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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	51	<li><a href="#t_function">Function Type</a></li>
				52	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	66	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				67	<li><a href="#undefvalues">Undefined Values</a></li>
				68	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	77	<li><a href="#instref">Instruction Reference</a>
				78	<ol>
				79	<li><a href="#terminators">Terminator Instructions</a>
				80	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				82	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	83	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				84	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	97	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				98	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				99	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	100	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				101	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				102	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	107	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				108	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				109	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	115	<li><a href="#vectorops">Vector Operations</a>
				116	<ol>
				117	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				118	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				119	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	122	<li><a href="#aggregateops">Aggregate Operations</a>
				123	<ol>
				124	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				125	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				126	</ol>
				127	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	130	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				131	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				132	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	133	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				134	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				135	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	139	<ol>
				140	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	145	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				148	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	149	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				150	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	156	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				157	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	158	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	159	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	161	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	162	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	163	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	164	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	166	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	167	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	168	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				169	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	170	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				171	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				172	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	173	</ol>
				174	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	175	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				176	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	177	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				178	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				179	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	180	</ol>
				181	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	182	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				183	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	184	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				185	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				186	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				187	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				188	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				189	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				190	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	191	</ol>
				192	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	193	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				194	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	195	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	200	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				202	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	203	</ol>
				204	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	205	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	206	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	207	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	208	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				209	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				210	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	211	</ol>
				212	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	213	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				214	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	215	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				216	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	220	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	221	</ol>
				222	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	223	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	224	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	225	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	226	<ol>
				227	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	228	</ol>
				229	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	230	<li><a href="#int_atomics">Atomic intrinsics</a>
				231	<ol>
				232	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				233	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				234	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				235	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				236	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				237	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				238	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				239	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				240	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				241	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				242	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				243	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				244	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				245	</ol>
				246	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	247	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	248	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	249	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	250	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	251	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	252	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	253	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				255	<li><a href="#int_stackprotector">
				256	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	257	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	258	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	259	</ol>
				260	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	261	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	262
				263	<div class="doc_author">
				264	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				265	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	266	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	267
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	268	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	269	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				270	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	272	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	274	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	275	type safety, low-level operations, flexibility, and the capability of
				276	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	representation used throughout all phases of the LLVM compilation
				278	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	279	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	280
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	281	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	282	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				283	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	285	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	286
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	287	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	288	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	289	representation (suitable for fast loading by a Just-In-Time compiler),
				290	and as a human readable assembly language representation. This allows
				291	LLVM to provide a powerful intermediate representation for efficient
				292	compiler transformations and analysis, while providing a natural means
				293	to debug and visualize the transformations. The three different forms
				294	of LLVM are all equivalent. This document describes the human readable
				295	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	296
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	297	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	298	while being expressive, typed, and extensible at the same time. It
				299	aims to be a "universal IR" of sorts, by being at a low enough level
				300	that high-level ideas may be cleanly mapped to it (similar to how
				301	microprocessors are "universal IR's", allowing many source languages to
				302	be mapped to them). By providing type information, LLVM can be used as
				303	the target of optimizations: for example, through pointer analysis, it
				304	can be proven that a C automatic variable is never accessed outside of
				305	the current function... allowing it to be promoted to a simple SSA
				306	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	307
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	308	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	309
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	310	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	311	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	312
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	313	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	314
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<p>It is important to note that this document describes 'well formed'
				316	LLVM assembly language. There is a difference between what the parser
				317	accepts and what is considered 'well formed'. For example, the
				318	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	319
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	320	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	321	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	322	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	326	<p>...because the definition of <tt>%x</tt> does not dominate all of
				327	its uses. The LLVM infrastructure provides a verification pass that may
				328	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	329	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	330	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	331	by the verifier pass indicate bugs in transformation passes or input to
				332	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	333	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	334
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	335	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	337	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	338	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	339	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	341	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	343	<p>LLVM identifiers come in two basic types: global and local. Global
				344	identifiers (functions, global variables) begin with the @ character. Local
				345	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	346	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	347
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	348	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	349	<li>Named values are represented as a string of characters with their prefix.
				350	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				351	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	352	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	353	with quotes. Special characters may be escaped using "\xx" where xx is the
				354	ASCII code for the character in hexadecimal. In this way, any character can
				355	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	356
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	357	<li>Unnamed values are represented as an unsigned numeric value with their
				358	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	359
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	360	<li>Constants, which are described in a <a href="#constants">section about
				361	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	362	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	364	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	365	don't need to worry about name clashes with reserved words, and the set of
				366	reserved words may be expanded in the future without penalty. Additionally,
				367	unnamed identifiers allow a compiler to quickly come up with a temporary
				368	variable without having to avoid symbol table conflicts.</p>
				369
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	370	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	371	languages. There are keywords for different opcodes
				372	('<tt><a href="#i_add">add</a></tt>',
				373	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				374	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	375	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	377	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	378
				379	<p>Here is an example of LLVM code to multiply the integer variable
				380	'<tt>%X</tt>' by 8:</p>
				381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	382	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	383
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	384	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	385	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	386	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	390	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	394	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	398	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	402	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				403	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				404	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	406	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	407
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	408	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				409	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	410
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	411	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	412
				413	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				414	line.</li>
				415
				416	<li>Unnamed temporaries are created when the result of a computation is not
				417	assigned to a named value.</li>
				418
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	419	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	420
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	421	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	423	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424	demonstrating instructions, we will follow an instruction with a comment that
				425	defines the type and name of value produced. Comments are shown in italic
				426	text.</p>
				427
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	428	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	429
				430	<!-- *********************************************************************** -->
				431	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				432	<!-- *********************************************************************** -->
				433
				434	<!-- ======================================================================= -->
				435	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				436	</div>
				437
				438	<div class="doc_text">
				439
				440	<p>LLVM programs are composed of "Module"s, each of which is a
				441	translation unit of the input programs. Each module consists of
				442	functions, global variables, and symbol table entries. Modules may be
				443	combined together with the LLVM linker, which merges function (and
				444	global variable) definitions, resolves forward declarations, and merges
				445	symbol table entries. Here is an example of the "hello world" module:</p>
				446
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	447	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	448	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	449	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				450	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	451
				452	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	454
				455	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	456	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	457	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	459	href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	460
				461	<i>; Call puts function to write out the string to stdout...</i>
				462	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	463	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	464	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	465	href="#i_ret">ret</a> i32 0<br>}<br>
				466	</pre>
				467	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468
				469	<p>This example is made up of a <a href="#globalvars">global variable</a>
				470	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				471	function, and a <a href="#functionstructure">function definition</a>
				472	for "<tt>main</tt>".</p>
				473
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	474	<p>In general, a module is made up of a list of global values,
				475	where both functions and global variables are global values. Global values are
				476	represented by a pointer to a memory location (in this case, a pointer to an
				477	array of char, and a pointer to a function), and have one of the following <a
				478	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	479
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	480	</div>
				481
				482	<!-- ======================================================================= -->
				483	<div class="doc_subsection">
				484	<a name="linkage">Linkage Types</a>
				485	</div>
				486
				487	<div class="doc_text">
				488
				489	<p>
				490	All Global Variables and Functions have one of the following types of linkage:
				491	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	492
				493	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	494
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	495	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				496
				497	<dd>Global values with private linkage are only directly accessible by
				498	objects in the current module. In particular, linking code into a module with
				499	an private global value may cause the private to be renamed as necessary to
				500	avoid collisions. Because the symbol is private to the module, all
				501	references can be updated. This doesn't show up in any symbol table in the
				502	object file.
				503	</dd>
				504
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	505	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	506
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	507	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	508	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	509	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	510	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	512	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				513	</dt>
				514
				515	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				516	into the object file corresponding to the LLVM module. They exist to
				517	allow inlining and other optimizations to take place given knowledge of the
				518	definition of the global, which is known to be somewhere outside the module.
				519	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				520	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				521	type is only allowed on definitions, not declarations.</dd>
				522
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	523	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	524
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	525	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				526	the same name when linkage occurs. This is typically used to implement
				527	inline functions, templates, or other code which must be generated in each
				528	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				529	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	530	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	531
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	532	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				533
				534	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				535	linkage, except that unreferenced <tt>common</tt> globals may not be
				536	discarded. This is used for globals that may be emitted in multiple
				537	translation units, but that are not guaranteed to be emitted into every
				538	translation unit that uses them. One example of this is tentative
				539	definitions in C, such as "<tt>int X;</tt>" at global scope.
				540	</dd>
				541
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	542	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	543
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	544	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				545	that some targets may choose to emit different assembly sequences for them
				546	for target-dependent reasons. This is used for globals that are declared
				547	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	548	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	549
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	550	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	551
				552	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				553	pointer to array type. When two global variables with appending linkage are
				554	linked together, the two global arrays are appended together. This is the
				555	LLVM, typesafe, equivalent of having the system linker append together
				556	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	557	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	558
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	559	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	560
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	561	<dd>The semantics of this linkage follow the ELF object file model: the
				562	symbol is weak until linked, if not linked, the symbol becomes null instead
				563	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	564	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	565
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	566	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	567	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	568	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	569	functions with different semantics. Other languages, such as <tt>C++</tt>,
				570	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	571	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	572	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				573	be merged with equivalent globals. These linkage types are otherwise the
				574	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	575	</dd>
				576
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	577	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	578
				579	<dd>If none of the above identifiers are used, the global is externally
				580	visible, meaning that it participates in linkage and can be used to resolve
				581	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	582	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	583	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	584
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	585	<p>
				586	The next two types of linkage are targeted for Microsoft Windows platform
				587	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	588	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	589	</p>
				590
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	591	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	592	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				593
				594	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				595	or variable via a global pointer to a pointer that is set up by the DLL
				596	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	597	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	598	</dd>
				599
				600	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				601
				602	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				603	pointer to a pointer in a DLL, so that it can be referenced with the
				604	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	605	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	606	name.
				607	</dd>
				608
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	609	</dl>
				610
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	611	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	612	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				613	variable and was linked with this one, one of the two would be renamed,
				614	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				615	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	616	outside of the current module.</p>
				617	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	618	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				619	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	620	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				621	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	622	</div>
				623
				624	<!-- ======================================================================= -->
				625	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	626	<a name="callingconv">Calling Conventions</a>
				627	</div>
				628
				629	<div class="doc_text">
				630
				631	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				632	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				633	specified for the call. The calling convention of any pair of dynamic
				634	caller/callee must match, or the behavior of the program is undefined. The
				635	following calling conventions are supported by LLVM, and more may be added in
				636	the future:</p>
				637
				638	<dl>
				639	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				640
				641	<dd>This calling convention (the default if no other calling convention is
				642	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	643	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	644	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	645	</dd>
				646
				647	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				648
				649	<dd>This calling convention attempts to make calls as fast as possible
				650	(e.g. by passing things in registers). This calling convention allows the
				651	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	652	without having to conform to an externally specified ABI (Application Binary
				653	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	654	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				655	supported. This calling convention does not support varargs and requires the
				656	prototype of all callees to exactly match the prototype of the function
				657	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	658	</dd>
				659
				660	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				661
				662	<dd>This calling convention attempts to make code in the caller as efficient
				663	as possible under the assumption that the call is not commonly executed. As
				664	such, these calls often preserve all registers so that the call does not break
				665	any live ranges in the caller side. This calling convention does not support
				666	varargs and requires the prototype of all callees to exactly match the
				667	prototype of the function definition.
				668	</dd>
				669
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	670	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	671
				672	<dd>Any calling convention may be specified by number, allowing
				673	target-specific calling conventions to be used. Target specific calling
				674	conventions start at 64.
				675	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	676	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	677
				678	<p>More calling conventions can be added/defined on an as-needed basis, to
				679	support pascal conventions or any other well-known target-independent
				680	convention.</p>
				681
				682	</div>
				683
				684	<!-- ======================================================================= -->
				685	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	686	<a name="visibility">Visibility Styles</a>
				687	</div>
				688
				689	<div class="doc_text">
				690
				691	<p>
				692	All Global Variables and Functions have one of the following visibility styles:
				693	</p>
				694
				695	<dl>
				696	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				697
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	698	<dd>On targets that use the ELF object file format, default visibility means
				699	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	700	modules and, in shared libraries, means that the declared entity may be
				701	overridden. On Darwin, default visibility means that the declaration is
				702	visible to other modules. Default visibility corresponds to "external
				703	linkage" in the language.
				704	</dd>
				705
				706	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				707
				708	<dd>Two declarations of an object with hidden visibility refer to the same
				709	object if they are in the same shared object. Usually, hidden visibility
				710	indicates that the symbol will not be placed into the dynamic symbol table,
				711	so no other module (executable or shared library) can reference it
				712	directly.
				713	</dd>
				714
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	715	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				716
				717	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				718	the dynamic symbol table, but that references within the defining module will
				719	bind to the local symbol. That is, the symbol cannot be overridden by another
				720	module.
				721	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	722	</dl>
				723
				724	</div>
				725
				726	<!-- ======================================================================= -->
				727	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	728	<a name="namedtypes">Named Types</a>
				729	</div>
				730
				731	<div class="doc_text">
				732
				733	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				734	it easier to read the IR and make the IR more condensed (particularly when
				735	recursive types are involved). An example of a name specification is:
				736	</p>
				737
				738	<div class="doc_code">
				739	<pre>
				740	%mytype = type { %mytype*, i32 }
				741	</pre>
				742	</div>
				743
				744	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				745	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				746	expected with the syntax "%mytype".</p>
				747
				748	<p>Note that type names are aliases for the structural type that they indicate,
				749	and that you can therefore specify multiple names for the same type. This often
				750	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				751	structural typing, the name is not part of the type. When printing out LLVM IR,
				752	the printer will pick <em>one name</em> to render all types of a particular
				753	shape. This means that if you have code where two different source types end up
				754	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				755	unexpected type. This is an important design point and isn't going to
				756	change.</p>
				757
				758	</div>
				759
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	760	<!-- ======================================================================= -->
				761	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	762	<a name="globalvars">Global Variables</a>
				763	</div>
				764
				765	<div class="doc_text">
				766
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	767	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	768	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	769	an explicit section to be placed in, and may have an optional explicit alignment
				770	specified. A variable may be defined as "thread_local", which means that it
				771	will not be shared by threads (each thread will have a separated copy of the
				772	variable). A variable may be defined as a global "constant," which indicates
				773	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	774	optimization, allowing the global data to be placed in the read-only section of
				775	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	776	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	777
				778	<p>
				779	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				780	constant, even if the final definition of the global is not. This capability
				781	can be used to enable slightly better optimization of the program, but requires
				782	the language definition to guarantee that optimizations based on the
				783	'constantness' are valid for the translation units that do not include the
				784	definition.
				785	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	786
				787	<p>As SSA values, global variables define pointer values that are in
				788	scope (i.e. they dominate) all basic blocks in the program. Global
				789	variables always define a pointer to their "content" type because they
				790	describe a region of memory, and all memory objects in LLVM are
				791	accessed through pointers.</p>
				792
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	793	<p>A global variable may be declared to reside in a target-specifc numbered
				794	address space. For targets that support them, address spaces may affect how
				795	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	796	the variable. The default address space is zero. The address space qualifier
				797	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	798
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	799	<p>LLVM allows an explicit section to be specified for globals. If the target
				800	supports it, it will emit globals to the section specified.</p>
				801
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	802	<p>An explicit alignment may be specified for a global. If not present, or if
				803	the alignment is set to zero, the alignment of the global is set by the target
				804	to whatever it feels convenient. If an explicit alignment is specified, the
				805	global is forced to have at least that much alignment. All alignments must be
				806	a power of 2.</p>
				807
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	808	<p>For example, the following defines a global in a numbered address space with
				809	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	810
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	811	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	812	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	813	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	815	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	817	</div>
				818
				819
				820	<!-- ======================================================================= -->
				821	<div class="doc_subsection">
				822	<a name="functionstructure">Functions</a>
				823	</div>
				824
				825	<div class="doc_text">
				826
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	827	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				828	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	829	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	830	<a href="#callingconv">calling convention</a>, a return type, an optional
				831	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				832	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	833	<a href="#paramattrs">parameter attributes</a>), optional
				834	<a href="#fnattrs">function attributes</a>, an optional section,
				835	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	836	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	837
				838	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				839	optional <a href="#linkage">linkage type</a>, an optional
				840	<a href="#visibility">visibility style</a>, an optional
				841	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	842	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	843	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	844	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	845
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	846	<p>A function definition contains a list of basic blocks, forming the CFG
				847	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	848	the function. Each basic block may optionally start with a label (giving the
				849	basic block a symbol table entry), contains a list of instructions, and ends
				850	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				851	function return).</p>
				852
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	853	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	854	executed on entrance to the function, and it is not allowed to have predecessor
				855	basic blocks (i.e. there can not be any branches to the entry block of a
				856	function). Because the block can have no predecessors, it also cannot have any
				857	<a href="#i_phi">PHI nodes</a>.</p>
				858
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	859	<p>LLVM allows an explicit section to be specified for functions. If the target
				860	supports it, it will emit functions to the section specified.</p>
				861
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	862	<p>An explicit alignment may be specified for a function. If not present, or if
				863	the alignment is set to zero, the alignment of the function is set by the target
				864	to whatever it feels convenient. If an explicit alignment is specified, the
				865	function is forced to have at least that much alignment. All alignments must be
				866	a power of 2.</p>
				867
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	868	<h5>Syntax:</h5>
				869
				870	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	871	<tt>
				872	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				873	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				874	<ResultType> @<FunctionName> ([argument list])
				875	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				876	[<a href="#gc">gc</a>] { ... }
				877	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	878	</div>
				879
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	880	</div>
				881
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	882
				883	<!-- ======================================================================= -->
				884	<div class="doc_subsection">
				885	<a name="aliasstructure">Aliases</a>
				886	</div>
				887	<div class="doc_text">
				888	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	889	function, global variable, another alias or bitcast of global value). Aliases
				890	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	891	optional <a href="#visibility">visibility style</a>.</p>
				892
				893	<h5>Syntax:</h5>
				894
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	895	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	896	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	897	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	898	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	899	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	900
				901	</div>
				902
				903
				904
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	905	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	906	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				907	<div class="doc_text">
				908	<p>The return type and each parameter of a function type may have a set of
				909	<i>parameter attributes</i> associated with them. Parameter attributes are
				910	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	911	a function. Parameter attributes are considered to be part of the function,
				912	not of the function type, so functions with different parameter attributes
				913	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	914
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	915	<p>Parameter attributes are simple keywords that follow the type specified. If
				916	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	917	example:</p>
				918
				919	<div class="doc_code">
				920	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	921	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	922	declare i32 @atoi(i8 zeroext)
				923	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	924	</pre>
				925	</div>
				926
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	927	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				928	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	929
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	930	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	931	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	932	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	933	<dd>This indicates to the code generator that the parameter or return value
				934	should be zero-extended to a 32-bit value by the caller (for a parameter)
				935	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	936
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	937	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	938	<dd>This indicates to the code generator that the parameter or return value
				939	should be sign-extended to a 32-bit value by the caller (for a parameter)
				940	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	941
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	942	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	943	<dd>This indicates that this parameter or return value should be treated
				944	in a special target-dependent fashion during while emitting code for a
				945	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	946	to memory, though some targets use it to distinguish between two different
				947	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	948
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	949	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	950	<dd>This indicates that the pointer parameter should really be passed by
				951	value to the function. The attribute implies that a hidden copy of the
				952	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	953	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	954	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	955	value, but is also valid on pointers to scalars. The copy is considered to
				956	belong to the caller not the callee (for example,
				957	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	958	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	959	values. The byval attribute also supports specifying an alignment with the
				960	align attribute. This has a target-specific effect on the code generator
				961	that usually indicates a desired alignment for the synthesized stack
				962	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	963
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	964	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	965	<dd>This indicates that the pointer parameter specifies the address of a
				966	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	967	This pointer must be guaranteed by the caller to be valid: loads and stores
				968	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	969	be applied to the first parameter. This is not a valid attribute for
				970	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	971
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	972	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	973	<dd>This indicates that the pointer does not alias any global or any other
				974	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	975	case. On a function return value, <tt>noalias</tt> additionally indicates
				976	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	977	caller. For further details, please see the discussion of the NoAlias
				978	response in
				979	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				980	analysis</a>.</dd>
				981
				982	<dt><tt>nocapture</tt></dt>
				983	<dd>This indicates that the callee does not make any copies of the pointer
				984	that outlive the callee itself. This is not a valid attribute for return
				985	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	986
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	987	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	988	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	989	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				990	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	991	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	992
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	993	</div>
				994
				995	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	996	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	997	<a name="gc">Garbage Collector Names</a>
				998	</div>
				999
				1000	<div class="doc_text">
				1001	<p>Each function may specify a garbage collector name, which is simply a
				1002	string.</p>
				1003
				1004	<div class="doc_code"><pre
				1005	>define void @f() gc "name" { ...</pre></div>
				1006
				1007	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1008	collector which will cause the compiler to alter its output in order to support
				1009	the named garbage collection algorithm.</p>
				1010	</div>
				1011
				1012	<!-- ======================================================================= -->
				1013	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1014	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1015	</div>
				1016
				1017	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1018
				1019	<p>Function attributes are set to communicate additional information about
				1020	a function. Function attributes are considered to be part of the function,
				1021	not of the function type, so functions with different parameter attributes
				1022	can have the same function type.</p>
				1023
				1024	<p>Function attributes are simple keywords that follow the type specified. If
				1025	multiple attributes are needed, they are space separated. For
				1026	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1027
				1028	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1029	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1030	define void @f() noinline { ... }
				1031	define void @f() alwaysinline { ... }
				1032	define void @f() alwaysinline optsize { ... }
				1033	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1034	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1035	</div>
				1036
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1037	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1038	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1039	<dd>This attribute indicates that the inliner should attempt to inline this
				1040	function into callers whenever possible, ignoring any active inlining size
				1041	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1042
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1043	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1044	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1045	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1046	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1047
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1048	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1049	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	make choices that keep the code size of this function low, and otherwise do
				1051	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1052
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1053	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	<dd>This function attribute indicates that the function never returns normally.
				1055	This produces undefined behavior at runtime if the function ever does
				1056	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1057
				1058	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1059	<dd>This function attribute indicates that the function never returns with an
				1060	unwind or exceptional control flow. If the function does unwind, its runtime
				1061	behavior is undefined.</dd>
				1062
				1063	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1064	<dd>This attribute indicates that the function computes its result (or decides to
				1065	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1066	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1067	registers, etc) visible to caller functions. It does not write through any
				1068	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1069	never changes any state visible to callers. This means that it cannot unwind
				1070	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1071	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1072
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1073	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1074	<dd>This attribute indicates that the function does not write through any
				1075	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1076	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1077	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1078	be set in the caller. A readonly function always returns the same value (or
				1079	unwinds an exception identically) when called with the same set of arguments
				1080	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1081	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1082
				1083	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1084	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1085	protector. It is in the form of a "canary"—a random value placed on the
				1086	stack before the local variables that's checked upon return from the function to
				1087	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1089
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1090	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1091	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1092	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1093
				1094	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1095	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1096	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1097	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1098
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1099	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1100	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1101	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1102	an <tt>sspreq</tt> attribute.</dd>
				1103
				1104	<dt><tt>noredzone</tt></dt>
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1105	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	125473b	2009-06-15 21:18:01 +0000	[diff] [blame]	1106	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1107	</dd>
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1108
				1109	<dt><tt>noimplicitfloat</tt></dt>
				1110	<dd>This attributes disables implicit floating point instructions.</dd>
				1111
Anton Korobeynikov	c5ec8a7	2009-07-17 18:07:26 +0000	[diff] [blame]	1112	<dt><tt>naked</tt></dt>
Chris Lattner	0c542ff	2009-07-17 21:14:28 +0000	[diff] [blame]	1113	<dd>This attribute disables prologue / epilogue emission for the function.
				1114	This can have very system-specific consequences.</dd>
Anton Korobeynikov	c5ec8a7	2009-07-17 18:07:26 +0000	[diff] [blame]	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
				2045	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2046
				2047	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2048	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2049
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2050	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2051
				2052	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2053	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2054
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2055
				2056	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2057
				2058	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2059	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2060
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2061	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2062
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2063	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2064	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]	2065	binary</a> operations. The constraints on operands are the same as those for
				2066	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2067	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2068	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2069	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2070
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2071	<!-- ======================================================================= -->
				2072	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2073	</div>
				2074
				2075	<div class="doc_text">
				2076
				2077	<p>Embedded metadata provides a way to attach arbitrary data to the
				2078	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2079	two metadata primitives, strings and nodes. All metadata has the
				2080	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2081	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2082	</p>
				2083
				2084	<p>A metadata string is a string surrounded by double quotes. It can contain
				2085	any character by escaping non-printable characters with "\xx" where "xx" is
				2086	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2087	</p>
				2088
				2089	<p>Metadata nodes are represented with notation similar to structure constants
				2090	(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]	2091	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2092	</p>
				2093
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2094	<p>A metadata node will attempt to track changes to the values it holds. In
				2095	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]	2096	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2097
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2098	<p>Optimizations may rely on metadata to provide additional information about
				2099	the program that isn't available in the instructions, or that isn't easily
				2100	computable. Similarly, the code generator may expect a certain metadata format
				2101	to be used to express debugging information.</p>
				2102	</div>
				2103
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2104	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2105	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2106	<!-- *********************************************************************** -->
				2107
				2108	<!-- ======================================================================= -->
				2109	<div class="doc_subsection">
				2110	<a name="inlineasm">Inline Assembler Expressions</a>
				2111	</div>
				2112
				2113	<div class="doc_text">
				2114
				2115	<p>
				2116	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2117	Module-Level Inline Assembly</a>) through the use of a special value. This
				2118	value represents the inline assembler as a string (containing the instructions
				2119	to emit), a list of operand constraints (stored as a string), and a flag that
				2120	indicates whether or not the inline asm expression has side effects. An example
				2121	inline assembler expression is:
				2122	</p>
				2123
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2124	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2125	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2126	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2127	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2128	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2129
				2130	<p>
				2131	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2132	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2133	</p>
				2134
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2135	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2136	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2137	%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]	2138	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2139	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2140
				2141	<p>
				2142	Inline asms with side effects not visible in the constraint list must be marked
				2143	as having side effects. This is done through the use of the
				2144	'<tt>sideeffect</tt>' keyword, like so:
				2145	</p>
				2146
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2147	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2148	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2149	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2150	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2151	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2152
				2153	<p>TODO: The format of the asm and constraints string still need to be
				2154	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]	2155	need to be documented). This is probably best done by reference to another
				2156	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2157	</p>
				2158
				2159	</div>
				2160
				2161	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2162	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2163	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2164
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2165	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2166
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	<p>The LLVM instruction set consists of several different
				2168	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2169	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2170	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2171	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2172	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2173
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2174	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2175
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2176	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2177	<div class="doc_subsection"> <a name="terminators">Terminator
				2178	Instructions</a> </div>
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 class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2181
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2182	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2183	basic block in a program ends with a "Terminator" instruction, which
				2184	indicates which block should be executed after the current block is
				2185	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2186	value: they produce control flow, not values (the one exception being
				2187	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2188	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2189	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2190	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2191	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2192	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2193	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2194
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2195	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2196
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2198	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2199	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2200	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2202	<pre>
				2203	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]	2204	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2206
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2208
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2209	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2210	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2211	<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]	2212	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]	2213	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2214
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2215	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2216
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2217	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2218	the return value. The type of the return value must be a
				2219	'<a href="#t_firstclass">first class</a>' type.</p>
				2220
				2221	<p>A function is not <a href="#wellformed">well formed</a> if
				2222	it it has a non-void return type and contains a '<tt>ret</tt>'
				2223	instruction with no return value or a return value with a type that
				2224	does not match its type, or if it has a void return type and contains
				2225	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2226
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2228
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2229	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2230	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]	2231	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2232	the instruction after the call. If the caller was an "<a
				2233	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2234	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2235	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]	2236	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2237
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2238	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2239
				2240	<pre>
				2241	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2242	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2243	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]	2244	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2245
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2246	<p>Note that the code generator does not yet fully support large
				2247	return values. The specific sizes that are currently supported are
				2248	dependent on the target. For integers, on 32-bit targets the limit
				2249	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2250	For aggregate types, the current limits are dependent on the element
				2251	types; for example targets are often limited to 2 total integer
				2252	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2253
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2254	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2255	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2256	<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]	2257	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2258	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2259	<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]	2260	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2262	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2263	transfer to a different basic block in the current function. There are
				2264	two forms of this instruction, corresponding to a conditional branch
				2265	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2267	<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]	2268	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2269	unconditional form of the '<tt>br</tt>' instruction takes a single
				2270	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2271	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2272	<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]	2273	argument is evaluated. If the value is <tt>true</tt>, control flows
				2274	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2275	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2277	<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]	2278	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]	2279	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2280	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2281	<div class="doc_subsubsection">
				2282	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2283	</div>
				2284
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2285	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2286	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2287
				2288	<pre>
				2289	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2290	</pre>
				2291
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2292	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2293
				2294	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2295	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2296	instruction, allowing a branch to occur to one of many possible
				2297	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2298
				2299
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2300	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2301
				2302	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2303	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2304	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2305	table is not allowed to contain duplicate constant entries.</p>
				2306
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2307	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2308
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2309	<p>The <tt>switch</tt> instruction specifies a table of values and
				2310	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2311	table is searched for the given value. If the value is found, control flow is
				2312	transfered to the corresponding destination; otherwise, control flow is
				2313	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2314
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2315	<h5>Implementation:</h5>
				2316
				2317	<p>Depending on properties of the target machine and the particular
				2318	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2319	ways. For example, it could be generated as a series of chained conditional
				2320	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2321
				2322	<h5>Example:</h5>
				2323
				2324	<pre>
				2325	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2326	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2327	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2328
				2329	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2330	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2331
				2332	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2333	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2334	i32 1, label %onone
				2335	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2336	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2337	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2338
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2339	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2340	<div class="doc_subsubsection">
				2341	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2342	</div>
				2343
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2344	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2345
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2346	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2347
				2348	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2349	<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]	2350	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2351	</pre>
				2352
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2353	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2354
				2355	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2356	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2357	'<tt>normal</tt>' label or the
				2358	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2359	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2360	"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]	2361	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2362	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2363
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2364	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2366	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2367
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2368	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2369	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2370	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2371	convention</a> the call should use. If none is specified, the call defaults
				2372	to using C calling conventions.
				2373	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2374
				2375	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2376	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2377	and '<tt>inreg</tt>' attributes are valid here.</li>
				2378
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2379	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2380	function value being invoked. In most cases, this is a direct function
				2381	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2382	an arbitrary pointer to function value.
				2383	</li>
				2384
				2385	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2386	function to be invoked. </li>
				2387
				2388	<li>'<tt>function args</tt>': argument list whose types match the function
				2389	signature argument types. If the function signature indicates the function
				2390	accepts a variable number of arguments, the extra arguments can be
				2391	specified. </li>
				2392
				2393	<li>'<tt>normal label</tt>': the label reached when the called function
				2394	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2395
				2396	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2397	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2398
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2399	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2400	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2401	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2402	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2403
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2404	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2405
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2406	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2407	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2408	difference is that it establishes an association with a label, which is used by
				2409	the runtime library to unwind the stack.</p>
				2410
				2411	<p>This instruction is used in languages with destructors to ensure that proper
				2412	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2413	exception. Additionally, this is important for implementation of
				2414	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2415
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2416	<p>For the purposes of the SSA form, the definition of the value
				2417	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2418	the edge from the current block to the "normal" label. If the callee
				2419	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2420
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2421	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2422	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2423	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2424	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2425	%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]	2426	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2427	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2428	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2429
				2430
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2431	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2432
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2433	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2434	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2435
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2436	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2437
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2438	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2439	<pre>
				2440	unwind
				2441	</pre>
				2442
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2443	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2444
				2445	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2446	at the first callee in the dynamic call stack which used an <a
				2447	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2448	primarily used to implement exception handling.</p>
				2449
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2450	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2451
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2452	<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]	2453	immediately halt. The dynamic call stack is then searched for the first <a
				2454	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2455	execution continues at the "exceptional" destination block specified by the
				2456	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2457	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2458	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2459
				2460	<!-- _______________________________________________________________________ -->
				2461
				2462	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2463	Instruction</a> </div>
				2464
				2465	<div class="doc_text">
				2466
				2467	<h5>Syntax:</h5>
				2468	<pre>
				2469	unreachable
				2470	</pre>
				2471
				2472	<h5>Overview:</h5>
				2473
				2474	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2475	instruction is used to inform the optimizer that a particular portion of the
				2476	code is not reachable. This can be used to indicate that the code after a
				2477	no-return function cannot be reached, and other facts.</p>
				2478
				2479	<h5>Semantics:</h5>
				2480
				2481	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2482	</div>
				2483
				2484
				2485
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2486	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2487	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2488	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2489	<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]	2490	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]	2491	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2492	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]	2493	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2495	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2497	<div class="doc_subsubsection">
				2498	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2499	</div>
				2500
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2502
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2503	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
				2505	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2506	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2507	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2511	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2512
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2513	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
				2515	<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]	2516	href="#t_integer">integer</a> or
				2517	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2518	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2519
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2520	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2521
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2522	<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]	2523
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2524	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2525	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2526	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2527
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2528	<p>Because LLVM integers use a two's complement representation, this
				2529	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2530
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2531	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2532
				2533	<pre>
				2534	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2535	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2536	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2537	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2538	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2539	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2540	</div>
				2541
				2542	<div class="doc_text">
				2543
				2544	<h5>Syntax:</h5>
				2545
				2546	<pre>
				2547	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2548	</pre>
				2549
				2550	<h5>Overview:</h5>
				2551
				2552	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2553
				2554	<h5>Arguments:</h5>
				2555
				2556	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2557	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2558	floating point values. Both arguments must have identical types.</p>
				2559
				2560	<h5>Semantics:</h5>
				2561
				2562	<p>The value produced is the floating point sum of the two operands.</p>
				2563
				2564	<h5>Example:</h5>
				2565
				2566	<pre>
				2567	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2568	</pre>
				2569	</div>
				2570	<!-- _______________________________________________________________________ -->
				2571	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2572	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2573	</div>
				2574
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2575	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2576
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2577	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2578
				2579	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2580	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2581	</pre>
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>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2584
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2585	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2586	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2587
				2588	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2589	'<tt>neg</tt>' instruction present in most other intermediate
				2590	representations.</p>
				2591
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2592	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
				2594	<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]	2595	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2596	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2597
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2598	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2599
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2600	<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]	2601
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2602	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2603	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2604	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2606	<p>Because LLVM integers use a two's complement representation, this
				2607	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2608
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2609	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2610	<pre>
				2611	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2612	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2614	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2616	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2617	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2618	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2619	</div>
				2620
				2621	<div class="doc_text">
				2622
				2623	<h5>Syntax:</h5>
				2624
				2625	<pre>
				2626	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2627	</pre>
				2628
				2629	<h5>Overview:</h5>
				2630
				2631	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2632	operands.</p>
				2633
				2634	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2635	'<tt>fneg</tt>' instruction present in most other intermediate
				2636	representations.</p>
				2637
				2638	<h5>Arguments:</h5>
				2639
				2640	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2641	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2642	of floating point values. Both arguments must have identical types.</p>
				2643
				2644	<h5>Semantics:</h5>
				2645
				2646	<p>The value produced is the floating point difference of the two operands.</p>
				2647
				2648	<h5>Example:</h5>
				2649	<pre>
				2650	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2651	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2652	</pre>
				2653	</div>
				2654
				2655	<!-- _______________________________________________________________________ -->
				2656	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2657	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2658	</div>
				2659
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2660	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2661
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2663	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2664	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2666	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2667	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2668
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2669	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2670
				2671	<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]	2672	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2673	values. Both arguments must have identical types.</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>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2676
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2677	<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]	2678
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2679	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2680	the result returned is the mathematical result modulo
				2681	2<sup>n</sup>, where n is the bit width of the result.</p>
				2682	<p>Because LLVM integers use a two's complement representation, and the
				2683	result is the same width as the operands, this instruction returns the
				2684	correct result for both signed and unsigned integers. If a full product
				2685	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2686	should be sign-extended or zero-extended as appropriate to the
				2687	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2688	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2689	<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]	2690	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2691	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2692
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2693	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2694	<div class="doc_subsubsection">
				2695	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2696	</div>
				2697
				2698	<div class="doc_text">
				2699
				2700	<h5>Syntax:</h5>
				2701	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2702	</pre>
				2703	<h5>Overview:</h5>
				2704	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2705	operands.</p>
				2706
				2707	<h5>Arguments:</h5>
				2708
				2709	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2710	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2711	of floating point values. Both arguments must have identical types.</p>
				2712
				2713	<h5>Semantics:</h5>
				2714
				2715	<p>The value produced is the floating point product of the two operands.</p>
				2716
				2717	<h5>Example:</h5>
				2718	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2719	</pre>
				2720	</div>
				2721
				2722	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2723	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2724	</a></div>
				2725	<div class="doc_text">
				2726	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2727	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2728	</pre>
				2729	<h5>Overview:</h5>
				2730	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2731	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2732
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2733	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2734
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2735	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2736	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2737	values. Both arguments must have identical types.</p>
				2738
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2739	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2740
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2741	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2742	<p>Note that unsigned integer division and signed integer division are distinct
				2743	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2744	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2745	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2746	<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]	2747	</pre>
				2748	</div>
				2749	<!-- _______________________________________________________________________ -->
				2750	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2751	</a> </div>
				2752	<div class="doc_text">
				2753	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2754	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2755	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2756	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2757
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2758	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2759
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2760	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2761	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2762
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2763	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2764
				2765	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2766	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2767	values. Both arguments must have identical types.</p>
				2768
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2769	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2770	<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]	2771	<p>Note that signed integer division and unsigned integer division are distinct
				2772	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2773	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2774	undefined behavior; this is a rare case, but can occur, for example,
				2775	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2776	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2777	<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]	2778	</pre>
				2779	</div>
				2780	<!-- _______________________________________________________________________ -->
				2781	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2782	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2783	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2784	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2785	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2786	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2787	</pre>
				2788	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2789
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2790	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2791	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2792
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2793	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2794
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2795	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2796	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2797	of floating point values. Both arguments must have identical types.</p>
				2798
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2799	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2800
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2801	<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]	2802
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2803	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2804
				2805	<pre>
				2806	<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]	2807	</pre>
				2808	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2809
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2810	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2811	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2812	</div>
				2813	<div class="doc_text">
				2814	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2815	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2816	</pre>
				2817	<h5>Overview:</h5>
				2818	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2819	unsigned division of its two arguments.</p>
				2820	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2821	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2822	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2823	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2824	<h5>Semantics:</h5>
				2825	<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]	2826	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2827	<p>Note that unsigned integer remainder and signed integer remainder are
				2828	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2829	<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]	2830	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2831	<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]	2832	</pre>
				2833
				2834	</div>
				2835	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2836	<div class="doc_subsubsection">
				2837	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2838	</div>
				2839
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2840	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2841
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2842	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2843
				2844	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2845	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2846	</pre>
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>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2849
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2850	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2851	signed division of its two operands. This instruction can also take
				2852	<a href="#t_vector">vector</a> versions of the values in which case
				2853	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2854
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2855	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2856
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2857	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2858	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2859	values. Both arguments must have identical types.</p>
				2860
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2861	<h5>Semantics:</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>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]	2864	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2865	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]	2866	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2867	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]	2868	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]	2869	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2870	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2871	<p>Note that signed integer remainder and unsigned integer remainder are
				2872	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2873	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2874	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2875	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2876	(The remainder doesn't actually overflow, but this rule lets srem be
				2877	implemented using instructions that return both the result of the division
				2878	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2879	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2880	<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]	2881	</pre>
				2882
				2883	</div>
				2884	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2885	<div class="doc_subsubsection">
				2886	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2887
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2888	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2889
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2890	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2891	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2892	</pre>
				2893	<h5>Overview:</h5>
				2894	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2895	division of its two operands.</p>
				2896	<h5>Arguments:</h5>
				2897	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2898	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2899	of floating point values. Both arguments must have identical types.</p>
				2900
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2901	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2902
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2903	<p>This instruction returns the <i>remainder</i> of a division.
				2904	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2905
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2906	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2907
				2908	<pre>
				2909	<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]	2910	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2911	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2912
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2913	<!-- ======================================================================= -->
				2914	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2915	Operations</a> </div>
				2916	<div class="doc_text">
				2917	<p>Bitwise binary operators are used to do various forms of
				2918	bit-twiddling in a program. They are generally very efficient
				2919	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2920	instructions. They require two operands of the same type, execute an operation on them,
				2921	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]	2922	</div>
				2923
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2924	<!-- _______________________________________________________________________ -->
				2925	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2926	Instruction</a> </div>
				2927	<div class="doc_text">
				2928	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2929	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2931
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2932	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2933
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2934	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2935	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2936
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2937	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2938
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2939	<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]	2940	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]	2941	type. '<tt>op2</tt>' is treated as an unsigned value.</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>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2944
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2945	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2946	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]	2947	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2948	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2949	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2950
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2951	<h5>Example:</h5><pre>
				2952	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2953	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2954	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2955	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2956	<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]	2957	</pre>
				2958	</div>
				2959	<!-- _______________________________________________________________________ -->
				2960	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2961	Instruction</a> </div>
				2962	<div class="doc_text">
				2963	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2964	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2965	</pre>
				2966
				2967	<h5>Overview:</h5>
				2968	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2969	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]	2970
				2971	<h5>Arguments:</h5>
				2972	<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]	2973	<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]	2974	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2975
				2976	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2977
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2978	<p>This instruction always performs a logical shift right operation. The most
				2979	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]	2980	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]	2981	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2982	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2983	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2984
				2985	<h5>Example:</h5>
				2986	<pre>
				2987	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2988	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2989	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2990	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2991	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2992	<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]	2993	</pre>
				2994	</div>
				2995
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2996	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2997	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2998	Instruction</a> </div>
				2999	<div class="doc_text">
				3000
				3001	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3002	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3003	</pre>
				3004
				3005	<h5>Overview:</h5>
				3006	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3007	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]	3008
				3009	<h5>Arguments:</h5>
				3010	<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]	3011	<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]	3012	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3013
				3014	<h5>Semantics:</h5>
				3015	<p>This instruction always performs an arithmetic shift right operation,
				3016	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]	3017	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]	3018	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3019	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3020	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3021
				3022	<h5>Example:</h5>
				3023	<pre>
				3024	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3025	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3026	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3027	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3028	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3029	<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]	3030	</pre>
				3031	</div>
				3032
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3033	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3034	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3035	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3036
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3037	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3038
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3039	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3040
				3041	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3042	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3043	</pre>
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>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3046
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3047	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3048	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3049
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3050	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3051
				3052	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3053	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3054	values. Both arguments must have identical types.</p>
				3055
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3056	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3057	<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]	3058	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3059	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3060	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3061	<tbody>
				3062	<tr>
				3063	<td>In0</td>
				3064	<td>In1</td>
				3065	<td>Out</td>
				3066	</tr>
				3067	<tr>
				3068	<td>0</td>
				3069	<td>0</td>
				3070	<td>0</td>
				3071	</tr>
				3072	<tr>
				3073	<td>0</td>
				3074	<td>1</td>
				3075	<td>0</td>
				3076	</tr>
				3077	<tr>
				3078	<td>1</td>
				3079	<td>0</td>
				3080	<td>0</td>
				3081	</tr>
				3082	<tr>
				3083	<td>1</td>
				3084	<td>1</td>
				3085	<td>1</td>
				3086	</tr>
				3087	</tbody>
				3088	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3089	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3090	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3091	<pre>
				3092	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3093	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3094	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3096	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3097	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3098	<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]	3099	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3100	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3101	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3102	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3103	<h5>Overview:</h5>
				3104	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3105	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3107
				3108	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3109	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3110	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3111	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3112	<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]	3113	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3114	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3115	<table border="1" cellspacing="0" cellpadding="4">
				3116	<tbody>
				3117	<tr>
				3118	<td>In0</td>
				3119	<td>In1</td>
				3120	<td>Out</td>
				3121	</tr>
				3122	<tr>
				3123	<td>0</td>
				3124	<td>0</td>
				3125	<td>0</td>
				3126	</tr>
				3127	<tr>
				3128	<td>0</td>
				3129	<td>1</td>
				3130	<td>1</td>
				3131	</tr>
				3132	<tr>
				3133	<td>1</td>
				3134	<td>0</td>
				3135	<td>1</td>
				3136	</tr>
				3137	<tr>
				3138	<td>1</td>
				3139	<td>1</td>
				3140	<td>1</td>
				3141	</tr>
				3142	</tbody>
				3143	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3144	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3145	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3146	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3147	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3148	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3149	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3150	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3152	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3153	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3154	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3156	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3158	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3159	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3160	or of its two operands. The <tt>xor</tt> is used to implement the
				3161	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3162	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3163	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3164	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3165	values. Both arguments must have identical types.</p>
				3166
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3167	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3168
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3169	<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]	3170	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3171	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3172	<table border="1" cellspacing="0" cellpadding="4">
				3173	<tbody>
				3174	<tr>
				3175	<td>In0</td>
				3176	<td>In1</td>
				3177	<td>Out</td>
				3178	</tr>
				3179	<tr>
				3180	<td>0</td>
				3181	<td>0</td>
				3182	<td>0</td>
				3183	</tr>
				3184	<tr>
				3185	<td>0</td>
				3186	<td>1</td>
				3187	<td>1</td>
				3188	</tr>
				3189	<tr>
				3190	<td>1</td>
				3191	<td>0</td>
				3192	<td>1</td>
				3193	</tr>
				3194	<tr>
				3195	<td>1</td>
				3196	<td>1</td>
				3197	<td>0</td>
				3198	</tr>
				3199	</tbody>
				3200	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3201	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3202	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3203	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3204	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3205	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3206	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3207	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3208	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3209	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3210
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3211	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3212	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3213	<a name="vectorops">Vector Operations</a>
				3214	</div>
				3215
				3216	<div class="doc_text">
				3217
				3218	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3219	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3220	vector-specific operations needed to process vectors effectively. While LLVM
				3221	does directly support these vector operations, many sophisticated algorithms
				3222	will want to use target-specific intrinsics to take full advantage of a specific
				3223	target.</p>
				3224
				3225	</div>
				3226
				3227	<!-- _______________________________________________________________________ -->
				3228	<div class="doc_subsubsection">
				3229	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3230	</div>
				3231
				3232	<div class="doc_text">
				3233
				3234	<h5>Syntax:</h5>
				3235
				3236	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3237	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3238	</pre>
				3239
				3240	<h5>Overview:</h5>
				3241
				3242	<p>
				3243	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3244	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3245	</p>
				3246
				3247
				3248	<h5>Arguments:</h5>
				3249
				3250	<p>
				3251	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3252	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]	3253	an index indicating the position from which to extract the element.
				3254	The index may be a variable.</p>
				3255
				3256	<h5>Semantics:</h5>
				3257
				3258	<p>
				3259	The result is a scalar of the same type as the element type of
				3260	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3261	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3262	results are undefined.
				3263	</p>
				3264
				3265	<h5>Example:</h5>
				3266
				3267	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3268	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3269	</pre>
				3270	</div>
				3271
				3272
				3273	<!-- _______________________________________________________________________ -->
				3274	<div class="doc_subsubsection">
				3275	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3276	</div>
				3277
				3278	<div class="doc_text">
				3279
				3280	<h5>Syntax:</h5>
				3281
				3282	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3283	<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]	3284	</pre>
				3285
				3286	<h5>Overview:</h5>
				3287
				3288	<p>
				3289	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3290	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3291	</p>
				3292
				3293
				3294	<h5>Arguments:</h5>
				3295
				3296	<p>
				3297	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3298	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]	3299	scalar value whose type must equal the element type of the first
				3300	operand. The third operand is an index indicating the position at
				3301	which to insert the value. The index may be a variable.</p>
				3302
				3303	<h5>Semantics:</h5>
				3304
				3305	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3306	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]	3307	element values are those of <tt>val</tt> except at position
				3308	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3309	exceeds the length of <tt>val</tt>, the results are undefined.
				3310	</p>
				3311
				3312	<h5>Example:</h5>
				3313
				3314	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3315	%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]	3316	</pre>
				3317	</div>
				3318
				3319	<!-- _______________________________________________________________________ -->
				3320	<div class="doc_subsubsection">
				3321	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3322	</div>
				3323
				3324	<div class="doc_text">
				3325
				3326	<h5>Syntax:</h5>
				3327
				3328	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3329	<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]	3330	</pre>
				3331
				3332	<h5>Overview:</h5>
				3333
				3334	<p>
				3335	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3336	from two input vectors, returning a vector with the same element type as
				3337	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3338	</p>
				3339
				3340	<h5>Arguments:</h5>
				3341
				3342	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3343	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3344	with types that match each other. The third argument is a shuffle mask whose
				3345	element type is always 'i32'. The result of the instruction is a vector whose
				3346	length is the same as the shuffle mask and whose element type is the same as
				3347	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3348	</p>
				3349
				3350	<p>
				3351	The shuffle mask operand is required to be a constant vector with either
				3352	constant integer or undef values.
				3353	</p>
				3354
				3355	<h5>Semantics:</h5>
				3356
				3357	<p>
				3358	The elements of the two input vectors are numbered from left to right across
				3359	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]	3360	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]	3361	gets. The element selector may be undef (meaning "don't care") and the second
				3362	operand may be undef if performing a shuffle from only one vector.
				3363	</p>
				3364
				3365	<h5>Example:</h5>
				3366
				3367	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3368	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3369	<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]	3370	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3371	<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]	3372	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3373	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3374	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3375	<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]	3376	</pre>
				3377	</div>
				3378
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3379
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3380	<!-- ======================================================================= -->
				3381	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3382	<a name="aggregateops">Aggregate Operations</a>
				3383	</div>
				3384
				3385	<div class="doc_text">
				3386
				3387	<p>LLVM supports several instructions for working with aggregate values.
				3388	</p>
				3389
				3390	</div>
				3391
				3392	<!-- _______________________________________________________________________ -->
				3393	<div class="doc_subsubsection">
				3394	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3395	</div>
				3396
				3397	<div class="doc_text">
				3398
				3399	<h5>Syntax:</h5>
				3400
				3401	<pre>
				3402	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3403	</pre>
				3404
				3405	<h5>Overview:</h5>
				3406
				3407	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3408	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3409	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3410	</p>
				3411
				3412
				3413	<h5>Arguments:</h5>
				3414
				3415	<p>
				3416	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3417	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]	3418	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3419	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3420	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3421	</p>
				3422
				3423	<h5>Semantics:</h5>
				3424
				3425	<p>
				3426	The result is the value at the position in the aggregate specified by
				3427	the index operands.
				3428	</p>
				3429
				3430	<h5>Example:</h5>
				3431
				3432	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3433	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3434	</pre>
				3435	</div>
				3436
				3437
				3438	<!-- _______________________________________________________________________ -->
				3439	<div class="doc_subsubsection">
				3440	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3441	</div>
				3442
				3443	<div class="doc_text">
				3444
				3445	<h5>Syntax:</h5>
				3446
				3447	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3448	<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]	3449	</pre>
				3450
				3451	<h5>Overview:</h5>
				3452
				3453	<p>
				3454	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3455	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3456	</p>
				3457
				3458
				3459	<h5>Arguments:</h5>
				3460
				3461	<p>
				3462	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3463	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3464	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3465	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3466	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]	3467	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3468	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3469	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]	3470	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3471	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3472
				3473	<h5>Semantics:</h5>
				3474
				3475	<p>
				3476	The result is an aggregate of the same type as <tt>val</tt>. Its
				3477	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]	3478	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3479	</p>
				3480
				3481	<h5>Example:</h5>
				3482
				3483	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3484	%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]	3485	</pre>
				3486	</div>
				3487
				3488
				3489	<!-- ======================================================================= -->
				3490	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3491	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3492	</div>
				3493
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3494	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3495
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3496	<p>A key design point of an SSA-based representation is how it
				3497	represents memory. In LLVM, no memory locations are in SSA form, which
				3498	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3499	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3500
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3501	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3502
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3503	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3504	<div class="doc_subsubsection">
				3505	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3506	</div>
				3507
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3508	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3509
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3510	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3511
				3512	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3513	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3514	</pre>
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>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3517
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3518	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3519	heap and returns a pointer to it. The object is always allocated in the generic
				3520	address space (address space zero).</p>
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>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3523
				3524	<p>The '<tt>malloc</tt>' instruction allocates
				3525	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3526	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]	3527	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3528	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3529	If a constant alignment is specified, the value result of the allocation is
				3530	guaranteed to be aligned to at least that boundary. If not specified, or if
				3531	zero, the target can choose to align the allocation on any convenient boundary
				3532	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3534	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3535
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3536	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3537
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3538	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3539	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]	3540	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3541
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3542	<h5>Example:</h5>
				3543
				3544	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3545	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3546
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3547	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3548	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3549	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3550	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3551	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3552	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3553
				3554	<p>Note that the code generator does not yet respect the
				3555	alignment value.</p>
				3556
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3557	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3558
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3559	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3560	<div class="doc_subsubsection">
				3561	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3562	</div>
				3563
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3564	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3565
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3566	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3567
				3568	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3569	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3570	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3571
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3572	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3573
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3574	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3575	memory heap to be reallocated in the future.</p>
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>Arguments:</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>'<tt>value</tt>' shall be a pointer value that points to a value
				3580	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3581	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3582
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3583	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3584
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3585	<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]	3586	after this instruction executes. If the pointer is null, the operation
				3587	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3588
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3589	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3590
				3591	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3592	%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]	3593	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3594	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3595	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3596
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3597	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3598	<div class="doc_subsubsection">
				3599	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3600	</div>
				3601
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3602	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3603
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3604	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3605
				3606	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3607	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3608	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3609
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3610	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3611
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3612	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3613	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3614	returns to its caller. The object is always allocated in the generic address
				3615	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3616
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3617	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3618
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3619	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3620	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3621	appropriate type to the program. If "NumElements" is specified, it is the
				3622	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3623	If a constant alignment is specified, the value result of the allocation is
				3624	guaranteed to be aligned to at least that boundary. If not specified, or if
				3625	zero, the target can choose to align the allocation on any convenient boundary
				3626	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3627
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3628	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3629
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3630	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3631
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3632	<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]	3633	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3634	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3635	instruction is commonly used to represent automatic variables that must
				3636	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]	3637	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]	3638	instructions), the memory is reclaimed. Allocating zero bytes
				3639	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3640
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3641	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3642
				3643	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3644	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3645	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3646	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3647	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3648	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3649	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3650
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3651	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3652	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3653	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3654	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3655	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3656	<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]	3657	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3658	<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]	3659	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3660	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3661	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3662	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]	3663	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]	3664	the number or order of execution of this <tt>load</tt> with other
				3665	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3666	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3667	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3668	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3669	(that is, the alignment of the memory address). A value of 0 or an
				3670	omitted "align" argument means that the operation has the preferential
				3671	alignment for the target. It is the responsibility of the code emitter
				3672	to ensure that the alignment information is correct. Overestimating
				3673	the alignment results in an undefined behavior. Underestimating the
				3674	alignment may produce less efficient code. An alignment of 1 is always
				3675	safe.
				3676	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3677	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3678	<p>The location of memory pointed to is loaded. If the value being loaded
				3679	is of scalar type then the number of bytes read does not exceed the minimum
				3680	number of bytes needed to hold all bits of the type. For example, loading an
				3681	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3682	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3683	is undefined if the value was not originally written using a store of the
				3684	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3685	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3686	<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]	3687	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3688	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3689	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3690	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3691	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3692	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3693	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3694	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3695	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3696	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3697	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3698	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3699	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3700	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3701	<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]	3702	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3703	<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]	3704	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]	3705	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3706	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3707	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]	3708	optimizer is not allowed to modify the number or order of execution of
				3709	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3710	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3711	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3712	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3713	(that is, the alignment of the memory address). A value of 0 or an
				3714	omitted "align" argument means that the operation has the preferential
				3715	alignment for the target. It is the responsibility of the code emitter
				3716	to ensure that the alignment information is correct. Overestimating
				3717	the alignment results in an undefined behavior. Underestimating the
				3718	alignment may produce less efficient code. An alignment of 1 is always
				3719	safe.
				3720	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3721	<h5>Semantics:</h5>
				3722	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3723	at the location specified by the '<tt><pointer></tt>' operand.
				3724	If '<tt><value></tt>' is of scalar type then the number of bytes
				3725	written does not exceed the minimum number of bytes needed to hold all
				3726	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3727	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3728	size that is not an integral number of bytes, it is unspecified what
				3729	happens to the extra bits that do not belong to the type, but they will
				3730	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3731	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3732	<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]	3733	store i32 3, i32* %ptr <i>; yields {void}</i>
				3734	%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]	3735	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3736	</div>
				3737
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3738	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3739	<div class="doc_subsubsection">
				3740	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3741	</div>
				3742
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3743	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3744	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3745	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3746	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3747	</pre>
				3748
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3749	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3750
				3751	<p>
				3752	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]	3753	subelement of an aggregate data structure. It performs address calculation only
				3754	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3755
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3756	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3757
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3758	<p>The first argument is always a pointer, and forms the basis of the
				3759	calculation. The remaining arguments are indices, that indicate which of the
				3760	elements of the aggregate object are indexed. The interpretation of each index
				3761	is dependent on the type being indexed into. The first index always indexes the
				3762	pointer value given as the first argument, the second index indexes a value of
				3763	the type pointed to (not necessarily the value directly pointed to, since the
				3764	first index can be non-zero), etc. The first type indexed into must be a pointer
				3765	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3766	types being indexed into can never be pointers, since that would require loading
				3767	the pointer before continuing calculation.</p>
				3768
				3769	<p>The type of each index argument depends on the type it is indexing into.
				3770	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3771	<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]	3772	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3773
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3774	<p>For example, let's consider a C code fragment and how it gets
				3775	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3776
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3777	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3778	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3779	struct RT {
				3780	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3781	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3782	char C;
				3783	};
				3784	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3785	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3786	double Y;
				3787	struct RT Z;
				3788	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3789
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3790	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3791	return &s[1].Z.B[5][13];
				3792	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3793	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3794	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3795
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3796	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3797
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3798	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3799	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3800	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3801	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3802
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3803	define i32* %foo(%ST* %s) {
				3804	entry:
				3805	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3806	ret i32* %reg
				3807	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3808	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3809	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3810
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3811	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3812
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3813	<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]	3814	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]	3815	}</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]	3816	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3817	i8 }</tt>' type, another structure. The third index indexes into the second
				3818	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]	3819	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3820	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3821	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]	3822
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3823	<p>Note that it is perfectly legal to index partially through a
				3824	structure, returning a pointer to an inner element. Because of this,
				3825	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3826
				3827	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3828	define i32* %foo(%ST* %s) {
				3829	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3830	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3831	%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]	3832	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3833	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3834	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3835	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3836	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3837
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3838	<p>Note that it is undefined to access an array out of bounds: array
				3839	and pointer indexes must always be within the defined bounds of the
				3840	array type when accessed with an instruction that dereferences the
				3841	pointer (e.g. a load or store instruction). The one exception for
				3842	this rule is zero length arrays. These arrays are defined to be
				3843	accessible as variable length arrays, which requires access beyond the
				3844	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3845
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3846	<p>The getelementptr instruction is often confusing. For some more insight
				3847	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3848	FAQ</a>.</p>
				3849
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3850	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3851
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3852	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3853	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3854	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3855	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3856	%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]	3857	<i>; yields i8*:eptr</i>
				3858	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3859	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3860	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3861	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3862	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3863
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3864	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3865	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3866	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3867	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3868	<p>The instructions in this category are the conversion instructions (casting)
				3869	which all take a single operand and a type. They perform various bit conversions
				3870	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3871	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3872
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3873	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3874	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3875	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3876	</div>
				3877	<div class="doc_text">
				3878
				3879	<h5>Syntax:</h5>
				3880	<pre>
				3881	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3882	</pre>
				3883
				3884	<h5>Overview:</h5>
				3885	<p>
				3886	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3887	</p>
				3888
				3889	<h5>Arguments:</h5>
				3890	<p>
				3891	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3892	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]	3893	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]	3894	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3895	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3896
				3897	<h5>Semantics:</h5>
				3898	<p>
				3899	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]	3900	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3901	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3902	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3903
				3904	<h5>Example:</h5>
				3905	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3906	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3907	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3908	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3909	</pre>
				3910	</div>
				3911
				3912	<!-- _______________________________________________________________________ -->
				3913	<div class="doc_subsubsection">
				3914	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3915	</div>
				3916	<div class="doc_text">
				3917
				3918	<h5>Syntax:</h5>
				3919	<pre>
				3920	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3921	</pre>
				3922
				3923	<h5>Overview:</h5>
				3924	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3925	<tt>ty2</tt>.</p>
				3926
				3927
				3928	<h5>Arguments:</h5>
				3929	<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]	3930	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3931	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]	3932	<tt>value</tt> must be smaller than the bit size of the destination type,
				3933	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3934
				3935	<h5>Semantics:</h5>
				3936	<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]	3937	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]	3938
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3939	<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]	3940
				3941	<h5>Example:</h5>
				3942	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3943	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3944	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3945	</pre>
				3946	</div>
				3947
				3948	<!-- _______________________________________________________________________ -->
				3949	<div class="doc_subsubsection">
				3950	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3951	</div>
				3952	<div class="doc_text">
				3953
				3954	<h5>Syntax:</h5>
				3955	<pre>
				3956	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3957	</pre>
				3958
				3959	<h5>Overview:</h5>
				3960	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3961
				3962	<h5>Arguments:</h5>
				3963	<p>
				3964	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]	3965	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3966	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]	3967	<tt>value</tt> must be smaller than the bit size of the destination type,
				3968	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3969
				3970	<h5>Semantics:</h5>
				3971	<p>
				3972	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3973	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]	3974	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3975
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3976	<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]	3977
				3978	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3979	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3980	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3981	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3982	</pre>
				3983	</div>
				3984
				3985	<!-- _______________________________________________________________________ -->
				3986	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3987	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3988	</div>
				3989
				3990	<div class="doc_text">
				3991
				3992	<h5>Syntax:</h5>
				3993
				3994	<pre>
				3995	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3996	</pre>
				3997
				3998	<h5>Overview:</h5>
				3999	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				4000	<tt>ty2</tt>.</p>
				4001
				4002
				4003	<h5>Arguments:</h5>
				4004	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4005	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4006	cast it to. The size of <tt>value</tt> must be larger than the size of
				4007	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4008	<i>no-op cast</i>.</p>
				4009
				4010	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4011	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4012	<a href="#t_floating">floating point</a> type to a smaller
				4013	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4014	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4015
				4016	<h5>Example:</h5>
				4017	<pre>
				4018	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4019	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4020	</pre>
				4021	</div>
				4022
				4023	<!-- _______________________________________________________________________ -->
				4024	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4025	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4026	</div>
				4027	<div class="doc_text">
				4028
				4029	<h5>Syntax:</h5>
				4030	<pre>
				4031	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4032	</pre>
				4033
				4034	<h5>Overview:</h5>
				4035	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4036	floating point value.</p>
				4037
				4038	<h5>Arguments:</h5>
				4039	<p>The '<tt>fpext</tt>' instruction takes a
				4040	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4041	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4042	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4043
				4044	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4045	<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]	4046	<a href="#t_floating">floating point</a> type to a larger
				4047	<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]	4048	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]	4049	<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]	4050
				4051	<h5>Example:</h5>
				4052	<pre>
				4053	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4054	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4055	</pre>
				4056	</div>
				4057
				4058	<!-- _______________________________________________________________________ -->
				4059	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4060	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4061	</div>
				4062	<div class="doc_text">
				4063
				4064	<h5>Syntax:</h5>
				4065	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4066	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4067	</pre>
				4068
				4069	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4070	<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]	4071	unsigned integer equivalent of type <tt>ty2</tt>.
				4072	</p>
				4073
				4074	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4075	<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]	4076	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4077	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4078	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4079	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]	4080
				4081	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4082	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4083	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4084	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4085	the results are undefined.</p>
				4086
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4087	<h5>Example:</h5>
				4088	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4089	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4090	%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]	4091	%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]	4092	</pre>
				4093	</div>
				4094
				4095	<!-- _______________________________________________________________________ -->
				4096	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4097	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4098	</div>
				4099	<div class="doc_text">
				4100
				4101	<h5>Syntax:</h5>
				4102	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4103	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4104	</pre>
				4105
				4106	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4107	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4108	<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]	4109	</p>
				4110
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4111	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4112	<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]	4113	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4114	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4115	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4116	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]	4117
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4118	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4119	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4120	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4121	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4122	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4123
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4124	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4125	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4126	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4127	%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]	4128	%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]	4129	</pre>
				4130	</div>
				4131
				4132	<!-- _______________________________________________________________________ -->
				4133	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4134	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4135	</div>
				4136	<div class="doc_text">
				4137
				4138	<h5>Syntax:</h5>
				4139	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4140	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4141	</pre>
				4142
				4143	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4144	<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]	4145	integer and converts that value to the <tt>ty2</tt> type.</p>
				4146
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4147	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4148	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4149	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4150	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4151	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4152	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]	4153
				4154	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4155	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4156	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4157	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]	4158
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4159	<h5>Example:</h5>
				4160	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4161	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4162	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4163	</pre>
				4164	</div>
				4165
				4166	<!-- _______________________________________________________________________ -->
				4167	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4168	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4169	</div>
				4170	<div class="doc_text">
				4171
				4172	<h5>Syntax:</h5>
				4173	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4174	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4175	</pre>
				4176
				4177	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4178	<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]	4179	integer and converts that value to the <tt>ty2</tt> type.</p>
				4180
				4181	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4182	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4183	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4184	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4185	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4186	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]	4187
				4188	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4189	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4190	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4191	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]	4192
				4193	<h5>Example:</h5>
				4194	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4195	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4196	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4197	</pre>
				4198	</div>
				4199
				4200	<!-- _______________________________________________________________________ -->
				4201	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4202	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4203	</div>
				4204	<div class="doc_text">
				4205
				4206	<h5>Syntax:</h5>
				4207	<pre>
				4208	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4209	</pre>
				4210
				4211	<h5>Overview:</h5>
				4212	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4213	the integer type <tt>ty2</tt>.</p>
				4214
				4215	<h5>Arguments:</h5>
				4216	<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]	4217	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]	4218	<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]	4219
				4220	<h5>Semantics:</h5>
				4221	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4222	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4223	truncating or zero extending that value to the size of the integer type. If
				4224	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4225	<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]	4226	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4227	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4228
				4229	<h5>Example:</h5>
				4230	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4231	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4232	%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]	4233	</pre>
				4234	</div>
				4235
				4236	<!-- _______________________________________________________________________ -->
				4237	<div class="doc_subsubsection">
				4238	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4239	</div>
				4240	<div class="doc_text">
				4241
				4242	<h5>Syntax:</h5>
				4243	<pre>
				4244	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4245	</pre>
				4246
				4247	<h5>Overview:</h5>
				4248	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4249	a pointer type, <tt>ty2</tt>.</p>
				4250
				4251	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4252	<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]	4253	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]	4254	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4255
				4256	<h5>Semantics:</h5>
				4257	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4258	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4259	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4260	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4261	the size of a pointer then a zero extension is done. If they are the same size,
				4262	nothing is done (<i>no-op cast</i>).</p>
				4263
				4264	<h5>Example:</h5>
				4265	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4266	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4267	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4268	%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]	4269	</pre>
				4270	</div>
				4271
				4272	<!-- _______________________________________________________________________ -->
				4273	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4274	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4275	</div>
				4276	<div class="doc_text">
				4277
				4278	<h5>Syntax:</h5>
				4279	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4280	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4281	</pre>
				4282
				4283	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4284
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4285	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4286	<tt>ty2</tt> without changing any bits.</p>
				4287
				4288	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4289
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4290	<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]	4291	a non-aggregate first class value, and a type to cast it to, which must also be
				4292	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4293	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4294	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]	4295	type is a pointer, the destination type must also be a pointer. This
				4296	instruction supports bitwise conversion of vectors to integers and to vectors
				4297	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4298
				4299	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4300	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4301	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4302	this conversion. The conversion is done as if the <tt>value</tt> had been
				4303	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4304	converted to other pointer types with this instruction. To convert pointers to
				4305	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4306	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4307
				4308	<h5>Example:</h5>
				4309	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4310	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4311	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4312	%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]	4313	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4314	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4315
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4316	<!-- ======================================================================= -->
				4317	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4318	<div class="doc_text">
				4319	<p>The instructions in this category are the "miscellaneous"
				4320	instructions, which defy better classification.</p>
				4321	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4322
				4323	<!-- _______________________________________________________________________ -->
				4324	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4325	</div>
				4326	<div class="doc_text">
				4327	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4328	<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]	4329	</pre>
				4330	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4331	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4332	a vector of boolean values based on comparison
				4333	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4334	<h5>Arguments:</h5>
				4335	<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]	4336	the condition code indicating the kind of comparison to perform. It is not
				4337	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4338	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4339	<ol>
				4340	<li><tt>eq</tt>: equal</li>
				4341	<li><tt>ne</tt>: not equal </li>
				4342	<li><tt>ugt</tt>: unsigned greater than</li>
				4343	<li><tt>uge</tt>: unsigned greater or equal</li>
				4344	<li><tt>ult</tt>: unsigned less than</li>
				4345	<li><tt>ule</tt>: unsigned less or equal</li>
				4346	<li><tt>sgt</tt>: signed greater than</li>
				4347	<li><tt>sge</tt>: signed greater or equal</li>
				4348	<li><tt>slt</tt>: signed less than</li>
				4349	<li><tt>sle</tt>: signed less or equal</li>
				4350	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4351	<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]	4352	<a href="#t_pointer">pointer</a>
				4353	or integer <a href="#t_vector">vector</a> typed.
				4354	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4355	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4356	<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]	4357	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4358	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]	4359	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4360	<ol>
				4361	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4362	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4363	</li>
				4364	<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]	4365	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4366	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4367	<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]	4368	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4369	<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]	4370	<li><tt>ult</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 less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4372	<li><tt>ule</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 less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4374	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4375	<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]	4376	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4377	<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]	4378	<li><tt>slt</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 less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4380	<li><tt>sle</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 less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4382	</ol>
				4383	<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]	4384	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4385	<p>If the operands are integer vectors, then they are compared
				4386	element by element. The result is an <tt>i1</tt> vector with
				4387	the same number of elements as the values being compared.
				4388	Otherwise, the result is an <tt>i1</tt>.
				4389	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4390
				4391	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4392	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4393	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4394	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4395	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4396	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4397	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4398	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4399
				4400	<p>Note that the code generator does not yet support vector types with
				4401	the <tt>icmp</tt> instruction.</p>
				4402
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4403	</div>
				4404
				4405	<!-- _______________________________________________________________________ -->
				4406	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4407	</div>
				4408	<div class="doc_text">
				4409	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4410	<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]	4411	</pre>
				4412	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4413	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4414	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4415	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4416	<p>
				4417	If the operands are floating point scalars, then the result
				4418	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4419	</p>
				4420	<p>If the operands are floating point vectors, then the result type
				4421	is a vector of boolean with the same number of elements as the
				4422	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4423	<h5>Arguments:</h5>
				4424	<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]	4425	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]	4426	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4427	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4428	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4429	<li><tt>oeq</tt>: ordered and equal</li>
				4430	<li><tt>ogt</tt>: ordered and greater than </li>
				4431	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4432	<li><tt>olt</tt>: ordered and less than </li>
				4433	<li><tt>ole</tt>: ordered and less than or equal</li>
				4434	<li><tt>one</tt>: ordered and not equal</li>
				4435	<li><tt>ord</tt>: ordered (no nans)</li>
				4436	<li><tt>ueq</tt>: unordered or equal</li>
				4437	<li><tt>ugt</tt>: unordered or greater than </li>
				4438	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4439	<li><tt>ult</tt>: unordered or less than </li>
				4440	<li><tt>ule</tt>: unordered or less than or equal</li>
				4441	<li><tt>une</tt>: unordered or not equal</li>
				4442	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4443	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4444	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4445	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4446	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4447	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4448	either a <a href="#t_floating">floating point</a> type
				4449	or a <a href="#t_vector">vector</a> of floating point type.
				4450	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4451	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4452	<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]	4453	according to the condition code given as <tt>cond</tt>.
				4454	If the operands are vectors, then the vectors are compared
				4455	element by element.
				4456	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4457	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]	4458	<ol>
				4459	<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]	4460	<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]	4461	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4462	<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]	4463	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4464	<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]	4465	<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]	4466	<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]	4467	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4468	<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]	4469	<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]	4470	<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]	4471	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4472	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4473	<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]	4474	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4475	<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]	4476	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4477	<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]	4478	<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]	4479	<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]	4480	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4481	<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]	4482	<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]	4483	<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]	4484	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4485	<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]	4486	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4487	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4488
				4489	<h5>Example:</h5>
				4490	<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]	4491	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4492	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4493	<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]	4494	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4495
				4496	<p>Note that the code generator does not yet support vector types with
				4497	the <tt>fcmp</tt> instruction.</p>
				4498
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4499	</div>
				4500
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4501	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4502	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4503	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4504	</div>
				4505
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4506	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4507
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4508	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4509
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4510	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4511	<h5>Overview:</h5>
				4512	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4513	the SSA graph representing the function.</p>
				4514	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4515
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4516	<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]	4517	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4518	as arguments, with one pair for each predecessor basic block of the
				4519	current block. Only values of <a href="#t_firstclass">first class</a>
				4520	type may be used as the value arguments to the PHI node. Only labels
				4521	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4522
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4523	<p>There must be no non-phi instructions between the start of a basic
				4524	block and the PHI instructions: i.e. PHI instructions must be first in
				4525	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4526
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4527	<p>For the purposes of the SSA form, the use of each incoming value is
				4528	deemed to occur on the edge from the corresponding predecessor block
				4529	to the current block (but after any definition of an '<tt>invoke</tt>'
				4530	instruction's return value on the same edge).</p>
				4531
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4532	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4533
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4534	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4535	specified by the pair corresponding to the predecessor basic block that executed
				4536	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4537
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4538	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4539	<pre>
				4540	Loop: ; Infinite loop that counts from 0 on up...
				4541	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4542	%nextindvar = add i32 %indvar, 1
				4543	br label %Loop
				4544	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4545	</div>
				4546
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4547	<!-- _______________________________________________________________________ -->
				4548	<div class="doc_subsubsection">
				4549	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4550	</div>
				4551
				4552	<div class="doc_text">
				4553
				4554	<h5>Syntax:</h5>
				4555
				4556	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4557	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4558
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4559	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4560	</pre>
				4561
				4562	<h5>Overview:</h5>
				4563
				4564	<p>
				4565	The '<tt>select</tt>' instruction is used to choose one value based on a
				4566	condition, without branching.
				4567	</p>
				4568
				4569
				4570	<h5>Arguments:</h5>
				4571
				4572	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4573	The '<tt>select</tt>' instruction requires an 'i1' value or
				4574	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4575	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]	4576	type. If the val1/val2 are vectors and
				4577	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4578	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4579	</p>
				4580
				4581	<h5>Semantics:</h5>
				4582
				4583	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4584	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]	4585	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4586	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4587	<p>
				4588	If the condition is a vector of i1, then the value arguments must
				4589	be vectors of the same size, and the selection is done element
				4590	by element.
				4591	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4592
				4593	<h5>Example:</h5>
				4594
				4595	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4596	%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]	4597	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4598
				4599	<p>Note that the code generator does not yet support conditions
				4600	with vector type.</p>
				4601
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4602	</div>
				4603
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4604
				4605	<!-- _______________________________________________________________________ -->
				4606	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4607	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4608	</div>
				4609
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4610	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4611
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4612	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4613	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4614	<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]	4615	</pre>
				4616
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4617	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4618
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4619	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4620
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4621	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4622
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4623	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4624
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4625	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4626	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4627	<p>The optional "tail" marker indicates whether the callee function accesses
				4628	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]	4629	function call is eligible for tail call optimization. Note that calls may
				4630	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4631	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4632	</li>
				4633	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4634	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4635	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]	4636	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4637	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4638
				4639	<li>
				4640	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4641	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4642	and '<tt>inreg</tt>' attributes are valid here.</p>
				4643	</li>
				4644
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4645	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4646	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4647	the type of the return value. Functions that return no value are marked
				4648	<tt><a href="#t_void">void</a></tt>.</p>
				4649	</li>
				4650	<li>
				4651	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4652	value being invoked. The argument types must match the types implied by
				4653	this signature. This type can be omitted if the function is not varargs
				4654	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]	4655	</li>
				4656	<li>
				4657	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4658	be invoked. In most cases, this is a direct function invocation, but
				4659	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]	4660	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4661	</li>
				4662	<li>
				4663	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4664	function signature argument types. All arguments must be of
				4665	<a href="#t_firstclass">first class</a> type. If the function signature
				4666	indicates the function accepts a variable number of arguments, the extra
				4667	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4668	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4669	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4670	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4671	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4672	'<tt>readnone</tt>' attributes are valid here.</p>
				4673	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4674	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4675
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4676	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4677
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4678	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4679	transfer to a specified function, with its incoming arguments bound to
				4680	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4681	instruction in the called function, control flow continues with the
				4682	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4683	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4684
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4685	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4686
				4687	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4688	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4689	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4690	%X = tail call i32 @foo() <i>; yields i32</i>
				4691	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4692	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4693
				4694	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4695	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4696	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4697	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4698	%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]	4699	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4700	</pre>
				4701
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4702	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4703
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4704	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4705	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4706	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4707	</div>
				4708
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4709	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4710
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4711	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4712
				4713	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4714	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4715	</pre>
				4716
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4717	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4718
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4719	<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]	4720	the "variable argument" area of a function call. It is used to implement the
				4721	<tt>va_arg</tt> macro in C.</p>
				4722
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4723	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4724
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4725	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4726	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4727	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]	4728	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4729
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4730	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4731
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4732	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4733	type from the specified <tt>va_list</tt> and causes the
				4734	<tt>va_list</tt> to point to the next argument. For more information,
				4735	see the variable argument handling <a href="#int_varargs">Intrinsic
				4736	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4737
				4738	<p>It is legal for this instruction to be called in a function which does not
				4739	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4740	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4741
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4742	<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]	4743	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4744	argument.</p>
				4745
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4746	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4747
				4748	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4749
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4750	<p>Note that the code generator does not yet fully support va_arg
				4751	on many targets. Also, it does not currently support va_arg with
				4752	aggregate types on any target.</p>
				4753
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4754	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4755
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4756	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4757	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4758	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4759
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4760	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4761
				4762	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4763	well known names and semantics and are required to follow certain restrictions.
				4764	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4765	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]	4766	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]	4767
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4768	<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]	4769	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4770	begin with this prefix. Intrinsic functions must always be external functions:
				4771	you cannot define the body of intrinsic functions. Intrinsic functions may
				4772	only be used in call or invoke instructions: it is illegal to take the address
				4773	of an intrinsic function. Additionally, because intrinsic functions are part
				4774	of the LLVM language, it is required if any are added that they be documented
				4775	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4776
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4777	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4778	a family of functions that perform the same operation but on different data
				4779	types. Because LLVM can represent over 8 million different integer types,
				4780	overloading is used commonly to allow an intrinsic function to operate on any
				4781	integer type. One or more of the argument types or the result type can be
				4782	overloaded to accept any integer type. Argument types may also be defined as
				4783	exactly matching a previous argument's type or the result type. This allows an
				4784	intrinsic function which accepts multiple arguments, but needs all of them to
				4785	be of the same type, to only be overloaded with respect to a single argument or
				4786	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4787
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4788	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4789	encoded into its function name, each preceded by a period. Only those types
				4790	which are overloaded result in a name suffix. Arguments whose type is matched
				4791	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4792	take an integer of any width and returns an integer of exactly the same integer
				4793	width. This leads to a family of functions such as
				4794	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4795	Only one type, the return type, is overloaded, and only one type suffix is
				4796	required. Because the argument's type is matched against the return type, it
				4797	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4798
				4799	<p>To learn how to add an intrinsic function, please see the
				4800	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4801	</p>
				4802
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4803	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4804
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4805	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4806	<div class="doc_subsection">
				4807	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4808	</div>
				4809
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4810	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4811
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4812	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4813	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]	4814	intrinsic functions. These functions are related to the similarly
				4815	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4816
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4817	<p>All of these functions operate on arguments that use a
				4818	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4819	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4820	transformations should be prepared to handle these functions regardless of
				4821	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4822
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4823	<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]	4824	instruction and the variable argument handling intrinsic functions are
				4825	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4826
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4827	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4828	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4829	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4830	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4831	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4832	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4833	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4834
				4835	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4836	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4837
				4838	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4839	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4840	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4841	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4842	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4843
				4844	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4845	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4846	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4847	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4848
				4849	declare void @llvm.va_start(i8*)
				4850	declare void @llvm.va_copy(i8, i8)
				4851	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4852	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4853	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4854
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4855	</div>
				4856
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4857	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4858	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4859	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4860	</div>
				4861
				4862
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4863	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4864	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4865	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4866	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4867	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4868	<tt>*<arglist></tt> for subsequent use by <tt><a
				4869	href="#i_va_arg">va_arg</a></tt>.</p>
				4870
				4871	<h5>Arguments:</h5>
				4872
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4873	<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]	4874
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4875	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4876
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4877	<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]	4878	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4879	<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]	4880	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4881	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]	4882	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]	4883
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4884	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4885
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4886	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4887	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4888	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4889	</div>
				4890
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4891	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4892	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4893	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4894	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4895
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4896	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4897	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]	4898	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]	4899
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4900	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4901
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4902	<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]	4903
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4904	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4905
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4906	<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]	4907	macro available in C. In a target-dependent way, it destroys the
				4908	<tt>va_list</tt> element to which the argument points. Calls to <a
				4909	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4910	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4911	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4912
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4913	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4914
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4915	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4916	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4917	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4918	</div>
				4919
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4920	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4921
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4922	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4923
				4924	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4925	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4926	</pre>
				4927
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4928	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4929
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4930	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4931	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4932
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4933	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4934
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4935	<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]	4936	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]	4937
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4938
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4939	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4940
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4941	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4942	macro available in C. In a target-dependent way, it copies the source
				4943	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4944	intrinsic is necessary because the <tt><a href="#int_va_start">
				4945	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4946	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4947
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4948	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4949
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4950	<!-- ======================================================================= -->
				4951	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4952	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4953	</div>
				4954
				4955	<div class="doc_text">
				4956
				4957	<p>
				4958	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4959	Collection</a> (GC) requires the implementation and generation of these
				4960	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4961	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]	4962	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4963	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]	4964	Front-ends for type-safe garbage collected languages should generate these
				4965	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4966	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4967	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4968
				4969	<p>The garbage collection intrinsics only operate on objects in the generic
				4970	address space (address space zero).</p>
				4971
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4972	</div>
				4973
				4974	<!-- _______________________________________________________________________ -->
				4975	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4976	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4977	</div>
				4978
				4979	<div class="doc_text">
				4980
				4981	<h5>Syntax:</h5>
				4982
				4983	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4984	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4985	</pre>
				4986
				4987	<h5>Overview:</h5>
				4988
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4989	<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]	4990	the code generator, and allows some metadata to be associated with it.</p>
				4991
				4992	<h5>Arguments:</h5>
				4993
				4994	<p>The first argument specifies the address of a stack object that contains the
				4995	root pointer. The second pointer (which must be either a constant or a global
				4996	value address) contains the meta-data to be associated with the root.</p>
				4997
				4998	<h5>Semantics:</h5>
				4999
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	5000	<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]	5001	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5002	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5003	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5004	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5005
				5006	</div>
				5007
				5008
				5009	<!-- _______________________________________________________________________ -->
				5010	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5011	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5012	</div>
				5013
				5014	<div class="doc_text">
				5015
				5016	<h5>Syntax:</h5>
				5017
				5018	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5019	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5020	</pre>
				5021
				5022	<h5>Overview:</h5>
				5023
				5024	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5025	locations, allowing garbage collector implementations that require read
				5026	barriers.</p>
				5027
				5028	<h5>Arguments:</h5>
				5029
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5030	<p>The second argument is the address to read from, which should be an address
				5031	allocated from the garbage collector. The first object is a pointer to the
				5032	start of the referenced object, if needed by the language runtime (otherwise
				5033	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5034
				5035	<h5>Semantics:</h5>
				5036
				5037	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5038	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5039	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5040	may only be used in a function which <a href="#gc">specifies a GC
				5041	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5042
				5043	</div>
				5044
				5045
				5046	<!-- _______________________________________________________________________ -->
				5047	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5048	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5049	</div>
				5050
				5051	<div class="doc_text">
				5052
				5053	<h5>Syntax:</h5>
				5054
				5055	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5056	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5057	</pre>
				5058
				5059	<h5>Overview:</h5>
				5060
				5061	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5062	locations, allowing garbage collector implementations that require write
				5063	barriers (such as generational or reference counting collectors).</p>
				5064
				5065	<h5>Arguments:</h5>
				5066
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5067	<p>The first argument is the reference to store, the second is the start of the
				5068	object to store it to, and the third is the address of the field of Obj to
				5069	store to. If the runtime does not require a pointer to the object, Obj may be
				5070	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5071
				5072	<h5>Semantics:</h5>
				5073
				5074	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5075	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5076	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5077	may only be used in a function which <a href="#gc">specifies a GC
				5078	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5079
				5080	</div>
				5081
				5082
				5083
				5084	<!-- ======================================================================= -->
				5085	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5086	<a name="int_codegen">Code Generator Intrinsics</a>
				5087	</div>
				5088
				5089	<div class="doc_text">
				5090	<p>
				5091	These intrinsics are provided by LLVM to expose special features that may only
				5092	be implemented with code generator support.
				5093	</p>
				5094
				5095	</div>
				5096
				5097	<!-- _______________________________________________________________________ -->
				5098	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5099	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5100	</div>
				5101
				5102	<div class="doc_text">
				5103
				5104	<h5>Syntax:</h5>
				5105	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5106	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5107	</pre>
				5108
				5109	<h5>Overview:</h5>
				5110
				5111	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5112	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5113	target-specific value indicating the return address of the current function
				5114	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5115	</p>
				5116
				5117	<h5>Arguments:</h5>
				5118
				5119	<p>
				5120	The argument to this intrinsic indicates which function to return the address
				5121	for. Zero indicates the calling function, one indicates its caller, etc. The
				5122	argument is <b>required</b> to be a constant integer value.
				5123	</p>
				5124
				5125	<h5>Semantics:</h5>
				5126
				5127	<p>
				5128	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5129	the return address of the specified call frame, or zero if it cannot be
				5130	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5131	for arguments other than zero, so it should only be used for debugging purposes.
				5132	</p>
				5133
				5134	<p>
				5135	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5136	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]	5137	source-language caller.
				5138	</p>
				5139	</div>
				5140
				5141
				5142	<!-- _______________________________________________________________________ -->
				5143	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5144	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5145	</div>
				5146
				5147	<div class="doc_text">
				5148
				5149	<h5>Syntax:</h5>
				5150	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5151	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5152	</pre>
				5153
				5154	<h5>Overview:</h5>
				5155
				5156	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5157	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5158	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5159	</p>
				5160
				5161	<h5>Arguments:</h5>
				5162
				5163	<p>
				5164	The argument to this intrinsic indicates which function to return the frame
				5165	pointer for. Zero indicates the calling function, one indicates its caller,
				5166	etc. The argument is <b>required</b> to be a constant integer value.
				5167	</p>
				5168
				5169	<h5>Semantics:</h5>
				5170
				5171	<p>
				5172	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5173	the frame address of the specified call frame, or zero if it cannot be
				5174	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5175	for arguments other than zero, so it should only be used for debugging purposes.
				5176	</p>
				5177
				5178	<p>
				5179	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5180	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]	5181	source-language caller.
				5182	</p>
				5183	</div>
				5184
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5185	<!-- _______________________________________________________________________ -->
				5186	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5187	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5188	</div>
				5189
				5190	<div class="doc_text">
				5191
				5192	<h5>Syntax:</h5>
				5193	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5194	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5195	</pre>
				5196
				5197	<h5>Overview:</h5>
				5198
				5199	<p>
				5200	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]	5201	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5202	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5203	features like scoped automatic variable sized arrays in C99.
				5204	</p>
				5205
				5206	<h5>Semantics:</h5>
				5207
				5208	<p>
				5209	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]	5210	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5211	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5212	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5213	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5214	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5215	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5216	</p>
				5217
				5218	</div>
				5219
				5220	<!-- _______________________________________________________________________ -->
				5221	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5222	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5223	</div>
				5224
				5225	<div class="doc_text">
				5226
				5227	<h5>Syntax:</h5>
				5228	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5229	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5230	</pre>
				5231
				5232	<h5>Overview:</h5>
				5233
				5234	<p>
				5235	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5236	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]	5237	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5238	useful for implementing language features like scoped automatic variable sized
				5239	arrays in C99.
				5240	</p>
				5241
				5242	<h5>Semantics:</h5>
				5243
				5244	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5245	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]	5246	</p>
				5247
				5248	</div>
				5249
				5250
				5251	<!-- _______________________________________________________________________ -->
				5252	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5253	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5254	</div>
				5255
				5256	<div class="doc_text">
				5257
				5258	<h5>Syntax:</h5>
				5259	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5260	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5261	</pre>
				5262
				5263	<h5>Overview:</h5>
				5264
				5265
				5266	<p>
				5267	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]	5268	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5269	no
				5270	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5271	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5272	</p>
				5273
				5274	<h5>Arguments:</h5>
				5275
				5276	<p>
				5277	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5278	determining if the fetch should be for a read (0) or write (1), and
				5279	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5280	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]	5281	<tt>locality</tt> arguments must be constant integers.
				5282	</p>
				5283
				5284	<h5>Semantics:</h5>
				5285
				5286	<p>
				5287	This intrinsic does not modify the behavior of the program. In particular,
				5288	prefetches cannot trap and do not produce a value. On targets that support this
				5289	intrinsic, the prefetch can provide hints to the processor cache for better
				5290	performance.
				5291	</p>
				5292
				5293	</div>
				5294
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5295	<!-- _______________________________________________________________________ -->
				5296	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5297	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5298	</div>
				5299
				5300	<div class="doc_text">
				5301
				5302	<h5>Syntax:</h5>
				5303	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5304	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5305	</pre>
				5306
				5307	<h5>Overview:</h5>
				5308
				5309
				5310	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5311	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]	5312	(PC) in a region of
				5313	code to simulators and other tools. The method is target specific, but it is
				5314	expected that the marker will use exported symbols to transmit the PC of the
				5315	marker.
				5316	The marker makes no guarantees that it will remain with any specific instruction
				5317	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]	5318	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5319	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5320	</p>
				5321
				5322	<h5>Arguments:</h5>
				5323
				5324	<p>
				5325	<tt>id</tt> is a numerical id identifying the marker.
				5326	</p>
				5327
				5328	<h5>Semantics:</h5>
				5329
				5330	<p>
				5331	This intrinsic does not modify the behavior of the program. Backends that do not
				5332	support this intrinisic may ignore it.
				5333	</p>
				5334
				5335	</div>
				5336
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5337	<!-- _______________________________________________________________________ -->
				5338	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5339	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5340	</div>
				5341
				5342	<div class="doc_text">
				5343
				5344	<h5>Syntax:</h5>
				5345	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5346	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5347	</pre>
				5348
				5349	<h5>Overview:</h5>
				5350
				5351
				5352	<p>
				5353	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5354	counter register (or similar low latency, high accuracy clocks) on those targets
				5355	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5356	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5357	should only be used for small timings.
				5358	</p>
				5359
				5360	<h5>Semantics:</h5>
				5361
				5362	<p>
				5363	When directly supported, reading the cycle counter should not modify any memory.
				5364	Implementations are allowed to either return a application specific value or a
				5365	system wide value. On backends without support, this is lowered to a constant 0.
				5366	</p>
				5367
				5368	</div>
				5369
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5370	<!-- ======================================================================= -->
				5371	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5372	<a name="int_libc">Standard C Library Intrinsics</a>
				5373	</div>
				5374
				5375	<div class="doc_text">
				5376	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5377	LLVM provides intrinsics for a few important standard C library functions.
				5378	These intrinsics allow source-language front-ends to pass information about the
				5379	alignment of the pointer arguments to the code generator, providing opportunity
				5380	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5381	</p>
				5382
				5383	</div>
				5384
				5385	<!-- _______________________________________________________________________ -->
				5386	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5387	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5388	</div>
				5389
				5390	<div class="doc_text">
				5391
				5392	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5393	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5394	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5395	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5396	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5397	i8 <len>, i32 <align>)
				5398	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5399	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5400	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5401	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5402	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5403	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5404	</pre>
				5405
				5406	<h5>Overview:</h5>
				5407
				5408	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5409	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]	5410	location to the destination location.
				5411	</p>
				5412
				5413	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5414	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5415	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5416	</p>
				5417
				5418	<h5>Arguments:</h5>
				5419
				5420	<p>
				5421	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]	5422	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5423	specifying the number of bytes to copy, and the fourth argument is the alignment
				5424	of the source and destination locations.
				5425	</p>
				5426
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5427	<p>
				5428	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]	5429	the caller guarantees that both the source and destination pointers are aligned
				5430	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5431	</p>
				5432
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5433	<h5>Semantics:</h5>
				5434
				5435	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5436	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]	5437	location to the destination location, which are not allowed to overlap. It
				5438	copies "len" bytes of memory over. If the argument is known to be aligned to
				5439	some boundary, this can be specified as the fourth argument, otherwise it should
				5440	be set to 0 or 1.
				5441	</p>
				5442	</div>
				5443
				5444
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5445	<!-- _______________________________________________________________________ -->
				5446	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5447	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5448	</div>
				5449
				5450	<div class="doc_text">
				5451
				5452	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5453	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5454	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5455	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5456	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5457	i8 <len>, i32 <align>)
				5458	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5459	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5460	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5461	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5462	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5463	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5464	</pre>
				5465
				5466	<h5>Overview:</h5>
				5467
				5468	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5469	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5470	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5471	'<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]	5472	</p>
				5473
				5474	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5475	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5476	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5477	</p>
				5478
				5479	<h5>Arguments:</h5>
				5480
				5481	<p>
				5482	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]	5483	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5484	specifying the number of bytes to copy, and the fourth argument is the alignment
				5485	of the source and destination locations.
				5486	</p>
				5487
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5488	<p>
				5489	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]	5490	the caller guarantees that the source and destination pointers are aligned to
				5491	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5492	</p>
				5493
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5494	<h5>Semantics:</h5>
				5495
				5496	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5497	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]	5498	location to the destination location, which may overlap. It
				5499	copies "len" bytes of memory over. If the argument is known to be aligned to
				5500	some boundary, this can be specified as the fourth argument, otherwise it should
				5501	be set to 0 or 1.
				5502	</p>
				5503	</div>
				5504
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5505
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5506	<!-- _______________________________________________________________________ -->
				5507	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5508	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5509	</div>
				5510
				5511	<div class="doc_text">
				5512
				5513	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5514	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5515	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5516	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5517	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5518	i8 <len>, i32 <align>)
				5519	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5520	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5521	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5522	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5523	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5524	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5525	</pre>
				5526
				5527	<h5>Overview:</h5>
				5528
				5529	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5530	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]	5531	byte value.
				5532	</p>
				5533
				5534	<p>
				5535	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5536	does not return a value, and takes an extra alignment argument.
				5537	</p>
				5538
				5539	<h5>Arguments:</h5>
				5540
				5541	<p>
				5542	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]	5543	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5544	argument specifying the number of bytes to fill, and the fourth argument is the
				5545	known alignment of destination location.
				5546	</p>
				5547
				5548	<p>
				5549	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]	5550	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5551	</p>
				5552
				5553	<h5>Semantics:</h5>
				5554
				5555	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5556	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5557	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5558	destination location. If the argument is known to be aligned to some boundary,
				5559	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5560	1.
				5561	</p>
				5562	</div>
				5563
				5564
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5565	<!-- _______________________________________________________________________ -->
				5566	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5567	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5568	</div>
				5569
				5570	<div class="doc_text">
				5571
				5572	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5573	<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]	5574	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]	5575	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5576	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5577	declare float @llvm.sqrt.f32(float %Val)
				5578	declare double @llvm.sqrt.f64(double %Val)
				5579	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5580	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5581	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5582	</pre>
				5583
				5584	<h5>Overview:</h5>
				5585
				5586	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5587	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]	5588	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]	5589	<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]	5590	negative numbers other than -0.0 (which allows for better optimization, because
				5591	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5592	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5593	</p>
				5594
				5595	<h5>Arguments:</h5>
				5596
				5597	<p>
				5598	The argument and return value are floating point numbers of the same type.
				5599	</p>
				5600
				5601	<h5>Semantics:</h5>
				5602
				5603	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5604	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]	5605	floating point number.
				5606	</p>
				5607	</div>
				5608
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5609	<!-- _______________________________________________________________________ -->
				5610	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5611	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5612	</div>
				5613
				5614	<div class="doc_text">
				5615
				5616	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5617	<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]	5618	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]	5619	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5620	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5621	declare float @llvm.powi.f32(float %Val, i32 %power)
				5622	declare double @llvm.powi.f64(double %Val, i32 %power)
				5623	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5624	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5625	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5626	</pre>
				5627
				5628	<h5>Overview:</h5>
				5629
				5630	<p>
				5631	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5632	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5633	multiplications is not defined. When a vector of floating point type is
				5634	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5635	</p>
				5636
				5637	<h5>Arguments:</h5>
				5638
				5639	<p>
				5640	The second argument is an integer power, and the first is a value to raise to
				5641	that power.
				5642	</p>
				5643
				5644	<h5>Semantics:</h5>
				5645
				5646	<p>
				5647	This function returns the first value raised to the second power with an
				5648	unspecified sequence of rounding operations.</p>
				5649	</div>
				5650
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5651	<!-- _______________________________________________________________________ -->
				5652	<div class="doc_subsubsection">
				5653	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5654	</div>
				5655
				5656	<div class="doc_text">
				5657
				5658	<h5>Syntax:</h5>
				5659	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5660	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]	5661	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5662	<pre>
				5663	declare float @llvm.sin.f32(float %Val)
				5664	declare double @llvm.sin.f64(double %Val)
				5665	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5666	declare fp128 @llvm.sin.f128(fp128 %Val)
				5667	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5668	</pre>
				5669
				5670	<h5>Overview:</h5>
				5671
				5672	<p>
				5673	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5674	</p>
				5675
				5676	<h5>Arguments:</h5>
				5677
				5678	<p>
				5679	The argument and return value are floating point numbers of the same type.
				5680	</p>
				5681
				5682	<h5>Semantics:</h5>
				5683
				5684	<p>
				5685	This function returns the sine of the specified operand, returning the
				5686	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]	5687	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5688	</div>
				5689
				5690	<!-- _______________________________________________________________________ -->
				5691	<div class="doc_subsubsection">
				5692	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5693	</div>
				5694
				5695	<div class="doc_text">
				5696
				5697	<h5>Syntax:</h5>
				5698	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5699	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]	5700	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5701	<pre>
				5702	declare float @llvm.cos.f32(float %Val)
				5703	declare double @llvm.cos.f64(double %Val)
				5704	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5705	declare fp128 @llvm.cos.f128(fp128 %Val)
				5706	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5707	</pre>
				5708
				5709	<h5>Overview:</h5>
				5710
				5711	<p>
				5712	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5713	</p>
				5714
				5715	<h5>Arguments:</h5>
				5716
				5717	<p>
				5718	The argument and return value are floating point numbers of the same type.
				5719	</p>
				5720
				5721	<h5>Semantics:</h5>
				5722
				5723	<p>
				5724	This function returns the cosine of the specified operand, returning the
				5725	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]	5726	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5727	</div>
				5728
				5729	<!-- _______________________________________________________________________ -->
				5730	<div class="doc_subsubsection">
				5731	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5732	</div>
				5733
				5734	<div class="doc_text">
				5735
				5736	<h5>Syntax:</h5>
				5737	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5738	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]	5739	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5740	<pre>
				5741	declare float @llvm.pow.f32(float %Val, float %Power)
				5742	declare double @llvm.pow.f64(double %Val, double %Power)
				5743	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5744	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5745	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5746	</pre>
				5747
				5748	<h5>Overview:</h5>
				5749
				5750	<p>
				5751	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5752	specified (positive or negative) power.
				5753	</p>
				5754
				5755	<h5>Arguments:</h5>
				5756
				5757	<p>
				5758	The second argument is a floating point power, and the first is a value to
				5759	raise to that power.
				5760	</p>
				5761
				5762	<h5>Semantics:</h5>
				5763
				5764	<p>
				5765	This function returns the first value raised to the second power,
				5766	returning the
				5767	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]	5768	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5769	</div>
				5770
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5771
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5772	<!-- ======================================================================= -->
				5773	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5774	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5775	</div>
				5776
				5777	<div class="doc_text">
				5778	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5779	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5780	These allow efficient code generation for some algorithms.
				5781	</p>
				5782
				5783	</div>
				5784
				5785	<!-- _______________________________________________________________________ -->
				5786	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5787	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5788	</div>
				5789
				5790	<div class="doc_text">
				5791
				5792	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5793	<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]	5794	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]	5795	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5796	declare i16 @llvm.bswap.i16(i16 <id>)
				5797	declare i32 @llvm.bswap.i32(i32 <id>)
				5798	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5799	</pre>
				5800
				5801	<h5>Overview:</h5>
				5802
				5803	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5804	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]	5805	values with an even number of bytes (positive multiple of 16 bits). These are
				5806	useful for performing operations on data that is not in the target's native
				5807	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5808	</p>
				5809
				5810	<h5>Semantics:</h5>
				5811
				5812	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5813	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]	5814	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5815	intrinsic returns an i32 value that has the four bytes of the input i32
				5816	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]	5817	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5818	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5819	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5820	</p>
				5821
				5822	</div>
				5823
				5824	<!-- _______________________________________________________________________ -->
				5825	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5826	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5827	</div>
				5828
				5829	<div class="doc_text">
				5830
				5831	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5832	<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]	5833	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5834	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5835	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5836	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5837	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5838	declare i64 @llvm.ctpop.i64(i64 <src>)
				5839	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5840	</pre>
				5841
				5842	<h5>Overview:</h5>
				5843
				5844	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5845	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5846	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5847	</p>
				5848
				5849	<h5>Arguments:</h5>
				5850
				5851	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5852	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]	5853	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5854	</p>
				5855
				5856	<h5>Semantics:</h5>
				5857
				5858	<p>
				5859	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5860	</p>
				5861	</div>
				5862
				5863	<!-- _______________________________________________________________________ -->
				5864	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5865	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5866	</div>
				5867
				5868	<div class="doc_text">
				5869
				5870	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5871	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5872	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5873	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5874	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5875	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5876	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5877	declare i64 @llvm.ctlz.i64(i64 <src>)
				5878	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5879	</pre>
				5880
				5881	<h5>Overview:</h5>
				5882
				5883	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5884	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5885	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5886	</p>
				5887
				5888	<h5>Arguments:</h5>
				5889
				5890	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5891	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5892	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5893	</p>
				5894
				5895	<h5>Semantics:</h5>
				5896
				5897	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5898	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5899	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]	5900	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5901	</p>
				5902	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5903
				5904
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5905
				5906	<!-- _______________________________________________________________________ -->
				5907	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5908	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5909	</div>
				5910
				5911	<div class="doc_text">
				5912
				5913	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5914	<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]	5915	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5916	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5917	declare i8 @llvm.cttz.i8 (i8 <src>)
				5918	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5919	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5920	declare i64 @llvm.cttz.i64(i64 <src>)
				5921	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5922	</pre>
				5923
				5924	<h5>Overview:</h5>
				5925
				5926	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5927	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5928	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5929	</p>
				5930
				5931	<h5>Arguments:</h5>
				5932
				5933	<p>
				5934	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]	5935	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5936	</p>
				5937
				5938	<h5>Semantics:</h5>
				5939
				5940	<p>
				5941	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5942	in a variable. If the src == 0 then the result is the size in bits of the type
				5943	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5944	</p>
				5945	</div>
				5946
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5947
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5948	<!-- ======================================================================= -->
				5949	<div class="doc_subsection">
				5950	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5951	</div>
				5952
				5953	<div class="doc_text">
				5954	<p>
				5955	LLVM provides intrinsics for some arithmetic with overflow operations.
				5956	</p>
				5957
				5958	</div>
				5959
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5960	<!-- _______________________________________________________________________ -->
				5961	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5962	<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]	5963	</div>
				5964
				5965	<div class="doc_text">
				5966
				5967	<h5>Syntax:</h5>
				5968
				5969	<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]	5970	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5971
				5972	<pre>
				5973	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5974	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5975	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5976	</pre>
				5977
				5978	<h5>Overview:</h5>
				5979
				5980	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5981	a signed addition of the two arguments, and indicate whether an overflow
				5982	occurred during the signed summation.</p>
				5983
				5984	<h5>Arguments:</h5>
				5985
				5986	<p>The arguments (%a and %b) and the first element of the result structure may
				5987	be of integer types of any bit width, but they must have the same bit width. The
				5988	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				5989	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				5990
				5991	<h5>Semantics:</h5>
				5992
				5993	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5994	a signed addition of the two variables. They return a structure — the
				5995	first element of which is the signed summation, and the second element of which
				5996	is a bit specifying if the signed summation resulted in an overflow.</p>
				5997
				5998	<h5>Examples:</h5>
				5999	<pre>
				6000	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6001	%sum = extractvalue {i32, i1} %res, 0
				6002	%obit = extractvalue {i32, i1} %res, 1
				6003	br i1 %obit, label %overflow, label %normal
				6004	</pre>
				6005
				6006	</div>
				6007
				6008	<!-- _______________________________________________________________________ -->
				6009	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6010	<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]	6011	</div>
				6012
				6013	<div class="doc_text">
				6014
				6015	<h5>Syntax:</h5>
				6016
				6017	<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]	6018	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6019
				6020	<pre>
				6021	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6022	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6023	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6024	</pre>
				6025
				6026	<h5>Overview:</h5>
				6027
				6028	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6029	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6030	during the unsigned summation.</p>
				6031
				6032	<h5>Arguments:</h5>
				6033
				6034	<p>The arguments (%a and %b) and the first element of the result structure may
				6035	be of integer types of any bit width, but they must have the same bit width. The
				6036	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6037	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6038
				6039	<h5>Semantics:</h5>
				6040
				6041	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6042	an unsigned addition of the two arguments. They return a structure — the
				6043	first element of which is the sum, and the second element of which is a bit
				6044	specifying if the unsigned summation resulted in a carry.</p>
				6045
				6046	<h5>Examples:</h5>
				6047	<pre>
				6048	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6049	%sum = extractvalue {i32, i1} %res, 0
				6050	%obit = extractvalue {i32, i1} %res, 1
				6051	br i1 %obit, label %carry, label %normal
				6052	</pre>
				6053
				6054	</div>
				6055
				6056	<!-- _______________________________________________________________________ -->
				6057	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6058	<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]	6059	</div>
				6060
				6061	<div class="doc_text">
				6062
				6063	<h5>Syntax:</h5>
				6064
				6065	<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]	6066	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6067
				6068	<pre>
				6069	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6070	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6071	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6072	</pre>
				6073
				6074	<h5>Overview:</h5>
				6075
				6076	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6077	a signed subtraction of the two arguments, and indicate whether an overflow
				6078	occurred during the signed subtraction.</p>
				6079
				6080	<h5>Arguments:</h5>
				6081
				6082	<p>The arguments (%a and %b) and the first element of the result structure may
				6083	be of integer types of any bit width, but they must have the same bit width. The
				6084	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6085	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6086
				6087	<h5>Semantics:</h5>
				6088
				6089	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6090	a signed subtraction of the two arguments. They return a structure — the
				6091	first element of which is the subtraction, and the second element of which is a bit
				6092	specifying if the signed subtraction resulted in an overflow.</p>
				6093
				6094	<h5>Examples:</h5>
				6095	<pre>
				6096	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6097	%sum = extractvalue {i32, i1} %res, 0
				6098	%obit = extractvalue {i32, i1} %res, 1
				6099	br i1 %obit, label %overflow, label %normal
				6100	</pre>
				6101
				6102	</div>
				6103
				6104	<!-- _______________________________________________________________________ -->
				6105	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6106	<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]	6107	</div>
				6108
				6109	<div class="doc_text">
				6110
				6111	<h5>Syntax:</h5>
				6112
				6113	<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]	6114	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6115
				6116	<pre>
				6117	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6118	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6119	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6120	</pre>
				6121
				6122	<h5>Overview:</h5>
				6123
				6124	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6125	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6126	occurred during the unsigned subtraction.</p>
				6127
				6128	<h5>Arguments:</h5>
				6129
				6130	<p>The arguments (%a and %b) and the first element of the result structure may
				6131	be of integer types of any bit width, but they must have the same bit width. The
				6132	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6133	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6134
				6135	<h5>Semantics:</h5>
				6136
				6137	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6138	an unsigned subtraction of the two arguments. They return a structure — the
				6139	first element of which is the subtraction, and the second element of which is a bit
				6140	specifying if the unsigned subtraction resulted in an overflow.</p>
				6141
				6142	<h5>Examples:</h5>
				6143	<pre>
				6144	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6145	%sum = extractvalue {i32, i1} %res, 0
				6146	%obit = extractvalue {i32, i1} %res, 1
				6147	br i1 %obit, label %overflow, label %normal
				6148	</pre>
				6149
				6150	</div>
				6151
				6152	<!-- _______________________________________________________________________ -->
				6153	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6154	<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]	6155	</div>
				6156
				6157	<div class="doc_text">
				6158
				6159	<h5>Syntax:</h5>
				6160
				6161	<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]	6162	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6163
				6164	<pre>
				6165	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6166	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6167	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6168	</pre>
				6169
				6170	<h5>Overview:</h5>
				6171
				6172	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6173	a signed multiplication of the two arguments, and indicate whether an overflow
				6174	occurred during the signed multiplication.</p>
				6175
				6176	<h5>Arguments:</h5>
				6177
				6178	<p>The arguments (%a and %b) and the first element of the result structure may
				6179	be of integer types of any bit width, but they must have the same bit width. The
				6180	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6181	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6182
				6183	<h5>Semantics:</h5>
				6184
				6185	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6186	a signed multiplication of the two arguments. They return a structure —
				6187	the first element of which is the multiplication, and the second element of
				6188	which is a bit specifying if the signed multiplication resulted in an
				6189	overflow.</p>
				6190
				6191	<h5>Examples:</h5>
				6192	<pre>
				6193	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6194	%sum = extractvalue {i32, i1} %res, 0
				6195	%obit = extractvalue {i32, i1} %res, 1
				6196	br i1 %obit, label %overflow, label %normal
				6197	</pre>
				6198
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6199	</div>
				6200
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6201	<!-- _______________________________________________________________________ -->
				6202	<div class="doc_subsubsection">
				6203	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6204	</div>
				6205
				6206	<div class="doc_text">
				6207
				6208	<h5>Syntax:</h5>
				6209
				6210	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6211	on any integer bit width.</p>
				6212
				6213	<pre>
				6214	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6215	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6216	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6217	</pre>
				6218
				6219	<h5>Overview:</h5>
				6220
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6221	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6222	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6223	occurred during the unsigned multiplication.</p>
				6224
				6225	<h5>Arguments:</h5>
				6226
				6227	<p>The arguments (%a and %b) and the first element of the result structure may
				6228	be of integer types of any bit width, but they must have the same bit width. The
				6229	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6230	and <tt>%b</tt> are the two values that will undergo unsigned
				6231	multiplication.</p>
				6232
				6233	<h5>Semantics:</h5>
				6234
				6235	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6236	an unsigned multiplication of the two arguments. They return a structure —
				6237	the first element of which is the multiplication, and the second element of
				6238	which is a bit specifying if the unsigned multiplication resulted in an
				6239	overflow.</p>
				6240
				6241	<h5>Examples:</h5>
				6242	<pre>
				6243	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6244	%sum = extractvalue {i32, i1} %res, 0
				6245	%obit = extractvalue {i32, i1} %res, 1
				6246	br i1 %obit, label %overflow, label %normal
				6247	</pre>
				6248
				6249	</div>
				6250
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6251	<!-- ======================================================================= -->
				6252	<div class="doc_subsection">
				6253	<a name="int_debugger">Debugger Intrinsics</a>
				6254	</div>
				6255
				6256	<div class="doc_text">
				6257	<p>
				6258	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6259	are described in the <a
				6260	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6261	Debugging</a> document.
				6262	</p>
				6263	</div>
				6264
				6265
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6266	<!-- ======================================================================= -->
				6267	<div class="doc_subsection">
				6268	<a name="int_eh">Exception Handling Intrinsics</a>
				6269	</div>
				6270
				6271	<div class="doc_text">
				6272	<p> The LLVM exception handling intrinsics (which all start with
				6273	<tt>llvm.eh.</tt> prefix), are described in the <a
				6274	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6275	Handling</a> document. </p>
				6276	</div>
				6277
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6278	<!-- ======================================================================= -->
				6279	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6280	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6281	</div>
				6282
				6283	<div class="doc_text">
				6284	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6285	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6286	the <tt>nest</tt> attribute, from a function. The result is a callable
				6287	function pointer lacking the nest parameter - the caller does not need
				6288	to provide a value for it. Instead, the value to use is stored in
				6289	advance in a "trampoline", a block of memory usually allocated
				6290	on the stack, which also contains code to splice the nest value into the
				6291	argument list. This is used to implement the GCC nested function address
				6292	extension.
				6293	</p>
				6294	<p>
				6295	For example, if the function is
				6296	<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]	6297	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]	6298	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6299	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6300	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6301	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6302	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6303	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6304	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6305	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]	6306	</div>
				6307
				6308	<!-- _______________________________________________________________________ -->
				6309	<div class="doc_subsubsection">
				6310	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6311	</div>
				6312	<div class="doc_text">
				6313	<h5>Syntax:</h5>
				6314	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6315	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6316	</pre>
				6317	<h5>Overview:</h5>
				6318	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6319	This fills the memory pointed to by <tt>tramp</tt> with code
				6320	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6321	</p>
				6322	<h5>Arguments:</h5>
				6323	<p>
				6324	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6325	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6326	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]	6327	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6328	currently provides no portable way of determining them, so a front-end that
				6329	generates this intrinsic needs to have some target-specific knowledge.
				6330	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]	6331	</p>
				6332	<h5>Semantics:</h5>
				6333	<p>
				6334	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]	6335	dependent code, turning it into a function. A pointer to this function is
				6336	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6337	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6338	before being called. The new function's signature is the same as that of
				6339	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6340	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6341	of pointer type. Calling the new function is equivalent to calling
				6342	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6343	missing <tt>nest</tt> argument. If, after calling
				6344	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6345	modified, then the effect of any later call to the returned function pointer is
				6346	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6347	</p>
				6348	</div>
				6349
				6350	<!-- ======================================================================= -->
				6351	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6352	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6353	</div>
				6354
				6355	<div class="doc_text">
				6356	<p>
				6357	These intrinsic functions expand the "universal IR" of LLVM to represent
				6358	hardware constructs for atomic operations and memory synchronization. This
				6359	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]	6360	is aimed at a low enough level to allow any programming models or APIs
				6361	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6362	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6363	hardware behavior. Just as hardware provides a "universal IR" for source
				6364	languages, it also provides a starting point for developing a "universal"
				6365	atomic operation and synchronization IR.
				6366	</p>
				6367	<p>
				6368	These do <em>not</em> form an API such as high-level threading libraries,
				6369	software transaction memory systems, atomic primitives, and intrinsic
				6370	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6371	application libraries. The hardware interface provided by LLVM should allow
				6372	a clean implementation of all of these APIs and parallel programming models.
				6373	No one model or paradigm should be selected above others unless the hardware
				6374	itself ubiquitously does so.
				6375
				6376	</p>
				6377	</div>
				6378
				6379	<!-- _______________________________________________________________________ -->
				6380	<div class="doc_subsubsection">
				6381	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6382	</div>
				6383	<div class="doc_text">
				6384	<h5>Syntax:</h5>
				6385	<pre>
				6386	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6387	i1 <device> )
				6388
				6389	</pre>
				6390	<h5>Overview:</h5>
				6391	<p>
				6392	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6393	specific pairs of memory access types.
				6394	</p>
				6395	<h5>Arguments:</h5>
				6396	<p>
				6397	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6398	The first four arguments enables a specific barrier as listed below. The fith
				6399	argument specifies that the barrier applies to io or device or uncached memory.
				6400
				6401	</p>
				6402	<ul>
				6403	<li><tt>ll</tt>: load-load barrier</li>
				6404	<li><tt>ls</tt>: load-store barrier</li>
				6405	<li><tt>sl</tt>: store-load barrier</li>
				6406	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6407	<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]	6408	</ul>
				6409	<h5>Semantics:</h5>
				6410	<p>
				6411	This intrinsic causes the system to enforce some ordering constraints upon
				6412	the loads and stores of the program. This barrier does not indicate
				6413	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6414	which they occur. For any of the specified pairs of load and store operations
				6415	(f.ex. load-load, or store-load), all of the first operations preceding the
				6416	barrier will complete before any of the second operations succeeding the
				6417	barrier begin. Specifically the semantics for each pairing is as follows:
				6418	</p>
				6419	<ul>
				6420	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6421	after the barrier begins.</li>
				6422
				6423	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6424	store after the barrier begins.</li>
				6425	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6426	store after the barrier begins.</li>
				6427	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6428	load after the barrier begins.</li>
				6429	</ul>
				6430	<p>
				6431	These semantics are applied with a logical "and" behavior when more than one
				6432	is enabled in a single memory barrier intrinsic.
				6433	</p>
				6434	<p>
				6435	Backends may implement stronger barriers than those requested when they do not
				6436	support as fine grained a barrier as requested. Some architectures do not
				6437	need all types of barriers and on such architectures, these become noops.
				6438	</p>
				6439	<h5>Example:</h5>
				6440	<pre>
				6441	%ptr = malloc i32
				6442	store i32 4, %ptr
				6443
				6444	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6445	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6446	<i>; guarantee the above finishes</i>
				6447	store i32 8, %ptr <i>; before this begins</i>
				6448	</pre>
				6449	</div>
				6450
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6451	<!-- _______________________________________________________________________ -->
				6452	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6453	<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]	6454	</div>
				6455	<div class="doc_text">
				6456	<h5>Syntax:</h5>
				6457	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6458	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6459	any integer bit width and for different address spaces. Not all targets
				6460	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6461
				6462	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6463	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6464	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6465	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6466	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]	6467
				6468	</pre>
				6469	<h5>Overview:</h5>
				6470	<p>
				6471	This loads a value in memory and compares it to a given value. If they are
				6472	equal, it stores a new value into the memory.
				6473	</p>
				6474	<h5>Arguments:</h5>
				6475	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6476	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]	6477	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6478	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6479	this integer type. While any bit width integer may be used, targets may only
				6480	lower representations they support in hardware.
				6481
				6482	</p>
				6483	<h5>Semantics:</h5>
				6484	<p>
				6485	This entire intrinsic must be executed atomically. It first loads the value
				6486	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6487	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6488	loaded value is yielded in all cases. This provides the equivalent of an
				6489	atomic compare-and-swap operation within the SSA framework.
				6490	</p>
				6491	<h5>Examples:</h5>
				6492
				6493	<pre>
				6494	%ptr = malloc i32
				6495	store i32 4, %ptr
				6496
				6497	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6498	%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]	6499	<i>; yields {i32}:result1 = 4</i>
				6500	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6501	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6502
				6503	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6504	%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]	6505	<i>; yields {i32}:result2 = 8</i>
				6506	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6507
				6508	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6509	</pre>
				6510	</div>
				6511
				6512	<!-- _______________________________________________________________________ -->
				6513	<div class="doc_subsubsection">
				6514	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6515	</div>
				6516	<div class="doc_text">
				6517	<h5>Syntax:</h5>
				6518
				6519	<p>
				6520	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6521	integer bit width. Not all targets support all bit widths however.</p>
				6522	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6523	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6524	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6525	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6526	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6527
				6528	</pre>
				6529	<h5>Overview:</h5>
				6530	<p>
				6531	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6532	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6533	at <tt>ptr</tt>.
				6534	</p>
				6535	<h5>Arguments:</h5>
				6536
				6537	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6538	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6539	<tt>val</tt> argument and the result must be integers of the same bit width.
				6540	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6541	integer type. The targets may only lower integer representations they
				6542	support.
				6543	</p>
				6544	<h5>Semantics:</h5>
				6545	<p>
				6546	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6547	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6548	equivalent of an atomic swap operation within the SSA framework.
				6549
				6550	</p>
				6551	<h5>Examples:</h5>
				6552	<pre>
				6553	%ptr = malloc i32
				6554	store i32 4, %ptr
				6555
				6556	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6557	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6558	<i>; yields {i32}:result1 = 4</i>
				6559	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6560	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6561
				6562	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6563	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6564	<i>; yields {i32}:result2 = 8</i>
				6565
				6566	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6567	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6568	</pre>
				6569	</div>
				6570
				6571	<!-- _______________________________________________________________________ -->
				6572	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6573	<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]	6574
				6575	</div>
				6576	<div class="doc_text">
				6577	<h5>Syntax:</h5>
				6578	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6579	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]	6580	integer bit width. Not all targets support all bit widths however.</p>
				6581	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6582	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6583	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6584	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6585	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6586
				6587	</pre>
				6588	<h5>Overview:</h5>
				6589	<p>
				6590	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6591	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6592	</p>
				6593	<h5>Arguments:</h5>
				6594	<p>
				6595
				6596	The intrinsic takes two arguments, the first a pointer to an integer value
				6597	and the second an integer value. The result is also an integer value. These
				6598	integer types can have any bit width, but they must all have the same bit
				6599	width. The targets may only lower integer representations they support.
				6600	</p>
				6601	<h5>Semantics:</h5>
				6602	<p>
				6603	This intrinsic does a series of operations atomically. It first loads the
				6604	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6605	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6606	</p>
				6607
				6608	<h5>Examples:</h5>
				6609	<pre>
				6610	%ptr = malloc i32
				6611	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6612	%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]	6613	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6614	%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]	6615	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6616	%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]	6617	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6618	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6619	</pre>
				6620	</div>
				6621
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6622	<!-- _______________________________________________________________________ -->
				6623	<div class="doc_subsubsection">
				6624	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6625
				6626	</div>
				6627	<div class="doc_text">
				6628	<h5>Syntax:</h5>
				6629	<p>
				6630	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]	6631	any integer bit width and for different address spaces. Not all targets
				6632	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6633	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6634	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6635	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6636	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6637	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]	6638
				6639	</pre>
				6640	<h5>Overview:</h5>
				6641	<p>
				6642	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6643	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6644	</p>
				6645	<h5>Arguments:</h5>
				6646	<p>
				6647
				6648	The intrinsic takes two arguments, the first a pointer to an integer value
				6649	and the second an integer value. The result is also an integer value. These
				6650	integer types can have any bit width, but they must all have the same bit
				6651	width. The targets may only lower integer representations they support.
				6652	</p>
				6653	<h5>Semantics:</h5>
				6654	<p>
				6655	This intrinsic does a series of operations atomically. It first loads the
				6656	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6657	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6658	</p>
				6659
				6660	<h5>Examples:</h5>
				6661	<pre>
				6662	%ptr = malloc i32
				6663	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6664	%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]	6665	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6666	%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]	6667	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6668	%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]	6669	<i>; yields {i32}:result3 = 2</i>
				6670	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6671	</pre>
				6672	</div>
				6673
				6674	<!-- _______________________________________________________________________ -->
				6675	<div class="doc_subsubsection">
				6676	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6677	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6678	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6679	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6680
				6681	</div>
				6682	<div class="doc_text">
				6683	<h5>Syntax:</h5>
				6684	<p>
				6685	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6686	<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]	6687	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6688	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6689	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6690	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6691	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6692	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6693	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]	6694
				6695	</pre>
				6696
				6697	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6698	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6699	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6700	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6701	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]	6702
				6703	</pre>
				6704
				6705	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6706	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6707	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6708	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6709	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]	6710
				6711	</pre>
				6712
				6713	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6714	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6715	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6716	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6717	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]	6718
				6719	</pre>
				6720	<h5>Overview:</h5>
				6721	<p>
				6722	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6723	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6724	at <tt>ptr</tt>.
				6725	</p>
				6726	<h5>Arguments:</h5>
				6727	<p>
				6728
				6729	These intrinsics take two arguments, the first a pointer to an integer value
				6730	and the second an integer value. The result is also an integer value. These
				6731	integer types can have any bit width, but they must all have the same bit
				6732	width. The targets may only lower integer representations they support.
				6733	</p>
				6734	<h5>Semantics:</h5>
				6735	<p>
				6736	These intrinsics does a series of operations atomically. They first load the
				6737	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6738	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6739	value stored at <tt>ptr</tt>.
				6740	</p>
				6741
				6742	<h5>Examples:</h5>
				6743	<pre>
				6744	%ptr = malloc i32
				6745	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6746	%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]	6747	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6748	%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]	6749	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6750	%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]	6751	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6752	%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]	6753	<i>; yields {i32}:result3 = FF</i>
				6754	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6755	</pre>
				6756	</div>
				6757
				6758
				6759	<!-- _______________________________________________________________________ -->
				6760	<div class="doc_subsubsection">
				6761	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6762	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6763	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6764	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6765
				6766	</div>
				6767	<div class="doc_text">
				6768	<h5>Syntax:</h5>
				6769	<p>
				6770	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6771	<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]	6772	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6773	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6774	support all bit widths however.</p>
				6775	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6776	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6777	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6778	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6779	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]	6780
				6781	</pre>
				6782
				6783	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6784	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6785	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6786	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6787	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]	6788
				6789	</pre>
				6790
				6791	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6792	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6793	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6794	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6795	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]	6796
				6797	</pre>
				6798
				6799	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6800	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6801	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6802	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6803	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]	6804
				6805	</pre>
				6806	<h5>Overview:</h5>
				6807	<p>
				6808	These intrinsics takes the signed or unsigned minimum or maximum of
				6809	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6810	original value at <tt>ptr</tt>.
				6811	</p>
				6812	<h5>Arguments:</h5>
				6813	<p>
				6814
				6815	These intrinsics take two arguments, the first a pointer to an integer value
				6816	and the second an integer value. The result is also an integer value. These
				6817	integer types can have any bit width, but they must all have the same bit
				6818	width. The targets may only lower integer representations they support.
				6819	</p>
				6820	<h5>Semantics:</h5>
				6821	<p>
				6822	These intrinsics does a series of operations atomically. They first load the
				6823	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6824	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6825	the original value stored at <tt>ptr</tt>.
				6826	</p>
				6827
				6828	<h5>Examples:</h5>
				6829	<pre>
				6830	%ptr = malloc i32
				6831	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6832	%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]	6833	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6834	%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]	6835	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6836	%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]	6837	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6838	%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]	6839	<i>; yields {i32}:result3 = 8</i>
				6840	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6841	</pre>
				6842	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6843
				6844	<!-- ======================================================================= -->
				6845	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6846	<a name="int_general">General Intrinsics</a>
				6847	</div>
				6848
				6849	<div class="doc_text">
				6850	<p> This class of intrinsics is designed to be generic and has
				6851	no specific purpose. </p>
				6852	</div>
				6853
				6854	<!-- _______________________________________________________________________ -->
				6855	<div class="doc_subsubsection">
				6856	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6857	</div>
				6858
				6859	<div class="doc_text">
				6860
				6861	<h5>Syntax:</h5>
				6862	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6863	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]	6864	</pre>
				6865
				6866	<h5>Overview:</h5>
				6867
				6868	<p>
				6869	The '<tt>llvm.var.annotation</tt>' intrinsic
				6870	</p>
				6871
				6872	<h5>Arguments:</h5>
				6873
				6874	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6875	The first argument is a pointer to a value, the second is a pointer to a
				6876	global string, the third is a pointer to a global string which is the source
				6877	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6878	</p>
				6879
				6880	<h5>Semantics:</h5>
				6881
				6882	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6883	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6884	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]	6885	annotations. These have no other defined use, they are ignored by code
				6886	generation and optimization.
				6887	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6888	</div>
				6889
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6890	<!-- _______________________________________________________________________ -->
				6891	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6892	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6893	</div>
				6894
				6895	<div class="doc_text">
				6896
				6897	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6898	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6899	any integer bit width.
				6900	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6901	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6902	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6903	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6904	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6905	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6906	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]	6907	</pre>
				6908
				6909	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6910
				6911	<p>
				6912	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6913	</p>
				6914
				6915	<h5>Arguments:</h5>
				6916
				6917	<p>
				6918	The first argument is an integer value (result of some expression),
				6919	the second is a pointer to a global string, the third is a pointer to a global
				6920	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]	6921	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6922	</p>
				6923
				6924	<h5>Semantics:</h5>
				6925
				6926	<p>
				6927	This intrinsic allows annotations to be put on arbitrary expressions
				6928	with arbitrary strings. This can be useful for special purpose optimizations
				6929	that want to look for these annotations. These have no other defined use, they
				6930	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6931	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6932	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6933
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6934	<!-- _______________________________________________________________________ -->
				6935	<div class="doc_subsubsection">
				6936	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6937	</div>
				6938
				6939	<div class="doc_text">
				6940
				6941	<h5>Syntax:</h5>
				6942	<pre>
				6943	declare void @llvm.trap()
				6944	</pre>
				6945
				6946	<h5>Overview:</h5>
				6947
				6948	<p>
				6949	The '<tt>llvm.trap</tt>' intrinsic
				6950	</p>
				6951
				6952	<h5>Arguments:</h5>
				6953
				6954	<p>
				6955	None
				6956	</p>
				6957
				6958	<h5>Semantics:</h5>
				6959
				6960	<p>
				6961	This intrinsics is lowered to the target dependent trap instruction. If the
				6962	target does not have a trap instruction, this intrinsic will be lowered to the
				6963	call of the abort() function.
				6964	</p>
				6965	</div>
				6966
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6967	<!-- _______________________________________________________________________ -->
				6968	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	6969	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6970	</div>
				6971	<div class="doc_text">
				6972	<h5>Syntax:</h5>
				6973	<pre>
				6974	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6975
				6976	</pre>
				6977	<h5>Overview:</h5>
				6978	<p>
				6979	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				6980	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				6981	it is placed on the stack before local variables.
				6982	</p>
				6983	<h5>Arguments:</h5>
				6984	<p>
				6985	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				6986	first argument is the value loaded from the stack guard
				6987	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				6988	has enough space to hold the value of the guard.
				6989	</p>
				6990	<h5>Semantics:</h5>
				6991	<p>
				6992	This intrinsic causes the prologue/epilogue inserter to force the position of
				6993	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				6994	stack. This is to ensure that if a local variable on the stack is overwritten,
				6995	it will destroy the value of the guard. When the function exits, the guard on
				6996	the stack is checked against the original guard. If they're different, then
				6997	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				6998	</p>
				6999	</div>
				7000
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7001	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7002	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7003	<address>
				7004	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7005	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]	7006	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7007	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]	7008
				7009	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7010	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7011	Last modified: $Date$
				7012	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7013
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7014	</body>
				7015	</html>