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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
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1112	</dl>
				1113
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1114	</div>
				1115
				1116	<!-- ======================================================================= -->
				1117	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1118	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1119	</div>
				1120
				1121	<div class="doc_text">
				1122	<p>
				1123	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1124	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1125	LLVM and treated as a single unit, but may be separated in the .ll file if
				1126	desired. The syntax is very simple:
				1127	</p>
				1128
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1129	<div class="doc_code">
				1130	<pre>
				1131	module asm "inline asm code goes here"
				1132	module asm "more can go here"
				1133	</pre>
				1134	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1135
				1136	<p>The strings can contain any character by escaping non-printable characters.
				1137	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1138	for the number.
				1139	</p>
				1140
				1141	<p>
				1142	The inline asm code is simply printed to the machine code .s file when
				1143	assembly code is generated.
				1144	</p>
				1145	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1146
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1147	<!-- ======================================================================= -->
				1148	<div class="doc_subsection">
				1149	<a name="datalayout">Data Layout</a>
				1150	</div>
				1151
				1152	<div class="doc_text">
				1153	<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]	1154	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1155	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1156	<p>The <i>layout specification</i> consists of a list of specifications
				1157	separated by the minus sign character ('-'). Each specification starts with a
				1158	letter and may include other information after the letter to define some
				1159	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1160	<dl>
				1161	<dt><tt>E</tt></dt>
				1162	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1163	bits with the most significance have the lowest address location.</dd>
				1164	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1165	<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]	1166	the bits with the least significance have the lowest address location.</dd>
				1167	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1168	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1169	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1170	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1171	too.</dd>
				1172	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1173	<dd>This specifies the alignment for an integer type of a given bit
				1174	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1175	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1176	<dd>This specifies the alignment for a vector type of a given bit
				1177	<i>size</i>.</dd>
				1178	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1179	<dd>This specifies the alignment for a floating point type of a given bit
				1180	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1181	(double).</dd>
				1182	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1183	<dd>This specifies the alignment for an aggregate type of a given bit
				1184	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1185	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1186	<dd>This specifies the alignment for a stack object of a given bit
				1187	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1188	</dl>
				1189	<p>When constructing the data layout for a given target, LLVM starts with a
				1190	default set of specifications which are then (possibly) overriden by the
				1191	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1192	are given in this list:</p>
				1193	<ul>
				1194	<li><tt>E</tt> - big endian</li>
				1195	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1196	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1197	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1198	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1199	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1200	<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]	1201	alignment of 64-bits</li>
				1202	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1203	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1204	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1205	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1206	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1207	<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]	1208	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1209	<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]	1210	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1211	<ol>
				1212	<li>If the type sought is an exact match for one of the specifications, that
				1213	specification is used.</li>
				1214	<li>If no match is found, and the type sought is an integer type, then the
				1215	smallest integer type that is larger than the bitwidth of the sought type is
				1216	used. If none of the specifications are larger than the bitwidth then the the
				1217	largest integer type is used. For example, given the default specifications
				1218	above, the i7 type will use the alignment of i8 (next largest) while both
				1219	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1220	<li>If no match is found, and the type sought is a vector type, then the
				1221	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]	1222	as a fall back. This happens because <128 x double> can be implemented
				1223	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1224	</ol>
				1225	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1226
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1227	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1228	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1229	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1230
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1231	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1232
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1233	<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]	1234	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1235	optimizations to be performed on the intermediate representation directly,
				1236	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1237	extra analyses on the side before the transformation. A strong type
				1238	system makes it easier to read the generated code and enables novel
				1239	analyses and transformations that are not feasible to perform on normal
				1240	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1241
				1242	</div>
				1243
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1244	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1245	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1246	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1247	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1248	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1250
				1251	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1253	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1254	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1255	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1256	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1257	</tr>
				1258	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1259	<td><a href="#t_floating">floating point</a></td>
				1260	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1261	</tr>
				1262	<tr>
				1263	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1264	<td><a href="#t_integer">integer</a>,
				1265	<a href="#t_floating">floating point</a>,
				1266	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1267	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1268	<a href="#t_struct">structure</a>,
				1269	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1270	<a href="#t_label">label</a>,
				1271	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1272	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1273	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1274	<tr>
				1275	<td><a href="#t_primitive">primitive</a></td>
				1276	<td><a href="#t_label">label</a>,
				1277	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1278	<a href="#t_floating">floating point</a>,
				1279	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1280	</tr>
				1281	<tr>
				1282	<td><a href="#t_derived">derived</a></td>
				1283	<td><a href="#t_integer">integer</a>,
				1284	<a href="#t_array">array</a>,
				1285	<a href="#t_function">function</a>,
				1286	<a href="#t_pointer">pointer</a>,
				1287	<a href="#t_struct">structure</a>,
				1288	<a href="#t_pstruct">packed structure</a>,
				1289	<a href="#t_vector">vector</a>,
				1290	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1291	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1292	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1293	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1294	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1295
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1296	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1297	most important. Values of these types are the only ones which can be
				1298	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1299	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1300	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1301
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1302	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1303	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1304
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1305	<div class="doc_text">
				1306	<p>The primitive types are the fundamental building blocks of the LLVM
				1307	system.</p>
				1308
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1309	</div>
				1310
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1311	<!-- _______________________________________________________________________ -->
				1312	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1313
				1314	<div class="doc_text">
				1315	<table>
				1316	<tbody>
				1317	<tr><th>Type</th><th>Description</th></tr>
				1318	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1319	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1320	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1321	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1322	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1323	</tbody>
				1324	</table>
				1325	</div>
				1326
				1327	<!-- _______________________________________________________________________ -->
				1328	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1329
				1330	<div class="doc_text">
				1331	<h5>Overview:</h5>
				1332	<p>The void type does not represent any value and has no size.</p>
				1333
				1334	<h5>Syntax:</h5>
				1335
				1336	<pre>
				1337	void
				1338	</pre>
				1339	</div>
				1340
				1341	<!-- _______________________________________________________________________ -->
				1342	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1343
				1344	<div class="doc_text">
				1345	<h5>Overview:</h5>
				1346	<p>The label type represents code labels.</p>
				1347
				1348	<h5>Syntax:</h5>
				1349
				1350	<pre>
				1351	label
				1352	</pre>
				1353	</div>
				1354
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1355	<!-- _______________________________________________________________________ -->
				1356	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1357
				1358	<div class="doc_text">
				1359	<h5>Overview:</h5>
				1360	<p>The metadata type represents embedded metadata. The only derived type that
				1361	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1362	takes metadata typed parameters, but not pointer to metadata types.</p>
				1363
				1364	<h5>Syntax:</h5>
				1365
				1366	<pre>
				1367	metadata
				1368	</pre>
				1369	</div>
				1370
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1371
				1372	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1373	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1374
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1375	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1376
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1377	<p>The real power in LLVM comes from the derived types in the system.
				1378	This is what allows a programmer to represent arrays, functions,
				1379	pointers, and other useful types. Note that these derived types may be
				1380	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]	1381
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1382	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1383
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1384	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1385	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1386
				1387	<div class="doc_text">
				1388
				1389	<h5>Overview:</h5>
				1390	<p>The integer type is a very simple derived type that simply specifies an
				1391	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1392	2^23-1 (about 8 million) can be specified.</p>
				1393
				1394	<h5>Syntax:</h5>
				1395
				1396	<pre>
				1397	iN
				1398	</pre>
				1399
				1400	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1401	value.</p>
				1402
				1403	<h5>Examples:</h5>
				1404	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1405	<tr class="layout">
				1406	<td class="left"><tt>i1</tt></td>
				1407	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1408	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1409	<tr class="layout">
				1410	<td class="left"><tt>i32</tt></td>
				1411	<td class="left">a 32-bit integer.</td>
				1412	</tr>
				1413	<tr class="layout">
				1414	<td class="left"><tt>i1942652</tt></td>
				1415	<td class="left">a really big integer of over 1 million bits.</td>
				1416	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1417	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1418
				1419	<p>Note that the code generator does not yet support large integer types
				1420	to be used as function return types. The specific limit on how large a
				1421	return type the code generator can currently handle is target-dependent;
				1422	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1423	targets.</p>
				1424
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1425	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1426
				1427	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1428	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1429
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1430	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1431
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1432	<h5>Overview:</h5>
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	<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]	1435	sequentially in memory. The array type requires a size (number of
				1436	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1437
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1438	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1439
				1440	<pre>
				1441	[<# elements> x <elementtype>]
				1442	</pre>
				1443
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1444	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1445	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1446
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1447	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1448	<table class="layout">
				1449	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1450	<td class="left"><tt>[40 x i32]</tt></td>
				1451	<td class="left">Array of 40 32-bit integer values.</td>
				1452	</tr>
				1453	<tr class="layout">
				1454	<td class="left"><tt>[41 x i32]</tt></td>
				1455	<td class="left">Array of 41 32-bit integer values.</td>
				1456	</tr>
				1457	<tr class="layout">
				1458	<td class="left"><tt>[4 x i8]</tt></td>
				1459	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1460	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1461	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1462	<p>Here are some examples of multidimensional arrays:</p>
				1463	<table class="layout">
				1464	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1465	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1466	<td class="left">3x4 array of 32-bit integer values.</td>
				1467	</tr>
				1468	<tr class="layout">
				1469	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1470	<td class="left">12x10 array of single precision floating point values.</td>
				1471	</tr>
				1472	<tr class="layout">
				1473	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1474	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1475	</tr>
				1476	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1477
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1478	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1479	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]	1480	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1481	As a special case, however, zero length arrays are recognized to be variable
				1482	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1483	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1484
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1485	<p>Note that the code generator does not yet support large aggregate types
				1486	to be used as function return types. The specific limit on how large an
				1487	aggregate return type the code generator can currently handle is
				1488	target-dependent, and also dependent on the aggregate element types.</p>
				1489
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1490	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1491
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1492	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1493	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1494	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1495
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1496	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1497
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1498	<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]	1499	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]	1500	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]	1501	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]	1502	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1503
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1504	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1505
				1506	<pre>
				1507	<returntype list> (<parameter list>)
				1508	</pre>
				1509
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1510	<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]	1511	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1512	which indicates that the function takes a variable number of arguments.
				1513	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1514	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1515	'<tt><returntype list></tt>' is a comma-separated list of
				1516	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1517
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1518	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1519	<table class="layout">
				1520	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1521	<td class="left"><tt>i32 (i32)</tt></td>
				1522	<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]	1523	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1524	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1525	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1526	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1527	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1528	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1529	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1530	<tt>float</tt>.
				1531	</td>
				1532	</tr><tr class="layout">
				1533	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1534	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1535	<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]	1536	which returns an integer. This is the signature for <tt>printf</tt> in
				1537	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1538	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1539	</tr><tr class="layout">
				1540	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1541	<td class="left">A function taking an <tt>i32</tt>, returning two
				1542	<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]	1543	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1544	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1545	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1546
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1547	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1548	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1549	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1550	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1551	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1552	<p>The structure type is used to represent a collection of data members
				1553	together in memory. The packing of the field types is defined to match
				1554	the ABI of the underlying processor. The elements of a structure may
				1555	be any type that has a size.</p>
				1556	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1557	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1558	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1559	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1560	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1561	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1562	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1563	<table class="layout">
				1564	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1565	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1566	<td class="left">A triple of three <tt>i32</tt> values</td>
				1567	</tr><tr class="layout">
				1568	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1569	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1570	second element is a <a href="#t_pointer">pointer</a> to a
				1571	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1572	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1573	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1574	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1575
				1576	<p>Note that the code generator does not yet support large aggregate types
				1577	to be used as function return types. The specific limit on how large an
				1578	aggregate return type the code generator can currently handle is
				1579	target-dependent, and also dependent on the aggregate element types.</p>
				1580
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1581	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1582
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1583	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1584	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1585	</div>
				1586	<div class="doc_text">
				1587	<h5>Overview:</h5>
				1588	<p>The packed structure type is used to represent a collection of data members
				1589	together in memory. There is no padding between fields. Further, the alignment
				1590	of a packed structure is 1 byte. The elements of a packed structure may
				1591	be any type that has a size.</p>
				1592	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1593	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1594	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1595	instruction.</p>
				1596	<h5>Syntax:</h5>
				1597	<pre> < { <type list> } > <br></pre>
				1598	<h5>Examples:</h5>
				1599	<table class="layout">
				1600	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1601	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1602	<td class="left">A triple of three <tt>i32</tt> values</td>
				1603	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1604	<td class="left">
				1605	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1606	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1607	second element is a <a href="#t_pointer">pointer</a> to a
				1608	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1609	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1610	</tr>
				1611	</table>
				1612	</div>
				1613
				1614	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1615	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1616	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1617	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1618	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1619	reference to another object, which must live in memory. Pointer types may have
				1620	an optional address space attribute defining the target-specific numbered
				1621	address space where the pointed-to object resides. The default address space is
				1622	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1623
				1624	<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]	1625	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]	1626
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1627	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1628	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1629	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1630	<table class="layout">
				1631	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1632	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1633	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1634	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1635	</tr>
				1636	<tr class="layout">
				1637	<td class="left"><tt>i32 (i32 ) </tt></td>
				1638	<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]	1639	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]	1640	<tt>i32</tt>.</td>
				1641	</tr>
				1642	<tr class="layout">
				1643	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1644	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1645	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1646	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1647	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1648	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1649
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1650	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1651	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1652	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1653
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1654	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1655
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1656	<p>A vector type is a simple derived type that represents a vector
				1657	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1658	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1659	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1660	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1661	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1662	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1663
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1664	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1665
				1666	<pre>
				1667	< <# elements> x <elementtype> >
				1668	</pre>
				1669
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1670	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1671	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1672
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1673	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1674
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1675	<table class="layout">
				1676	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1677	<td class="left"><tt><4 x i32></tt></td>
				1678	<td class="left">Vector of 4 32-bit integer values.</td>
				1679	</tr>
				1680	<tr class="layout">
				1681	<td class="left"><tt><8 x float></tt></td>
				1682	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1683	</tr>
				1684	<tr class="layout">
				1685	<td class="left"><tt><2 x i64></tt></td>
				1686	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1687	</tr>
				1688	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1689
				1690	<p>Note that the code generator does not yet support large vector types
				1691	to be used as function return types. The specific limit on how large a
				1692	vector return type codegen can currently handle is target-dependent;
				1693	currently it's often a few times longer than a hardware vector register.</p>
				1694
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1695	</div>
				1696
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1697	<!-- _______________________________________________________________________ -->
				1698	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1699	<div class="doc_text">
				1700
				1701	<h5>Overview:</h5>
				1702
				1703	<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]	1704	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]	1705	In LLVM, opaque types can eventually be resolved to any type (not just a
				1706	structure type).</p>
				1707
				1708	<h5>Syntax:</h5>
				1709
				1710	<pre>
				1711	opaque
				1712	</pre>
				1713
				1714	<h5>Examples:</h5>
				1715
				1716	<table class="layout">
				1717	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1718	<td class="left"><tt>opaque</tt></td>
				1719	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1720	</tr>
				1721	</table>
				1722	</div>
				1723
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1724	<!-- ======================================================================= -->
				1725	<div class="doc_subsection">
				1726	<a name="t_uprefs">Type Up-references</a>
				1727	</div>
				1728
				1729	<div class="doc_text">
				1730	<h5>Overview:</h5>
				1731	<p>
				1732	An "up reference" allows you to refer to a lexically enclosing type without
				1733	requiring it to have a name. For instance, a structure declaration may contain a
				1734	pointer to any of the types it is lexically a member of. Example of up
				1735	references (with their equivalent as named type declarations) include:</p>
				1736
				1737	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1738	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1739	{ \2 }* %y = type { %y }*
				1740	\1* %z = type %z*
				1741	</pre>
				1742
				1743	<p>
				1744	An up reference is needed by the asmprinter for printing out cyclic types when
				1745	there is no declared name for a type in the cycle. Because the asmprinter does
				1746	not want to print out an infinite type string, it needs a syntax to handle
				1747	recursive types that have no names (all names are optional in llvm IR).
				1748	</p>
				1749
				1750	<h5>Syntax:</h5>
				1751	<pre>
				1752	\<level>
				1753	</pre>
				1754
				1755	<p>
				1756	The level is the count of the lexical type that is being referred to.
				1757	</p>
				1758
				1759	<h5>Examples:</h5>
				1760
				1761	<table class="layout">
				1762	<tr class="layout">
				1763	<td class="left"><tt>\1*</tt></td>
				1764	<td class="left">Self-referential pointer.</td>
				1765	</tr>
				1766	<tr class="layout">
				1767	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1768	<td class="left">Recursive structure where the upref refers to the out-most
				1769	structure.</td>
				1770	</tr>
				1771	</table>
				1772	</div>
				1773
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1774
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1775	<!-- *********************************************************************** -->
				1776	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1777	<!-- *********************************************************************** -->
				1778
				1779	<div class="doc_text">
				1780
				1781	<p>LLVM has several different basic types of constants. This section describes
				1782	them all and their syntax.</p>
				1783
				1784	</div>
				1785
				1786	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1787	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1788
				1789	<div class="doc_text">
				1790
				1791	<dl>
				1792	<dt><b>Boolean constants</b></dt>
				1793
				1794	<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]	1795	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1796	</dd>
				1797
				1798	<dt><b>Integer constants</b></dt>
				1799
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1800	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1801	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1802	integer types.
				1803	</dd>
				1804
				1805	<dt><b>Floating point constants</b></dt>
				1806
				1807	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1808	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1809	notation (see below). The assembler requires the exact decimal value of
				1810	a floating-point constant. For example, the assembler accepts 1.25 but
				1811	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1812	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]	1813
				1814	<dt><b>Null pointer constants</b></dt>
				1815
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1816	<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]	1817	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1818
				1819	</dl>
				1820
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1821	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1822	of floating point constants. For example, the form '<tt>double
				1823	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1824	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]	1825	(and the only time that they are generated by the disassembler) is when a
				1826	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]	1827	decimal floating point number in a reasonable number of digits. For example,
				1828	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1829	special values are represented in their IEEE hexadecimal format so that
				1830	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]	1831	<p>When using the hexadecimal form, constants of types float and double are
				1832	represented using the 16-digit form shown above (which matches the IEEE754
				1833	representation for double); float values must, however, be exactly representable
				1834	as IEE754 single precision.
				1835	Hexadecimal format is always used for long
				1836	double, and there are three forms of long double. The 80-bit
				1837	format used by x86 is represented as <tt>0xK</tt>
				1838	followed by 20 hexadecimal digits.
				1839	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1840	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1841	format is represented
				1842	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1843	target uses this format. Long doubles will only work if they match
				1844	the long double format on your target. All hexadecimal formats are big-endian
				1845	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1846	</div>
				1847
				1848	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1849	<div class="doc_subsection">
				1850	<a name="aggregateconstants"> <!-- old anchor -->
				1851	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1852	</div>
				1853
				1854	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1855	<p>Complex constants are a (potentially recursive) combination of simple
				1856	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1857
				1858	<dl>
				1859	<dt><b>Structure constants</b></dt>
				1860
				1861	<dd>Structure constants are represented with notation similar to structure
				1862	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1863	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1864	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]	1865	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]	1866	types of elements must match those specified by the type.
				1867	</dd>
				1868
				1869	<dt><b>Array constants</b></dt>
				1870
				1871	<dd>Array constants are represented with notation similar to array type
				1872	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1873	(<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]	1874	constants must have <a href="#t_array">array type</a>, and the number and
				1875	types of elements must match those specified by the type.
				1876	</dd>
				1877
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1878	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1879
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1880	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1881	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1882	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1883	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1884	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]	1885	match those specified by the type.
				1886	</dd>
				1887
				1888	<dt><b>Zero initialization</b></dt>
				1889
				1890	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1891	value to zero of <em>any</em> type, including scalar and aggregate types.
				1892	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]	1893	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1894	initializers.
				1895	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1896
				1897	<dt><b>Metadata node</b></dt>
				1898
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1899	<dd>A metadata node is a structure-like constant with
				1900	<a href="#t_metadata">metadata type</a>. For example:
				1901	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1902	that are meant to be interpreted as part of the instruction stream, metadata
				1903	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1904	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1905	</dl>
				1906
				1907	</div>
				1908
				1909	<!-- ======================================================================= -->
				1910	<div class="doc_subsection">
				1911	<a name="globalconstants">Global Variable and Function Addresses</a>
				1912	</div>
				1913
				1914	<div class="doc_text">
				1915
				1916	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1917	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1918	constants. These constants are explicitly referenced when the <a
				1919	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]	1920	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1921	file:</p>
				1922
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1923	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1924	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1925	@X = global i32 17
				1926	@Y = global i32 42
				1927	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1928	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1929	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1930
				1931	</div>
				1932
				1933	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1934	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1935	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1936	<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]	1937	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]	1938	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1939
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1940	<p>Undefined values indicate to the compiler that the program is well defined
				1941	no matter what value is used, giving the compiler more freedom to optimize.
				1942	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1943	</div>
				1944
				1945	<!-- ======================================================================= -->
				1946	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1947	</div>
				1948
				1949	<div class="doc_text">
				1950
				1951	<p>Constant expressions are used to allow expressions involving other constants
				1952	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1953	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]	1954	that does not have side effects (e.g. load and call are not supported). The
				1955	following is the syntax for constant expressions:</p>
				1956
				1957	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1958	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1959	<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]	1960	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1961
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1962	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1963	<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]	1964	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]	1965
				1966	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1967	<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]	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>fptrunc ( CST to TYPE )</tt></b></dt>
				1971	<dd>Truncate a floating point constant to another floating point type. The
				1972	size of CST must be larger than the size of TYPE. Both types must be
				1973	floating point.</dd>
				1974
				1975	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1976	<dd>Floating point extend a constant to another type. The size of CST must be
				1977	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1978
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1979	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1980	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1981	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1982	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1983	of the same number of elements. If the value won't fit in the integer type,
				1984	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1985
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1986	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1987	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1988	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1989	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1990	of the same number of elements. If the value won't fit in the integer type,
				1991	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1992
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1993	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1994	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1995	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1996	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1997	of the same number of elements. If the value won't fit in the floating point
				1998	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1999
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2000	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2001	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2002	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2003	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2004	of the same number of elements. If the value won't fit in the floating point
				2005	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2006
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2007	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2008	<dd>Convert a pointer typed constant to the corresponding integer constant
				2009	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2010	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2011
				2012	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2013	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2014	pointer type. CST must be of integer type. The CST value is zero extended,
				2015	truncated, or unchanged to make it fit in a pointer size. This one is
				2016	<i>really</i> dangerous!</dd>
				2017
				2018	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2019	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2020	are the same as those for the <a href="#i_bitcast">bitcast
				2021	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2022
				2023	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2024
				2025	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2026	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2027	instruction, the index list may have zero or more indexes, which are required
				2028	to make sense for the type of "CSTPTR".</dd>
				2029
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2030	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2031
				2032	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2033	constants.</dd>
				2034
				2035	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2036	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2037
				2038	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2039	<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]	2040
				2041	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2042
				2043	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2044	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2045
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2046	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2047
				2048	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2049	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2050
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2051
				2052	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2053
				2054	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2055	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2056
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2057	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2058
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2059	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2060	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]	2061	binary</a> operations. The constraints on operands are the same as those for
				2062	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2063	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2064	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2065	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2066
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2067	<!-- ======================================================================= -->
				2068	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2069	</div>
				2070
				2071	<div class="doc_text">
				2072
				2073	<p>Embedded metadata provides a way to attach arbitrary data to the
				2074	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2075	two metadata primitives, strings and nodes. All metadata has the
				2076	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2077	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2078	</p>
				2079
				2080	<p>A metadata string is a string surrounded by double quotes. It can contain
				2081	any character by escaping non-printable characters with "\xx" where "xx" is
				2082	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2083	</p>
				2084
				2085	<p>Metadata nodes are represented with notation similar to structure constants
				2086	(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]	2087	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2088	</p>
				2089
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2090	<p>A metadata node will attempt to track changes to the values it holds. In
				2091	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]	2092	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2093
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2094	<p>Optimizations may rely on metadata to provide additional information about
				2095	the program that isn't available in the instructions, or that isn't easily
				2096	computable. Similarly, the code generator may expect a certain metadata format
				2097	to be used to express debugging information.</p>
				2098	</div>
				2099
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2100	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2101	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2102	<!-- *********************************************************************** -->
				2103
				2104	<!-- ======================================================================= -->
				2105	<div class="doc_subsection">
				2106	<a name="inlineasm">Inline Assembler Expressions</a>
				2107	</div>
				2108
				2109	<div class="doc_text">
				2110
				2111	<p>
				2112	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2113	Module-Level Inline Assembly</a>) through the use of a special value. This
				2114	value represents the inline assembler as a string (containing the instructions
				2115	to emit), a list of operand constraints (stored as a string), and a flag that
				2116	indicates whether or not the inline asm expression has side effects. An example
				2117	inline assembler expression is:
				2118	</p>
				2119
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2120	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2121	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2122	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2123	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2124	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2125
				2126	<p>
				2127	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2128	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2129	</p>
				2130
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2131	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2132	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2133	%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]	2134	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2135	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2136
				2137	<p>
				2138	Inline asms with side effects not visible in the constraint list must be marked
				2139	as having side effects. This is done through the use of the
				2140	'<tt>sideeffect</tt>' keyword, like so:
				2141	</p>
				2142
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2143	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2144	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2145	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2146	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2147	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2148
				2149	<p>TODO: The format of the asm and constraints string still need to be
				2150	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]	2151	need to be documented). This is probably best done by reference to another
				2152	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2153	</p>
				2154
				2155	</div>
				2156
				2157	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2158	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2159	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2160
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2161	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2162
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2163	<p>The LLVM instruction set consists of several different
				2164	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2165	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2166	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2168	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2169
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2171
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2172	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2173	<div class="doc_subsection"> <a name="terminators">Terminator
				2174	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2175
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2176	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2177
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2178	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2179	basic block in a program ends with a "Terminator" instruction, which
				2180	indicates which block should be executed after the current block is
				2181	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2182	value: they produce control flow, not values (the one exception being
				2183	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2184	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2185	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2186	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2187	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2188	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2189	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2190
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2191	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2192
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2193	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2194	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2195	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2196	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2198	<pre>
				2199	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]	2200	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2201	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2202
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2204
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2205	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2206	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2207	<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]	2208	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]	2209	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2210
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2211	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2212
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2213	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2214	the return value. The type of the return value must be a
				2215	'<a href="#t_firstclass">first class</a>' type.</p>
				2216
				2217	<p>A function is not <a href="#wellformed">well formed</a> if
				2218	it it has a non-void return type and contains a '<tt>ret</tt>'
				2219	instruction with no return value or a return value with a type that
				2220	does not match its type, or if it has a void return type and contains
				2221	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2222
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2223	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2224
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2225	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2226	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]	2227	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2228	the instruction after the call. If the caller was an "<a
				2229	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2230	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2231	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]	2232	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2233
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2234	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2235
				2236	<pre>
				2237	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2238	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2239	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]	2240	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2241
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2242	<p>Note that the code generator does not yet fully support large
				2243	return values. The specific sizes that are currently supported are
				2244	dependent on the target. For integers, on 32-bit targets the limit
				2245	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2246	For aggregate types, the current limits are dependent on the element
				2247	types; for example targets are often limited to 2 total integer
				2248	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2249
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2250	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2251	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2252	<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]	2253	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2254	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2255	<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]	2256	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2257	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2258	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2259	transfer to a different basic block in the current function. There are
				2260	two forms of this instruction, corresponding to a conditional branch
				2261	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2262	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2263	<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]	2264	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2265	unconditional form of the '<tt>br</tt>' instruction takes a single
				2266	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2267	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2268	<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]	2269	argument is evaluated. If the value is <tt>true</tt>, control flows
				2270	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2271	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2272	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2273	<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]	2274	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]	2275	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2277	<div class="doc_subsubsection">
				2278	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2279	</div>
				2280
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2281	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2283
				2284	<pre>
				2285	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2286	</pre>
				2287
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2288	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2289
				2290	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2291	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2292	instruction, allowing a branch to occur to one of many possible
				2293	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2294
				2295
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2296	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2297
				2298	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2299	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2300	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2301	table is not allowed to contain duplicate constant entries.</p>
				2302
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2303	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2304
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2305	<p>The <tt>switch</tt> instruction specifies a table of values and
				2306	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2307	table is searched for the given value. If the value is found, control flow is
				2308	transfered to the corresponding destination; otherwise, control flow is
				2309	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2310
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2311	<h5>Implementation:</h5>
				2312
				2313	<p>Depending on properties of the target machine and the particular
				2314	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2315	ways. For example, it could be generated as a series of chained conditional
				2316	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2317
				2318	<h5>Example:</h5>
				2319
				2320	<pre>
				2321	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2322	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2323	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2324
				2325	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2326	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2327
				2328	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2329	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2330	i32 1, label %onone
				2331	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2332	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2333	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2334
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2335	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2336	<div class="doc_subsubsection">
				2337	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2338	</div>
				2339
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2340	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2341
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2342	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2343
				2344	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2345	<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]	2346	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2347	</pre>
				2348
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2349	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2350
				2351	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2352	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2353	'<tt>normal</tt>' label or the
				2354	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2355	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2356	"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]	2357	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2358	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2359
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2360	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2361
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2362	<p>This instruction requires several arguments:</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	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2365	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2366	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2367	convention</a> the call should use. If none is specified, the call defaults
				2368	to using C calling conventions.
				2369	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2370
				2371	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2372	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2373	and '<tt>inreg</tt>' attributes are valid here.</li>
				2374
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2375	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2376	function value being invoked. In most cases, this is a direct function
				2377	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2378	an arbitrary pointer to function value.
				2379	</li>
				2380
				2381	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2382	function to be invoked. </li>
				2383
				2384	<li>'<tt>function args</tt>': argument list whose types match the function
				2385	signature argument types. If the function signature indicates the function
				2386	accepts a variable number of arguments, the extra arguments can be
				2387	specified. </li>
				2388
				2389	<li>'<tt>normal label</tt>': the label reached when the called function
				2390	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2391
				2392	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2393	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2394
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2395	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2396	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2397	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2398	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2399
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2400	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2402	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2403	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2404	difference is that it establishes an association with a label, which is used by
				2405	the runtime library to unwind the stack.</p>
				2406
				2407	<p>This instruction is used in languages with destructors to ensure that proper
				2408	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2409	exception. Additionally, this is important for implementation of
				2410	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2411
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2412	<p>For the purposes of the SSA form, the definition of the value
				2413	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2414	the edge from the current block to the "normal" label. If the callee
				2415	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2416
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2417	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2418	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2419	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2420	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2421	%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]	2422	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2423	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2424	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2425
				2426
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2427	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2428
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2429	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2430	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2431
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2432	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2433
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2434	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2435	<pre>
				2436	unwind
				2437	</pre>
				2438
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2439	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2440
				2441	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2442	at the first callee in the dynamic call stack which used an <a
				2443	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2444	primarily used to implement exception handling.</p>
				2445
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2446	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2447
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2448	<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]	2449	immediately halt. The dynamic call stack is then searched for the first <a
				2450	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2451	execution continues at the "exceptional" destination block specified by the
				2452	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2453	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2454	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2455
				2456	<!-- _______________________________________________________________________ -->
				2457
				2458	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2459	Instruction</a> </div>
				2460
				2461	<div class="doc_text">
				2462
				2463	<h5>Syntax:</h5>
				2464	<pre>
				2465	unreachable
				2466	</pre>
				2467
				2468	<h5>Overview:</h5>
				2469
				2470	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2471	instruction is used to inform the optimizer that a particular portion of the
				2472	code is not reachable. This can be used to indicate that the code after a
				2473	no-return function cannot be reached, and other facts.</p>
				2474
				2475	<h5>Semantics:</h5>
				2476
				2477	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2478	</div>
				2479
				2480
				2481
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2482	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2483	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2484	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2485	<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]	2486	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]	2487	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2488	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]	2489	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2490	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2491	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2493	<div class="doc_subsubsection">
				2494	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2495	</div>
				2496
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2497	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2498
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2499	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2500
				2501	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2502	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2503	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2504
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2505	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2506
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2507	<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]	2508
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
				2511	<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]	2512	href="#t_integer">integer</a> or
				2513	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2514	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2515
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2516	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2517
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2518	<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]	2519
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2520	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2521	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2522	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2523
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2524	<p>Because LLVM integers use a two's complement representation, this
				2525	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2527	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2528
				2529	<pre>
				2530	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2531	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2532	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2533	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2534	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2535	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2536	</div>
				2537
				2538	<div class="doc_text">
				2539
				2540	<h5>Syntax:</h5>
				2541
				2542	<pre>
				2543	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2544	</pre>
				2545
				2546	<h5>Overview:</h5>
				2547
				2548	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2549
				2550	<h5>Arguments:</h5>
				2551
				2552	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2553	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2554	floating point values. Both arguments must have identical types.</p>
				2555
				2556	<h5>Semantics:</h5>
				2557
				2558	<p>The value produced is the floating point sum of the two operands.</p>
				2559
				2560	<h5>Example:</h5>
				2561
				2562	<pre>
				2563	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2564	</pre>
				2565	</div>
				2566	<!-- _______________________________________________________________________ -->
				2567	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2568	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2569	</div>
				2570
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2571	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2572
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2573	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2574
				2575	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2576	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2577	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2578
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2579	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2580
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2581	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2582	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
				2584	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2585	'<tt>neg</tt>' instruction present in most other intermediate
				2586	representations.</p>
				2587
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2588	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2589
				2590	<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]	2591	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2592	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2594	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2595
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2596	<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]	2597
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2598	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2599	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2600	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2601
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2602	<p>Because LLVM integers use a two's complement representation, this
				2603	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2605	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2606	<pre>
				2607	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2608	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2609	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2610	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2612	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2614	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2615	</div>
				2616
				2617	<div class="doc_text">
				2618
				2619	<h5>Syntax:</h5>
				2620
				2621	<pre>
				2622	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2623	</pre>
				2624
				2625	<h5>Overview:</h5>
				2626
				2627	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2628	operands.</p>
				2629
				2630	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2631	'<tt>fneg</tt>' instruction present in most other intermediate
				2632	representations.</p>
				2633
				2634	<h5>Arguments:</h5>
				2635
				2636	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2637	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2638	of floating point values. Both arguments must have identical types.</p>
				2639
				2640	<h5>Semantics:</h5>
				2641
				2642	<p>The value produced is the floating point difference of the two operands.</p>
				2643
				2644	<h5>Example:</h5>
				2645	<pre>
				2646	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2647	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2648	</pre>
				2649	</div>
				2650
				2651	<!-- _______________________________________________________________________ -->
				2652	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2653	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2654	</div>
				2655
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2656	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2657
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2658	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2659	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2660	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2662	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2663	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2664
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2665	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2666
				2667	<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]	2668	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2669	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2670
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2672
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2673	<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]	2674
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2675	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2676	the result returned is the mathematical result modulo
				2677	2<sup>n</sup>, where n is the bit width of the result.</p>
				2678	<p>Because LLVM integers use a two's complement representation, and the
				2679	result is the same width as the operands, this instruction returns the
				2680	correct result for both signed and unsigned integers. If a full product
				2681	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2682	should be sign-extended or zero-extended as appropriate to the
				2683	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2684	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2685	<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]	2686	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2687	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2688
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2689	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2690	<div class="doc_subsubsection">
				2691	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2692	</div>
				2693
				2694	<div class="doc_text">
				2695
				2696	<h5>Syntax:</h5>
				2697	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2698	</pre>
				2699	<h5>Overview:</h5>
				2700	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2701	operands.</p>
				2702
				2703	<h5>Arguments:</h5>
				2704
				2705	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2706	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2707	of floating point values. Both arguments must have identical types.</p>
				2708
				2709	<h5>Semantics:</h5>
				2710
				2711	<p>The value produced is the floating point product of the two operands.</p>
				2712
				2713	<h5>Example:</h5>
				2714	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2715	</pre>
				2716	</div>
				2717
				2718	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2719	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2720	</a></div>
				2721	<div class="doc_text">
				2722	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2723	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2724	</pre>
				2725	<h5>Overview:</h5>
				2726	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2727	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2728
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2729	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2730
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2731	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2732	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2733	values. Both arguments must have identical types.</p>
				2734
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2735	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2736
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2737	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2738	<p>Note that unsigned integer division and signed integer division are distinct
				2739	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2740	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2741	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2742	<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]	2743	</pre>
				2744	</div>
				2745	<!-- _______________________________________________________________________ -->
				2746	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2747	</a> </div>
				2748	<div class="doc_text">
				2749	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2750	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2751	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2752	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2753
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2754	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2755
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2756	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2757	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2758
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2759	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2760
				2761	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2762	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2763	values. Both arguments must have identical types.</p>
				2764
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2765	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2766	<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]	2767	<p>Note that signed integer division and unsigned integer division are distinct
				2768	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2769	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2770	undefined behavior; this is a rare case, but can occur, for example,
				2771	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2772	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2773	<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]	2774	</pre>
				2775	</div>
				2776	<!-- _______________________________________________________________________ -->
				2777	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2778	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2779	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2780	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2781	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2782	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2783	</pre>
				2784	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2785
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2786	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2787	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2788
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2789	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2790
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2791	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2792	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2793	of floating point values. Both arguments must have identical types.</p>
				2794
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2795	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2796
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2797	<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]	2798
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2799	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2800
				2801	<pre>
				2802	<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]	2803	</pre>
				2804	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2805
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2806	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2807	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2808	</div>
				2809	<div class="doc_text">
				2810	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2811	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2812	</pre>
				2813	<h5>Overview:</h5>
				2814	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2815	unsigned division of its two arguments.</p>
				2816	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2817	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2818	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2819	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2820	<h5>Semantics:</h5>
				2821	<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]	2822	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2823	<p>Note that unsigned integer remainder and signed integer remainder are
				2824	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2825	<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]	2826	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2827	<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]	2828	</pre>
				2829
				2830	</div>
				2831	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2832	<div class="doc_subsubsection">
				2833	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2834	</div>
				2835
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2836	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2837
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2838	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2839
				2840	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2841	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2842	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2843
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2844	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2845
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2846	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2847	signed division of its two operands. This instruction can also take
				2848	<a href="#t_vector">vector</a> versions of the values in which case
				2849	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2850
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2851	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2852
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2853	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2854	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2855	values. Both arguments must have identical types.</p>
				2856
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2857	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2858
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2859	<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]	2860	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2861	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]	2862	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2863	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]	2864	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]	2865	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2866	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2867	<p>Note that signed integer remainder and unsigned integer remainder are
				2868	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2869	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2870	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2871	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2872	(The remainder doesn't actually overflow, but this rule lets srem be
				2873	implemented using instructions that return both the result of the division
				2874	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2875	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2876	<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]	2877	</pre>
				2878
				2879	</div>
				2880	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2881	<div class="doc_subsubsection">
				2882	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2883
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2884	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2885
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2886	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2887	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2888	</pre>
				2889	<h5>Overview:</h5>
				2890	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2891	division of its two operands.</p>
				2892	<h5>Arguments:</h5>
				2893	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2894	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2895	of floating point values. Both arguments must have identical types.</p>
				2896
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2897	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2898
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2899	<p>This instruction returns the <i>remainder</i> of a division.
				2900	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2901
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2902	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2903
				2904	<pre>
				2905	<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]	2906	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2907	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2908
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2909	<!-- ======================================================================= -->
				2910	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2911	Operations</a> </div>
				2912	<div class="doc_text">
				2913	<p>Bitwise binary operators are used to do various forms of
				2914	bit-twiddling in a program. They are generally very efficient
				2915	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2916	instructions. They require two operands of the same type, execute an operation on them,
				2917	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]	2918	</div>
				2919
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2920	<!-- _______________________________________________________________________ -->
				2921	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2922	Instruction</a> </div>
				2923	<div class="doc_text">
				2924	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2925	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2926	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2927
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2928	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2929
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2931	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2932
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2933	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2934
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2935	<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]	2936	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]	2937	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
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	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2940
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2941	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2942	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]	2943	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2944	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2945	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2946
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2947	<h5>Example:</h5><pre>
				2948	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2949	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2950	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2951	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2952	<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]	2953	</pre>
				2954	</div>
				2955	<!-- _______________________________________________________________________ -->
				2956	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2957	Instruction</a> </div>
				2958	<div class="doc_text">
				2959	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2960	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2961	</pre>
				2962
				2963	<h5>Overview:</h5>
				2964	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2965	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]	2966
				2967	<h5>Arguments:</h5>
				2968	<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]	2969	<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]	2970	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2971
				2972	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2973
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2974	<p>This instruction always performs a logical shift right operation. The most
				2975	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]	2976	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]	2977	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2978	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2979	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2980
				2981	<h5>Example:</h5>
				2982	<pre>
				2983	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2984	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2985	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2986	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2987	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2988	<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]	2989	</pre>
				2990	</div>
				2991
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2992	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2993	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2994	Instruction</a> </div>
				2995	<div class="doc_text">
				2996
				2997	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2998	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2999	</pre>
				3000
				3001	<h5>Overview:</h5>
				3002	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3003	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]	3004
				3005	<h5>Arguments:</h5>
				3006	<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]	3007	<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]	3008	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3009
				3010	<h5>Semantics:</h5>
				3011	<p>This instruction always performs an arithmetic shift right operation,
				3012	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]	3013	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]	3014	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3015	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3016	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3017
				3018	<h5>Example:</h5>
				3019	<pre>
				3020	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3021	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3022	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3023	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3024	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3025	<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]	3026	</pre>
				3027	</div>
				3028
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3029	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3030	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3031	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3032
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3033	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3034
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3035	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3036
				3037	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3038	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3039	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3040
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3041	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3042
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3043	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3044	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3045
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3046	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3047
				3048	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3049	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3050	values. Both arguments must have identical types.</p>
				3051
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3052	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3053	<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]	3054	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3055	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3056	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3057	<tbody>
				3058	<tr>
				3059	<td>In0</td>
				3060	<td>In1</td>
				3061	<td>Out</td>
				3062	</tr>
				3063	<tr>
				3064	<td>0</td>
				3065	<td>0</td>
				3066	<td>0</td>
				3067	</tr>
				3068	<tr>
				3069	<td>0</td>
				3070	<td>1</td>
				3071	<td>0</td>
				3072	</tr>
				3073	<tr>
				3074	<td>1</td>
				3075	<td>0</td>
				3076	<td>0</td>
				3077	</tr>
				3078	<tr>
				3079	<td>1</td>
				3080	<td>1</td>
				3081	<td>1</td>
				3082	</tr>
				3083	</tbody>
				3084	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3085	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3086	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3087	<pre>
				3088	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3089	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3090	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3091	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3092	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3093	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3094	<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]	3095	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3097	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3098	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3099	<h5>Overview:</h5>
				3100	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3101	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3102	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3103
				3104	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3105	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3106	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3107	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3108	<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]	3109	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3110	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3111	<table border="1" cellspacing="0" cellpadding="4">
				3112	<tbody>
				3113	<tr>
				3114	<td>In0</td>
				3115	<td>In1</td>
				3116	<td>Out</td>
				3117	</tr>
				3118	<tr>
				3119	<td>0</td>
				3120	<td>0</td>
				3121	<td>0</td>
				3122	</tr>
				3123	<tr>
				3124	<td>0</td>
				3125	<td>1</td>
				3126	<td>1</td>
				3127	</tr>
				3128	<tr>
				3129	<td>1</td>
				3130	<td>0</td>
				3131	<td>1</td>
				3132	</tr>
				3133	<tr>
				3134	<td>1</td>
				3135	<td>1</td>
				3136	<td>1</td>
				3137	</tr>
				3138	</tbody>
				3139	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3140	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3141	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3142	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3143	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3144	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3145	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3146	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3147	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3148	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3149	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3150	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3152	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3153	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3154	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3155	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3156	or of its two operands. The <tt>xor</tt> is used to implement the
				3157	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3158	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3159	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3160	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3161	values. Both arguments must have identical types.</p>
				3162
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3164
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3165	<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]	3166	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3167	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3168	<table border="1" cellspacing="0" cellpadding="4">
				3169	<tbody>
				3170	<tr>
				3171	<td>In0</td>
				3172	<td>In1</td>
				3173	<td>Out</td>
				3174	</tr>
				3175	<tr>
				3176	<td>0</td>
				3177	<td>0</td>
				3178	<td>0</td>
				3179	</tr>
				3180	<tr>
				3181	<td>0</td>
				3182	<td>1</td>
				3183	<td>1</td>
				3184	</tr>
				3185	<tr>
				3186	<td>1</td>
				3187	<td>0</td>
				3188	<td>1</td>
				3189	</tr>
				3190	<tr>
				3191	<td>1</td>
				3192	<td>1</td>
				3193	<td>0</td>
				3194	</tr>
				3195	</tbody>
				3196	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3197	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3198	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3199	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3200	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3201	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3202	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3203	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3204	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3205	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3206
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3207	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3208	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3209	<a name="vectorops">Vector Operations</a>
				3210	</div>
				3211
				3212	<div class="doc_text">
				3213
				3214	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3215	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3216	vector-specific operations needed to process vectors effectively. While LLVM
				3217	does directly support these vector operations, many sophisticated algorithms
				3218	will want to use target-specific intrinsics to take full advantage of a specific
				3219	target.</p>
				3220
				3221	</div>
				3222
				3223	<!-- _______________________________________________________________________ -->
				3224	<div class="doc_subsubsection">
				3225	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3226	</div>
				3227
				3228	<div class="doc_text">
				3229
				3230	<h5>Syntax:</h5>
				3231
				3232	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3233	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3234	</pre>
				3235
				3236	<h5>Overview:</h5>
				3237
				3238	<p>
				3239	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3240	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3241	</p>
				3242
				3243
				3244	<h5>Arguments:</h5>
				3245
				3246	<p>
				3247	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3248	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]	3249	an index indicating the position from which to extract the element.
				3250	The index may be a variable.</p>
				3251
				3252	<h5>Semantics:</h5>
				3253
				3254	<p>
				3255	The result is a scalar of the same type as the element type of
				3256	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3257	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3258	results are undefined.
				3259	</p>
				3260
				3261	<h5>Example:</h5>
				3262
				3263	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3264	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3265	</pre>
				3266	</div>
				3267
				3268
				3269	<!-- _______________________________________________________________________ -->
				3270	<div class="doc_subsubsection">
				3271	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3272	</div>
				3273
				3274	<div class="doc_text">
				3275
				3276	<h5>Syntax:</h5>
				3277
				3278	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3279	<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]	3280	</pre>
				3281
				3282	<h5>Overview:</h5>
				3283
				3284	<p>
				3285	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3286	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3287	</p>
				3288
				3289
				3290	<h5>Arguments:</h5>
				3291
				3292	<p>
				3293	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3294	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]	3295	scalar value whose type must equal the element type of the first
				3296	operand. The third operand is an index indicating the position at
				3297	which to insert the value. The index may be a variable.</p>
				3298
				3299	<h5>Semantics:</h5>
				3300
				3301	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3302	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]	3303	element values are those of <tt>val</tt> except at position
				3304	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3305	exceeds the length of <tt>val</tt>, the results are undefined.
				3306	</p>
				3307
				3308	<h5>Example:</h5>
				3309
				3310	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3311	%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]	3312	</pre>
				3313	</div>
				3314
				3315	<!-- _______________________________________________________________________ -->
				3316	<div class="doc_subsubsection">
				3317	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3318	</div>
				3319
				3320	<div class="doc_text">
				3321
				3322	<h5>Syntax:</h5>
				3323
				3324	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3325	<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]	3326	</pre>
				3327
				3328	<h5>Overview:</h5>
				3329
				3330	<p>
				3331	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3332	from two input vectors, returning a vector with the same element type as
				3333	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3334	</p>
				3335
				3336	<h5>Arguments:</h5>
				3337
				3338	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3339	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3340	with types that match each other. The third argument is a shuffle mask whose
				3341	element type is always 'i32'. The result of the instruction is a vector whose
				3342	length is the same as the shuffle mask and whose element type is the same as
				3343	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3344	</p>
				3345
				3346	<p>
				3347	The shuffle mask operand is required to be a constant vector with either
				3348	constant integer or undef values.
				3349	</p>
				3350
				3351	<h5>Semantics:</h5>
				3352
				3353	<p>
				3354	The elements of the two input vectors are numbered from left to right across
				3355	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]	3356	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]	3357	gets. The element selector may be undef (meaning "don't care") and the second
				3358	operand may be undef if performing a shuffle from only one vector.
				3359	</p>
				3360
				3361	<h5>Example:</h5>
				3362
				3363	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3364	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3365	<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]	3366	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3367	<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]	3368	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3369	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3370	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3371	<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]	3372	</pre>
				3373	</div>
				3374
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3375
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3376	<!-- ======================================================================= -->
				3377	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3378	<a name="aggregateops">Aggregate Operations</a>
				3379	</div>
				3380
				3381	<div class="doc_text">
				3382
				3383	<p>LLVM supports several instructions for working with aggregate values.
				3384	</p>
				3385
				3386	</div>
				3387
				3388	<!-- _______________________________________________________________________ -->
				3389	<div class="doc_subsubsection">
				3390	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3391	</div>
				3392
				3393	<div class="doc_text">
				3394
				3395	<h5>Syntax:</h5>
				3396
				3397	<pre>
				3398	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3399	</pre>
				3400
				3401	<h5>Overview:</h5>
				3402
				3403	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3404	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3405	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3406	</p>
				3407
				3408
				3409	<h5>Arguments:</h5>
				3410
				3411	<p>
				3412	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3413	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]	3414	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3415	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3416	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3417	</p>
				3418
				3419	<h5>Semantics:</h5>
				3420
				3421	<p>
				3422	The result is the value at the position in the aggregate specified by
				3423	the index operands.
				3424	</p>
				3425
				3426	<h5>Example:</h5>
				3427
				3428	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3429	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3430	</pre>
				3431	</div>
				3432
				3433
				3434	<!-- _______________________________________________________________________ -->
				3435	<div class="doc_subsubsection">
				3436	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3437	</div>
				3438
				3439	<div class="doc_text">
				3440
				3441	<h5>Syntax:</h5>
				3442
				3443	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3444	<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]	3445	</pre>
				3446
				3447	<h5>Overview:</h5>
				3448
				3449	<p>
				3450	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3451	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3452	</p>
				3453
				3454
				3455	<h5>Arguments:</h5>
				3456
				3457	<p>
				3458	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3459	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3460	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3461	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3462	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]	3463	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3464	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3465	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]	3466	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3467	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3468
				3469	<h5>Semantics:</h5>
				3470
				3471	<p>
				3472	The result is an aggregate of the same type as <tt>val</tt>. Its
				3473	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]	3474	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3475	</p>
				3476
				3477	<h5>Example:</h5>
				3478
				3479	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3480	%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]	3481	</pre>
				3482	</div>
				3483
				3484
				3485	<!-- ======================================================================= -->
				3486	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3487	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3488	</div>
				3489
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3490	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3491
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3492	<p>A key design point of an SSA-based representation is how it
				3493	represents memory. In LLVM, no memory locations are in SSA form, which
				3494	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3495	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3496
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3497	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3498
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3499	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3500	<div class="doc_subsubsection">
				3501	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3502	</div>
				3503
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3504	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3505
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3506	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3507
				3508	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3509	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3510	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3511
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3512	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3513
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3514	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3515	heap and returns a pointer to it. The object is always allocated in the generic
				3516	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3517
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3518	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3519
				3520	<p>The '<tt>malloc</tt>' instruction allocates
				3521	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3522	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]	3523	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3524	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3525	If a constant alignment is specified, the value result of the allocation is
				3526	guaranteed to be aligned to at least that boundary. If not specified, or if
				3527	zero, the target can choose to align the allocation on any convenient boundary
				3528	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3529
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3530	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3531
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3532	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3534	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3535	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]	3536	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3537
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3538	<h5>Example:</h5>
				3539
				3540	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3541	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3542
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3543	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3544	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3545	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3546	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3547	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3548	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3549
				3550	<p>Note that the code generator does not yet respect the
				3551	alignment value.</p>
				3552
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3553	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3554
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3555	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3556	<div class="doc_subsubsection">
				3557	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3558	</div>
				3559
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3560	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3561
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3562	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3563
				3564	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3565	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3566	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3567
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3568	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3569
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3570	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3571	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3572
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3573	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3574
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3575	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3576	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3577	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3578
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3579	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3581	<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]	3582	after this instruction executes. If the pointer is null, the operation
				3583	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3584
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3585	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3586
				3587	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3588	%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]	3589	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3590	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3591	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3592
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3593	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3594	<div class="doc_subsubsection">
				3595	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3596	</div>
				3597
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3598	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3599
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3600	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3601
				3602	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3603	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3604	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3605
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3606	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3607
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3608	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3609	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3610	returns to its caller. The object is always allocated in the generic address
				3611	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3612
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3613	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3614
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3615	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3616	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3617	appropriate type to the program. If "NumElements" is specified, it is the
				3618	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3619	If a constant alignment is specified, the value result of the allocation is
				3620	guaranteed to be aligned to at least that boundary. If not specified, or if
				3621	zero, the target can choose to align the allocation on any convenient boundary
				3622	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3623
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3624	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3625
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3626	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3627
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3628	<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]	3629	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3630	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3631	instruction is commonly used to represent automatic variables that must
				3632	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]	3633	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]	3634	instructions), the memory is reclaimed. Allocating zero bytes
				3635	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3636
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3637	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3638
				3639	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3640	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3641	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3642	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3643	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3644	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3645	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3646
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3647	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3648	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3649	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3650	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3651	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3652	<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]	3653	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3654	<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]	3655	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3656	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3657	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3658	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]	3659	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]	3660	the number or order of execution of this <tt>load</tt> with other
				3661	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3662	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3663	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3664	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3665	(that is, the alignment of the memory address). A value of 0 or an
				3666	omitted "align" argument means that the operation has the preferential
				3667	alignment for the target. It is the responsibility of the code emitter
				3668	to ensure that the alignment information is correct. Overestimating
				3669	the alignment results in an undefined behavior. Underestimating the
				3670	alignment may produce less efficient code. An alignment of 1 is always
				3671	safe.
				3672	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3673	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3674	<p>The location of memory pointed to is loaded. If the value being loaded
				3675	is of scalar type then the number of bytes read does not exceed the minimum
				3676	number of bytes needed to hold all bits of the type. For example, loading an
				3677	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3678	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3679	is undefined if the value was not originally written using a store of the
				3680	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3681	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3682	<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]	3683	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3684	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3685	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3686	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3687	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3688	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3689	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3690	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3691	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3692	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3693	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3694	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3695	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3696	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3697	<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]	3698	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3699	<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]	3700	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]	3701	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3702	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3703	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]	3704	optimizer is not allowed to modify the number or order of execution of
				3705	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3706	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3707	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3708	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3709	(that is, the alignment of the memory address). A value of 0 or an
				3710	omitted "align" argument means that the operation has the preferential
				3711	alignment for the target. It is the responsibility of the code emitter
				3712	to ensure that the alignment information is correct. Overestimating
				3713	the alignment results in an undefined behavior. Underestimating the
				3714	alignment may produce less efficient code. An alignment of 1 is always
				3715	safe.
				3716	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3717	<h5>Semantics:</h5>
				3718	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3719	at the location specified by the '<tt><pointer></tt>' operand.
				3720	If '<tt><value></tt>' is of scalar type then the number of bytes
				3721	written does not exceed the minimum number of bytes needed to hold all
				3722	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3723	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3724	size that is not an integral number of bytes, it is unspecified what
				3725	happens to the extra bits that do not belong to the type, but they will
				3726	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3727	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3728	<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]	3729	store i32 3, i32* %ptr <i>; yields {void}</i>
				3730	%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]	3731	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3732	</div>
				3733
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3734	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3735	<div class="doc_subsubsection">
				3736	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3737	</div>
				3738
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3739	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3740	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3741	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3742	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3743	</pre>
				3744
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3745	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3746
				3747	<p>
				3748	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]	3749	subelement of an aggregate data structure. It performs address calculation only
				3750	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3751
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3752	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3753
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3754	<p>The first argument is always a pointer, and forms the basis of the
				3755	calculation. The remaining arguments are indices, that indicate which of the
				3756	elements of the aggregate object are indexed. The interpretation of each index
				3757	is dependent on the type being indexed into. The first index always indexes the
				3758	pointer value given as the first argument, the second index indexes a value of
				3759	the type pointed to (not necessarily the value directly pointed to, since the
				3760	first index can be non-zero), etc. The first type indexed into must be a pointer
				3761	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3762	types being indexed into can never be pointers, since that would require loading
				3763	the pointer before continuing calculation.</p>
				3764
				3765	<p>The type of each index argument depends on the type it is indexing into.
				3766	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3767	<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]	3768	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3769
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3770	<p>For example, let's consider a C code fragment and how it gets
				3771	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3772
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3773	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3774	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3775	struct RT {
				3776	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3777	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3778	char C;
				3779	};
				3780	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3781	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3782	double Y;
				3783	struct RT Z;
				3784	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3785
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3786	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3787	return &s[1].Z.B[5][13];
				3788	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3789	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3790	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3791
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3792	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3793
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3794	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3795	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3796	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3797	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3798
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3799	define i32* %foo(%ST* %s) {
				3800	entry:
				3801	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3802	ret i32* %reg
				3803	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3804	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3805	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3806
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3807	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3808
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3809	<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]	3810	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]	3811	}</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]	3812	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3813	i8 }</tt>' type, another structure. The third index indexes into the second
				3814	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]	3815	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3816	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3817	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]	3818
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3819	<p>Note that it is perfectly legal to index partially through a
				3820	structure, returning a pointer to an inner element. Because of this,
				3821	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3822
				3823	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3824	define i32* %foo(%ST* %s) {
				3825	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3826	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3827	%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]	3828	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3829	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3830	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3831	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3832	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3833
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3834	<p>Note that it is undefined to access an array out of bounds: array
				3835	and pointer indexes must always be within the defined bounds of the
				3836	array type when accessed with an instruction that dereferences the
				3837	pointer (e.g. a load or store instruction). The one exception for
				3838	this rule is zero length arrays. These arrays are defined to be
				3839	accessible as variable length arrays, which requires access beyond the
				3840	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3841
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3842	<p>The getelementptr instruction is often confusing. For some more insight
				3843	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3844	FAQ</a>.</p>
				3845
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3846	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3847
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3848	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3849	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3850	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3851	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3852	%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]	3853	<i>; yields i8*:eptr</i>
				3854	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3855	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3856	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3857	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3858	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3859
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3860	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3861	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3862	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3863	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3864	<p>The instructions in this category are the conversion instructions (casting)
				3865	which all take a single operand and a type. They perform various bit conversions
				3866	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3867	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3868
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3869	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3870	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3871	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3872	</div>
				3873	<div class="doc_text">
				3874
				3875	<h5>Syntax:</h5>
				3876	<pre>
				3877	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3878	</pre>
				3879
				3880	<h5>Overview:</h5>
				3881	<p>
				3882	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3883	</p>
				3884
				3885	<h5>Arguments:</h5>
				3886	<p>
				3887	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3888	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]	3889	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]	3890	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3891	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3892
				3893	<h5>Semantics:</h5>
				3894	<p>
				3895	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]	3896	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3897	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3898	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3899
				3900	<h5>Example:</h5>
				3901	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3902	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3903	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3904	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3905	</pre>
				3906	</div>
				3907
				3908	<!-- _______________________________________________________________________ -->
				3909	<div class="doc_subsubsection">
				3910	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3911	</div>
				3912	<div class="doc_text">
				3913
				3914	<h5>Syntax:</h5>
				3915	<pre>
				3916	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3917	</pre>
				3918
				3919	<h5>Overview:</h5>
				3920	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3921	<tt>ty2</tt>.</p>
				3922
				3923
				3924	<h5>Arguments:</h5>
				3925	<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]	3926	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3927	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]	3928	<tt>value</tt> must be smaller than the bit size of the destination type,
				3929	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3930
				3931	<h5>Semantics:</h5>
				3932	<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]	3933	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]	3934
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3935	<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]	3936
				3937	<h5>Example:</h5>
				3938	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3939	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3940	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3941	</pre>
				3942	</div>
				3943
				3944	<!-- _______________________________________________________________________ -->
				3945	<div class="doc_subsubsection">
				3946	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3947	</div>
				3948	<div class="doc_text">
				3949
				3950	<h5>Syntax:</h5>
				3951	<pre>
				3952	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3953	</pre>
				3954
				3955	<h5>Overview:</h5>
				3956	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3957
				3958	<h5>Arguments:</h5>
				3959	<p>
				3960	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]	3961	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3962	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]	3963	<tt>value</tt> must be smaller than the bit size of the destination type,
				3964	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3965
				3966	<h5>Semantics:</h5>
				3967	<p>
				3968	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3969	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]	3970	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3971
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3972	<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]	3973
				3974	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3975	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3976	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3977	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3978	</pre>
				3979	</div>
				3980
				3981	<!-- _______________________________________________________________________ -->
				3982	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3983	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3984	</div>
				3985
				3986	<div class="doc_text">
				3987
				3988	<h5>Syntax:</h5>
				3989
				3990	<pre>
				3991	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3992	</pre>
				3993
				3994	<h5>Overview:</h5>
				3995	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3996	<tt>ty2</tt>.</p>
				3997
				3998
				3999	<h5>Arguments:</h5>
				4000	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4001	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4002	cast it to. The size of <tt>value</tt> must be larger than the size of
				4003	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4004	<i>no-op cast</i>.</p>
				4005
				4006	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4007	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4008	<a href="#t_floating">floating point</a> type to a smaller
				4009	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4010	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4011
				4012	<h5>Example:</h5>
				4013	<pre>
				4014	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4015	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4016	</pre>
				4017	</div>
				4018
				4019	<!-- _______________________________________________________________________ -->
				4020	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4021	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4022	</div>
				4023	<div class="doc_text">
				4024
				4025	<h5>Syntax:</h5>
				4026	<pre>
				4027	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4028	</pre>
				4029
				4030	<h5>Overview:</h5>
				4031	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4032	floating point value.</p>
				4033
				4034	<h5>Arguments:</h5>
				4035	<p>The '<tt>fpext</tt>' instruction takes a
				4036	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4037	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4038	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4039
				4040	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4041	<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]	4042	<a href="#t_floating">floating point</a> type to a larger
				4043	<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]	4044	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]	4045	<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]	4046
				4047	<h5>Example:</h5>
				4048	<pre>
				4049	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4050	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4051	</pre>
				4052	</div>
				4053
				4054	<!-- _______________________________________________________________________ -->
				4055	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4056	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4057	</div>
				4058	<div class="doc_text">
				4059
				4060	<h5>Syntax:</h5>
				4061	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4062	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4063	</pre>
				4064
				4065	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4066	<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]	4067	unsigned integer equivalent of type <tt>ty2</tt>.
				4068	</p>
				4069
				4070	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4071	<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]	4072	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4073	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4074	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4075	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]	4076
				4077	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4078	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4079	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4080	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4081	the results are undefined.</p>
				4082
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4083	<h5>Example:</h5>
				4084	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4085	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4086	%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]	4087	%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]	4088	</pre>
				4089	</div>
				4090
				4091	<!-- _______________________________________________________________________ -->
				4092	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4093	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4094	</div>
				4095	<div class="doc_text">
				4096
				4097	<h5>Syntax:</h5>
				4098	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4099	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4100	</pre>
				4101
				4102	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4103	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4104	<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]	4105	</p>
				4106
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4107	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4108	<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]	4109	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4110	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4111	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4112	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]	4113
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4114	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4115	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4116	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4117	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4118	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4119
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4120	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4121	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4122	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4123	%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]	4124	%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]	4125	</pre>
				4126	</div>
				4127
				4128	<!-- _______________________________________________________________________ -->
				4129	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4130	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4131	</div>
				4132	<div class="doc_text">
				4133
				4134	<h5>Syntax:</h5>
				4135	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4136	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4137	</pre>
				4138
				4139	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4140	<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]	4141	integer and converts that value to the <tt>ty2</tt> type.</p>
				4142
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4143	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4144	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4145	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4146	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4147	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4148	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]	4149
				4150	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4151	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4152	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4153	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]	4154
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4155	<h5>Example:</h5>
				4156	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4157	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4158	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4159	</pre>
				4160	</div>
				4161
				4162	<!-- _______________________________________________________________________ -->
				4163	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4164	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4165	</div>
				4166	<div class="doc_text">
				4167
				4168	<h5>Syntax:</h5>
				4169	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4170	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4171	</pre>
				4172
				4173	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4174	<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]	4175	integer and converts that value to the <tt>ty2</tt> type.</p>
				4176
				4177	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4178	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4179	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4180	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4181	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4182	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]	4183
				4184	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4185	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4186	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4187	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]	4188
				4189	<h5>Example:</h5>
				4190	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4191	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4192	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4193	</pre>
				4194	</div>
				4195
				4196	<!-- _______________________________________________________________________ -->
				4197	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4198	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4199	</div>
				4200	<div class="doc_text">
				4201
				4202	<h5>Syntax:</h5>
				4203	<pre>
				4204	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4205	</pre>
				4206
				4207	<h5>Overview:</h5>
				4208	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4209	the integer type <tt>ty2</tt>.</p>
				4210
				4211	<h5>Arguments:</h5>
				4212	<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]	4213	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]	4214	<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]	4215
				4216	<h5>Semantics:</h5>
				4217	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4218	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4219	truncating or zero extending that value to the size of the integer type. If
				4220	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4221	<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]	4222	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4223	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4224
				4225	<h5>Example:</h5>
				4226	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4227	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4228	%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]	4229	</pre>
				4230	</div>
				4231
				4232	<!-- _______________________________________________________________________ -->
				4233	<div class="doc_subsubsection">
				4234	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4235	</div>
				4236	<div class="doc_text">
				4237
				4238	<h5>Syntax:</h5>
				4239	<pre>
				4240	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4241	</pre>
				4242
				4243	<h5>Overview:</h5>
				4244	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4245	a pointer type, <tt>ty2</tt>.</p>
				4246
				4247	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4248	<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]	4249	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]	4250	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4251
				4252	<h5>Semantics:</h5>
				4253	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4254	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4255	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4256	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4257	the size of a pointer then a zero extension is done. If they are the same size,
				4258	nothing is done (<i>no-op cast</i>).</p>
				4259
				4260	<h5>Example:</h5>
				4261	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4262	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4263	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4264	%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]	4265	</pre>
				4266	</div>
				4267
				4268	<!-- _______________________________________________________________________ -->
				4269	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4270	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4271	</div>
				4272	<div class="doc_text">
				4273
				4274	<h5>Syntax:</h5>
				4275	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4276	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4277	</pre>
				4278
				4279	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4280
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4281	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4282	<tt>ty2</tt> without changing any bits.</p>
				4283
				4284	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4285
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4286	<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]	4287	a non-aggregate first class value, and a type to cast it to, which must also be
				4288	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4289	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4290	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]	4291	type is a pointer, the destination type must also be a pointer. This
				4292	instruction supports bitwise conversion of vectors to integers and to vectors
				4293	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4294
				4295	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4296	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4297	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4298	this conversion. The conversion is done as if the <tt>value</tt> had been
				4299	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4300	converted to other pointer types with this instruction. To convert pointers to
				4301	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4302	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4303
				4304	<h5>Example:</h5>
				4305	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4306	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4307	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4308	%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]	4309	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4310	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4311
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4312	<!-- ======================================================================= -->
				4313	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4314	<div class="doc_text">
				4315	<p>The instructions in this category are the "miscellaneous"
				4316	instructions, which defy better classification.</p>
				4317	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4318
				4319	<!-- _______________________________________________________________________ -->
				4320	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4321	</div>
				4322	<div class="doc_text">
				4323	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4324	<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]	4325	</pre>
				4326	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4327	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4328	a vector of boolean values based on comparison
				4329	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4330	<h5>Arguments:</h5>
				4331	<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]	4332	the condition code indicating the kind of comparison to perform. It is not
				4333	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4334	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4335	<ol>
				4336	<li><tt>eq</tt>: equal</li>
				4337	<li><tt>ne</tt>: not equal </li>
				4338	<li><tt>ugt</tt>: unsigned greater than</li>
				4339	<li><tt>uge</tt>: unsigned greater or equal</li>
				4340	<li><tt>ult</tt>: unsigned less than</li>
				4341	<li><tt>ule</tt>: unsigned less or equal</li>
				4342	<li><tt>sgt</tt>: signed greater than</li>
				4343	<li><tt>sge</tt>: signed greater or equal</li>
				4344	<li><tt>slt</tt>: signed less than</li>
				4345	<li><tt>sle</tt>: signed less or equal</li>
				4346	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4347	<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]	4348	<a href="#t_pointer">pointer</a>
				4349	or integer <a href="#t_vector">vector</a> typed.
				4350	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4351	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4352	<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]	4353	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4354	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]	4355	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4356	<ol>
				4357	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4358	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4359	</li>
				4360	<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]	4361	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4362	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4363	<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]	4364	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4365	<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]	4366	<li><tt>ult</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 less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4368	<li><tt>ule</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 less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4370	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4371	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4372	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4373	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4374	<li><tt>slt</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 less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4376	<li><tt>sle</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 less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4378	</ol>
				4379	<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]	4380	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4381	<p>If the operands are integer vectors, then they are compared
				4382	element by element. The result is an <tt>i1</tt> vector with
				4383	the same number of elements as the values being compared.
				4384	Otherwise, the result is an <tt>i1</tt>.
				4385	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4386
				4387	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4388	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4389	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4390	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4391	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4392	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4393	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4394	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4395
				4396	<p>Note that the code generator does not yet support vector types with
				4397	the <tt>icmp</tt> instruction.</p>
				4398
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4399	</div>
				4400
				4401	<!-- _______________________________________________________________________ -->
				4402	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4403	</div>
				4404	<div class="doc_text">
				4405	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4406	<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]	4407	</pre>
				4408	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4409	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4410	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4411	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4412	<p>
				4413	If the operands are floating point scalars, then the result
				4414	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4415	</p>
				4416	<p>If the operands are floating point vectors, then the result type
				4417	is a vector of boolean with the same number of elements as the
				4418	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4419	<h5>Arguments:</h5>
				4420	<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]	4421	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]	4422	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4423	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4424	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4425	<li><tt>oeq</tt>: ordered and equal</li>
				4426	<li><tt>ogt</tt>: ordered and greater than </li>
				4427	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4428	<li><tt>olt</tt>: ordered and less than </li>
				4429	<li><tt>ole</tt>: ordered and less than or equal</li>
				4430	<li><tt>one</tt>: ordered and not equal</li>
				4431	<li><tt>ord</tt>: ordered (no nans)</li>
				4432	<li><tt>ueq</tt>: unordered or equal</li>
				4433	<li><tt>ugt</tt>: unordered or greater than </li>
				4434	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4435	<li><tt>ult</tt>: unordered or less than </li>
				4436	<li><tt>ule</tt>: unordered or less than or equal</li>
				4437	<li><tt>une</tt>: unordered or not equal</li>
				4438	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4439	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4440	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4441	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4442	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4443	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4444	either a <a href="#t_floating">floating point</a> type
				4445	or a <a href="#t_vector">vector</a> of floating point type.
				4446	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4447	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4448	<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]	4449	according to the condition code given as <tt>cond</tt>.
				4450	If the operands are vectors, then the vectors are compared
				4451	element by element.
				4452	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4453	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]	4454	<ol>
				4455	<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]	4456	<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]	4457	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4458	<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]	4459	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4460	<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]	4461	<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]	4462	<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]	4463	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4464	<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]	4465	<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]	4466	<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]	4467	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4468	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4469	<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]	4470	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4471	<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]	4472	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4473	<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]	4474	<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]	4475	<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]	4476	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4477	<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]	4478	<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]	4479	<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]	4480	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4481	<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]	4482	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4483	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4484
				4485	<h5>Example:</h5>
				4486	<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]	4487	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4488	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4489	<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]	4490	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4491
				4492	<p>Note that the code generator does not yet support vector types with
				4493	the <tt>fcmp</tt> instruction.</p>
				4494
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4495	</div>
				4496
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4497	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4498	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4499	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4500	</div>
				4501
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4502	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4503
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4504	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4505
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4506	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4507	<h5>Overview:</h5>
				4508	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4509	the SSA graph representing the function.</p>
				4510	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4511
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4512	<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]	4513	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4514	as arguments, with one pair for each predecessor basic block of the
				4515	current block. Only values of <a href="#t_firstclass">first class</a>
				4516	type may be used as the value arguments to the PHI node. Only labels
				4517	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4518
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4519	<p>There must be no non-phi instructions between the start of a basic
				4520	block and the PHI instructions: i.e. PHI instructions must be first in
				4521	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4522
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4523	<p>For the purposes of the SSA form, the use of each incoming value is
				4524	deemed to occur on the edge from the corresponding predecessor block
				4525	to the current block (but after any definition of an '<tt>invoke</tt>'
				4526	instruction's return value on the same edge).</p>
				4527
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4528	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4529
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4530	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4531	specified by the pair corresponding to the predecessor basic block that executed
				4532	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4533
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4534	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4535	<pre>
				4536	Loop: ; Infinite loop that counts from 0 on up...
				4537	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4538	%nextindvar = add i32 %indvar, 1
				4539	br label %Loop
				4540	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4541	</div>
				4542
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4543	<!-- _______________________________________________________________________ -->
				4544	<div class="doc_subsubsection">
				4545	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4546	</div>
				4547
				4548	<div class="doc_text">
				4549
				4550	<h5>Syntax:</h5>
				4551
				4552	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4553	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4554
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4555	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4556	</pre>
				4557
				4558	<h5>Overview:</h5>
				4559
				4560	<p>
				4561	The '<tt>select</tt>' instruction is used to choose one value based on a
				4562	condition, without branching.
				4563	</p>
				4564
				4565
				4566	<h5>Arguments:</h5>
				4567
				4568	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4569	The '<tt>select</tt>' instruction requires an 'i1' value or
				4570	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4571	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]	4572	type. If the val1/val2 are vectors and
				4573	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4574	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4575	</p>
				4576
				4577	<h5>Semantics:</h5>
				4578
				4579	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4580	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]	4581	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4582	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4583	<p>
				4584	If the condition is a vector of i1, then the value arguments must
				4585	be vectors of the same size, and the selection is done element
				4586	by element.
				4587	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4588
				4589	<h5>Example:</h5>
				4590
				4591	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4592	%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]	4593	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4594
				4595	<p>Note that the code generator does not yet support conditions
				4596	with vector type.</p>
				4597
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4598	</div>
				4599
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4600
				4601	<!-- _______________________________________________________________________ -->
				4602	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4603	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4604	</div>
				4605
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4606	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4607
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4608	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4609	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4610	<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]	4611	</pre>
				4612
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4613	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4614
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4615	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4616
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4617	<h5>Arguments:</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>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4620
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4621	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4622	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4623	<p>The optional "tail" marker indicates whether the callee function accesses
				4624	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]	4625	function call is eligible for tail call optimization. Note that calls may
				4626	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4627	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4628	</li>
				4629	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4630	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4631	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]	4632	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4633	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4634
				4635	<li>
				4636	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4637	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4638	and '<tt>inreg</tt>' attributes are valid here.</p>
				4639	</li>
				4640
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4641	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4642	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4643	the type of the return value. Functions that return no value are marked
				4644	<tt><a href="#t_void">void</a></tt>.</p>
				4645	</li>
				4646	<li>
				4647	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4648	value being invoked. The argument types must match the types implied by
				4649	this signature. This type can be omitted if the function is not varargs
				4650	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]	4651	</li>
				4652	<li>
				4653	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4654	be invoked. In most cases, this is a direct function invocation, but
				4655	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]	4656	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4657	</li>
				4658	<li>
				4659	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4660	function signature argument types. All arguments must be of
				4661	<a href="#t_firstclass">first class</a> type. If the function signature
				4662	indicates the function accepts a variable number of arguments, the extra
				4663	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4664	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4665	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4666	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4667	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4668	'<tt>readnone</tt>' attributes are valid here.</p>
				4669	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4670	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4671
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4672	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4673
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4674	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4675	transfer to a specified function, with its incoming arguments bound to
				4676	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4677	instruction in the called function, control flow continues with the
				4678	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4679	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4680
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4681	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4682
				4683	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4684	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4685	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4686	%X = tail call i32 @foo() <i>; yields i32</i>
				4687	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4688	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4689
				4690	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4691	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4692	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4693	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4694	%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]	4695	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4696	</pre>
				4697
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4698	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4699
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4700	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4701	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4702	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4703	</div>
				4704
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4705	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4706
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4707	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4708
				4709	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4710	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4711	</pre>
				4712
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4713	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4714
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4715	<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]	4716	the "variable argument" area of a function call. It is used to implement the
				4717	<tt>va_arg</tt> macro in C.</p>
				4718
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4719	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4720
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4721	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4722	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4723	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]	4724	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4725
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4726	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4727
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4728	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4729	type from the specified <tt>va_list</tt> and causes the
				4730	<tt>va_list</tt> to point to the next argument. For more information,
				4731	see the variable argument handling <a href="#int_varargs">Intrinsic
				4732	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4733
				4734	<p>It is legal for this instruction to be called in a function which does not
				4735	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4736	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4737
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4738	<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]	4739	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4740	argument.</p>
				4741
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4742	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4743
				4744	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4745
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4746	<p>Note that the code generator does not yet fully support va_arg
				4747	on many targets. Also, it does not currently support va_arg with
				4748	aggregate types on any target.</p>
				4749
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4750	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4751
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4752	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4753	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4754	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4755
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4756	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4757
				4758	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4759	well known names and semantics and are required to follow certain restrictions.
				4760	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4761	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]	4762	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]	4763
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4764	<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]	4765	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4766	begin with this prefix. Intrinsic functions must always be external functions:
				4767	you cannot define the body of intrinsic functions. Intrinsic functions may
				4768	only be used in call or invoke instructions: it is illegal to take the address
				4769	of an intrinsic function. Additionally, because intrinsic functions are part
				4770	of the LLVM language, it is required if any are added that they be documented
				4771	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4772
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4773	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4774	a family of functions that perform the same operation but on different data
				4775	types. Because LLVM can represent over 8 million different integer types,
				4776	overloading is used commonly to allow an intrinsic function to operate on any
				4777	integer type. One or more of the argument types or the result type can be
				4778	overloaded to accept any integer type. Argument types may also be defined as
				4779	exactly matching a previous argument's type or the result type. This allows an
				4780	intrinsic function which accepts multiple arguments, but needs all of them to
				4781	be of the same type, to only be overloaded with respect to a single argument or
				4782	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4783
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4784	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4785	encoded into its function name, each preceded by a period. Only those types
				4786	which are overloaded result in a name suffix. Arguments whose type is matched
				4787	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4788	take an integer of any width and returns an integer of exactly the same integer
				4789	width. This leads to a family of functions such as
				4790	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4791	Only one type, the return type, is overloaded, and only one type suffix is
				4792	required. Because the argument's type is matched against the return type, it
				4793	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4794
				4795	<p>To learn how to add an intrinsic function, please see the
				4796	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4797	</p>
				4798
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4799	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4800
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4801	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4802	<div class="doc_subsection">
				4803	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4804	</div>
				4805
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4806	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4807
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4808	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4809	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]	4810	intrinsic functions. These functions are related to the similarly
				4811	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4812
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4813	<p>All of these functions operate on arguments that use a
				4814	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4815	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4816	transformations should be prepared to handle these functions regardless of
				4817	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4818
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4819	<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]	4820	instruction and the variable argument handling intrinsic functions are
				4821	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4822
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4823	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4824	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4825	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4826	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4827	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4828	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4829	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4830
				4831	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4832	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4833
				4834	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4835	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4836	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4837	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4838	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4839
				4840	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4841	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4842	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4843	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4844
				4845	declare void @llvm.va_start(i8*)
				4846	declare void @llvm.va_copy(i8, i8)
				4847	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4848	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4849	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4850
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4851	</div>
				4852
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4853	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4854	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4855	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4856	</div>
				4857
				4858
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4859	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4860	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4861	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4862	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4863	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4864	<tt>*<arglist></tt> for subsequent use by <tt><a
				4865	href="#i_va_arg">va_arg</a></tt>.</p>
				4866
				4867	<h5>Arguments:</h5>
				4868
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4869	<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]	4870
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4871	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4872
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4873	<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]	4874	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4875	<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]	4876	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4877	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]	4878	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]	4879
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4880	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4881
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4882	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4883	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4884	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4885	</div>
				4886
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4887	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4888	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4889	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4890	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4891
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4892	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4893	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]	4894	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]	4895
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4896	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4897
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4898	<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]	4899
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4900	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4901
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4902	<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]	4903	macro available in C. In a target-dependent way, it destroys the
				4904	<tt>va_list</tt> element to which the argument points. Calls to <a
				4905	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4906	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4907	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4908
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4909	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4910
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4911	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4912	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4913	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4914	</div>
				4915
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4916	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4917
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4918	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4919
				4920	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4921	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4922	</pre>
				4923
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4924	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4925
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4926	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4927	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4928
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4929	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4930
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4931	<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]	4932	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]	4933
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4934
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4935	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4936
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4937	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4938	macro available in C. In a target-dependent way, it copies the source
				4939	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4940	intrinsic is necessary because the <tt><a href="#int_va_start">
				4941	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4942	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4943
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4944	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4945
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4946	<!-- ======================================================================= -->
				4947	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4948	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4949	</div>
				4950
				4951	<div class="doc_text">
				4952
				4953	<p>
				4954	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4955	Collection</a> (GC) requires the implementation and generation of these
				4956	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4957	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]	4958	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4959	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]	4960	Front-ends for type-safe garbage collected languages should generate these
				4961	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4962	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4963	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4964
				4965	<p>The garbage collection intrinsics only operate on objects in the generic
				4966	address space (address space zero).</p>
				4967
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4968	</div>
				4969
				4970	<!-- _______________________________________________________________________ -->
				4971	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4972	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4973	</div>
				4974
				4975	<div class="doc_text">
				4976
				4977	<h5>Syntax:</h5>
				4978
				4979	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	4980	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4981	</pre>
				4982
				4983	<h5>Overview:</h5>
				4984
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	4985	<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]	4986	the code generator, and allows some metadata to be associated with it.</p>
				4987
				4988	<h5>Arguments:</h5>
				4989
				4990	<p>The first argument specifies the address of a stack object that contains the
				4991	root pointer. The second pointer (which must be either a constant or a global
				4992	value address) contains the meta-data to be associated with the root.</p>
				4993
				4994	<h5>Semantics:</h5>
				4995
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	4996	<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]	4997	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	4998	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4999	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5000	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5001
				5002	</div>
				5003
				5004
				5005	<!-- _______________________________________________________________________ -->
				5006	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5007	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5008	</div>
				5009
				5010	<div class="doc_text">
				5011
				5012	<h5>Syntax:</h5>
				5013
				5014	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5015	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5016	</pre>
				5017
				5018	<h5>Overview:</h5>
				5019
				5020	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5021	locations, allowing garbage collector implementations that require read
				5022	barriers.</p>
				5023
				5024	<h5>Arguments:</h5>
				5025
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5026	<p>The second argument is the address to read from, which should be an address
				5027	allocated from the garbage collector. The first object is a pointer to the
				5028	start of the referenced object, if needed by the language runtime (otherwise
				5029	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5030
				5031	<h5>Semantics:</h5>
				5032
				5033	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5034	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5035	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5036	may only be used in a function which <a href="#gc">specifies a GC
				5037	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5038
				5039	</div>
				5040
				5041
				5042	<!-- _______________________________________________________________________ -->
				5043	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5044	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5045	</div>
				5046
				5047	<div class="doc_text">
				5048
				5049	<h5>Syntax:</h5>
				5050
				5051	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5052	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5053	</pre>
				5054
				5055	<h5>Overview:</h5>
				5056
				5057	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5058	locations, allowing garbage collector implementations that require write
				5059	barriers (such as generational or reference counting collectors).</p>
				5060
				5061	<h5>Arguments:</h5>
				5062
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5063	<p>The first argument is the reference to store, the second is the start of the
				5064	object to store it to, and the third is the address of the field of Obj to
				5065	store to. If the runtime does not require a pointer to the object, Obj may be
				5066	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5067
				5068	<h5>Semantics:</h5>
				5069
				5070	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5071	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5072	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5073	may only be used in a function which <a href="#gc">specifies a GC
				5074	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5075
				5076	</div>
				5077
				5078
				5079
				5080	<!-- ======================================================================= -->
				5081	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5082	<a name="int_codegen">Code Generator Intrinsics</a>
				5083	</div>
				5084
				5085	<div class="doc_text">
				5086	<p>
				5087	These intrinsics are provided by LLVM to expose special features that may only
				5088	be implemented with code generator support.
				5089	</p>
				5090
				5091	</div>
				5092
				5093	<!-- _______________________________________________________________________ -->
				5094	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5095	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5096	</div>
				5097
				5098	<div class="doc_text">
				5099
				5100	<h5>Syntax:</h5>
				5101	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5102	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5103	</pre>
				5104
				5105	<h5>Overview:</h5>
				5106
				5107	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5108	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5109	target-specific value indicating the return address of the current function
				5110	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5111	</p>
				5112
				5113	<h5>Arguments:</h5>
				5114
				5115	<p>
				5116	The argument to this intrinsic indicates which function to return the address
				5117	for. Zero indicates the calling function, one indicates its caller, etc. The
				5118	argument is <b>required</b> to be a constant integer value.
				5119	</p>
				5120
				5121	<h5>Semantics:</h5>
				5122
				5123	<p>
				5124	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5125	the return address of the specified call frame, or zero if it cannot be
				5126	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5127	for arguments other than zero, so it should only be used for debugging purposes.
				5128	</p>
				5129
				5130	<p>
				5131	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5132	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]	5133	source-language caller.
				5134	</p>
				5135	</div>
				5136
				5137
				5138	<!-- _______________________________________________________________________ -->
				5139	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5140	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5141	</div>
				5142
				5143	<div class="doc_text">
				5144
				5145	<h5>Syntax:</h5>
				5146	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5147	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5148	</pre>
				5149
				5150	<h5>Overview:</h5>
				5151
				5152	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5153	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5154	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5155	</p>
				5156
				5157	<h5>Arguments:</h5>
				5158
				5159	<p>
				5160	The argument to this intrinsic indicates which function to return the frame
				5161	pointer for. Zero indicates the calling function, one indicates its caller,
				5162	etc. The argument is <b>required</b> to be a constant integer value.
				5163	</p>
				5164
				5165	<h5>Semantics:</h5>
				5166
				5167	<p>
				5168	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5169	the frame address of the specified call frame, or zero if it cannot be
				5170	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5171	for arguments other than zero, so it should only be used for debugging purposes.
				5172	</p>
				5173
				5174	<p>
				5175	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5176	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]	5177	source-language caller.
				5178	</p>
				5179	</div>
				5180
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5181	<!-- _______________________________________________________________________ -->
				5182	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5183	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5184	</div>
				5185
				5186	<div class="doc_text">
				5187
				5188	<h5>Syntax:</h5>
				5189	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5190	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5191	</pre>
				5192
				5193	<h5>Overview:</h5>
				5194
				5195	<p>
				5196	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]	5197	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5198	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5199	features like scoped automatic variable sized arrays in C99.
				5200	</p>
				5201
				5202	<h5>Semantics:</h5>
				5203
				5204	<p>
				5205	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]	5206	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5207	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5208	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5209	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5210	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5211	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5212	</p>
				5213
				5214	</div>
				5215
				5216	<!-- _______________________________________________________________________ -->
				5217	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5218	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5219	</div>
				5220
				5221	<div class="doc_text">
				5222
				5223	<h5>Syntax:</h5>
				5224	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5225	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5226	</pre>
				5227
				5228	<h5>Overview:</h5>
				5229
				5230	<p>
				5231	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5232	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]	5233	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5234	useful for implementing language features like scoped automatic variable sized
				5235	arrays in C99.
				5236	</p>
				5237
				5238	<h5>Semantics:</h5>
				5239
				5240	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5241	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]	5242	</p>
				5243
				5244	</div>
				5245
				5246
				5247	<!-- _______________________________________________________________________ -->
				5248	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5249	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5250	</div>
				5251
				5252	<div class="doc_text">
				5253
				5254	<h5>Syntax:</h5>
				5255	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5256	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5257	</pre>
				5258
				5259	<h5>Overview:</h5>
				5260
				5261
				5262	<p>
				5263	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]	5264	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5265	no
				5266	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5267	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5268	</p>
				5269
				5270	<h5>Arguments:</h5>
				5271
				5272	<p>
				5273	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5274	determining if the fetch should be for a read (0) or write (1), and
				5275	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5276	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]	5277	<tt>locality</tt> arguments must be constant integers.
				5278	</p>
				5279
				5280	<h5>Semantics:</h5>
				5281
				5282	<p>
				5283	This intrinsic does not modify the behavior of the program. In particular,
				5284	prefetches cannot trap and do not produce a value. On targets that support this
				5285	intrinsic, the prefetch can provide hints to the processor cache for better
				5286	performance.
				5287	</p>
				5288
				5289	</div>
				5290
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5291	<!-- _______________________________________________________________________ -->
				5292	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5293	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5294	</div>
				5295
				5296	<div class="doc_text">
				5297
				5298	<h5>Syntax:</h5>
				5299	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5300	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5301	</pre>
				5302
				5303	<h5>Overview:</h5>
				5304
				5305
				5306	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5307	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]	5308	(PC) in a region of
				5309	code to simulators and other tools. The method is target specific, but it is
				5310	expected that the marker will use exported symbols to transmit the PC of the
				5311	marker.
				5312	The marker makes no guarantees that it will remain with any specific instruction
				5313	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]	5314	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5315	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5316	</p>
				5317
				5318	<h5>Arguments:</h5>
				5319
				5320	<p>
				5321	<tt>id</tt> is a numerical id identifying the marker.
				5322	</p>
				5323
				5324	<h5>Semantics:</h5>
				5325
				5326	<p>
				5327	This intrinsic does not modify the behavior of the program. Backends that do not
				5328	support this intrinisic may ignore it.
				5329	</p>
				5330
				5331	</div>
				5332
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5333	<!-- _______________________________________________________________________ -->
				5334	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5335	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5336	</div>
				5337
				5338	<div class="doc_text">
				5339
				5340	<h5>Syntax:</h5>
				5341	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5342	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5343	</pre>
				5344
				5345	<h5>Overview:</h5>
				5346
				5347
				5348	<p>
				5349	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5350	counter register (or similar low latency, high accuracy clocks) on those targets
				5351	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5352	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5353	should only be used for small timings.
				5354	</p>
				5355
				5356	<h5>Semantics:</h5>
				5357
				5358	<p>
				5359	When directly supported, reading the cycle counter should not modify any memory.
				5360	Implementations are allowed to either return a application specific value or a
				5361	system wide value. On backends without support, this is lowered to a constant 0.
				5362	</p>
				5363
				5364	</div>
				5365
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5366	<!-- ======================================================================= -->
				5367	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5368	<a name="int_libc">Standard C Library Intrinsics</a>
				5369	</div>
				5370
				5371	<div class="doc_text">
				5372	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5373	LLVM provides intrinsics for a few important standard C library functions.
				5374	These intrinsics allow source-language front-ends to pass information about the
				5375	alignment of the pointer arguments to the code generator, providing opportunity
				5376	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5377	</p>
				5378
				5379	</div>
				5380
				5381	<!-- _______________________________________________________________________ -->
				5382	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5383	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5384	</div>
				5385
				5386	<div class="doc_text">
				5387
				5388	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5389	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5390	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5391	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5392	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5393	i8 <len>, i32 <align>)
				5394	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5395	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5396	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5397	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5398	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5399	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5400	</pre>
				5401
				5402	<h5>Overview:</h5>
				5403
				5404	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5405	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]	5406	location to the destination location.
				5407	</p>
				5408
				5409	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5410	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5411	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5412	</p>
				5413
				5414	<h5>Arguments:</h5>
				5415
				5416	<p>
				5417	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]	5418	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5419	specifying the number of bytes to copy, and the fourth argument is the alignment
				5420	of the source and destination locations.
				5421	</p>
				5422
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5423	<p>
				5424	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]	5425	the caller guarantees that both the source and destination pointers are aligned
				5426	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5427	</p>
				5428
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5429	<h5>Semantics:</h5>
				5430
				5431	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5432	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]	5433	location to the destination location, which are not allowed to overlap. It
				5434	copies "len" bytes of memory over. If the argument is known to be aligned to
				5435	some boundary, this can be specified as the fourth argument, otherwise it should
				5436	be set to 0 or 1.
				5437	</p>
				5438	</div>
				5439
				5440
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5441	<!-- _______________________________________________________________________ -->
				5442	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5443	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5444	</div>
				5445
				5446	<div class="doc_text">
				5447
				5448	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5449	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5450	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5451	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5452	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5453	i8 <len>, i32 <align>)
				5454	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5455	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5456	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5457	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5458	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5459	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5460	</pre>
				5461
				5462	<h5>Overview:</h5>
				5463
				5464	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5465	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5466	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5467	'<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]	5468	</p>
				5469
				5470	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5471	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5472	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5473	</p>
				5474
				5475	<h5>Arguments:</h5>
				5476
				5477	<p>
				5478	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]	5479	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5480	specifying the number of bytes to copy, and the fourth argument is the alignment
				5481	of the source and destination locations.
				5482	</p>
				5483
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5484	<p>
				5485	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]	5486	the caller guarantees that the source and destination pointers are aligned to
				5487	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5488	</p>
				5489
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5490	<h5>Semantics:</h5>
				5491
				5492	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5493	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]	5494	location to the destination location, which may overlap. It
				5495	copies "len" bytes of memory over. If the argument is known to be aligned to
				5496	some boundary, this can be specified as the fourth argument, otherwise it should
				5497	be set to 0 or 1.
				5498	</p>
				5499	</div>
				5500
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5501
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5502	<!-- _______________________________________________________________________ -->
				5503	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5504	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5505	</div>
				5506
				5507	<div class="doc_text">
				5508
				5509	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5510	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5511	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5512	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5513	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5514	i8 <len>, i32 <align>)
				5515	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5516	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5517	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5518	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5519	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5520	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5521	</pre>
				5522
				5523	<h5>Overview:</h5>
				5524
				5525	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5526	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]	5527	byte value.
				5528	</p>
				5529
				5530	<p>
				5531	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5532	does not return a value, and takes an extra alignment argument.
				5533	</p>
				5534
				5535	<h5>Arguments:</h5>
				5536
				5537	<p>
				5538	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]	5539	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5540	argument specifying the number of bytes to fill, and the fourth argument is the
				5541	known alignment of destination location.
				5542	</p>
				5543
				5544	<p>
				5545	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]	5546	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5547	</p>
				5548
				5549	<h5>Semantics:</h5>
				5550
				5551	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5552	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5553	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5554	destination location. If the argument is known to be aligned to some boundary,
				5555	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5556	1.
				5557	</p>
				5558	</div>
				5559
				5560
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5561	<!-- _______________________________________________________________________ -->
				5562	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5563	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5564	</div>
				5565
				5566	<div class="doc_text">
				5567
				5568	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5569	<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]	5570	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]	5571	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5572	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5573	declare float @llvm.sqrt.f32(float %Val)
				5574	declare double @llvm.sqrt.f64(double %Val)
				5575	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5576	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5577	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5578	</pre>
				5579
				5580	<h5>Overview:</h5>
				5581
				5582	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5583	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]	5584	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]	5585	<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]	5586	negative numbers other than -0.0 (which allows for better optimization, because
				5587	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5588	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5589	</p>
				5590
				5591	<h5>Arguments:</h5>
				5592
				5593	<p>
				5594	The argument and return value are floating point numbers of the same type.
				5595	</p>
				5596
				5597	<h5>Semantics:</h5>
				5598
				5599	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5600	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]	5601	floating point number.
				5602	</p>
				5603	</div>
				5604
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5605	<!-- _______________________________________________________________________ -->
				5606	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5607	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5608	</div>
				5609
				5610	<div class="doc_text">
				5611
				5612	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5613	<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]	5614	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]	5615	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5616	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5617	declare float @llvm.powi.f32(float %Val, i32 %power)
				5618	declare double @llvm.powi.f64(double %Val, i32 %power)
				5619	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5620	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5621	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5622	</pre>
				5623
				5624	<h5>Overview:</h5>
				5625
				5626	<p>
				5627	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5628	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5629	multiplications is not defined. When a vector of floating point type is
				5630	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5631	</p>
				5632
				5633	<h5>Arguments:</h5>
				5634
				5635	<p>
				5636	The second argument is an integer power, and the first is a value to raise to
				5637	that power.
				5638	</p>
				5639
				5640	<h5>Semantics:</h5>
				5641
				5642	<p>
				5643	This function returns the first value raised to the second power with an
				5644	unspecified sequence of rounding operations.</p>
				5645	</div>
				5646
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5647	<!-- _______________________________________________________________________ -->
				5648	<div class="doc_subsubsection">
				5649	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5650	</div>
				5651
				5652	<div class="doc_text">
				5653
				5654	<h5>Syntax:</h5>
				5655	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5656	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5657	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5658	<pre>
				5659	declare float @llvm.sin.f32(float %Val)
				5660	declare double @llvm.sin.f64(double %Val)
				5661	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5662	declare fp128 @llvm.sin.f128(fp128 %Val)
				5663	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5664	</pre>
				5665
				5666	<h5>Overview:</h5>
				5667
				5668	<p>
				5669	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5670	</p>
				5671
				5672	<h5>Arguments:</h5>
				5673
				5674	<p>
				5675	The argument and return value are floating point numbers of the same type.
				5676	</p>
				5677
				5678	<h5>Semantics:</h5>
				5679
				5680	<p>
				5681	This function returns the sine of the specified operand, returning the
				5682	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]	5683	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5684	</div>
				5685
				5686	<!-- _______________________________________________________________________ -->
				5687	<div class="doc_subsubsection">
				5688	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5689	</div>
				5690
				5691	<div class="doc_text">
				5692
				5693	<h5>Syntax:</h5>
				5694	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5695	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5696	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5697	<pre>
				5698	declare float @llvm.cos.f32(float %Val)
				5699	declare double @llvm.cos.f64(double %Val)
				5700	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5701	declare fp128 @llvm.cos.f128(fp128 %Val)
				5702	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5703	</pre>
				5704
				5705	<h5>Overview:</h5>
				5706
				5707	<p>
				5708	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5709	</p>
				5710
				5711	<h5>Arguments:</h5>
				5712
				5713	<p>
				5714	The argument and return value are floating point numbers of the same type.
				5715	</p>
				5716
				5717	<h5>Semantics:</h5>
				5718
				5719	<p>
				5720	This function returns the cosine of the specified operand, returning the
				5721	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]	5722	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5723	</div>
				5724
				5725	<!-- _______________________________________________________________________ -->
				5726	<div class="doc_subsubsection">
				5727	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5728	</div>
				5729
				5730	<div class="doc_text">
				5731
				5732	<h5>Syntax:</h5>
				5733	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5734	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]	5735	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5736	<pre>
				5737	declare float @llvm.pow.f32(float %Val, float %Power)
				5738	declare double @llvm.pow.f64(double %Val, double %Power)
				5739	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5740	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5741	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5742	</pre>
				5743
				5744	<h5>Overview:</h5>
				5745
				5746	<p>
				5747	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5748	specified (positive or negative) power.
				5749	</p>
				5750
				5751	<h5>Arguments:</h5>
				5752
				5753	<p>
				5754	The second argument is a floating point power, and the first is a value to
				5755	raise to that power.
				5756	</p>
				5757
				5758	<h5>Semantics:</h5>
				5759
				5760	<p>
				5761	This function returns the first value raised to the second power,
				5762	returning the
				5763	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]	5764	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5765	</div>
				5766
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5767
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5768	<!-- ======================================================================= -->
				5769	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5770	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5771	</div>
				5772
				5773	<div class="doc_text">
				5774	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5775	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5776	These allow efficient code generation for some algorithms.
				5777	</p>
				5778
				5779	</div>
				5780
				5781	<!-- _______________________________________________________________________ -->
				5782	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5783	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5784	</div>
				5785
				5786	<div class="doc_text">
				5787
				5788	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5789	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5790	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]	5791	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5792	declare i16 @llvm.bswap.i16(i16 <id>)
				5793	declare i32 @llvm.bswap.i32(i32 <id>)
				5794	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5795	</pre>
				5796
				5797	<h5>Overview:</h5>
				5798
				5799	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5800	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]	5801	values with an even number of bytes (positive multiple of 16 bits). These are
				5802	useful for performing operations on data that is not in the target's native
				5803	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5804	</p>
				5805
				5806	<h5>Semantics:</h5>
				5807
				5808	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5809	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]	5810	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5811	intrinsic returns an i32 value that has the four bytes of the input i32
				5812	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]	5813	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5814	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5815	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5816	</p>
				5817
				5818	</div>
				5819
				5820	<!-- _______________________________________________________________________ -->
				5821	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5822	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5823	</div>
				5824
				5825	<div class="doc_text">
				5826
				5827	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5828	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5829	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5830	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5831	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5832	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5833	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5834	declare i64 @llvm.ctpop.i64(i64 <src>)
				5835	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5836	</pre>
				5837
				5838	<h5>Overview:</h5>
				5839
				5840	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5841	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5842	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5843	</p>
				5844
				5845	<h5>Arguments:</h5>
				5846
				5847	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5848	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5849	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5850	</p>
				5851
				5852	<h5>Semantics:</h5>
				5853
				5854	<p>
				5855	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5856	</p>
				5857	</div>
				5858
				5859	<!-- _______________________________________________________________________ -->
				5860	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5861	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5862	</div>
				5863
				5864	<div class="doc_text">
				5865
				5866	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5867	<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]	5868	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5869	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5870	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5871	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5872	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5873	declare i64 @llvm.ctlz.i64(i64 <src>)
				5874	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5875	</pre>
				5876
				5877	<h5>Overview:</h5>
				5878
				5879	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5880	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5881	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5882	</p>
				5883
				5884	<h5>Arguments:</h5>
				5885
				5886	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5887	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]	5888	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5889	</p>
				5890
				5891	<h5>Semantics:</h5>
				5892
				5893	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5894	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5895	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]	5896	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5897	</p>
				5898	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5899
				5900
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5901
				5902	<!-- _______________________________________________________________________ -->
				5903	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5904	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5905	</div>
				5906
				5907	<div class="doc_text">
				5908
				5909	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5910	<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]	5911	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5912	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5913	declare i8 @llvm.cttz.i8 (i8 <src>)
				5914	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5915	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5916	declare i64 @llvm.cttz.i64(i64 <src>)
				5917	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5918	</pre>
				5919
				5920	<h5>Overview:</h5>
				5921
				5922	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5923	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5924	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5925	</p>
				5926
				5927	<h5>Arguments:</h5>
				5928
				5929	<p>
				5930	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]	5931	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5932	</p>
				5933
				5934	<h5>Semantics:</h5>
				5935
				5936	<p>
				5937	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5938	in a variable. If the src == 0 then the result is the size in bits of the type
				5939	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5940	</p>
				5941	</div>
				5942
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5943
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5944	<!-- ======================================================================= -->
				5945	<div class="doc_subsection">
				5946	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5947	</div>
				5948
				5949	<div class="doc_text">
				5950	<p>
				5951	LLVM provides intrinsics for some arithmetic with overflow operations.
				5952	</p>
				5953
				5954	</div>
				5955
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5956	<!-- _______________________________________________________________________ -->
				5957	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5958	<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]	5959	</div>
				5960
				5961	<div class="doc_text">
				5962
				5963	<h5>Syntax:</h5>
				5964
				5965	<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]	5966	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5967
				5968	<pre>
				5969	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5970	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5971	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5972	</pre>
				5973
				5974	<h5>Overview:</h5>
				5975
				5976	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5977	a signed addition of the two arguments, and indicate whether an overflow
				5978	occurred during the signed summation.</p>
				5979
				5980	<h5>Arguments:</h5>
				5981
				5982	<p>The arguments (%a and %b) and the first element of the result structure may
				5983	be of integer types of any bit width, but they must have the same bit width. The
				5984	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				5985	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				5986
				5987	<h5>Semantics:</h5>
				5988
				5989	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				5990	a signed addition of the two variables. They return a structure — the
				5991	first element of which is the signed summation, and the second element of which
				5992	is a bit specifying if the signed summation resulted in an overflow.</p>
				5993
				5994	<h5>Examples:</h5>
				5995	<pre>
				5996	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5997	%sum = extractvalue {i32, i1} %res, 0
				5998	%obit = extractvalue {i32, i1} %res, 1
				5999	br i1 %obit, label %overflow, label %normal
				6000	</pre>
				6001
				6002	</div>
				6003
				6004	<!-- _______________________________________________________________________ -->
				6005	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6006	<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]	6007	</div>
				6008
				6009	<div class="doc_text">
				6010
				6011	<h5>Syntax:</h5>
				6012
				6013	<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]	6014	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6015
				6016	<pre>
				6017	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6018	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6019	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6020	</pre>
				6021
				6022	<h5>Overview:</h5>
				6023
				6024	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6025	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6026	during the unsigned summation.</p>
				6027
				6028	<h5>Arguments:</h5>
				6029
				6030	<p>The arguments (%a and %b) and the first element of the result structure may
				6031	be of integer types of any bit width, but they must have the same bit width. The
				6032	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6033	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6034
				6035	<h5>Semantics:</h5>
				6036
				6037	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6038	an unsigned addition of the two arguments. They return a structure — the
				6039	first element of which is the sum, and the second element of which is a bit
				6040	specifying if the unsigned summation resulted in a carry.</p>
				6041
				6042	<h5>Examples:</h5>
				6043	<pre>
				6044	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6045	%sum = extractvalue {i32, i1} %res, 0
				6046	%obit = extractvalue {i32, i1} %res, 1
				6047	br i1 %obit, label %carry, label %normal
				6048	</pre>
				6049
				6050	</div>
				6051
				6052	<!-- _______________________________________________________________________ -->
				6053	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6054	<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]	6055	</div>
				6056
				6057	<div class="doc_text">
				6058
				6059	<h5>Syntax:</h5>
				6060
				6061	<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]	6062	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6063
				6064	<pre>
				6065	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6066	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6067	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6068	</pre>
				6069
				6070	<h5>Overview:</h5>
				6071
				6072	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6073	a signed subtraction of the two arguments, and indicate whether an overflow
				6074	occurred during the signed subtraction.</p>
				6075
				6076	<h5>Arguments:</h5>
				6077
				6078	<p>The arguments (%a and %b) and the first element of the result structure may
				6079	be of integer types of any bit width, but they must have the same bit width. The
				6080	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6081	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6082
				6083	<h5>Semantics:</h5>
				6084
				6085	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6086	a signed subtraction of the two arguments. They return a structure — the
				6087	first element of which is the subtraction, and the second element of which is a bit
				6088	specifying if the signed subtraction resulted in an overflow.</p>
				6089
				6090	<h5>Examples:</h5>
				6091	<pre>
				6092	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6093	%sum = extractvalue {i32, i1} %res, 0
				6094	%obit = extractvalue {i32, i1} %res, 1
				6095	br i1 %obit, label %overflow, label %normal
				6096	</pre>
				6097
				6098	</div>
				6099
				6100	<!-- _______________________________________________________________________ -->
				6101	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6102	<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]	6103	</div>
				6104
				6105	<div class="doc_text">
				6106
				6107	<h5>Syntax:</h5>
				6108
				6109	<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]	6110	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6111
				6112	<pre>
				6113	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6114	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6115	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6116	</pre>
				6117
				6118	<h5>Overview:</h5>
				6119
				6120	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6121	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6122	occurred during the unsigned subtraction.</p>
				6123
				6124	<h5>Arguments:</h5>
				6125
				6126	<p>The arguments (%a and %b) and the first element of the result structure may
				6127	be of integer types of any bit width, but they must have the same bit width. The
				6128	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6129	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6130
				6131	<h5>Semantics:</h5>
				6132
				6133	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6134	an unsigned subtraction of the two arguments. They return a structure — the
				6135	first element of which is the subtraction, and the second element of which is a bit
				6136	specifying if the unsigned subtraction resulted in an overflow.</p>
				6137
				6138	<h5>Examples:</h5>
				6139	<pre>
				6140	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6141	%sum = extractvalue {i32, i1} %res, 0
				6142	%obit = extractvalue {i32, i1} %res, 1
				6143	br i1 %obit, label %overflow, label %normal
				6144	</pre>
				6145
				6146	</div>
				6147
				6148	<!-- _______________________________________________________________________ -->
				6149	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6150	<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]	6151	</div>
				6152
				6153	<div class="doc_text">
				6154
				6155	<h5>Syntax:</h5>
				6156
				6157	<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]	6158	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6159
				6160	<pre>
				6161	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6162	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6163	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6164	</pre>
				6165
				6166	<h5>Overview:</h5>
				6167
				6168	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6169	a signed multiplication of the two arguments, and indicate whether an overflow
				6170	occurred during the signed multiplication.</p>
				6171
				6172	<h5>Arguments:</h5>
				6173
				6174	<p>The arguments (%a and %b) and the first element of the result structure may
				6175	be of integer types of any bit width, but they must have the same bit width. The
				6176	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6177	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6178
				6179	<h5>Semantics:</h5>
				6180
				6181	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6182	a signed multiplication of the two arguments. They return a structure —
				6183	the first element of which is the multiplication, and the second element of
				6184	which is a bit specifying if the signed multiplication resulted in an
				6185	overflow.</p>
				6186
				6187	<h5>Examples:</h5>
				6188	<pre>
				6189	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6190	%sum = extractvalue {i32, i1} %res, 0
				6191	%obit = extractvalue {i32, i1} %res, 1
				6192	br i1 %obit, label %overflow, label %normal
				6193	</pre>
				6194
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6195	</div>
				6196
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6197	<!-- _______________________________________________________________________ -->
				6198	<div class="doc_subsubsection">
				6199	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6200	</div>
				6201
				6202	<div class="doc_text">
				6203
				6204	<h5>Syntax:</h5>
				6205
				6206	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6207	on any integer bit width.</p>
				6208
				6209	<pre>
				6210	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6211	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6212	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6213	</pre>
				6214
				6215	<h5>Overview:</h5>
				6216
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6217	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6218	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6219	occurred during the unsigned multiplication.</p>
				6220
				6221	<h5>Arguments:</h5>
				6222
				6223	<p>The arguments (%a and %b) and the first element of the result structure may
				6224	be of integer types of any bit width, but they must have the same bit width. The
				6225	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6226	and <tt>%b</tt> are the two values that will undergo unsigned
				6227	multiplication.</p>
				6228
				6229	<h5>Semantics:</h5>
				6230
				6231	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6232	an unsigned multiplication of the two arguments. They return a structure —
				6233	the first element of which is the multiplication, and the second element of
				6234	which is a bit specifying if the unsigned multiplication resulted in an
				6235	overflow.</p>
				6236
				6237	<h5>Examples:</h5>
				6238	<pre>
				6239	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6240	%sum = extractvalue {i32, i1} %res, 0
				6241	%obit = extractvalue {i32, i1} %res, 1
				6242	br i1 %obit, label %overflow, label %normal
				6243	</pre>
				6244
				6245	</div>
				6246
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6247	<!-- ======================================================================= -->
				6248	<div class="doc_subsection">
				6249	<a name="int_debugger">Debugger Intrinsics</a>
				6250	</div>
				6251
				6252	<div class="doc_text">
				6253	<p>
				6254	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6255	are described in the <a
				6256	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6257	Debugging</a> document.
				6258	</p>
				6259	</div>
				6260
				6261
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6262	<!-- ======================================================================= -->
				6263	<div class="doc_subsection">
				6264	<a name="int_eh">Exception Handling Intrinsics</a>
				6265	</div>
				6266
				6267	<div class="doc_text">
				6268	<p> The LLVM exception handling intrinsics (which all start with
				6269	<tt>llvm.eh.</tt> prefix), are described in the <a
				6270	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6271	Handling</a> document. </p>
				6272	</div>
				6273
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6274	<!-- ======================================================================= -->
				6275	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6276	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6277	</div>
				6278
				6279	<div class="doc_text">
				6280	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6281	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6282	the <tt>nest</tt> attribute, from a function. The result is a callable
				6283	function pointer lacking the nest parameter - the caller does not need
				6284	to provide a value for it. Instead, the value to use is stored in
				6285	advance in a "trampoline", a block of memory usually allocated
				6286	on the stack, which also contains code to splice the nest value into the
				6287	argument list. This is used to implement the GCC nested function address
				6288	extension.
				6289	</p>
				6290	<p>
				6291	For example, if the function is
				6292	<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]	6293	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]	6294	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6295	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6296	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6297	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6298	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6299	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6300	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6301	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]	6302	</div>
				6303
				6304	<!-- _______________________________________________________________________ -->
				6305	<div class="doc_subsubsection">
				6306	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6307	</div>
				6308	<div class="doc_text">
				6309	<h5>Syntax:</h5>
				6310	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6311	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6312	</pre>
				6313	<h5>Overview:</h5>
				6314	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6315	This fills the memory pointed to by <tt>tramp</tt> with code
				6316	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6317	</p>
				6318	<h5>Arguments:</h5>
				6319	<p>
				6320	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6321	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6322	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]	6323	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6324	currently provides no portable way of determining them, so a front-end that
				6325	generates this intrinsic needs to have some target-specific knowledge.
				6326	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]	6327	</p>
				6328	<h5>Semantics:</h5>
				6329	<p>
				6330	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]	6331	dependent code, turning it into a function. A pointer to this function is
				6332	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6333	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6334	before being called. The new function's signature is the same as that of
				6335	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6336	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6337	of pointer type. Calling the new function is equivalent to calling
				6338	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6339	missing <tt>nest</tt> argument. If, after calling
				6340	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6341	modified, then the effect of any later call to the returned function pointer is
				6342	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6343	</p>
				6344	</div>
				6345
				6346	<!-- ======================================================================= -->
				6347	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6348	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6349	</div>
				6350
				6351	<div class="doc_text">
				6352	<p>
				6353	These intrinsic functions expand the "universal IR" of LLVM to represent
				6354	hardware constructs for atomic operations and memory synchronization. This
				6355	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]	6356	is aimed at a low enough level to allow any programming models or APIs
				6357	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6358	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6359	hardware behavior. Just as hardware provides a "universal IR" for source
				6360	languages, it also provides a starting point for developing a "universal"
				6361	atomic operation and synchronization IR.
				6362	</p>
				6363	<p>
				6364	These do <em>not</em> form an API such as high-level threading libraries,
				6365	software transaction memory systems, atomic primitives, and intrinsic
				6366	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6367	application libraries. The hardware interface provided by LLVM should allow
				6368	a clean implementation of all of these APIs and parallel programming models.
				6369	No one model or paradigm should be selected above others unless the hardware
				6370	itself ubiquitously does so.
				6371
				6372	</p>
				6373	</div>
				6374
				6375	<!-- _______________________________________________________________________ -->
				6376	<div class="doc_subsubsection">
				6377	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6378	</div>
				6379	<div class="doc_text">
				6380	<h5>Syntax:</h5>
				6381	<pre>
				6382	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6383	i1 <device> )
				6384
				6385	</pre>
				6386	<h5>Overview:</h5>
				6387	<p>
				6388	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6389	specific pairs of memory access types.
				6390	</p>
				6391	<h5>Arguments:</h5>
				6392	<p>
				6393	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6394	The first four arguments enables a specific barrier as listed below. The fith
				6395	argument specifies that the barrier applies to io or device or uncached memory.
				6396
				6397	</p>
				6398	<ul>
				6399	<li><tt>ll</tt>: load-load barrier</li>
				6400	<li><tt>ls</tt>: load-store barrier</li>
				6401	<li><tt>sl</tt>: store-load barrier</li>
				6402	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6403	<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]	6404	</ul>
				6405	<h5>Semantics:</h5>
				6406	<p>
				6407	This intrinsic causes the system to enforce some ordering constraints upon
				6408	the loads and stores of the program. This barrier does not indicate
				6409	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6410	which they occur. For any of the specified pairs of load and store operations
				6411	(f.ex. load-load, or store-load), all of the first operations preceding the
				6412	barrier will complete before any of the second operations succeeding the
				6413	barrier begin. Specifically the semantics for each pairing is as follows:
				6414	</p>
				6415	<ul>
				6416	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6417	after the barrier begins.</li>
				6418
				6419	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6420	store after the barrier begins.</li>
				6421	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6422	store after the barrier begins.</li>
				6423	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6424	load after the barrier begins.</li>
				6425	</ul>
				6426	<p>
				6427	These semantics are applied with a logical "and" behavior when more than one
				6428	is enabled in a single memory barrier intrinsic.
				6429	</p>
				6430	<p>
				6431	Backends may implement stronger barriers than those requested when they do not
				6432	support as fine grained a barrier as requested. Some architectures do not
				6433	need all types of barriers and on such architectures, these become noops.
				6434	</p>
				6435	<h5>Example:</h5>
				6436	<pre>
				6437	%ptr = malloc i32
				6438	store i32 4, %ptr
				6439
				6440	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6441	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6442	<i>; guarantee the above finishes</i>
				6443	store i32 8, %ptr <i>; before this begins</i>
				6444	</pre>
				6445	</div>
				6446
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6447	<!-- _______________________________________________________________________ -->
				6448	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6449	<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]	6450	</div>
				6451	<div class="doc_text">
				6452	<h5>Syntax:</h5>
				6453	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6454	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6455	any integer bit width and for different address spaces. Not all targets
				6456	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6457
				6458	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6459	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6460	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6461	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6462	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]	6463
				6464	</pre>
				6465	<h5>Overview:</h5>
				6466	<p>
				6467	This loads a value in memory and compares it to a given value. If they are
				6468	equal, it stores a new value into the memory.
				6469	</p>
				6470	<h5>Arguments:</h5>
				6471	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6472	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]	6473	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6474	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6475	this integer type. While any bit width integer may be used, targets may only
				6476	lower representations they support in hardware.
				6477
				6478	</p>
				6479	<h5>Semantics:</h5>
				6480	<p>
				6481	This entire intrinsic must be executed atomically. It first loads the value
				6482	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6483	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6484	loaded value is yielded in all cases. This provides the equivalent of an
				6485	atomic compare-and-swap operation within the SSA framework.
				6486	</p>
				6487	<h5>Examples:</h5>
				6488
				6489	<pre>
				6490	%ptr = malloc i32
				6491	store i32 4, %ptr
				6492
				6493	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6494	%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]	6495	<i>; yields {i32}:result1 = 4</i>
				6496	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6497	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6498
				6499	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6500	%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]	6501	<i>; yields {i32}:result2 = 8</i>
				6502	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6503
				6504	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6505	</pre>
				6506	</div>
				6507
				6508	<!-- _______________________________________________________________________ -->
				6509	<div class="doc_subsubsection">
				6510	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6511	</div>
				6512	<div class="doc_text">
				6513	<h5>Syntax:</h5>
				6514
				6515	<p>
				6516	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6517	integer bit width. Not all targets support all bit widths however.</p>
				6518	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6519	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6520	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6521	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6522	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6523
				6524	</pre>
				6525	<h5>Overview:</h5>
				6526	<p>
				6527	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6528	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6529	at <tt>ptr</tt>.
				6530	</p>
				6531	<h5>Arguments:</h5>
				6532
				6533	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6534	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6535	<tt>val</tt> argument and the result must be integers of the same bit width.
				6536	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6537	integer type. The targets may only lower integer representations they
				6538	support.
				6539	</p>
				6540	<h5>Semantics:</h5>
				6541	<p>
				6542	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6543	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6544	equivalent of an atomic swap operation within the SSA framework.
				6545
				6546	</p>
				6547	<h5>Examples:</h5>
				6548	<pre>
				6549	%ptr = malloc i32
				6550	store i32 4, %ptr
				6551
				6552	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6553	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6554	<i>; yields {i32}:result1 = 4</i>
				6555	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6556	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6557
				6558	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6559	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6560	<i>; yields {i32}:result2 = 8</i>
				6561
				6562	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6563	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6564	</pre>
				6565	</div>
				6566
				6567	<!-- _______________________________________________________________________ -->
				6568	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6569	<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]	6570
				6571	</div>
				6572	<div class="doc_text">
				6573	<h5>Syntax:</h5>
				6574	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6575	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]	6576	integer bit width. Not all targets support all bit widths however.</p>
				6577	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6578	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6579	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6580	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6581	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6582
				6583	</pre>
				6584	<h5>Overview:</h5>
				6585	<p>
				6586	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6587	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6588	</p>
				6589	<h5>Arguments:</h5>
				6590	<p>
				6591
				6592	The intrinsic takes two arguments, the first a pointer to an integer value
				6593	and the second an integer value. The result is also an integer value. These
				6594	integer types can have any bit width, but they must all have the same bit
				6595	width. The targets may only lower integer representations they support.
				6596	</p>
				6597	<h5>Semantics:</h5>
				6598	<p>
				6599	This intrinsic does a series of operations atomically. It first loads the
				6600	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6601	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6602	</p>
				6603
				6604	<h5>Examples:</h5>
				6605	<pre>
				6606	%ptr = malloc i32
				6607	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6608	%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]	6609	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6610	%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]	6611	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6612	%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]	6613	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6614	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6615	</pre>
				6616	</div>
				6617
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6618	<!-- _______________________________________________________________________ -->
				6619	<div class="doc_subsubsection">
				6620	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6621
				6622	</div>
				6623	<div class="doc_text">
				6624	<h5>Syntax:</h5>
				6625	<p>
				6626	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]	6627	any integer bit width and for different address spaces. Not all targets
				6628	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6629	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6630	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6631	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6632	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6633	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]	6634
				6635	</pre>
				6636	<h5>Overview:</h5>
				6637	<p>
				6638	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6639	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6640	</p>
				6641	<h5>Arguments:</h5>
				6642	<p>
				6643
				6644	The intrinsic takes two arguments, the first a pointer to an integer value
				6645	and the second an integer value. The result is also an integer value. These
				6646	integer types can have any bit width, but they must all have the same bit
				6647	width. The targets may only lower integer representations they support.
				6648	</p>
				6649	<h5>Semantics:</h5>
				6650	<p>
				6651	This intrinsic does a series of operations atomically. It first loads the
				6652	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6653	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6654	</p>
				6655
				6656	<h5>Examples:</h5>
				6657	<pre>
				6658	%ptr = malloc i32
				6659	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6660	%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]	6661	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6662	%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]	6663	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6664	%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]	6665	<i>; yields {i32}:result3 = 2</i>
				6666	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6667	</pre>
				6668	</div>
				6669
				6670	<!-- _______________________________________________________________________ -->
				6671	<div class="doc_subsubsection">
				6672	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6673	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6674	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6675	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6676
				6677	</div>
				6678	<div class="doc_text">
				6679	<h5>Syntax:</h5>
				6680	<p>
				6681	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6682	<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]	6683	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6684	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6685	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6686	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6687	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6688	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6689	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]	6690
				6691	</pre>
				6692
				6693	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6694	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6695	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6696	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6697	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]	6698
				6699	</pre>
				6700
				6701	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6702	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6703	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6704	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6705	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]	6706
				6707	</pre>
				6708
				6709	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6710	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6711	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6712	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6713	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]	6714
				6715	</pre>
				6716	<h5>Overview:</h5>
				6717	<p>
				6718	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6719	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6720	at <tt>ptr</tt>.
				6721	</p>
				6722	<h5>Arguments:</h5>
				6723	<p>
				6724
				6725	These intrinsics take two arguments, the first a pointer to an integer value
				6726	and the second an integer value. The result is also an integer value. These
				6727	integer types can have any bit width, but they must all have the same bit
				6728	width. The targets may only lower integer representations they support.
				6729	</p>
				6730	<h5>Semantics:</h5>
				6731	<p>
				6732	These intrinsics does a series of operations atomically. They first load the
				6733	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6734	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6735	value stored at <tt>ptr</tt>.
				6736	</p>
				6737
				6738	<h5>Examples:</h5>
				6739	<pre>
				6740	%ptr = malloc i32
				6741	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6742	%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]	6743	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6744	%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]	6745	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6746	%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]	6747	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6748	%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]	6749	<i>; yields {i32}:result3 = FF</i>
				6750	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6751	</pre>
				6752	</div>
				6753
				6754
				6755	<!-- _______________________________________________________________________ -->
				6756	<div class="doc_subsubsection">
				6757	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6758	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6759	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6760	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6761
				6762	</div>
				6763	<div class="doc_text">
				6764	<h5>Syntax:</h5>
				6765	<p>
				6766	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6767	<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]	6768	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6769	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6770	support all bit widths however.</p>
				6771	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6772	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6773	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6774	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6775	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]	6776
				6777	</pre>
				6778
				6779	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6780	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6781	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6782	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6783	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]	6784
				6785	</pre>
				6786
				6787	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6788	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6789	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6790	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6791	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]	6792
				6793	</pre>
				6794
				6795	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6796	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6797	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6798	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6799	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]	6800
				6801	</pre>
				6802	<h5>Overview:</h5>
				6803	<p>
				6804	These intrinsics takes the signed or unsigned minimum or maximum of
				6805	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6806	original value at <tt>ptr</tt>.
				6807	</p>
				6808	<h5>Arguments:</h5>
				6809	<p>
				6810
				6811	These intrinsics take two arguments, the first a pointer to an integer value
				6812	and the second an integer value. The result is also an integer value. These
				6813	integer types can have any bit width, but they must all have the same bit
				6814	width. The targets may only lower integer representations they support.
				6815	</p>
				6816	<h5>Semantics:</h5>
				6817	<p>
				6818	These intrinsics does a series of operations atomically. They first load the
				6819	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6820	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6821	the original value stored at <tt>ptr</tt>.
				6822	</p>
				6823
				6824	<h5>Examples:</h5>
				6825	<pre>
				6826	%ptr = malloc i32
				6827	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6828	%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]	6829	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6830	%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]	6831	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6832	%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]	6833	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6834	%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]	6835	<i>; yields {i32}:result3 = 8</i>
				6836	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6837	</pre>
				6838	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6839
				6840	<!-- ======================================================================= -->
				6841	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6842	<a name="int_general">General Intrinsics</a>
				6843	</div>
				6844
				6845	<div class="doc_text">
				6846	<p> This class of intrinsics is designed to be generic and has
				6847	no specific purpose. </p>
				6848	</div>
				6849
				6850	<!-- _______________________________________________________________________ -->
				6851	<div class="doc_subsubsection">
				6852	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6853	</div>
				6854
				6855	<div class="doc_text">
				6856
				6857	<h5>Syntax:</h5>
				6858	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6859	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]	6860	</pre>
				6861
				6862	<h5>Overview:</h5>
				6863
				6864	<p>
				6865	The '<tt>llvm.var.annotation</tt>' intrinsic
				6866	</p>
				6867
				6868	<h5>Arguments:</h5>
				6869
				6870	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6871	The first argument is a pointer to a value, the second is a pointer to a
				6872	global string, the third is a pointer to a global string which is the source
				6873	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6874	</p>
				6875
				6876	<h5>Semantics:</h5>
				6877
				6878	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6879	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6880	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]	6881	annotations. These have no other defined use, they are ignored by code
				6882	generation and optimization.
				6883	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6884	</div>
				6885
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6886	<!-- _______________________________________________________________________ -->
				6887	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6888	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6889	</div>
				6890
				6891	<div class="doc_text">
				6892
				6893	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6894	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6895	any integer bit width.
				6896	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6897	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6898	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6899	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6900	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6901	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6902	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]	6903	</pre>
				6904
				6905	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6906
				6907	<p>
				6908	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6909	</p>
				6910
				6911	<h5>Arguments:</h5>
				6912
				6913	<p>
				6914	The first argument is an integer value (result of some expression),
				6915	the second is a pointer to a global string, the third is a pointer to a global
				6916	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]	6917	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6918	</p>
				6919
				6920	<h5>Semantics:</h5>
				6921
				6922	<p>
				6923	This intrinsic allows annotations to be put on arbitrary expressions
				6924	with arbitrary strings. This can be useful for special purpose optimizations
				6925	that want to look for these annotations. These have no other defined use, they
				6926	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6927	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6928	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6929
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6930	<!-- _______________________________________________________________________ -->
				6931	<div class="doc_subsubsection">
				6932	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6933	</div>
				6934
				6935	<div class="doc_text">
				6936
				6937	<h5>Syntax:</h5>
				6938	<pre>
				6939	declare void @llvm.trap()
				6940	</pre>
				6941
				6942	<h5>Overview:</h5>
				6943
				6944	<p>
				6945	The '<tt>llvm.trap</tt>' intrinsic
				6946	</p>
				6947
				6948	<h5>Arguments:</h5>
				6949
				6950	<p>
				6951	None
				6952	</p>
				6953
				6954	<h5>Semantics:</h5>
				6955
				6956	<p>
				6957	This intrinsics is lowered to the target dependent trap instruction. If the
				6958	target does not have a trap instruction, this intrinsic will be lowered to the
				6959	call of the abort() function.
				6960	</p>
				6961	</div>
				6962
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6963	<!-- _______________________________________________________________________ -->
				6964	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	6965	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6966	</div>
				6967	<div class="doc_text">
				6968	<h5>Syntax:</h5>
				6969	<pre>
				6970	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6971
				6972	</pre>
				6973	<h5>Overview:</h5>
				6974	<p>
				6975	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				6976	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				6977	it is placed on the stack before local variables.
				6978	</p>
				6979	<h5>Arguments:</h5>
				6980	<p>
				6981	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				6982	first argument is the value loaded from the stack guard
				6983	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				6984	has enough space to hold the value of the guard.
				6985	</p>
				6986	<h5>Semantics:</h5>
				6987	<p>
				6988	This intrinsic causes the prologue/epilogue inserter to force the position of
				6989	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				6990	stack. This is to ensure that if a local variable on the stack is overwritten,
				6991	it will destroy the value of the guard. When the function exits, the guard on
				6992	the stack is checked against the original guard. If they're different, then
				6993	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				6994	</p>
				6995	</div>
				6996
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6997	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	6998	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	6999	<address>
				7000	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7001	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]	7002	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7003	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]	7004
				7005	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7006	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7007	Last modified: $Date$
				7008	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7009
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7010	</body>
				7011	</html>