugging purposes.
				5283	</p>
				5284
				5285	<p>
				5286	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5287	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]	5288	source-language caller.
				5289	</p>
				5290	</div>
				5291
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5292	<!-- _______________________________________________________________________ -->
				5293	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5294	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5295	</div>
				5296
				5297	<div class="doc_text">
				5298
				5299	<h5>Syntax:</h5>
				5300	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5301	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5302	</pre>
				5303
				5304	<h5>Overview:</h5>
				5305
				5306	<p>
				5307	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]	5308	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5309	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5310	features like scoped automatic variable sized arrays in C99.
				5311	</p>
				5312
				5313	<h5>Semantics:</h5>
				5314
				5315	<p>
				5316	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]	5317	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5318	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5319	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5320	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5321	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5322	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5323	</p>
				5324
				5325	</div>
				5326
				5327	<!-- _______________________________________________________________________ -->
				5328	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5329	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5330	</div>
				5331
				5332	<div class="doc_text">
				5333
				5334	<h5>Syntax:</h5>
				5335	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5336	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5337	</pre>
				5338
				5339	<h5>Overview:</h5>
				5340
				5341	<p>
				5342	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5343	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]	5344	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5345	useful for implementing language features like scoped automatic variable sized
				5346	arrays in C99.
				5347	</p>
				5348
				5349	<h5>Semantics:</h5>
				5350
				5351	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5352	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]	5353	</p>
				5354
				5355	</div>
				5356
				5357
				5358	<!-- _______________________________________________________________________ -->
				5359	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5360	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5361	</div>
				5362
				5363	<div class="doc_text">
				5364
				5365	<h5>Syntax:</h5>
				5366	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5367	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5368	</pre>
				5369
				5370	<h5>Overview:</h5>
				5371
				5372
				5373	<p>
				5374	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]	5375	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5376	no
				5377	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5378	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5379	</p>
				5380
				5381	<h5>Arguments:</h5>
				5382
				5383	<p>
				5384	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5385	determining if the fetch should be for a read (0) or write (1), and
				5386	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5387	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]	5388	<tt>locality</tt> arguments must be constant integers.
				5389	</p>
				5390
				5391	<h5>Semantics:</h5>
				5392
				5393	<p>
				5394	This intrinsic does not modify the behavior of the program. In particular,
				5395	prefetches cannot trap and do not produce a value. On targets that support this
				5396	intrinsic, the prefetch can provide hints to the processor cache for better
				5397	performance.
				5398	</p>
				5399
				5400	</div>
				5401
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5402	<!-- _______________________________________________________________________ -->
				5403	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5404	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5405	</div>
				5406
				5407	<div class="doc_text">
				5408
				5409	<h5>Syntax:</h5>
				5410	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5411	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5412	</pre>
				5413
				5414	<h5>Overview:</h5>
				5415
				5416
				5417	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5418	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]	5419	(PC) in a region of
				5420	code to simulators and other tools. The method is target specific, but it is
				5421	expected that the marker will use exported symbols to transmit the PC of the
				5422	marker.
				5423	The marker makes no guarantees that it will remain with any specific instruction
				5424	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]	5425	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5426	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5427	</p>
				5428
				5429	<h5>Arguments:</h5>
				5430
				5431	<p>
				5432	<tt>id</tt> is a numerical id identifying the marker.
				5433	</p>
				5434
				5435	<h5>Semantics:</h5>
				5436
				5437	<p>
				5438	This intrinsic does not modify the behavior of the program. Backends that do not
				5439	support this intrinisic may ignore it.
				5440	</p>
				5441
				5442	</div>
				5443
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +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_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5447	</div>
				5448
				5449	<div class="doc_text">
				5450
				5451	<h5>Syntax:</h5>
				5452	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5453	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5454	</pre>
				5455
				5456	<h5>Overview:</h5>
				5457
				5458
				5459	<p>
				5460	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5461	counter register (or similar low latency, high accuracy clocks) on those targets
				5462	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5463	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5464	should only be used for small timings.
				5465	</p>
				5466
				5467	<h5>Semantics:</h5>
				5468
				5469	<p>
				5470	When directly supported, reading the cycle counter should not modify any memory.
				5471	Implementations are allowed to either return a application specific value or a
				5472	system wide value. On backends without support, this is lowered to a constant 0.
				5473	</p>
				5474
				5475	</div>
				5476
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5477	<!-- ======================================================================= -->
				5478	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5479	<a name="int_libc">Standard C Library Intrinsics</a>
				5480	</div>
				5481
				5482	<div class="doc_text">
				5483	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5484	LLVM provides intrinsics for a few important standard C library functions.
				5485	These intrinsics allow source-language front-ends to pass information about the
				5486	alignment of the pointer arguments to the code generator, providing opportunity
				5487	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5488	</p>
				5489
				5490	</div>
				5491
				5492	<!-- _______________________________________________________________________ -->
				5493	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5494	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5495	</div>
				5496
				5497	<div class="doc_text">
				5498
				5499	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5500	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5501	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5502	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5503	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5504	i8 <len>, i32 <align>)
				5505	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5506	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5507	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5508	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5509	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5510	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5511	</pre>
				5512
				5513	<h5>Overview:</h5>
				5514
				5515	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5516	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]	5517	location to the destination location.
				5518	</p>
				5519
				5520	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5521	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5522	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5523	</p>
				5524
				5525	<h5>Arguments:</h5>
				5526
				5527	<p>
				5528	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]	5529	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5530	specifying the number of bytes to copy, and the fourth argument is the alignment
				5531	of the source and destination locations.
				5532	</p>
				5533
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5534	<p>
				5535	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]	5536	the caller guarantees that both the source and destination pointers are aligned
				5537	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5538	</p>
				5539
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5540	<h5>Semantics:</h5>
				5541
				5542	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5543	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]	5544	location to the destination location, which are not allowed to overlap. It
				5545	copies "len" bytes of memory over. If the argument is known to be aligned to
				5546	some boundary, this can be specified as the fourth argument, otherwise it should
				5547	be set to 0 or 1.
				5548	</p>
				5549	</div>
				5550
				5551
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5552	<!-- _______________________________________________________________________ -->
				5553	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5554	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5555	</div>
				5556
				5557	<div class="doc_text">
				5558
				5559	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5560	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5561	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5562	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5563	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5564	i8 <len>, i32 <align>)
				5565	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5566	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5567	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5568	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5569	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5570	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5571	</pre>
				5572
				5573	<h5>Overview:</h5>
				5574
				5575	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5576	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5577	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5578	'<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]	5579	</p>
				5580
				5581	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5582	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5583	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5584	</p>
				5585
				5586	<h5>Arguments:</h5>
				5587
				5588	<p>
				5589	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]	5590	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5591	specifying the number of bytes to copy, and the fourth argument is the alignment
				5592	of the source and destination locations.
				5593	</p>
				5594
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5595	<p>
				5596	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]	5597	the caller guarantees that the source and destination pointers are aligned to
				5598	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5599	</p>
				5600
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5601	<h5>Semantics:</h5>
				5602
				5603	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5604	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]	5605	location to the destination location, which may overlap. It
				5606	copies "len" bytes of memory over. If the argument is known to be aligned to
				5607	some boundary, this can be specified as the fourth argument, otherwise it should
				5608	be set to 0 or 1.
				5609	</p>
				5610	</div>
				5611
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5612
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5613	<!-- _______________________________________________________________________ -->
				5614	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5615	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5616	</div>
				5617
				5618	<div class="doc_text">
				5619
				5620	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5621	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5622	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5623	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5624	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5625	i8 <len>, i32 <align>)
				5626	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5627	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5628	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5629	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5630	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5631	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5632	</pre>
				5633
				5634	<h5>Overview:</h5>
				5635
				5636	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5637	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]	5638	byte value.
				5639	</p>
				5640
				5641	<p>
				5642	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5643	does not return a value, and takes an extra alignment argument.
				5644	</p>
				5645
				5646	<h5>Arguments:</h5>
				5647
				5648	<p>
				5649	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]	5650	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5651	argument specifying the number of bytes to fill, and the fourth argument is the
				5652	known alignment of destination location.
				5653	</p>
				5654
				5655	<p>
				5656	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]	5657	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5658	</p>
				5659
				5660	<h5>Semantics:</h5>
				5661
				5662	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5663	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5664	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5665	destination location. If the argument is known to be aligned to some boundary,
				5666	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5667	1.
				5668	</p>
				5669	</div>
				5670
				5671
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5672	<!-- _______________________________________________________________________ -->
				5673	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5674	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5675	</div>
				5676
				5677	<div class="doc_text">
				5678
				5679	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5680	<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]	5681	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]	5682	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5683	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5684	declare float @llvm.sqrt.f32(float %Val)
				5685	declare double @llvm.sqrt.f64(double %Val)
				5686	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5687	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5688	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5689	</pre>
				5690
				5691	<h5>Overview:</h5>
				5692
				5693	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5694	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]	5695	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]	5696	<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]	5697	negative numbers other than -0.0 (which allows for better optimization, because
				5698	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5699	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5700	</p>
				5701
				5702	<h5>Arguments:</h5>
				5703
				5704	<p>
				5705	The argument and return value are floating point numbers of the same type.
				5706	</p>
				5707
				5708	<h5>Semantics:</h5>
				5709
				5710	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5711	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]	5712	floating point number.
				5713	</p>
				5714	</div>
				5715
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5716	<!-- _______________________________________________________________________ -->
				5717	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5718	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5719	</div>
				5720
				5721	<div class="doc_text">
				5722
				5723	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5724	<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]	5725	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]	5726	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5727	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5728	declare float @llvm.powi.f32(float %Val, i32 %power)
				5729	declare double @llvm.powi.f64(double %Val, i32 %power)
				5730	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5731	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5732	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5733	</pre>
				5734
				5735	<h5>Overview:</h5>
				5736
				5737	<p>
				5738	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5739	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5740	multiplications is not defined. When a vector of floating point type is
				5741	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5742	</p>
				5743
				5744	<h5>Arguments:</h5>
				5745
				5746	<p>
				5747	The second argument is an integer power, and the first is a value to raise to
				5748	that power.
				5749	</p>
				5750
				5751	<h5>Semantics:</h5>
				5752
				5753	<p>
				5754	This function returns the first value raised to the second power with an
				5755	unspecified sequence of rounding operations.</p>
				5756	</div>
				5757
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5758	<!-- _______________________________________________________________________ -->
				5759	<div class="doc_subsubsection">
				5760	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5761	</div>
				5762
				5763	<div class="doc_text">
				5764
				5765	<h5>Syntax:</h5>
				5766	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5767	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]	5768	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5769	<pre>
				5770	declare float @llvm.sin.f32(float %Val)
				5771	declare double @llvm.sin.f64(double %Val)
				5772	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5773	declare fp128 @llvm.sin.f128(fp128 %Val)
				5774	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5775	</pre>
				5776
				5777	<h5>Overview:</h5>
				5778
				5779	<p>
				5780	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5781	</p>
				5782
				5783	<h5>Arguments:</h5>
				5784
				5785	<p>
				5786	The argument and return value are floating point numbers of the same type.
				5787	</p>
				5788
				5789	<h5>Semantics:</h5>
				5790
				5791	<p>
				5792	This function returns the sine of the specified operand, returning the
				5793	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]	5794	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5795	</div>
				5796
				5797	<!-- _______________________________________________________________________ -->
				5798	<div class="doc_subsubsection">
				5799	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5800	</div>
				5801
				5802	<div class="doc_text">
				5803
				5804	<h5>Syntax:</h5>
				5805	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5806	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]	5807	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5808	<pre>
				5809	declare float @llvm.cos.f32(float %Val)
				5810	declare double @llvm.cos.f64(double %Val)
				5811	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5812	declare fp128 @llvm.cos.f128(fp128 %Val)
				5813	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5814	</pre>
				5815
				5816	<h5>Overview:</h5>
				5817
				5818	<p>
				5819	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5820	</p>
				5821
				5822	<h5>Arguments:</h5>
				5823
				5824	<p>
				5825	The argument and return value are floating point numbers of the same type.
				5826	</p>
				5827
				5828	<h5>Semantics:</h5>
				5829
				5830	<p>
				5831	This function returns the cosine of the specified operand, returning the
				5832	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]	5833	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5834	</div>
				5835
				5836	<!-- _______________________________________________________________________ -->
				5837	<div class="doc_subsubsection">
				5838	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5839	</div>
				5840
				5841	<div class="doc_text">
				5842
				5843	<h5>Syntax:</h5>
				5844	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5845	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]	5846	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5847	<pre>
				5848	declare float @llvm.pow.f32(float %Val, float %Power)
				5849	declare double @llvm.pow.f64(double %Val, double %Power)
				5850	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5851	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5852	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5853	</pre>
				5854
				5855	<h5>Overview:</h5>
				5856
				5857	<p>
				5858	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5859	specified (positive or negative) power.
				5860	</p>
				5861
				5862	<h5>Arguments:</h5>
				5863
				5864	<p>
				5865	The second argument is a floating point power, and the first is a value to
				5866	raise to that power.
				5867	</p>
				5868
				5869	<h5>Semantics:</h5>
				5870
				5871	<p>
				5872	This function returns the first value raised to the second power,
				5873	returning the
				5874	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]	5875	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5876	</div>
				5877
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5878
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5879	<!-- ======================================================================= -->
				5880	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5881	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5882	</div>
				5883
				5884	<div class="doc_text">
				5885	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5886	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5887	These allow efficient code generation for some algorithms.
				5888	</p>
				5889
				5890	</div>
				5891
				5892	<!-- _______________________________________________________________________ -->
				5893	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5894	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5895	</div>
				5896
				5897	<div class="doc_text">
				5898
				5899	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5900	<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]	5901	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]	5902	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5903	declare i16 @llvm.bswap.i16(i16 <id>)
				5904	declare i32 @llvm.bswap.i32(i32 <id>)
				5905	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5906	</pre>
				5907
				5908	<h5>Overview:</h5>
				5909
				5910	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5911	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]	5912	values with an even number of bytes (positive multiple of 16 bits). These are
				5913	useful for performing operations on data that is not in the target's native
				5914	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5915	</p>
				5916
				5917	<h5>Semantics:</h5>
				5918
				5919	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5920	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]	5921	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5922	intrinsic returns an i32 value that has the four bytes of the input i32
				5923	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]	5924	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5925	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5926	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5927	</p>
				5928
				5929	</div>
				5930
				5931	<!-- _______________________________________________________________________ -->
				5932	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5933	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5934	</div>
				5935
				5936	<div class="doc_text">
				5937
				5938	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5939	<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]	5940	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5941	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5942	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5943	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5944	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5945	declare i64 @llvm.ctpop.i64(i64 <src>)
				5946	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5947	</pre>
				5948
				5949	<h5>Overview:</h5>
				5950
				5951	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5952	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5953	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5954	</p>
				5955
				5956	<h5>Arguments:</h5>
				5957
				5958	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5959	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]	5960	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5961	</p>
				5962
				5963	<h5>Semantics:</h5>
				5964
				5965	<p>
				5966	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5967	</p>
				5968	</div>
				5969
				5970	<!-- _______________________________________________________________________ -->
				5971	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5972	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5973	</div>
				5974
				5975	<div class="doc_text">
				5976
				5977	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5978	<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]	5979	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5980	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5981	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5982	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5983	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5984	declare i64 @llvm.ctlz.i64(i64 <src>)
				5985	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5986	</pre>
				5987
				5988	<h5>Overview:</h5>
				5989
				5990	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5991	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5992	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5993	</p>
				5994
				5995	<h5>Arguments:</h5>
				5996
				5997	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5998	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]	5999	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	6000	</p>
				6001
				6002	<h5>Semantics:</h5>
				6003
				6004	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6005	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				6006	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]	6007	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	6008	</p>
				6009	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	6010
				6011
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6012
				6013	<!-- _______________________________________________________________________ -->
				6014	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	6015	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6016	</div>
				6017
				6018	<div class="doc_text">
				6019
				6020	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	6021	<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]	6022	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6023	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6024	declare i8 @llvm.cttz.i8 (i8 <src>)
				6025	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	6026	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6027	declare i64 @llvm.cttz.i64(i64 <src>)
				6028	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6029	</pre>
				6030
				6031	<h5>Overview:</h5>
				6032
				6033	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	6034	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				6035	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6036	</p>
				6037
				6038	<h5>Arguments:</h5>
				6039
				6040	<p>
				6041	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]	6042	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6043	</p>
				6044
				6045	<h5>Semantics:</h5>
				6046
				6047	<p>
				6048	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				6049	in a variable. If the src == 0 then the result is the size in bits of the type
				6050	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				6051	</p>
				6052	</div>
				6053
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	6054	<!-- _______________________________________________________________________ -->
				6055	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6056	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6057	</div>
				6058
				6059	<div class="doc_text">
				6060
				6061	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6062	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6063	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6064	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6065	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				6066	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6067	</pre>
				6068
				6069	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6070	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6071	range of bits from an integer value and returns them in the same bit width as
				6072	the original value.</p>
				6073
				6074	<h5>Arguments:</h5>
				6075	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				6076	any bit width but they must have the same bit width. The second and third
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	6077	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6078
				6079	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6080	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	6081	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				6082	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				6083	operates in forward mode.</p>
				6084	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				6085	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6086	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				6087	<ol>
				6088	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				6089	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				6090	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				6091	to determine the number of bits to retain.</li>
				6092	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6093	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6094	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	6095	<p>In reverse mode, a similar computation is made except that the bits are
				6096	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				6097	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				6098	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				6099	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6100	</div>
				6101
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6102	<div class="doc_subsubsection">
				6103	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				6104	</div>
				6105
				6106	<div class="doc_text">
				6107
				6108	<h5>Syntax:</h5>
				6109	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6110	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6111	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6112	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6113	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6114	</pre>
				6115
				6116	<h5>Overview:</h5>
				6117	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6118	of bits in an integer value with another integer value. It returns the integer
				6119	with the replaced bits.</p>
				6120
				6121	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6122	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6123	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6124	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6125	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6126	type since they specify only a bit index.</p>
				6127
				6128	<h5>Semantics:</h5>
				6129	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6130	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6131	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6132	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6133
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6134	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6135	truncating it down to the size of the replacement area or zero extending it
				6136	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6137
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6138	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6139	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6140	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6141	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6142
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6143	<p>In reverse mode, a similar computation is made except that the bits are
				6144	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6145	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6146
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6147	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6148
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6149	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6150	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6151	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6152	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6153	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6154	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	6155	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6156
				6157	</div>
				6158
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6159	<!-- ======================================================================= -->
				6160	<div class="doc_subsection">
				6161	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6162	</div>
				6163
				6164	<div class="doc_text">
				6165	<p>
				6166	LLVM provides intrinsics for some arithmetic with overflow operations.
				6167	</p>
				6168
				6169	</div>
				6170
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6171	<!-- _______________________________________________________________________ -->
				6172	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6173	<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]	6174	</div>
				6175
				6176	<div class="doc_text">
				6177
				6178	<h5>Syntax:</h5>
				6179
				6180	<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]	6181	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6182
				6183	<pre>
				6184	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6185	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6186	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6187	</pre>
				6188
				6189	<h5>Overview:</h5>
				6190
				6191	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6192	a signed addition of the two arguments, and indicate whether an overflow
				6193	occurred during the signed summation.</p>
				6194
				6195	<h5>Arguments:</h5>
				6196
				6197	<p>The arguments (%a and %b) and the first element of the result structure may
				6198	be of integer types of any bit width, but they must have the same bit width. The
				6199	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6200	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6201
				6202	<h5>Semantics:</h5>
				6203
				6204	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6205	a signed addition of the two variables. They return a structure — the
				6206	first element of which is the signed summation, and the second element of which
				6207	is a bit specifying if the signed summation resulted in an overflow.</p>
				6208
				6209	<h5>Examples:</h5>
				6210	<pre>
				6211	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6212	%sum = extractvalue {i32, i1} %res, 0
				6213	%obit = extractvalue {i32, i1} %res, 1
				6214	br i1 %obit, label %overflow, label %normal
				6215	</pre>
				6216
				6217	</div>
				6218
				6219	<!-- _______________________________________________________________________ -->
				6220	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6221	<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]	6222	</div>
				6223
				6224	<div class="doc_text">
				6225
				6226	<h5>Syntax:</h5>
				6227
				6228	<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]	6229	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6230
				6231	<pre>
				6232	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6233	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6234	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6235	</pre>
				6236
				6237	<h5>Overview:</h5>
				6238
				6239	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6240	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6241	during the unsigned summation.</p>
				6242
				6243	<h5>Arguments:</h5>
				6244
				6245	<p>The arguments (%a and %b) and the first element of the result structure may
				6246	be of integer types of any bit width, but they must have the same bit width. The
				6247	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6248	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6249
				6250	<h5>Semantics:</h5>
				6251
				6252	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6253	an unsigned addition of the two arguments. They return a structure — the
				6254	first element of which is the sum, and the second element of which is a bit
				6255	specifying if the unsigned summation resulted in a carry.</p>
				6256
				6257	<h5>Examples:</h5>
				6258	<pre>
				6259	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6260	%sum = extractvalue {i32, i1} %res, 0
				6261	%obit = extractvalue {i32, i1} %res, 1
				6262	br i1 %obit, label %carry, label %normal
				6263	</pre>
				6264
				6265	</div>
				6266
				6267	<!-- _______________________________________________________________________ -->
				6268	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6269	<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]	6270	</div>
				6271
				6272	<div class="doc_text">
				6273
				6274	<h5>Syntax:</h5>
				6275
				6276	<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]	6277	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6278
				6279	<pre>
				6280	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6281	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6282	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6283	</pre>
				6284
				6285	<h5>Overview:</h5>
				6286
				6287	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6288	a signed subtraction of the two arguments, and indicate whether an overflow
				6289	occurred during the signed subtraction.</p>
				6290
				6291	<h5>Arguments:</h5>
				6292
				6293	<p>The arguments (%a and %b) and the first element of the result structure may
				6294	be of integer types of any bit width, but they must have the same bit width. The
				6295	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6296	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6297
				6298	<h5>Semantics:</h5>
				6299
				6300	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6301	a signed subtraction of the two arguments. They return a structure — the
				6302	first element of which is the subtraction, and the second element of which is a bit
				6303	specifying if the signed subtraction resulted in an overflow.</p>
				6304
				6305	<h5>Examples:</h5>
				6306	<pre>
				6307	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6308	%sum = extractvalue {i32, i1} %res, 0
				6309	%obit = extractvalue {i32, i1} %res, 1
				6310	br i1 %obit, label %overflow, label %normal
				6311	</pre>
				6312
				6313	</div>
				6314
				6315	<!-- _______________________________________________________________________ -->
				6316	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6317	<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]	6318	</div>
				6319
				6320	<div class="doc_text">
				6321
				6322	<h5>Syntax:</h5>
				6323
				6324	<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]	6325	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6326
				6327	<pre>
				6328	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6329	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6330	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6331	</pre>
				6332
				6333	<h5>Overview:</h5>
				6334
				6335	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6336	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6337	occurred during the unsigned subtraction.</p>
				6338
				6339	<h5>Arguments:</h5>
				6340
				6341	<p>The arguments (%a and %b) and the first element of the result structure may
				6342	be of integer types of any bit width, but they must have the same bit width. The
				6343	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6344	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6345
				6346	<h5>Semantics:</h5>
				6347
				6348	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6349	an unsigned subtraction of the two arguments. They return a structure — the
				6350	first element of which is the subtraction, and the second element of which is a bit
				6351	specifying if the unsigned subtraction resulted in an overflow.</p>
				6352
				6353	<h5>Examples:</h5>
				6354	<pre>
				6355	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6356	%sum = extractvalue {i32, i1} %res, 0
				6357	%obit = extractvalue {i32, i1} %res, 1
				6358	br i1 %obit, label %overflow, label %normal
				6359	</pre>
				6360
				6361	</div>
				6362
				6363	<!-- _______________________________________________________________________ -->
				6364	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6365	<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]	6366	</div>
				6367
				6368	<div class="doc_text">
				6369
				6370	<h5>Syntax:</h5>
				6371
				6372	<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]	6373	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6374
				6375	<pre>
				6376	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6377	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6378	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6379	</pre>
				6380
				6381	<h5>Overview:</h5>
				6382
				6383	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6384	a signed multiplication of the two arguments, and indicate whether an overflow
				6385	occurred during the signed multiplication.</p>
				6386
				6387	<h5>Arguments:</h5>
				6388
				6389	<p>The arguments (%a and %b) and the first element of the result structure may
				6390	be of integer types of any bit width, but they must have the same bit width. The
				6391	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6392	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6393
				6394	<h5>Semantics:</h5>
				6395
				6396	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6397	a signed multiplication of the two arguments. They return a structure —
				6398	the first element of which is the multiplication, and the second element of
				6399	which is a bit specifying if the signed multiplication resulted in an
				6400	overflow.</p>
				6401
				6402	<h5>Examples:</h5>
				6403	<pre>
				6404	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6405	%sum = extractvalue {i32, i1} %res, 0
				6406	%obit = extractvalue {i32, i1} %res, 1
				6407	br i1 %obit, label %overflow, label %normal
				6408	</pre>
				6409
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6410	</div>
				6411
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6412	<!-- _______________________________________________________________________ -->
				6413	<div class="doc_subsubsection">
				6414	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6415	</div>
				6416
				6417	<div class="doc_text">
				6418
				6419	<h5>Syntax:</h5>
				6420
				6421	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6422	on any integer bit width.</p>
				6423
				6424	<pre>
				6425	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6426	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6427	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6428	</pre>
				6429
				6430	<h5>Overview:</h5>
				6431
				6432	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6433	actively being fixed, but it should not currently be used!</i></p>
				6434
				6435	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6436	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6437	occurred during the unsigned multiplication.</p>
				6438
				6439	<h5>Arguments:</h5>
				6440
				6441	<p>The arguments (%a and %b) and the first element of the result structure may
				6442	be of integer types of any bit width, but they must have the same bit width. The
				6443	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6444	and <tt>%b</tt> are the two values that will undergo unsigned
				6445	multiplication.</p>
				6446
				6447	<h5>Semantics:</h5>
				6448
				6449	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6450	an unsigned multiplication of the two arguments. They return a structure —
				6451	the first element of which is the multiplication, and the second element of
				6452	which is a bit specifying if the unsigned multiplication resulted in an
				6453	overflow.</p>
				6454
				6455	<h5>Examples:</h5>
				6456	<pre>
				6457	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6458	%sum = extractvalue {i32, i1} %res, 0
				6459	%obit = extractvalue {i32, i1} %res, 1
				6460	br i1 %obit, label %overflow, label %normal
				6461	</pre>
				6462
				6463	</div>
				6464
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6465	<!-- ======================================================================= -->
				6466	<div class="doc_subsection">
				6467	<a name="int_debugger">Debugger Intrinsics</a>
				6468	</div>
				6469
				6470	<div class="doc_text">
				6471	<p>
				6472	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6473	are described in the <a
				6474	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6475	Debugging</a> document.
				6476	</p>
				6477	</div>
				6478
				6479
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6480	<!-- ======================================================================= -->
				6481	<div class="doc_subsection">
				6482	<a name="int_eh">Exception Handling Intrinsics</a>
				6483	</div>
				6484
				6485	<div class="doc_text">
				6486	<p> The LLVM exception handling intrinsics (which all start with
				6487	<tt>llvm.eh.</tt> prefix), are described in the <a
				6488	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6489	Handling</a> document. </p>
				6490	</div>
				6491
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6492	<!-- ======================================================================= -->
				6493	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6494	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6495	</div>
				6496
				6497	<div class="doc_text">
				6498	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6499	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6500	the <tt>nest</tt> attribute, from a function. The result is a callable
				6501	function pointer lacking the nest parameter - the caller does not need
				6502	to provide a value for it. Instead, the value to use is stored in
				6503	advance in a "trampoline", a block of memory usually allocated
				6504	on the stack, which also contains code to splice the nest value into the
				6505	argument list. This is used to implement the GCC nested function address
				6506	extension.
				6507	</p>
				6508	<p>
				6509	For example, if the function is
				6510	<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]	6511	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]	6512	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6513	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6514	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6515	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6516	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6517	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6518	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6519	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]	6520	</div>
				6521
				6522	<!-- _______________________________________________________________________ -->
				6523	<div class="doc_subsubsection">
				6524	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6525	</div>
				6526	<div class="doc_text">
				6527	<h5>Syntax:</h5>
				6528	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6529	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6530	</pre>
				6531	<h5>Overview:</h5>
				6532	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6533	This fills the memory pointed to by <tt>tramp</tt> with code
				6534	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6535	</p>
				6536	<h5>Arguments:</h5>
				6537	<p>
				6538	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6539	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6540	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]	6541	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6542	currently provides no portable way of determining them, so a front-end that
				6543	generates this intrinsic needs to have some target-specific knowledge.
				6544	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]	6545	</p>
				6546	<h5>Semantics:</h5>
				6547	<p>
				6548	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]	6549	dependent code, turning it into a function. A pointer to this function is
				6550	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6551	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6552	before being called. The new function's signature is the same as that of
				6553	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6554	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6555	of pointer type. Calling the new function is equivalent to calling
				6556	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6557	missing <tt>nest</tt> argument. If, after calling
				6558	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6559	modified, then the effect of any later call to the returned function pointer is
				6560	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6561	</p>
				6562	</div>
				6563
				6564	<!-- ======================================================================= -->
				6565	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6566	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6567	</div>
				6568
				6569	<div class="doc_text">
				6570	<p>
				6571	These intrinsic functions expand the "universal IR" of LLVM to represent
				6572	hardware constructs for atomic operations and memory synchronization. This
				6573	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]	6574	is aimed at a low enough level to allow any programming models or APIs
				6575	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6576	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6577	hardware behavior. Just as hardware provides a "universal IR" for source
				6578	languages, it also provides a starting point for developing a "universal"
				6579	atomic operation and synchronization IR.
				6580	</p>
				6581	<p>
				6582	These do <em>not</em> form an API such as high-level threading libraries,
				6583	software transaction memory systems, atomic primitives, and intrinsic
				6584	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6585	application libraries. The hardware interface provided by LLVM should allow
				6586	a clean implementation of all of these APIs and parallel programming models.
				6587	No one model or paradigm should be selected above others unless the hardware
				6588	itself ubiquitously does so.
				6589
				6590	</p>
				6591	</div>
				6592
				6593	<!-- _______________________________________________________________________ -->
				6594	<div class="doc_subsubsection">
				6595	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6596	</div>
				6597	<div class="doc_text">
				6598	<h5>Syntax:</h5>
				6599	<pre>
				6600	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6601	i1 <device> )
				6602
				6603	</pre>
				6604	<h5>Overview:</h5>
				6605	<p>
				6606	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6607	specific pairs of memory access types.
				6608	</p>
				6609	<h5>Arguments:</h5>
				6610	<p>
				6611	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6612	The first four arguments enables a specific barrier as listed below. The fith
				6613	argument specifies that the barrier applies to io or device or uncached memory.
				6614
				6615	</p>
				6616	<ul>
				6617	<li><tt>ll</tt>: load-load barrier</li>
				6618	<li><tt>ls</tt>: load-store barrier</li>
				6619	<li><tt>sl</tt>: store-load barrier</li>
				6620	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6621	<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]	6622	</ul>
				6623	<h5>Semantics:</h5>
				6624	<p>
				6625	This intrinsic causes the system to enforce some ordering constraints upon
				6626	the loads and stores of the program. This barrier does not indicate
				6627	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6628	which they occur. For any of the specified pairs of load and store operations
				6629	(f.ex. load-load, or store-load), all of the first operations preceding the
				6630	barrier will complete before any of the second operations succeeding the
				6631	barrier begin. Specifically the semantics for each pairing is as follows:
				6632	</p>
				6633	<ul>
				6634	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6635	after the barrier begins.</li>
				6636
				6637	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6638	store after the barrier begins.</li>
				6639	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6640	store after the barrier begins.</li>
				6641	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6642	load after the barrier begins.</li>
				6643	</ul>
				6644	<p>
				6645	These semantics are applied with a logical "and" behavior when more than one
				6646	is enabled in a single memory barrier intrinsic.
				6647	</p>
				6648	<p>
				6649	Backends may implement stronger barriers than those requested when they do not
				6650	support as fine grained a barrier as requested. Some architectures do not
				6651	need all types of barriers and on such architectures, these become noops.
				6652	</p>
				6653	<h5>Example:</h5>
				6654	<pre>
				6655	%ptr = malloc i32
				6656	store i32 4, %ptr
				6657
				6658	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6659	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6660	<i>; guarantee the above finishes</i>
				6661	store i32 8, %ptr <i>; before this begins</i>
				6662	</pre>
				6663	</div>
				6664
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6665	<!-- _______________________________________________________________________ -->
				6666	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6667	<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]	6668	</div>
				6669	<div class="doc_text">
				6670	<h5>Syntax:</h5>
				6671	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6672	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6673	any integer bit width and for different address spaces. Not all targets
				6674	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6675
				6676	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6677	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6678	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6679	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6680	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]	6681
				6682	</pre>
				6683	<h5>Overview:</h5>
				6684	<p>
				6685	This loads a value in memory and compares it to a given value. If they are
				6686	equal, it stores a new value into the memory.
				6687	</p>
				6688	<h5>Arguments:</h5>
				6689	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6690	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]	6691	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6692	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6693	this integer type. While any bit width integer may be used, targets may only
				6694	lower representations they support in hardware.
				6695
				6696	</p>
				6697	<h5>Semantics:</h5>
				6698	<p>
				6699	This entire intrinsic must be executed atomically. It first loads the value
				6700	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6701	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6702	loaded value is yielded in all cases. This provides the equivalent of an
				6703	atomic compare-and-swap operation within the SSA framework.
				6704	</p>
				6705	<h5>Examples:</h5>
				6706
				6707	<pre>
				6708	%ptr = malloc i32
				6709	store i32 4, %ptr
				6710
				6711	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6712	%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]	6713	<i>; yields {i32}:result1 = 4</i>
				6714	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6715	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6716
				6717	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6718	%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]	6719	<i>; yields {i32}:result2 = 8</i>
				6720	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6721
				6722	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6723	</pre>
				6724	</div>
				6725
				6726	<!-- _______________________________________________________________________ -->
				6727	<div class="doc_subsubsection">
				6728	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6729	</div>
				6730	<div class="doc_text">
				6731	<h5>Syntax:</h5>
				6732
				6733	<p>
				6734	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6735	integer bit width. Not all targets support all bit widths however.</p>
				6736	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6737	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6738	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6739	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6740	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6741
				6742	</pre>
				6743	<h5>Overview:</h5>
				6744	<p>
				6745	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6746	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6747	at <tt>ptr</tt>.
				6748	</p>
				6749	<h5>Arguments:</h5>
				6750
				6751	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6752	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6753	<tt>val</tt> argument and the result must be integers of the same bit width.
				6754	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6755	integer type. The targets may only lower integer representations they
				6756	support.
				6757	</p>
				6758	<h5>Semantics:</h5>
				6759	<p>
				6760	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6761	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6762	equivalent of an atomic swap operation within the SSA framework.
				6763
				6764	</p>
				6765	<h5>Examples:</h5>
				6766	<pre>
				6767	%ptr = malloc i32
				6768	store i32 4, %ptr
				6769
				6770	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6771	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6772	<i>; yields {i32}:result1 = 4</i>
				6773	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6774	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6775
				6776	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6777	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6778	<i>; yields {i32}:result2 = 8</i>
				6779
				6780	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6781	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6782	</pre>
				6783	</div>
				6784
				6785	<!-- _______________________________________________________________________ -->
				6786	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6787	<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]	6788
				6789	</div>
				6790	<div class="doc_text">
				6791	<h5>Syntax:</h5>
				6792	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6793	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]	6794	integer bit width. Not all targets support all bit widths however.</p>
				6795	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6796	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6797	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6798	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6799	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6800
				6801	</pre>
				6802	<h5>Overview:</h5>
				6803	<p>
				6804	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6805	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6806	</p>
				6807	<h5>Arguments:</h5>
				6808	<p>
				6809
				6810	The intrinsic takes two arguments, the first a pointer to an integer value
				6811	and the second an integer value. The result is also an integer value. These
				6812	integer types can have any bit width, but they must all have the same bit
				6813	width. The targets may only lower integer representations they support.
				6814	</p>
				6815	<h5>Semantics:</h5>
				6816	<p>
				6817	This intrinsic does a series of operations atomically. It first loads the
				6818	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6819	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6820	</p>
				6821
				6822	<h5>Examples:</h5>
				6823	<pre>
				6824	%ptr = malloc i32
				6825	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6826	%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]	6827	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6828	%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]	6829	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6830	%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]	6831	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6832	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6833	</pre>
				6834	</div>
				6835
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6836	<!-- _______________________________________________________________________ -->
				6837	<div class="doc_subsubsection">
				6838	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6839
				6840	</div>
				6841	<div class="doc_text">
				6842	<h5>Syntax:</h5>
				6843	<p>
				6844	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]	6845	any integer bit width and for different address spaces. Not all targets
				6846	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6847	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6848	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6849	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6850	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6851	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]	6852
				6853	</pre>
				6854	<h5>Overview:</h5>
				6855	<p>
				6856	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6857	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6858	</p>
				6859	<h5>Arguments:</h5>
				6860	<p>
				6861
				6862	The intrinsic takes two arguments, the first a pointer to an integer value
				6863	and the second an integer value. The result is also an integer value. These
				6864	integer types can have any bit width, but they must all have the same bit
				6865	width. The targets may only lower integer representations they support.
				6866	</p>
				6867	<h5>Semantics:</h5>
				6868	<p>
				6869	This intrinsic does a series of operations atomically. It first loads the
				6870	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6871	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6872	</p>
				6873
				6874	<h5>Examples:</h5>
				6875	<pre>
				6876	%ptr = malloc i32
				6877	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6878	%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]	6879	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6880	%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]	6881	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6882	%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]	6883	<i>; yields {i32}:result3 = 2</i>
				6884	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6885	</pre>
				6886	</div>
				6887
				6888	<!-- _______________________________________________________________________ -->
				6889	<div class="doc_subsubsection">
				6890	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6891	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6892	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6893	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6894
				6895	</div>
				6896	<div class="doc_text">
				6897	<h5>Syntax:</h5>
				6898	<p>
				6899	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6900	<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]	6901	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6902	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6903	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6904	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6905	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6906	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6907	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]	6908
				6909	</pre>
				6910
				6911	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6912	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6913	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6914	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6915	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]	6916
				6917	</pre>
				6918
				6919	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6920	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6921	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6922	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6923	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]	6924
				6925	</pre>
				6926
				6927	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6928	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6929	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6930	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6931	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]	6932
				6933	</pre>
				6934	<h5>Overview:</h5>
				6935	<p>
				6936	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6937	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6938	at <tt>ptr</tt>.
				6939	</p>
				6940	<h5>Arguments:</h5>
				6941	<p>
				6942
				6943	These intrinsics take two arguments, the first a pointer to an integer value
				6944	and the second an integer value. The result is also an integer value. These
				6945	integer types can have any bit width, but they must all have the same bit
				6946	width. The targets may only lower integer representations they support.
				6947	</p>
				6948	<h5>Semantics:</h5>
				6949	<p>
				6950	These intrinsics does a series of operations atomically. They first load the
				6951	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6952	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6953	value stored at <tt>ptr</tt>.
				6954	</p>
				6955
				6956	<h5>Examples:</h5>
				6957	<pre>
				6958	%ptr = malloc i32
				6959	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6960	%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]	6961	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6962	%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]	6963	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6964	%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]	6965	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6966	%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]	6967	<i>; yields {i32}:result3 = FF</i>
				6968	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6969	</pre>
				6970	</div>
				6971
				6972
				6973	<!-- _______________________________________________________________________ -->
				6974	<div class="doc_subsubsection">
				6975	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6976	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6977	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6978	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6979
				6980	</div>
				6981	<div class="doc_text">
				6982	<h5>Syntax:</h5>
				6983	<p>
				6984	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6985	<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]	6986	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6987	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6988	support all bit widths however.</p>
				6989	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6990	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6991	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6992	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6993	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]	6994
				6995	</pre>
				6996
				6997	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6998	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6999	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				7000	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				7001	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]	7002
				7003	</pre>
				7004
				7005	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7006	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				7007	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				7008	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				7009	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]	7010
				7011	</pre>
				7012
				7013	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7014	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				7015	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				7016	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				7017	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]	7018
				7019	</pre>
				7020	<h5>Overview:</h5>
				7021	<p>
				7022	These intrinsics takes the signed or unsigned minimum or maximum of
				7023	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				7024	original value at <tt>ptr</tt>.
				7025	</p>
				7026	<h5>Arguments:</h5>
				7027	<p>
				7028
				7029	These intrinsics take two arguments, the first a pointer to an integer value
				7030	and the second an integer value. The result is also an integer value. These
				7031	integer types can have any bit width, but they must all have the same bit
				7032	width. The targets may only lower integer representations they support.
				7033	</p>
				7034	<h5>Semantics:</h5>
				7035	<p>
				7036	These intrinsics does a series of operations atomically. They first load the
				7037	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				7038	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				7039	the original value stored at <tt>ptr</tt>.
				7040	</p>
				7041
				7042	<h5>Examples:</h5>
				7043	<pre>
				7044	%ptr = malloc i32
				7045	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7046	%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]	7047	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7048	%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]	7049	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7050	%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]	7051	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7052	%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]	7053	<i>; yields {i32}:result3 = 8</i>
				7054	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				7055	</pre>
				7056	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	7057
				7058	<!-- ======================================================================= -->
				7059	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7060	<a name="int_general">General Intrinsics</a>
				7061	</div>
				7062
				7063	<div class="doc_text">
				7064	<p> This class of intrinsics is designed to be generic and has
				7065	no specific purpose. </p>
				7066	</div>
				7067
				7068	<!-- _______________________________________________________________________ -->
				7069	<div class="doc_subsubsection">
				7070	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				7071	</div>
				7072
				7073	<div class="doc_text">
				7074
				7075	<h5>Syntax:</h5>
				7076	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7077	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]	7078	</pre>
				7079
				7080	<h5>Overview:</h5>
				7081
				7082	<p>
				7083	The '<tt>llvm.var.annotation</tt>' intrinsic
				7084	</p>
				7085
				7086	<h5>Arguments:</h5>
				7087
				7088	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7089	The first argument is a pointer to a value, the second is a pointer to a
				7090	global string, the third is a pointer to a global string which is the source
				7091	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7092	</p>
				7093
				7094	<h5>Semantics:</h5>
				7095
				7096	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7097	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7098	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]	7099	annotations. These have no other defined use, they are ignored by code
				7100	generation and optimization.
				7101	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7102	</div>
				7103
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7104	<!-- _______________________________________________________________________ -->
				7105	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	7106	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7107	</div>
				7108
				7109	<div class="doc_text">
				7110
				7111	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7112	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7113	any integer bit width.
				7114	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7115	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	7116	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7117	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7118	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7119	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7120	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]	7121	</pre>
				7122
				7123	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7124
				7125	<p>
				7126	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7127	</p>
				7128
				7129	<h5>Arguments:</h5>
				7130
				7131	<p>
				7132	The first argument is an integer value (result of some expression),
				7133	the second is a pointer to a global string, the third is a pointer to a global
				7134	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]	7135	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7136	</p>
				7137
				7138	<h5>Semantics:</h5>
				7139
				7140	<p>
				7141	This intrinsic allows annotations to be put on arbitrary expressions
				7142	with arbitrary strings. This can be useful for special purpose optimizations
				7143	that want to look for these annotations. These have no other defined use, they
				7144	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	7145	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7146	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	7147
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7148	<!-- _______________________________________________________________________ -->
				7149	<div class="doc_subsubsection">
				7150	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7151	</div>
				7152
				7153	<div class="doc_text">
				7154
				7155	<h5>Syntax:</h5>
				7156	<pre>
				7157	declare void @llvm.trap()
				7158	</pre>
				7159
				7160	<h5>Overview:</h5>
				7161
				7162	<p>
				7163	The '<tt>llvm.trap</tt>' intrinsic
				7164	</p>
				7165
				7166	<h5>Arguments:</h5>
				7167
				7168	<p>
				7169	None
				7170	</p>
				7171
				7172	<h5>Semantics:</h5>
				7173
				7174	<p>
				7175	This intrinsics is lowered to the target dependent trap instruction. If the
				7176	target does not have a trap instruction, this intrinsic will be lowered to the
				7177	call of the abort() function.
				7178	</p>
				7179	</div>
				7180
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7181	<!-- _______________________________________________________________________ -->
				7182	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7183	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7184	</div>
				7185	<div class="doc_text">
				7186	<h5>Syntax:</h5>
				7187	<pre>
				7188	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7189
				7190	</pre>
				7191	<h5>Overview:</h5>
				7192	<p>
				7193	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7194	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7195	it is placed on the stack before local variables.
				7196	</p>
				7197	<h5>Arguments:</h5>
				7198	<p>
				7199	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7200	first argument is the value loaded from the stack guard
				7201	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7202	has enough space to hold the value of the guard.
				7203	</p>
				7204	<h5>Semantics:</h5>
				7205	<p>
				7206	This intrinsic causes the prologue/epilogue inserter to force the position of
				7207	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7208	stack. This is to ensure that if a local variable on the stack is overwritten,
				7209	it will destroy the value of the guard. When the function exits, the guard on
				7210	the stack is checked against the original guard. If they're different, then
				7211	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7212	</p>
				7213	</div>
				7214
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7215	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7216	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7217	<address>
				7218	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7219	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]	7220	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7221	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]	7222
				7223	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7224	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7225	Last modified: $Date$
				7226	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7227
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7228	</body>
				7229	</html>