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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	41	<li><a href="#t_floating">Floating Point Types</a></li>
				42	<li><a href="#t_void">Void Type</a></li>
				43	<li><a href="#t_label">Label Type</a></li>
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	51	<li><a href="#t_function">Function Type</a></li>
				52	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	66	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				67	<li><a href="#undefvalues">Undefined Values</a></li>
				68	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	77	<li><a href="#instref">Instruction Reference</a>
				78	<ol>
				79	<li><a href="#terminators">Terminator Instructions</a>
				80	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	81	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				82	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	83	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				84	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	97	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				98	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				99	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	100	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				101	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				102	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	107	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				108	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				109	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	115	<li><a href="#vectorops">Vector Operations</a>
				116	<ol>
				117	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				118	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				119	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	122	<li><a href="#aggregateops">Aggregate Operations</a>
				123	<ol>
				124	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				125	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				126	</ol>
				127	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	130	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				131	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				132	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	133	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				134	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				135	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	139	<ol>
				140	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				142	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	145	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				146	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				148	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	149	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				150	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	156	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				157	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	158	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				159	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	161	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	163	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	164	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	166	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	168	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	169	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	170	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				171	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	172	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				173	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				174	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	177	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				178	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	179	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				180	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				181	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	182	</ol>
				183	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	184	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				185	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	186	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				187	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				188	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				189	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				190	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				191	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				192	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	193	</ol>
				194	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	195	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				196	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	197	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				199	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	202	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				203	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				204	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	205	</ol>
				206	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	207	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	208	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	209	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	210	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				211	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				212	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	213	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				214	<li><a href="#int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	215	</ol>
				216	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	217	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				218	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	219	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				220	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				221	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				222	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				223	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	224	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	225	</ol>
				226	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	227	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	228	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	229	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	230	<ol>
				231	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	232	</ol>
				233	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	234	<li><a href="#int_atomics">Atomic intrinsics</a>
				235	<ol>
				236	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				237	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				238	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				239	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				240	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				241	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				242	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				243	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				244	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				245	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				246	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				247	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				248	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				249	</ol>
				250	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	251	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	252	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	253	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	255	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	256	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	257	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	258	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				259	<li><a href="#int_stackprotector">
				260	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	261	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	262	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	263	</ol>
				264	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	265	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	266
				267	<div class="doc_author">
				268	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				269	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	270	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	272	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				274	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	275
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	276	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	277	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	278	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	279	type safety, low-level operations, flexibility, and the capability of
				280	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	281	representation used throughout all phases of the LLVM compilation
				282	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				287	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	289	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	290
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	291	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	292	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	293	representation (suitable for fast loading by a Just-In-Time compiler),
				294	and as a human readable assembly language representation. This allows
				295	LLVM to provide a powerful intermediate representation for efficient
				296	compiler transformations and analysis, while providing a natural means
				297	to debug and visualize the transformations. The three different forms
				298	of LLVM are all equivalent. This document describes the human readable
				299	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	300
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	301	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	302	while being expressive, typed, and extensible at the same time. It
				303	aims to be a "universal IR" of sorts, by being at a low enough level
				304	that high-level ideas may be cleanly mapped to it (similar to how
				305	microprocessors are "universal IR's", allowing many source languages to
				306	be mapped to them). By providing type information, LLVM can be used as
				307	the target of optimizations: for example, through pointer analysis, it
				308	can be proven that a C automatic variable is never accessed outside of
				309	the current function... allowing it to be promoted to a simple SSA
				310	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	312	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	316
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	317	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	319	<p>It is important to note that this document describes 'well formed'
				320	LLVM assembly language. There is a difference between what the parser
				321	accepts and what is considered 'well formed'. For example, the
				322	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	323
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	324	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	325	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	326	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	327	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	328	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	329
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	330	<p>...because the definition of <tt>%x</tt> does not dominate all of
				331	its uses. The LLVM infrastructure provides a verification pass that may
				332	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	333	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	334	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	335	by the verifier pass indicate bugs in transformation passes or input to
				336	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	337	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	338
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	339	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	341	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	342	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	343	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	344
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	345	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	347	<p>LLVM identifiers come in two basic types: global and local. Global
				348	identifiers (functions, global variables) begin with the @ character. Local
				349	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	350	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	351
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	352	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	353	<li>Named values are represented as a string of characters with their prefix.
				354	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				355	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	356	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	357	with quotes. Special characters may be escaped using "\xx" where xx is the
				358	ASCII code for the character in hexadecimal. In this way, any character can
				359	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	361	<li>Unnamed values are represented as an unsigned numeric value with their
				362	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	364	<li>Constants, which are described in a <a href="#constants">section about
				365	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	366	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	368	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	don't need to worry about name clashes with reserved words, and the set of
				370	reserved words may be expanded in the future without penalty. Additionally,
				371	unnamed identifiers allow a compiler to quickly come up with a temporary
				372	variable without having to avoid symbol table conflicts.</p>
				373
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	374	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	375	languages. There are keywords for different opcodes
				376	('<tt><a href="#i_add">add</a></tt>',
				377	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				378	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	379	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	380	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	381	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382
				383	<p>Here is an example of LLVM code to multiply the integer variable
				384	'<tt>%X</tt>' by 8:</p>
				385
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	386	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	387
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	388	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	389	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	390	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	391	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	392	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	394	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	396	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	397	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	398	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	399	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	400	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	401
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	404	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	405	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	406	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				407	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				408	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	409	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	410	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	412	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				413	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	414
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	415	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	416
				417	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				418	line.</li>
				419
				420	<li>Unnamed temporaries are created when the result of a computation is not
				421	assigned to a named value.</li>
				422
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	423	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	425	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	426
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	427	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	428	demonstrating instructions, we will follow an instruction with a comment that
				429	defines the type and name of value produced. Comments are shown in italic
				430	text.</p>
				431
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	432	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	433
				434	<!-- *********************************************************************** -->
				435	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				436	<!-- *********************************************************************** -->
				437
				438	<!-- ======================================================================= -->
				439	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				440	</div>
				441
				442	<div class="doc_text">
				443
				444	<p>LLVM programs are composed of "Module"s, each of which is a
				445	translation unit of the input programs. Each module consists of
				446	functions, global variables, and symbol table entries. Modules may be
				447	combined together with the LLVM linker, which merges function (and
				448	global variable) definitions, resolves forward declarations, and merges
				449	symbol table entries. Here is an example of the "hello world" module:</p>
				450
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	451	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	452	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	453	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				454	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	455
				456	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	457	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	458
				459	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	460	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	461	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	462	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	463	href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	464
				465	<i>; Call puts function to write out the string to stdout...</i>
				466	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	467	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	469	href="#i_ret">ret</a> i32 0<br>}<br>
				470	</pre>
				471	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	472
				473	<p>This example is made up of a <a href="#globalvars">global variable</a>
				474	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				475	function, and a <a href="#functionstructure">function definition</a>
				476	for "<tt>main</tt>".</p>
				477
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	478	<p>In general, a module is made up of a list of global values,
				479	where both functions and global variables are global values. Global values are
				480	represented by a pointer to a memory location (in this case, a pointer to an
				481	array of char, and a pointer to a function), and have one of the following <a
				482	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	483
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	484	</div>
				485
				486	<!-- ======================================================================= -->
				487	<div class="doc_subsection">
				488	<a name="linkage">Linkage Types</a>
				489	</div>
				490
				491	<div class="doc_text">
				492
				493	<p>
				494	All Global Variables and Functions have one of the following types of linkage:
				495	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496
				497	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	498
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	499	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				500
				501	<dd>Global values with private linkage are only directly accessible by
				502	objects in the current module. In particular, linking code into a module with
				503	an private global value may cause the private to be renamed as necessary to
				504	avoid collisions. Because the symbol is private to the module, all
				505	references can be updated. This doesn't show up in any symbol table in the
				506	object file.
				507	</dd>
				508
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	511	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	512	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	513	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	516	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				517	</dt>
				518
				519	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				520	into the object file corresponding to the LLVM module. They exist to
				521	allow inlining and other optimizations to take place given knowledge of the
				522	definition of the global, which is known to be somewhere outside the module.
				523	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				524	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				525	type is only allowed on definitions, not declarations.</dd>
				526
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	527	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	528
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	529	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				530	the same name when linkage occurs. This is typically used to implement
				531	inline functions, templates, or other code which must be generated in each
				532	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				533	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	534	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	535
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	536	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				537
				538	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				539	linkage, except that unreferenced <tt>common</tt> globals may not be
				540	discarded. This is used for globals that may be emitted in multiple
				541	translation units, but that are not guaranteed to be emitted into every
				542	translation unit that uses them. One example of this is tentative
				543	definitions in C, such as "<tt>int X;</tt>" at global scope.
				544	</dd>
				545
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	547
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	548	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				549	that some targets may choose to emit different assembly sequences for them
				550	for target-dependent reasons. This is used for globals that are declared
				551	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	552	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	553
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	555
				556	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				557	pointer to array type. When two global variables with appending linkage are
				558	linked together, the two global arrays are appended together. This is the
				559	LLVM, typesafe, equivalent of having the system linker append together
				560	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	561	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	562
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	563	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	564
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	565	<dd>The semantics of this linkage follow the ELF object file model: the
				566	symbol is weak until linked, if not linked, the symbol becomes null instead
				567	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	568	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	569
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	570	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	571	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	572	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	573	functions with different semantics. Other languages, such as <tt>C++</tt>,
				574	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	575	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	576	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				577	be merged with equivalent globals. These linkage types are otherwise the
				578	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	579	</dd>
				580
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	581	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	582
				583	<dd>If none of the above identifiers are used, the global is externally
				584	visible, meaning that it participates in linkage and can be used to resolve
				585	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	586	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	587	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	588
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	589	<p>
				590	The next two types of linkage are targeted for Microsoft Windows platform
				591	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	592	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	593	</p>
				594
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	595	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	596	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				597
				598	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				599	or variable via a global pointer to a pointer that is set up by the DLL
				600	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	601	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	602	</dd>
				603
				604	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				605
				606	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				607	pointer to a pointer in a DLL, so that it can be referenced with the
				608	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	609	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	610	name.
				611	</dd>
				612
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	613	</dl>
				614
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	615	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	616	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				617	variable and was linked with this one, one of the two would be renamed,
				618	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				619	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	620	outside of the current module.</p>
				621	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	622	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				623	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	624	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				625	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	630	<a name="callingconv">Calling Conventions</a>
				631	</div>
				632
				633	<div class="doc_text">
				634
				635	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				636	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				637	specified for the call. The calling convention of any pair of dynamic
				638	caller/callee must match, or the behavior of the program is undefined. The
				639	following calling conventions are supported by LLVM, and more may be added in
				640	the future:</p>
				641
				642	<dl>
				643	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				644
				645	<dd>This calling convention (the default if no other calling convention is
				646	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	647	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	648	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	649	</dd>
				650
				651	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				652
				653	<dd>This calling convention attempts to make calls as fast as possible
				654	(e.g. by passing things in registers). This calling convention allows the
				655	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	656	without having to conform to an externally specified ABI (Application Binary
				657	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	658	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				659	supported. This calling convention does not support varargs and requires the
				660	prototype of all callees to exactly match the prototype of the function
				661	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	662	</dd>
				663
				664	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				665
				666	<dd>This calling convention attempts to make code in the caller as efficient
				667	as possible under the assumption that the call is not commonly executed. As
				668	such, these calls often preserve all registers so that the call does not break
				669	any live ranges in the caller side. This calling convention does not support
				670	varargs and requires the prototype of all callees to exactly match the
				671	prototype of the function definition.
				672	</dd>
				673
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	674	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	675
				676	<dd>Any calling convention may be specified by number, allowing
				677	target-specific calling conventions to be used. Target specific calling
				678	conventions start at 64.
				679	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	680	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	681
				682	<p>More calling conventions can be added/defined on an as-needed basis, to
				683	support pascal conventions or any other well-known target-independent
				684	convention.</p>
				685
				686	</div>
				687
				688	<!-- ======================================================================= -->
				689	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	690	<a name="visibility">Visibility Styles</a>
				691	</div>
				692
				693	<div class="doc_text">
				694
				695	<p>
				696	All Global Variables and Functions have one of the following visibility styles:
				697	</p>
				698
				699	<dl>
				700	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				701
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	702	<dd>On targets that use the ELF object file format, default visibility means
				703	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	704	modules and, in shared libraries, means that the declared entity may be
				705	overridden. On Darwin, default visibility means that the declaration is
				706	visible to other modules. Default visibility corresponds to "external
				707	linkage" in the language.
				708	</dd>
				709
				710	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				711
				712	<dd>Two declarations of an object with hidden visibility refer to the same
				713	object if they are in the same shared object. Usually, hidden visibility
				714	indicates that the symbol will not be placed into the dynamic symbol table,
				715	so no other module (executable or shared library) can reference it
				716	directly.
				717	</dd>
				718
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	719	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				720
				721	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				722	the dynamic symbol table, but that references within the defining module will
				723	bind to the local symbol. That is, the symbol cannot be overridden by another
				724	module.
				725	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	726	</dl>
				727
				728	</div>
				729
				730	<!-- ======================================================================= -->
				731	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	732	<a name="namedtypes">Named Types</a>
				733	</div>
				734
				735	<div class="doc_text">
				736
				737	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				738	it easier to read the IR and make the IR more condensed (particularly when
				739	recursive types are involved). An example of a name specification is:
				740	</p>
				741
				742	<div class="doc_code">
				743	<pre>
				744	%mytype = type { %mytype*, i32 }
				745	</pre>
				746	</div>
				747
				748	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				749	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				750	expected with the syntax "%mytype".</p>
				751
				752	<p>Note that type names are aliases for the structural type that they indicate,
				753	and that you can therefore specify multiple names for the same type. This often
				754	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				755	structural typing, the name is not part of the type. When printing out LLVM IR,
				756	the printer will pick <em>one name</em> to render all types of a particular
				757	shape. This means that if you have code where two different source types end up
				758	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				759	unexpected type. This is an important design point and isn't going to
				760	change.</p>
				761
				762	</div>
				763
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	764	<!-- ======================================================================= -->
				765	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	766	<a name="globalvars">Global Variables</a>
				767	</div>
				768
				769	<div class="doc_text">
				770
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	771	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	772	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	773	an explicit section to be placed in, and may have an optional explicit alignment
				774	specified. A variable may be defined as "thread_local", which means that it
				775	will not be shared by threads (each thread will have a separated copy of the
				776	variable). A variable may be defined as a global "constant," which indicates
				777	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	778	optimization, allowing the global data to be placed in the read-only section of
				779	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	780	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	781
				782	<p>
				783	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				784	constant, even if the final definition of the global is not. This capability
				785	can be used to enable slightly better optimization of the program, but requires
				786	the language definition to guarantee that optimizations based on the
				787	'constantness' are valid for the translation units that do not include the
				788	definition.
				789	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	790
				791	<p>As SSA values, global variables define pointer values that are in
				792	scope (i.e. they dominate) all basic blocks in the program. Global
				793	variables always define a pointer to their "content" type because they
				794	describe a region of memory, and all memory objects in LLVM are
				795	accessed through pointers.</p>
				796
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	797	<p>A global variable may be declared to reside in a target-specifc numbered
				798	address space. For targets that support them, address spaces may affect how
				799	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	800	the variable. The default address space is zero. The address space qualifier
				801	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	802
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	803	<p>LLVM allows an explicit section to be specified for globals. If the target
				804	supports it, it will emit globals to the section specified.</p>
				805
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	806	<p>An explicit alignment may be specified for a global. If not present, or if
				807	the alignment is set to zero, the alignment of the global is set by the target
				808	to whatever it feels convenient. If an explicit alignment is specified, the
				809	global is forced to have at least that much alignment. All alignments must be
				810	a power of 2.</p>
				811
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	812	<p>For example, the following defines a global in a numbered address space with
				813	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	814
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	815	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	816	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	817	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	818	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	819	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	820
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	821	</div>
				822
				823
				824	<!-- ======================================================================= -->
				825	<div class="doc_subsection">
				826	<a name="functionstructure">Functions</a>
				827	</div>
				828
				829	<div class="doc_text">
				830
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				832	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	833	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	834	<a href="#callingconv">calling convention</a>, a return type, an optional
				835	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				836	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	837	<a href="#paramattrs">parameter attributes</a>), optional
				838	<a href="#fnattrs">function attributes</a>, an optional section,
				839	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	840	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	841
				842	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				843	optional <a href="#linkage">linkage type</a>, an optional
				844	<a href="#visibility">visibility style</a>, an optional
				845	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	846	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	847	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	848	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	849
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	850	<p>A function definition contains a list of basic blocks, forming the CFG
				851	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	852	the function. Each basic block may optionally start with a label (giving the
				853	basic block a symbol table entry), contains a list of instructions, and ends
				854	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				855	function return).</p>
				856
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	857	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	858	executed on entrance to the function, and it is not allowed to have predecessor
				859	basic blocks (i.e. there can not be any branches to the entry block of a
				860	function). Because the block can have no predecessors, it also cannot have any
				861	<a href="#i_phi">PHI nodes</a>.</p>
				862
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	863	<p>LLVM allows an explicit section to be specified for functions. If the target
				864	supports it, it will emit functions to the section specified.</p>
				865
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	866	<p>An explicit alignment may be specified for a function. If not present, or if
				867	the alignment is set to zero, the alignment of the function is set by the target
				868	to whatever it feels convenient. If an explicit alignment is specified, the
				869	function is forced to have at least that much alignment. All alignments must be
				870	a power of 2.</p>
				871
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	872	<h5>Syntax:</h5>
				873
				874	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	875	<tt>
				876	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				877	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				878	<ResultType> @<FunctionName> ([argument list])
				879	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				880	[<a href="#gc">gc</a>] { ... }
				881	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	882	</div>
				883
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	884	</div>
				885
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	886
				887	<!-- ======================================================================= -->
				888	<div class="doc_subsection">
				889	<a name="aliasstructure">Aliases</a>
				890	</div>
				891	<div class="doc_text">
				892	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	893	function, global variable, another alias or bitcast of global value). Aliases
				894	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	895	optional <a href="#visibility">visibility style</a>.</p>
				896
				897	<h5>Syntax:</h5>
				898
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	899	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	900	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	901	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	902	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	903	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	904
				905	</div>
				906
				907
				908
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	909	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	910	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				911	<div class="doc_text">
				912	<p>The return type and each parameter of a function type may have a set of
				913	<i>parameter attributes</i> associated with them. Parameter attributes are
				914	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	915	a function. Parameter attributes are considered to be part of the function,
				916	not of the function type, so functions with different parameter attributes
				917	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	918
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	919	<p>Parameter attributes are simple keywords that follow the type specified. If
				920	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	921	example:</p>
				922
				923	<div class="doc_code">
				924	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	925	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	926	declare i32 @atoi(i8 zeroext)
				927	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	928	</pre>
				929	</div>
				930
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	931	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				932	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	933
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	934	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	935	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	936	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	937	<dd>This indicates to the code generator that the parameter or return value
				938	should be zero-extended to a 32-bit value by the caller (for a parameter)
				939	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	940
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	941	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	942	<dd>This indicates to the code generator that the parameter or return value
				943	should be sign-extended to a 32-bit value by the caller (for a parameter)
				944	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	945
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	946	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	947	<dd>This indicates that this parameter or return value should be treated
				948	in a special target-dependent fashion during while emitting code for a
				949	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	950	to memory, though some targets use it to distinguish between two different
				951	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	952
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	953	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	954	<dd>This indicates that the pointer parameter should really be passed by
				955	value to the function. The attribute implies that a hidden copy of the
				956	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	957	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	958	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	959	value, but is also valid on pointers to scalars. The copy is considered to
				960	belong to the caller not the callee (for example,
				961	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	962	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	963	values. The byval attribute also supports specifying an alignment with the
				964	align attribute. This has a target-specific effect on the code generator
				965	that usually indicates a desired alignment for the synthesized stack
				966	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	967
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	968	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	969	<dd>This indicates that the pointer parameter specifies the address of a
				970	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	971	This pointer must be guaranteed by the caller to be valid: loads and stores
				972	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	973	be applied to the first parameter. This is not a valid attribute for
				974	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	975
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	976	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	977	<dd>This indicates that the pointer does not alias any global or any other
				978	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	979	case. On a function return value, <tt>noalias</tt> additionally indicates
				980	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	981	caller. For further details, please see the discussion of the NoAlias
				982	response in
				983	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				984	analysis</a>.</dd>
				985
				986	<dt><tt>nocapture</tt></dt>
				987	<dd>This indicates that the callee does not make any copies of the pointer
				988	that outlive the callee itself. This is not a valid attribute for return
				989	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	990
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	991	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	992	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	993	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				994	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	995	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	996
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	997	</div>
				998
				999	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1000	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	1001	<a name="gc">Garbage Collector Names</a>
				1002	</div>
				1003
				1004	<div class="doc_text">
				1005	<p>Each function may specify a garbage collector name, which is simply a
				1006	string.</p>
				1007
				1008	<div class="doc_code"><pre
				1009	>define void @f() gc "name" { ...</pre></div>
				1010
				1011	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1012	collector which will cause the compiler to alter its output in order to support
				1013	the named garbage collection algorithm.</p>
				1014	</div>
				1015
				1016	<!-- ======================================================================= -->
				1017	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1018	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1019	</div>
				1020
				1021	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1022
				1023	<p>Function attributes are set to communicate additional information about
				1024	a function. Function attributes are considered to be part of the function,
				1025	not of the function type, so functions with different parameter attributes
				1026	can have the same function type.</p>
				1027
				1028	<p>Function attributes are simple keywords that follow the type specified. If
				1029	multiple attributes are needed, they are space separated. For
				1030	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1031
				1032	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1033	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1034	define void @f() noinline { ... }
				1035	define void @f() alwaysinline { ... }
				1036	define void @f() alwaysinline optsize { ... }
				1037	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1039	</div>
				1040
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1041	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1042	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1043	<dd>This attribute indicates that the inliner should attempt to inline this
				1044	function into callers whenever possible, ignoring any active inlining size
				1045	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1046
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1047	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1049	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1051
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1052	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1053	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1054	make choices that keep the code size of this function low, and otherwise do
				1055	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1056
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1057	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1058	<dd>This function attribute indicates that the function never returns normally.
				1059	This produces undefined behavior at runtime if the function ever does
				1060	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1061
				1062	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1063	<dd>This function attribute indicates that the function never returns with an
				1064	unwind or exceptional control flow. If the function does unwind, its runtime
				1065	behavior is undefined.</dd>
				1066
				1067	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1068	<dd>This attribute indicates that the function computes its result (or decides to
				1069	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1070	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1071	registers, etc) visible to caller functions. It does not write through any
				1072	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1073	never changes any state visible to callers. This means that it cannot unwind
				1074	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1075	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1076
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1077	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1078	<dd>This attribute indicates that the function does not write through any
				1079	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1080	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1081	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1082	be set in the caller. A readonly function always returns the same value (or
				1083	unwinds an exception identically) when called with the same set of arguments
				1084	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1085	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
				1087	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1089	protector. It is in the form of a "canary"—a random value placed on the
				1090	stack before the local variables that's checked upon return from the function to
				1091	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1092	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1093
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame^]	1094	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1095	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame^]	1096	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1097
				1098	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1099	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1100	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1101	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1102
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame^]	1103	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1104	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1105	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame^]	1106	an <tt>sspreq</tt> attribute.</dd>
				1107
				1108	<dt><tt>noredzone</tt></dt>
				1109	<dd>This attribute indicates that the code generator should not enforce red zone
				1110	mandated by target specific ABI.</dd>
				1111
				1112	<dt><tt>noimplicitfloat</tt></dt>
				1113	<dd>This attributes disables implicit floating point instructions.</dd>
				1114
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1115	</dl>
				1116
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1117	</div>
				1118
				1119	<!-- ======================================================================= -->
				1120	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1121	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1122	</div>
				1123
				1124	<div class="doc_text">
				1125	<p>
				1126	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1127	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1128	LLVM and treated as a single unit, but may be separated in the .ll file if
				1129	desired. The syntax is very simple:
				1130	</p>
				1131
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1132	<div class="doc_code">
				1133	<pre>
				1134	module asm "inline asm code goes here"
				1135	module asm "more can go here"
				1136	</pre>
				1137	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1138
				1139	<p>The strings can contain any character by escaping non-printable characters.
				1140	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1141	for the number.
				1142	</p>
				1143
				1144	<p>
				1145	The inline asm code is simply printed to the machine code .s file when
				1146	assembly code is generated.
				1147	</p>
				1148	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1149
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1150	<!-- ======================================================================= -->
				1151	<div class="doc_subsection">
				1152	<a name="datalayout">Data Layout</a>
				1153	</div>
				1154
				1155	<div class="doc_text">
				1156	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	1157	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1158	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1159	<p>The <i>layout specification</i> consists of a list of specifications
				1160	separated by the minus sign character ('-'). Each specification starts with a
				1161	letter and may include other information after the letter to define some
				1162	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1163	<dl>
				1164	<dt><tt>E</tt></dt>
				1165	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1166	bits with the most significance have the lowest address location.</dd>
				1167	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1168	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1169	the bits with the least significance have the lowest address location.</dd>
				1170	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1172	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1173	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1174	too.</dd>
				1175	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1176	<dd>This specifies the alignment for an integer type of a given bit
				1177	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1178	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1179	<dd>This specifies the alignment for a vector type of a given bit
				1180	<i>size</i>.</dd>
				1181	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1182	<dd>This specifies the alignment for a floating point type of a given bit
				1183	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1184	(double).</dd>
				1185	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1186	<dd>This specifies the alignment for an aggregate type of a given bit
				1187	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1188	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1189	<dd>This specifies the alignment for a stack object of a given bit
				1190	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1191	</dl>
				1192	<p>When constructing the data layout for a given target, LLVM starts with a
				1193	default set of specifications which are then (possibly) overriden by the
				1194	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1195	are given in this list:</p>
				1196	<ul>
				1197	<li><tt>E</tt> - big endian</li>
				1198	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1199	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1200	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1201	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1202	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1203	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1204	alignment of 64-bits</li>
				1205	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1206	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1207	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1208	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1209	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1210	<li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1211	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1212	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1213	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1214	<ol>
				1215	<li>If the type sought is an exact match for one of the specifications, that
				1216	specification is used.</li>
				1217	<li>If no match is found, and the type sought is an integer type, then the
				1218	smallest integer type that is larger than the bitwidth of the sought type is
				1219	used. If none of the specifications are larger than the bitwidth then the the
				1220	largest integer type is used. For example, given the default specifications
				1221	above, the i7 type will use the alignment of i8 (next largest) while both
				1222	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1223	<li>If no match is found, and the type sought is a vector type, then the
				1224	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1225	as a fall back. This happens because <128 x double> can be implemented
				1226	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1227	</ol>
				1228	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1229
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1230	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1231	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1232	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1233
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1234	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1235
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1236	<p>The LLVM type system is one of the most important features of the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1237	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1238	optimizations to be performed on the intermediate representation directly,
				1239	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	extra analyses on the side before the transformation. A strong type
				1241	system makes it easier to read the generated code and enables novel
				1242	analyses and transformations that are not feasible to perform on normal
				1243	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1244
				1245	</div>
				1246
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1247	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1248	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1250	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1251	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1253
				1254	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1255	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1256	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1257	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1258	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1259	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1260	</tr>
				1261	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1262	<td><a href="#t_floating">floating point</a></td>
				1263	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1264	</tr>
				1265	<tr>
				1266	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1267	<td><a href="#t_integer">integer</a>,
				1268	<a href="#t_floating">floating point</a>,
				1269	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1270	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1271	<a href="#t_struct">structure</a>,
				1272	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1273	<a href="#t_label">label</a>,
				1274	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1275	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1276	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1277	<tr>
				1278	<td><a href="#t_primitive">primitive</a></td>
				1279	<td><a href="#t_label">label</a>,
				1280	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1281	<a href="#t_floating">floating point</a>,
				1282	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1283	</tr>
				1284	<tr>
				1285	<td><a href="#t_derived">derived</a></td>
				1286	<td><a href="#t_integer">integer</a>,
				1287	<a href="#t_array">array</a>,
				1288	<a href="#t_function">function</a>,
				1289	<a href="#t_pointer">pointer</a>,
				1290	<a href="#t_struct">structure</a>,
				1291	<a href="#t_pstruct">packed structure</a>,
				1292	<a href="#t_vector">vector</a>,
				1293	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1294	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1295	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1296	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1297	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1298
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1299	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1300	most important. Values of these types are the only ones which can be
				1301	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1302	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1303	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1305	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1306	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1307
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1308	<div class="doc_text">
				1309	<p>The primitive types are the fundamental building blocks of the LLVM
				1310	system.</p>
				1311
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1312	</div>
				1313
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1314	<!-- _______________________________________________________________________ -->
				1315	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1316
				1317	<div class="doc_text">
				1318	<table>
				1319	<tbody>
				1320	<tr><th>Type</th><th>Description</th></tr>
				1321	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1322	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1323	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1324	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1325	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1326	</tbody>
				1327	</table>
				1328	</div>
				1329
				1330	<!-- _______________________________________________________________________ -->
				1331	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1332
				1333	<div class="doc_text">
				1334	<h5>Overview:</h5>
				1335	<p>The void type does not represent any value and has no size.</p>
				1336
				1337	<h5>Syntax:</h5>
				1338
				1339	<pre>
				1340	void
				1341	</pre>
				1342	</div>
				1343
				1344	<!-- _______________________________________________________________________ -->
				1345	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1346
				1347	<div class="doc_text">
				1348	<h5>Overview:</h5>
				1349	<p>The label type represents code labels.</p>
				1350
				1351	<h5>Syntax:</h5>
				1352
				1353	<pre>
				1354	label
				1355	</pre>
				1356	</div>
				1357
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1358	<!-- _______________________________________________________________________ -->
				1359	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1360
				1361	<div class="doc_text">
				1362	<h5>Overview:</h5>
				1363	<p>The metadata type represents embedded metadata. The only derived type that
				1364	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1365	takes metadata typed parameters, but not pointer to metadata types.</p>
				1366
				1367	<h5>Syntax:</h5>
				1368
				1369	<pre>
				1370	metadata
				1371	</pre>
				1372	</div>
				1373
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1374
				1375	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1376	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1377
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1378	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1379
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1380	<p>The real power in LLVM comes from the derived types in the system.
				1381	This is what allows a programmer to represent arrays, functions,
				1382	pointers, and other useful types. Note that these derived types may be
				1383	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1384
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1385	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1386
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1387	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1388	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1389
				1390	<div class="doc_text">
				1391
				1392	<h5>Overview:</h5>
				1393	<p>The integer type is a very simple derived type that simply specifies an
				1394	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1395	2^23-1 (about 8 million) can be specified.</p>
				1396
				1397	<h5>Syntax:</h5>
				1398
				1399	<pre>
				1400	iN
				1401	</pre>
				1402
				1403	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1404	value.</p>
				1405
				1406	<h5>Examples:</h5>
				1407	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1408	<tr class="layout">
				1409	<td class="left"><tt>i1</tt></td>
				1410	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1411	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1412	<tr class="layout">
				1413	<td class="left"><tt>i32</tt></td>
				1414	<td class="left">a 32-bit integer.</td>
				1415	</tr>
				1416	<tr class="layout">
				1417	<td class="left"><tt>i1942652</tt></td>
				1418	<td class="left">a really big integer of over 1 million bits.</td>
				1419	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1420	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1421
				1422	<p>Note that the code generator does not yet support large integer types
				1423	to be used as function return types. The specific limit on how large a
				1424	return type the code generator can currently handle is target-dependent;
				1425	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1426	targets.</p>
				1427
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1428	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1429
				1430	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1431	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1432
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1433	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1434
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1435	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1436
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1437	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1438	sequentially in memory. The array type requires a size (number of
				1439	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1440
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1441	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1442
				1443	<pre>
				1444	[<# elements> x <elementtype>]
				1445	</pre>
				1446
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1447	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1448	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1449
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1450	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1451	<table class="layout">
				1452	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1453	<td class="left"><tt>[40 x i32]</tt></td>
				1454	<td class="left">Array of 40 32-bit integer values.</td>
				1455	</tr>
				1456	<tr class="layout">
				1457	<td class="left"><tt>[41 x i32]</tt></td>
				1458	<td class="left">Array of 41 32-bit integer values.</td>
				1459	</tr>
				1460	<tr class="layout">
				1461	<td class="left"><tt>[4 x i8]</tt></td>
				1462	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1463	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1464	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1465	<p>Here are some examples of multidimensional arrays:</p>
				1466	<table class="layout">
				1467	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1468	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1469	<td class="left">3x4 array of 32-bit integer values.</td>
				1470	</tr>
				1471	<tr class="layout">
				1472	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1473	<td class="left">12x10 array of single precision floating point values.</td>
				1474	</tr>
				1475	<tr class="layout">
				1476	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1477	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1478	</tr>
				1479	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1480
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1481	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1482	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1483	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1484	As a special case, however, zero length arrays are recognized to be variable
				1485	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1486	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1487
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1488	<p>Note that the code generator does not yet support large aggregate types
				1489	to be used as function return types. The specific limit on how large an
				1490	aggregate return type the code generator can currently handle is
				1491	target-dependent, and also dependent on the aggregate element types.</p>
				1492
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1493	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1494
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1495	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1496	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1497	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1498
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1499	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1500
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1501	<p>The function type can be thought of as a function signature. It
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1502	consists of a return type and a list of formal parameter types. The
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1503	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	7a3ad1a	2008-03-24 20:52:42 +0000	[diff] [blame]	1504	If the return type is a struct type then all struct elements must be of first
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1505	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1506
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1507	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1508
				1509	<pre>
				1510	<returntype list> (<parameter list>)
				1511	</pre>
				1512
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1513	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	c24b758	2004-08-12 20:16:08 +0000	[diff] [blame]	1514	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1515	which indicates that the function takes a variable number of arguments.
				1516	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1517	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1518	'<tt><returntype list></tt>' is a comma-separated list of
				1519	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1520
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1521	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1522	<table class="layout">
				1523	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1524	<td class="left"><tt>i32 (i32)</tt></td>
				1525	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1526	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1527	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1528	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1529	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1530	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1531	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1532	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1533	<tt>float</tt>.
				1534	</td>
				1535	</tr><tr class="layout">
				1536	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1537	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1538	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1539	which returns an integer. This is the signature for <tt>printf</tt> in
				1540	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1541	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1542	</tr><tr class="layout">
				1543	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1544	<td class="left">A function taking an <tt>i32</tt>, returning two
				1545	<tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1546	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1547	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1548	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1549
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1550	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1551	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1552	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1553	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1554	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1555	<p>The structure type is used to represent a collection of data members
				1556	together in memory. The packing of the field types is defined to match
				1557	the ABI of the underlying processor. The elements of a structure may
				1558	be any type that has a size.</p>
				1559	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1560	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1561	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1562	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1563	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1564	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1565	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1566	<table class="layout">
				1567	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1568	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1569	<td class="left">A triple of three <tt>i32</tt> values</td>
				1570	</tr><tr class="layout">
				1571	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1572	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1573	second element is a <a href="#t_pointer">pointer</a> to a
				1574	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1575	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1576	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1577	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1578
				1579	<p>Note that the code generator does not yet support large aggregate types
				1580	to be used as function return types. The specific limit on how large an
				1581	aggregate return type the code generator can currently handle is
				1582	target-dependent, and also dependent on the aggregate element types.</p>
				1583
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1584	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1585
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1586	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1587	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1588	</div>
				1589	<div class="doc_text">
				1590	<h5>Overview:</h5>
				1591	<p>The packed structure type is used to represent a collection of data members
				1592	together in memory. There is no padding between fields. Further, the alignment
				1593	of a packed structure is 1 byte. The elements of a packed structure may
				1594	be any type that has a size.</p>
				1595	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1596	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1597	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1598	instruction.</p>
				1599	<h5>Syntax:</h5>
				1600	<pre> < { <type list> } > <br></pre>
				1601	<h5>Examples:</h5>
				1602	<table class="layout">
				1603	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1604	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1605	<td class="left">A triple of three <tt>i32</tt> values</td>
				1606	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1607	<td class="left">
				1608	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1609	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1610	second element is a <a href="#t_pointer">pointer</a> to a
				1611	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1612	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1613	</tr>
				1614	</table>
				1615	</div>
				1616
				1617	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1618	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1619	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1620	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1621	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1622	reference to another object, which must live in memory. Pointer types may have
				1623	an optional address space attribute defining the target-specific numbered
				1624	address space where the pointed-to object resides. The default address space is
				1625	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1626
				1627	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	e220e8c	2009-02-08 22:21:28 +0000	[diff] [blame]	1628	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1629
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1630	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1631	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1632	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1633	<table class="layout">
				1634	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1635	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1636	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1637	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1638	</tr>
				1639	<tr class="layout">
				1640	<td class="left"><tt>i32 (i32 ) </tt></td>
				1641	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1642	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1643	<tt>i32</tt>.</td>
				1644	</tr>
				1645	<tr class="layout">
				1646	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1647	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1648	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1649	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1650	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1651	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1652
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1653	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1654	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1655	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1656
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1657	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1658
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1659	<p>A vector type is a simple derived type that represents a vector
				1660	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1661	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1662	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1663	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1664	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1665	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1666
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1667	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1668
				1669	<pre>
				1670	< <# elements> x <elementtype> >
				1671	</pre>
				1672
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1673	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1674	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1675
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1676	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1677
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1678	<table class="layout">
				1679	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1680	<td class="left"><tt><4 x i32></tt></td>
				1681	<td class="left">Vector of 4 32-bit integer values.</td>
				1682	</tr>
				1683	<tr class="layout">
				1684	<td class="left"><tt><8 x float></tt></td>
				1685	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1686	</tr>
				1687	<tr class="layout">
				1688	<td class="left"><tt><2 x i64></tt></td>
				1689	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1690	</tr>
				1691	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1692
				1693	<p>Note that the code generator does not yet support large vector types
				1694	to be used as function return types. The specific limit on how large a
				1695	vector return type codegen can currently handle is target-dependent;
				1696	currently it's often a few times longer than a hardware vector register.</p>
				1697
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1698	</div>
				1699
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1700	<!-- _______________________________________________________________________ -->
				1701	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1702	<div class="doc_text">
				1703
				1704	<h5>Overview:</h5>
				1705
				1706	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	8ac04ff	2007-10-14 00:34:53 +0000	[diff] [blame]	1707	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1708	In LLVM, opaque types can eventually be resolved to any type (not just a
				1709	structure type).</p>
				1710
				1711	<h5>Syntax:</h5>
				1712
				1713	<pre>
				1714	opaque
				1715	</pre>
				1716
				1717	<h5>Examples:</h5>
				1718
				1719	<table class="layout">
				1720	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1721	<td class="left"><tt>opaque</tt></td>
				1722	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1723	</tr>
				1724	</table>
				1725	</div>
				1726
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1727	<!-- ======================================================================= -->
				1728	<div class="doc_subsection">
				1729	<a name="t_uprefs">Type Up-references</a>
				1730	</div>
				1731
				1732	<div class="doc_text">
				1733	<h5>Overview:</h5>
				1734	<p>
				1735	An "up reference" allows you to refer to a lexically enclosing type without
				1736	requiring it to have a name. For instance, a structure declaration may contain a
				1737	pointer to any of the types it is lexically a member of. Example of up
				1738	references (with their equivalent as named type declarations) include:</p>
				1739
				1740	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1741	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1742	{ \2 }* %y = type { %y }*
				1743	\1* %z = type %z*
				1744	</pre>
				1745
				1746	<p>
				1747	An up reference is needed by the asmprinter for printing out cyclic types when
				1748	there is no declared name for a type in the cycle. Because the asmprinter does
				1749	not want to print out an infinite type string, it needs a syntax to handle
				1750	recursive types that have no names (all names are optional in llvm IR).
				1751	</p>
				1752
				1753	<h5>Syntax:</h5>
				1754	<pre>
				1755	\<level>
				1756	</pre>
				1757
				1758	<p>
				1759	The level is the count of the lexical type that is being referred to.
				1760	</p>
				1761
				1762	<h5>Examples:</h5>
				1763
				1764	<table class="layout">
				1765	<tr class="layout">
				1766	<td class="left"><tt>\1*</tt></td>
				1767	<td class="left">Self-referential pointer.</td>
				1768	</tr>
				1769	<tr class="layout">
				1770	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1771	<td class="left">Recursive structure where the upref refers to the out-most
				1772	structure.</td>
				1773	</tr>
				1774	</table>
				1775	</div>
				1776
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1777
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1778	<!-- *********************************************************************** -->
				1779	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1780	<!-- *********************************************************************** -->
				1781
				1782	<div class="doc_text">
				1783
				1784	<p>LLVM has several different basic types of constants. This section describes
				1785	them all and their syntax.</p>
				1786
				1787	</div>
				1788
				1789	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1790	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1791
				1792	<div class="doc_text">
				1793
				1794	<dl>
				1795	<dt><b>Boolean constants</b></dt>
				1796
				1797	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1798	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1799	</dd>
				1800
				1801	<dt><b>Integer constants</b></dt>
				1802
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1803	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1804	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1805	integer types.
				1806	</dd>
				1807
				1808	<dt><b>Floating point constants</b></dt>
				1809
				1810	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1811	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1812	notation (see below). The assembler requires the exact decimal value of
				1813	a floating-point constant. For example, the assembler accepts 1.25 but
				1814	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1815	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1816
				1817	<dt><b>Null pointer constants</b></dt>
				1818
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1819	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1820	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1821
				1822	</dl>
				1823
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1824	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1825	of floating point constants. For example, the form '<tt>double
				1826	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1827	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1828	(and the only time that they are generated by the disassembler) is when a
				1829	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1830	decimal floating point number in a reasonable number of digits. For example,
				1831	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1832	special values are represented in their IEEE hexadecimal format so that
				1833	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1834	<p>When using the hexadecimal form, constants of types float and double are
				1835	represented using the 16-digit form shown above (which matches the IEEE754
				1836	representation for double); float values must, however, be exactly representable
				1837	as IEE754 single precision.
				1838	Hexadecimal format is always used for long
				1839	double, and there are three forms of long double. The 80-bit
				1840	format used by x86 is represented as <tt>0xK</tt>
				1841	followed by 20 hexadecimal digits.
				1842	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1843	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1844	format is represented
				1845	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1846	target uses this format. Long doubles will only work if they match
				1847	the long double format on your target. All hexadecimal formats are big-endian
				1848	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1849	</div>
				1850
				1851	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1852	<div class="doc_subsection">
				1853	<a name="aggregateconstants"> <!-- old anchor -->
				1854	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1855	</div>
				1856
				1857	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1858	<p>Complex constants are a (potentially recursive) combination of simple
				1859	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1860
				1861	<dl>
				1862	<dt><b>Structure constants</b></dt>
				1863
				1864	<dd>Structure constants are represented with notation similar to structure
				1865	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1866	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1867	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1868	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1869	types of elements must match those specified by the type.
				1870	</dd>
				1871
				1872	<dt><b>Array constants</b></dt>
				1873
				1874	<dd>Array constants are represented with notation similar to array type
				1875	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1876	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1877	constants must have <a href="#t_array">array type</a>, and the number and
				1878	types of elements must match those specified by the type.
				1879	</dd>
				1880
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1881	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1882
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1883	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1884	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1885	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1886	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1887	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1888	match those specified by the type.
				1889	</dd>
				1890
				1891	<dt><b>Zero initialization</b></dt>
				1892
				1893	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1894	value to zero of <em>any</em> type, including scalar and aggregate types.
				1895	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1896	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1897	initializers.
				1898	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1899
				1900	<dt><b>Metadata node</b></dt>
				1901
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1902	<dd>A metadata node is a structure-like constant with
				1903	<a href="#t_metadata">metadata type</a>. For example:
				1904	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1905	that are meant to be interpreted as part of the instruction stream, metadata
				1906	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1907	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1908	</dl>
				1909
				1910	</div>
				1911
				1912	<!-- ======================================================================= -->
				1913	<div class="doc_subsection">
				1914	<a name="globalconstants">Global Variable and Function Addresses</a>
				1915	</div>
				1916
				1917	<div class="doc_text">
				1918
				1919	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1920	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1921	constants. These constants are explicitly referenced when the <a
				1922	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1923	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1924	file:</p>
				1925
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1926	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1927	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1928	@X = global i32 17
				1929	@Y = global i32 42
				1930	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1931	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1932	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1933
				1934	</div>
				1935
				1936	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1937	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1938	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1939	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1940	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1941	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1942
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1943	<p>Undefined values indicate to the compiler that the program is well defined
				1944	no matter what value is used, giving the compiler more freedom to optimize.
				1945	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1946	</div>
				1947
				1948	<!-- ======================================================================= -->
				1949	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1950	</div>
				1951
				1952	<div class="doc_text">
				1953
				1954	<p>Constant expressions are used to allow expressions involving other constants
				1955	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1956	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1957	that does not have side effects (e.g. load and call are not supported). The
				1958	following is the syntax for constant expressions:</p>
				1959
				1960	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1961	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1962	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1963	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1964
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1965	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1966	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1967	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1968
				1969	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1970	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1971	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1972
				1973	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1974	<dd>Truncate a floating point constant to another floating point type. The
				1975	size of CST must be larger than the size of TYPE. Both types must be
				1976	floating point.</dd>
				1977
				1978	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1979	<dd>Floating point extend a constant to another type. The size of CST must be
				1980	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1981
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1982	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1983	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1984	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1985	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1986	of the same number of elements. If the value won't fit in the integer type,
				1987	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1988
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1989	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1990	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1991	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1992	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1993	of the same number of elements. If the value won't fit in the integer type,
				1994	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1995
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1996	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1997	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1998	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1999	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2000	of the same number of elements. If the value won't fit in the floating point
				2001	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2002
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2003	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2004	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2005	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2006	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2007	of the same number of elements. If the value won't fit in the floating point
				2008	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2009
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2010	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2011	<dd>Convert a pointer typed constant to the corresponding integer constant
				2012	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2013	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2014
				2015	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2016	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2017	pointer type. CST must be of integer type. The CST value is zero extended,
				2018	truncated, or unchanged to make it fit in a pointer size. This one is
				2019	<i>really</i> dangerous!</dd>
				2020
				2021	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2022	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2023	are the same as those for the <a href="#i_bitcast">bitcast
				2024	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2025
				2026	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2027
				2028	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2029	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2030	instruction, the index list may have zero or more indexes, which are required
				2031	to make sense for the type of "CSTPTR".</dd>
				2032
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2033	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2034
				2035	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2036	constants.</dd>
				2037
				2038	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2039	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2040
				2041	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2042	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2043
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	2044	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2045	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2046
				2047	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2048	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2049
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2050	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2051
				2052	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2053	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2054
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2055	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2056
				2057	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2058	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2059
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2060
				2061	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2062
				2063	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2064	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2065
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2066	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2067
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2068	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2069	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]	2070	binary</a> operations. The constraints on operands are the same as those for
				2071	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2072	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2073	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2074	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2075
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2076	<!-- ======================================================================= -->
				2077	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2078	</div>
				2079
				2080	<div class="doc_text">
				2081
				2082	<p>Embedded metadata provides a way to attach arbitrary data to the
				2083	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2084	two metadata primitives, strings and nodes. All metadata has the
				2085	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2086	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2087	</p>
				2088
				2089	<p>A metadata string is a string surrounded by double quotes. It can contain
				2090	any character by escaping non-printable characters with "\xx" where "xx" is
				2091	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2092	</p>
				2093
				2094	<p>Metadata nodes are represented with notation similar to structure constants
				2095	(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]	2096	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2097	</p>
				2098
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2099	<p>A metadata node will attempt to track changes to the values it holds. In
				2100	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]	2101	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2102
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2103	<p>Optimizations may rely on metadata to provide additional information about
				2104	the program that isn't available in the instructions, or that isn't easily
				2105	computable. Similarly, the code generator may expect a certain metadata format
				2106	to be used to express debugging information.</p>
				2107	</div>
				2108
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2109	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2110	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2111	<!-- *********************************************************************** -->
				2112
				2113	<!-- ======================================================================= -->
				2114	<div class="doc_subsection">
				2115	<a name="inlineasm">Inline Assembler Expressions</a>
				2116	</div>
				2117
				2118	<div class="doc_text">
				2119
				2120	<p>
				2121	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2122	Module-Level Inline Assembly</a>) through the use of a special value. This
				2123	value represents the inline assembler as a string (containing the instructions
				2124	to emit), a list of operand constraints (stored as a string), and a flag that
				2125	indicates whether or not the inline asm expression has side effects. An example
				2126	inline assembler expression is:
				2127	</p>
				2128
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2129	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2130	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2131	i32 (i32) asm "bswap $0", "=r,r"
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	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2134
				2135	<p>
				2136	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2137	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2138	</p>
				2139
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2140	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2141	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2142	%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]	2143	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2144	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2145
				2146	<p>
				2147	Inline asms with side effects not visible in the constraint list must be marked
				2148	as having side effects. This is done through the use of the
				2149	'<tt>sideeffect</tt>' keyword, like so:
				2150	</p>
				2151
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2152	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2153	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2154	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2155	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2156	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2157
				2158	<p>TODO: The format of the asm and constraints string still need to be
				2159	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]	2160	need to be documented). This is probably best done by reference to another
				2161	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2162	</p>
				2163
				2164	</div>
				2165
				2166	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2168	<!-- *********************************************************************** -->
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 class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2171
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2172	<p>The LLVM instruction set consists of several different
				2173	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2174	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2175	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2176	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2177	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2178
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2179	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2180
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2181	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2182	<div class="doc_subsection"> <a name="terminators">Terminator
				2183	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2184
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2185	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2186
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2187	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2188	basic block in a program ends with a "Terminator" instruction, which
				2189	indicates which block should be executed after the current block is
				2190	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2191	value: they produce control flow, not values (the one exception being
				2192	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2193	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2194	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2195	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2196	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2197	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2198	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2199
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2200	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2201
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2202	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2203	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2204	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2205	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2206	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2207	<pre>
				2208	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]	2209	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2210	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2211
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2212	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2213
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2214	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2215	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2216	<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]	2217	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]	2218	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2219
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2220	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2221
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2222	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2223	the return value. The type of the return value must be a
				2224	'<a href="#t_firstclass">first class</a>' type.</p>
				2225
				2226	<p>A function is not <a href="#wellformed">well formed</a> if
				2227	it it has a non-void return type and contains a '<tt>ret</tt>'
				2228	instruction with no return value or a return value with a type that
				2229	does not match its type, or if it has a void return type and contains
				2230	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2231
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2232	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2233
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2234	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2235	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]	2236	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2237	the instruction after the call. If the caller was an "<a
				2238	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2239	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2240	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]	2241	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2242
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2243	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2244
				2245	<pre>
				2246	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2247	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2248	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]	2249	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2250
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2251	<p>Note that the code generator does not yet fully support large
				2252	return values. The specific sizes that are currently supported are
				2253	dependent on the target. For integers, on 32-bit targets the limit
				2254	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2255	For aggregate types, the current limits are dependent on the element
				2256	types; for example targets are often limited to 2 total integer
				2257	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2258
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2259	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2260	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2261	<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]	2262	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2264	<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]	2265	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2267	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2268	transfer to a different basic block in the current function. There are
				2269	two forms of this instruction, corresponding to a conditional branch
				2270	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2271	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2272	<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]	2273	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2274	unconditional form of the '<tt>br</tt>' instruction takes a single
				2275	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2277	<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]	2278	argument is evaluated. If the value is <tt>true</tt>, control flows
				2279	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2280	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2281	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2282	<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]	2283	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]	2284	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2285	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2286	<div class="doc_subsubsection">
				2287	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2288	</div>
				2289
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2290	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2291	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2292
				2293	<pre>
				2294	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2295	</pre>
				2296
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2297	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2298
				2299	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2300	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2301	instruction, allowing a branch to occur to one of many possible
				2302	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2303
				2304
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2305	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2306
				2307	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2308	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2309	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2310	table is not allowed to contain duplicate constant entries.</p>
				2311
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2312	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2313
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2314	<p>The <tt>switch</tt> instruction specifies a table of values and
				2315	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2316	table is searched for the given value. If the value is found, control flow is
				2317	transfered to the corresponding destination; otherwise, control flow is
				2318	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2319
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2320	<h5>Implementation:</h5>
				2321
				2322	<p>Depending on properties of the target machine and the particular
				2323	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2324	ways. For example, it could be generated as a series of chained conditional
				2325	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2326
				2327	<h5>Example:</h5>
				2328
				2329	<pre>
				2330	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2331	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2332	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2333
				2334	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2335	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2336
				2337	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2338	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2339	i32 1, label %onone
				2340	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2341	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2342	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2343
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2344	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2345	<div class="doc_subsubsection">
				2346	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2347	</div>
				2348
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2349	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2350
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2351	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2352
				2353	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2354	<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]	2355	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2356	</pre>
				2357
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2358	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2359
				2360	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2361	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2362	'<tt>normal</tt>' label or the
				2363	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2364	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2365	"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]	2366	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2367	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2368
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2369	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2370
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2371	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2372
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2373	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2374	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2375	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2376	convention</a> the call should use. If none is specified, the call defaults
				2377	to using C calling conventions.
				2378	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2379
				2380	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2381	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2382	and '<tt>inreg</tt>' attributes are valid here.</li>
				2383
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2384	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2385	function value being invoked. In most cases, this is a direct function
				2386	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2387	an arbitrary pointer to function value.
				2388	</li>
				2389
				2390	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2391	function to be invoked. </li>
				2392
				2393	<li>'<tt>function args</tt>': argument list whose types match the function
				2394	signature argument types. If the function signature indicates the function
				2395	accepts a variable number of arguments, the extra arguments can be
				2396	specified. </li>
				2397
				2398	<li>'<tt>normal label</tt>': the label reached when the called function
				2399	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2400
				2401	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2402	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2403
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2404	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2405	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2406	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2407	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2408
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2409	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2410
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2411	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2412	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2413	difference is that it establishes an association with a label, which is used by
				2414	the runtime library to unwind the stack.</p>
				2415
				2416	<p>This instruction is used in languages with destructors to ensure that proper
				2417	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2418	exception. Additionally, this is important for implementation of
				2419	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2420
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2421	<p>For the purposes of the SSA form, the definition of the value
				2422	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2423	the edge from the current block to the "normal" label. If the callee
				2424	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2425
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2426	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2427	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2428	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2429	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2430	%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]	2431	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2432	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2433	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2434
				2435
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2436	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2437
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2438	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2439	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2440
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2441	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2442
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2443	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2444	<pre>
				2445	unwind
				2446	</pre>
				2447
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2448	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2449
				2450	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2451	at the first callee in the dynamic call stack which used an <a
				2452	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2453	primarily used to implement exception handling.</p>
				2454
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2455	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2456
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2457	<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]	2458	immediately halt. The dynamic call stack is then searched for the first <a
				2459	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2460	execution continues at the "exceptional" destination block specified by the
				2461	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2462	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2463	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2464
				2465	<!-- _______________________________________________________________________ -->
				2466
				2467	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2468	Instruction</a> </div>
				2469
				2470	<div class="doc_text">
				2471
				2472	<h5>Syntax:</h5>
				2473	<pre>
				2474	unreachable
				2475	</pre>
				2476
				2477	<h5>Overview:</h5>
				2478
				2479	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2480	instruction is used to inform the optimizer that a particular portion of the
				2481	code is not reachable. This can be used to indicate that the code after a
				2482	no-return function cannot be reached, and other facts.</p>
				2483
				2484	<h5>Semantics:</h5>
				2485
				2486	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2487	</div>
				2488
				2489
				2490
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2491	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2492	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2493	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2494	<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]	2495	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]	2496	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2497	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]	2498	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2499	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2501	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2502	<div class="doc_subsubsection">
				2503	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2504	</div>
				2505
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2506	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2508	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2509
				2510	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2511	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2512	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2514	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2515
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2516	<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]	2517
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2519
				2520	<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]	2521	href="#t_integer">integer</a> or
				2522	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2523	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2524
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2525	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2527	<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]	2528
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2529	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2530	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2531	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2532
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2533	<p>Because LLVM integers use a two's complement representation, this
				2534	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2535
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2536	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2537
				2538	<pre>
				2539	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2540	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2541	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2542	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2543	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2544	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2545	</div>
				2546
				2547	<div class="doc_text">
				2548
				2549	<h5>Syntax:</h5>
				2550
				2551	<pre>
				2552	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2553	</pre>
				2554
				2555	<h5>Overview:</h5>
				2556
				2557	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2558
				2559	<h5>Arguments:</h5>
				2560
				2561	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2562	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2563	floating point values. Both arguments must have identical types.</p>
				2564
				2565	<h5>Semantics:</h5>
				2566
				2567	<p>The value produced is the floating point sum of the two operands.</p>
				2568
				2569	<h5>Example:</h5>
				2570
				2571	<pre>
				2572	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2573	</pre>
				2574	</div>
				2575	<!-- _______________________________________________________________________ -->
				2576	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2577	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2578	</div>
				2579
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2580	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2581
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2582	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2583
				2584	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2585	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2586	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2587
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2588	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2589
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2590	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2591	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2592
				2593	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2594	'<tt>neg</tt>' instruction present in most other intermediate
				2595	representations.</p>
				2596
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2597	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2598
				2599	<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]	2600	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2601	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2602
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2603	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2605	<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]	2606
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2607	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2608	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2609	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2610
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2611	<p>Because LLVM integers use a two's complement representation, this
				2612	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2614	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2615	<pre>
				2616	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2617	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2618	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2619	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2620
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2621	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2622	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2623	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2624	</div>
				2625
				2626	<div class="doc_text">
				2627
				2628	<h5>Syntax:</h5>
				2629
				2630	<pre>
				2631	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2632	</pre>
				2633
				2634	<h5>Overview:</h5>
				2635
				2636	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2637	operands.</p>
				2638
				2639	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2640	'<tt>fneg</tt>' instruction present in most other intermediate
				2641	representations.</p>
				2642
				2643	<h5>Arguments:</h5>
				2644
				2645	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2646	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2647	of floating point values. Both arguments must have identical types.</p>
				2648
				2649	<h5>Semantics:</h5>
				2650
				2651	<p>The value produced is the floating point difference of the two operands.</p>
				2652
				2653	<h5>Example:</h5>
				2654	<pre>
				2655	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2656	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2657	</pre>
				2658	</div>
				2659
				2660	<!-- _______________________________________________________________________ -->
				2661	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2662	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2663	</div>
				2664
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2665	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2666
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2667	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2668	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2669	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2671	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2672	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2673
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2674	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2675
				2676	<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]	2677	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2678	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2679
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2680	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2681
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2682	<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]	2683
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2684	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2685	the result returned is the mathematical result modulo
				2686	2<sup>n</sup>, where n is the bit width of the result.</p>
				2687	<p>Because LLVM integers use a two's complement representation, and the
				2688	result is the same width as the operands, this instruction returns the
				2689	correct result for both signed and unsigned integers. If a full product
				2690	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2691	should be sign-extended or zero-extended as appropriate to the
				2692	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2693	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2694	<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]	2695	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2696	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2697
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2698	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2699	<div class="doc_subsubsection">
				2700	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2701	</div>
				2702
				2703	<div class="doc_text">
				2704
				2705	<h5>Syntax:</h5>
				2706	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2707	</pre>
				2708	<h5>Overview:</h5>
				2709	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2710	operands.</p>
				2711
				2712	<h5>Arguments:</h5>
				2713
				2714	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2715	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2716	of floating point values. Both arguments must have identical types.</p>
				2717
				2718	<h5>Semantics:</h5>
				2719
				2720	<p>The value produced is the floating point product of the two operands.</p>
				2721
				2722	<h5>Example:</h5>
				2723	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2724	</pre>
				2725	</div>
				2726
				2727	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2728	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2729	</a></div>
				2730	<div class="doc_text">
				2731	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2732	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2733	</pre>
				2734	<h5>Overview:</h5>
				2735	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2736	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2737
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2738	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2739
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2740	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2741	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2742	values. Both arguments must have identical types.</p>
				2743
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2744	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2745
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2746	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2747	<p>Note that unsigned integer division and signed integer division are distinct
				2748	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2749	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2750	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2751	<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]	2752	</pre>
				2753	</div>
				2754	<!-- _______________________________________________________________________ -->
				2755	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2756	</a> </div>
				2757	<div class="doc_text">
				2758	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2759	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2760	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2761	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2762
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2763	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2764
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2765	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2766	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2767
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2768	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2769
				2770	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2771	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2772	values. Both arguments must have identical types.</p>
				2773
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2774	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2775	<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]	2776	<p>Note that signed integer division and unsigned integer division are distinct
				2777	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2778	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2779	undefined behavior; this is a rare case, but can occur, for example,
				2780	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2781	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2782	<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]	2783	</pre>
				2784	</div>
				2785	<!-- _______________________________________________________________________ -->
				2786	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2787	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2788	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2789	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2790	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2791	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2792	</pre>
				2793	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2794
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2795	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2796	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2797
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2798	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2799
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2800	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2801	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2802	of floating point values. Both arguments must have identical types.</p>
				2803
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2804	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2805
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2806	<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]	2807
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2808	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2809
				2810	<pre>
				2811	<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]	2812	</pre>
				2813	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2814
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2815	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2816	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2817	</div>
				2818	<div class="doc_text">
				2819	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2820	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2821	</pre>
				2822	<h5>Overview:</h5>
				2823	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2824	unsigned division of its two arguments.</p>
				2825	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2826	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2827	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2828	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2829	<h5>Semantics:</h5>
				2830	<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]	2831	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2832	<p>Note that unsigned integer remainder and signed integer remainder are
				2833	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2834	<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]	2835	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2836	<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]	2837	</pre>
				2838
				2839	</div>
				2840	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2841	<div class="doc_subsubsection">
				2842	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2843	</div>
				2844
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2845	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2846
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2847	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2848
				2849	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2850	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2851	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2852
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2853	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2854
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2855	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2856	signed division of its two operands. This instruction can also take
				2857	<a href="#t_vector">vector</a> versions of the values in which case
				2858	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2859
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2860	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2861
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2862	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2863	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2864	values. Both arguments must have identical types.</p>
				2865
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2866	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2867
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2868	<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]	2869	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2870	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]	2871	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2872	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]	2873	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]	2874	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2875	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2876	<p>Note that signed integer remainder and unsigned integer remainder are
				2877	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2878	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2879	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2880	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2881	(The remainder doesn't actually overflow, but this rule lets srem be
				2882	implemented using instructions that return both the result of the division
				2883	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2884	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2885	<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]	2886	</pre>
				2887
				2888	</div>
				2889	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2890	<div class="doc_subsubsection">
				2891	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2892
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2893	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2894
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2895	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2896	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2897	</pre>
				2898	<h5>Overview:</h5>
				2899	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2900	division of its two operands.</p>
				2901	<h5>Arguments:</h5>
				2902	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2903	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2904	of floating point values. Both arguments must have identical types.</p>
				2905
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2906	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2907
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2908	<p>This instruction returns the <i>remainder</i> of a division.
				2909	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2910
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2911	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2912
				2913	<pre>
				2914	<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]	2915	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2916	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2917
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2918	<!-- ======================================================================= -->
				2919	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2920	Operations</a> </div>
				2921	<div class="doc_text">
				2922	<p>Bitwise binary operators are used to do various forms of
				2923	bit-twiddling in a program. They are generally very efficient
				2924	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2925	instructions. They require two operands of the same type, execute an operation on them,
				2926	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]	2927	</div>
				2928
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2929	<!-- _______________________________________________________________________ -->
				2930	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2931	Instruction</a> </div>
				2932	<div class="doc_text">
				2933	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2934	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2935	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2936
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2937	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2938
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2939	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2940	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2941
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2942	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2943
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2944	<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]	2945	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]	2946	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2947
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2948	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2949
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2950	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2951	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]	2952	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2953	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2954	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2955
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2956	<h5>Example:</h5><pre>
				2957	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2958	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2959	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2960	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2961	<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]	2962	</pre>
				2963	</div>
				2964	<!-- _______________________________________________________________________ -->
				2965	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2966	Instruction</a> </div>
				2967	<div class="doc_text">
				2968	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2969	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2970	</pre>
				2971
				2972	<h5>Overview:</h5>
				2973	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2974	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]	2975
				2976	<h5>Arguments:</h5>
				2977	<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]	2978	<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]	2979	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2980
				2981	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2982
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2983	<p>This instruction always performs a logical shift right operation. The most
				2984	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]	2985	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]	2986	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2987	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2988	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2989
				2990	<h5>Example:</h5>
				2991	<pre>
				2992	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2993	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2994	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2995	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2996	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2997	<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]	2998	</pre>
				2999	</div>
				3000
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	3001	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3002	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				3003	Instruction</a> </div>
				3004	<div class="doc_text">
				3005
				3006	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3007	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3008	</pre>
				3009
				3010	<h5>Overview:</h5>
				3011	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3012	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]	3013
				3014	<h5>Arguments:</h5>
				3015	<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]	3016	<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]	3017	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3018
				3019	<h5>Semantics:</h5>
				3020	<p>This instruction always performs an arithmetic shift right operation,
				3021	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]	3022	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]	3023	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3024	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3025	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3026
				3027	<h5>Example:</h5>
				3028	<pre>
				3029	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3030	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3031	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3032	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3033	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3034	<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]	3035	</pre>
				3036	</div>
				3037
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3038	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3039	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3040	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3041
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3042	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3043
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3044	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3045
				3046	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3047	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3048	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3049
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3050	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3051
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3052	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3053	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3054
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3055	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3056
				3057	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3058	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3059	values. Both arguments must have identical types.</p>
				3060
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3061	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3062	<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]	3063	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3064	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3065	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3066	<tbody>
				3067	<tr>
				3068	<td>In0</td>
				3069	<td>In1</td>
				3070	<td>Out</td>
				3071	</tr>
				3072	<tr>
				3073	<td>0</td>
				3074	<td>0</td>
				3075	<td>0</td>
				3076	</tr>
				3077	<tr>
				3078	<td>0</td>
				3079	<td>1</td>
				3080	<td>0</td>
				3081	</tr>
				3082	<tr>
				3083	<td>1</td>
				3084	<td>0</td>
				3085	<td>0</td>
				3086	</tr>
				3087	<tr>
				3088	<td>1</td>
				3089	<td>1</td>
				3090	<td>1</td>
				3091	</tr>
				3092	</tbody>
				3093	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3094	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3095	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3096	<pre>
				3097	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3098	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3099	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3100	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3101	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3102	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3103	<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]	3104	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3105	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3106	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3107	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3108	<h5>Overview:</h5>
				3109	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3110	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3111	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3112
				3113	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3114	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3115	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3116	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3117	<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]	3118	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3119	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3120	<table border="1" cellspacing="0" cellpadding="4">
				3121	<tbody>
				3122	<tr>
				3123	<td>In0</td>
				3124	<td>In1</td>
				3125	<td>Out</td>
				3126	</tr>
				3127	<tr>
				3128	<td>0</td>
				3129	<td>0</td>
				3130	<td>0</td>
				3131	</tr>
				3132	<tr>
				3133	<td>0</td>
				3134	<td>1</td>
				3135	<td>1</td>
				3136	</tr>
				3137	<tr>
				3138	<td>1</td>
				3139	<td>0</td>
				3140	<td>1</td>
				3141	</tr>
				3142	<tr>
				3143	<td>1</td>
				3144	<td>1</td>
				3145	<td>1</td>
				3146	</tr>
				3147	</tbody>
				3148	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3149	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3150	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3151	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3152	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3153	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3154	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3155	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3156	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3157	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3158	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3159	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3160	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3161	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3162	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3164	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3165	or of its two operands. The <tt>xor</tt> is used to implement the
				3166	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3167	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3168	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3169	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3170	values. Both arguments must have identical types.</p>
				3171
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3172	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3173
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3174	<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]	3175	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3176	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3177	<table border="1" cellspacing="0" cellpadding="4">
				3178	<tbody>
				3179	<tr>
				3180	<td>In0</td>
				3181	<td>In1</td>
				3182	<td>Out</td>
				3183	</tr>
				3184	<tr>
				3185	<td>0</td>
				3186	<td>0</td>
				3187	<td>0</td>
				3188	</tr>
				3189	<tr>
				3190	<td>0</td>
				3191	<td>1</td>
				3192	<td>1</td>
				3193	</tr>
				3194	<tr>
				3195	<td>1</td>
				3196	<td>0</td>
				3197	<td>1</td>
				3198	</tr>
				3199	<tr>
				3200	<td>1</td>
				3201	<td>1</td>
				3202	<td>0</td>
				3203	</tr>
				3204	</tbody>
				3205	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3206	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3207	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3208	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3209	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3210	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3211	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3212	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3213	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3214	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3215
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3216	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3217	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3218	<a name="vectorops">Vector Operations</a>
				3219	</div>
				3220
				3221	<div class="doc_text">
				3222
				3223	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3224	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3225	vector-specific operations needed to process vectors effectively. While LLVM
				3226	does directly support these vector operations, many sophisticated algorithms
				3227	will want to use target-specific intrinsics to take full advantage of a specific
				3228	target.</p>
				3229
				3230	</div>
				3231
				3232	<!-- _______________________________________________________________________ -->
				3233	<div class="doc_subsubsection">
				3234	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3235	</div>
				3236
				3237	<div class="doc_text">
				3238
				3239	<h5>Syntax:</h5>
				3240
				3241	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3242	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3243	</pre>
				3244
				3245	<h5>Overview:</h5>
				3246
				3247	<p>
				3248	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3249	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3250	</p>
				3251
				3252
				3253	<h5>Arguments:</h5>
				3254
				3255	<p>
				3256	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3257	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]	3258	an index indicating the position from which to extract the element.
				3259	The index may be a variable.</p>
				3260
				3261	<h5>Semantics:</h5>
				3262
				3263	<p>
				3264	The result is a scalar of the same type as the element type of
				3265	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3266	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3267	results are undefined.
				3268	</p>
				3269
				3270	<h5>Example:</h5>
				3271
				3272	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3273	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3274	</pre>
				3275	</div>
				3276
				3277
				3278	<!-- _______________________________________________________________________ -->
				3279	<div class="doc_subsubsection">
				3280	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3281	</div>
				3282
				3283	<div class="doc_text">
				3284
				3285	<h5>Syntax:</h5>
				3286
				3287	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3288	<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]	3289	</pre>
				3290
				3291	<h5>Overview:</h5>
				3292
				3293	<p>
				3294	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3295	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3296	</p>
				3297
				3298
				3299	<h5>Arguments:</h5>
				3300
				3301	<p>
				3302	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3303	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]	3304	scalar value whose type must equal the element type of the first
				3305	operand. The third operand is an index indicating the position at
				3306	which to insert the value. The index may be a variable.</p>
				3307
				3308	<h5>Semantics:</h5>
				3309
				3310	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3311	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]	3312	element values are those of <tt>val</tt> except at position
				3313	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3314	exceeds the length of <tt>val</tt>, the results are undefined.
				3315	</p>
				3316
				3317	<h5>Example:</h5>
				3318
				3319	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3320	%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]	3321	</pre>
				3322	</div>
				3323
				3324	<!-- _______________________________________________________________________ -->
				3325	<div class="doc_subsubsection">
				3326	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3327	</div>
				3328
				3329	<div class="doc_text">
				3330
				3331	<h5>Syntax:</h5>
				3332
				3333	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3334	<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]	3335	</pre>
				3336
				3337	<h5>Overview:</h5>
				3338
				3339	<p>
				3340	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3341	from two input vectors, returning a vector with the same element type as
				3342	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3343	</p>
				3344
				3345	<h5>Arguments:</h5>
				3346
				3347	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3348	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3349	with types that match each other. The third argument is a shuffle mask whose
				3350	element type is always 'i32'. The result of the instruction is a vector whose
				3351	length is the same as the shuffle mask and whose element type is the same as
				3352	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3353	</p>
				3354
				3355	<p>
				3356	The shuffle mask operand is required to be a constant vector with either
				3357	constant integer or undef values.
				3358	</p>
				3359
				3360	<h5>Semantics:</h5>
				3361
				3362	<p>
				3363	The elements of the two input vectors are numbered from left to right across
				3364	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]	3365	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]	3366	gets. The element selector may be undef (meaning "don't care") and the second
				3367	operand may be undef if performing a shuffle from only one vector.
				3368	</p>
				3369
				3370	<h5>Example:</h5>
				3371
				3372	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3373	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3374	<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]	3375	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3376	<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]	3377	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3378	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3379	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3380	<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]	3381	</pre>
				3382	</div>
				3383
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3384
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3385	<!-- ======================================================================= -->
				3386	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3387	<a name="aggregateops">Aggregate Operations</a>
				3388	</div>
				3389
				3390	<div class="doc_text">
				3391
				3392	<p>LLVM supports several instructions for working with aggregate values.
				3393	</p>
				3394
				3395	</div>
				3396
				3397	<!-- _______________________________________________________________________ -->
				3398	<div class="doc_subsubsection">
				3399	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3400	</div>
				3401
				3402	<div class="doc_text">
				3403
				3404	<h5>Syntax:</h5>
				3405
				3406	<pre>
				3407	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3408	</pre>
				3409
				3410	<h5>Overview:</h5>
				3411
				3412	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3413	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3414	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3415	</p>
				3416
				3417
				3418	<h5>Arguments:</h5>
				3419
				3420	<p>
				3421	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3422	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]	3423	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3424	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3425	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3426	</p>
				3427
				3428	<h5>Semantics:</h5>
				3429
				3430	<p>
				3431	The result is the value at the position in the aggregate specified by
				3432	the index operands.
				3433	</p>
				3434
				3435	<h5>Example:</h5>
				3436
				3437	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3438	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3439	</pre>
				3440	</div>
				3441
				3442
				3443	<!-- _______________________________________________________________________ -->
				3444	<div class="doc_subsubsection">
				3445	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3446	</div>
				3447
				3448	<div class="doc_text">
				3449
				3450	<h5>Syntax:</h5>
				3451
				3452	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3453	<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]	3454	</pre>
				3455
				3456	<h5>Overview:</h5>
				3457
				3458	<p>
				3459	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3460	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3461	</p>
				3462
				3463
				3464	<h5>Arguments:</h5>
				3465
				3466	<p>
				3467	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3468	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3469	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3470	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3471	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]	3472	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3473	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3474	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]	3475	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3476	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3477
				3478	<h5>Semantics:</h5>
				3479
				3480	<p>
				3481	The result is an aggregate of the same type as <tt>val</tt>. Its
				3482	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]	3483	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3484	</p>
				3485
				3486	<h5>Example:</h5>
				3487
				3488	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3489	%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]	3490	</pre>
				3491	</div>
				3492
				3493
				3494	<!-- ======================================================================= -->
				3495	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3496	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3497	</div>
				3498
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3499	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3500
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3501	<p>A key design point of an SSA-based representation is how it
				3502	represents memory. In LLVM, no memory locations are in SSA form, which
				3503	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3504	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3505
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3506	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3508	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3509	<div class="doc_subsubsection">
				3510	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3511	</div>
				3512
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3513	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3514
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3515	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3516
				3517	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3518	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3519	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3520
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3521	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3522
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3523	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3524	heap and returns a pointer to it. The object is always allocated in the generic
				3525	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3526
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3527	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3528
				3529	<p>The '<tt>malloc</tt>' instruction allocates
				3530	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3531	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]	3532	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3533	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3534	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3535	be aligned to at least that boundary. If not specified, or if zero, the target can
				3536	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3537
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3538	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3539
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3540	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3541
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3542	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3543	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]	3544	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3545
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3546	<h5>Example:</h5>
				3547
				3548	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3549	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3550
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3551	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3552	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3553	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3554	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3555	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3556	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3557
				3558	<p>Note that the code generator does not yet respect the
				3559	alignment value.</p>
				3560
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3561	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3562
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3563	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3564	<div class="doc_subsubsection">
				3565	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3566	</div>
				3567
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3568	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3569
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3570	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3571
				3572	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3573	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3574	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3575
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3576	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3577
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3578	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3579	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3581	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3582
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3583	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3584	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3585	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3586
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3587	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3588
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3589	<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]	3590	after this instruction executes. If the pointer is null, the operation
				3591	is a noop.</p>
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	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3594
				3595	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3596	%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]	3597	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3598	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3599	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3600
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3601	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3602	<div class="doc_subsubsection">
				3603	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3604	</div>
				3605
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3606	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3607
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3608	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3609
				3610	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3611	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3612	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3614	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3615
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3616	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3617	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3618	returns to its caller. The object is always allocated in the generic address
				3619	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3620
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3621	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3622
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3623	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3624	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3625	appropriate type to the program. If "NumElements" is specified, it is the
				3626	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3627	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3628	to be aligned to at least that boundary. If not specified, or if zero, the target
				3629	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3630
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3631	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3632
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3633	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3634
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3635	<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]	3636	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3637	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3638	instruction is commonly used to represent automatic variables that must
				3639	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]	3640	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]	3641	instructions), the memory is reclaimed. Allocating zero bytes
				3642	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3643
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3644	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3645
				3646	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3647	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3648	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3649	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3650	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3651	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3652	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3653
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3654	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3655	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3656	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3657	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3658	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3659	<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]	3660	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3661	<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]	3662	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3663	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3664	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3665	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]	3666	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]	3667	the number or order of execution of this <tt>load</tt> with other
				3668	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3669	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3670	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3671	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3672	(that is, the alignment of the memory address). A value of 0 or an
				3673	omitted "align" argument means that the operation has the preferential
				3674	alignment for the target. It is the responsibility of the code emitter
				3675	to ensure that the alignment information is correct. Overestimating
				3676	the alignment results in an undefined behavior. Underestimating the
				3677	alignment may produce less efficient code. An alignment of 1 is always
				3678	safe.
				3679	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3680	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3681	<p>The location of memory pointed to is loaded. If the value being loaded
				3682	is of scalar type then the number of bytes read does not exceed the minimum
				3683	number of bytes needed to hold all bits of the type. For example, loading an
				3684	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3685	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3686	is undefined if the value was not originally written using a store of the
				3687	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3688	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3689	<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]	3690	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3691	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3692	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3693	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3694	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3695	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3696	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3697	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3698	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3699	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3700	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3701	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3702	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3703	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3704	<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]	3705	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3706	<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]	3707	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]	3708	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3709	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3710	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]	3711	optimizer is not allowed to modify the number or order of execution of
				3712	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3713	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3714	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3715	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3716	(that is, the alignment of the memory address). A value of 0 or an
				3717	omitted "align" argument means that the operation has the preferential
				3718	alignment for the target. It is the responsibility of the code emitter
				3719	to ensure that the alignment information is correct. Overestimating
				3720	the alignment results in an undefined behavior. Underestimating the
				3721	alignment may produce less efficient code. An alignment of 1 is always
				3722	safe.
				3723	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3724	<h5>Semantics:</h5>
				3725	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3726	at the location specified by the '<tt><pointer></tt>' operand.
				3727	If '<tt><value></tt>' is of scalar type then the number of bytes
				3728	written does not exceed the minimum number of bytes needed to hold all
				3729	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3730	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3731	size that is not an integral number of bytes, it is unspecified what
				3732	happens to the extra bits that do not belong to the type, but they will
				3733	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3734	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3735	<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]	3736	store i32 3, i32* %ptr <i>; yields {void}</i>
				3737	%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]	3738	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3739	</div>
				3740
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3741	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3742	<div class="doc_subsubsection">
				3743	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3744	</div>
				3745
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3746	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3747	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3748	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3749	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3750	</pre>
				3751
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3752	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3753
				3754	<p>
				3755	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]	3756	subelement of an aggregate data structure. It performs address calculation only
				3757	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3758
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3759	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3760
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3761	<p>The first argument is always a pointer, and forms the basis of the
				3762	calculation. The remaining arguments are indices, that indicate which of the
				3763	elements of the aggregate object are indexed. The interpretation of each index
				3764	is dependent on the type being indexed into. The first index always indexes the
				3765	pointer value given as the first argument, the second index indexes a value of
				3766	the type pointed to (not necessarily the value directly pointed to, since the
				3767	first index can be non-zero), etc. The first type indexed into must be a pointer
				3768	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3769	types being indexed into can never be pointers, since that would require loading
				3770	the pointer before continuing calculation.</p>
				3771
				3772	<p>The type of each index argument depends on the type it is indexing into.
				3773	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3774	<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]	3775	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3776
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3777	<p>For example, let's consider a C code fragment and how it gets
				3778	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3779
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3780	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3781	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3782	struct RT {
				3783	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3784	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3785	char C;
				3786	};
				3787	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3788	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3789	double Y;
				3790	struct RT Z;
				3791	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3792
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3793	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3794	return &s[1].Z.B[5][13];
				3795	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3796	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3797	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3798
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3799	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3800
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3801	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3802	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3803	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3804	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3805
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3806	define i32* %foo(%ST* %s) {
				3807	entry:
				3808	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3809	ret i32* %reg
				3810	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3811	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3812	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3813
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3814	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3815
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3816	<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]	3817	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]	3818	}</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]	3819	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3820	i8 }</tt>' type, another structure. The third index indexes into the second
				3821	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]	3822	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3823	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3824	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]	3825
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3826	<p>Note that it is perfectly legal to index partially through a
				3827	structure, returning a pointer to an inner element. Because of this,
				3828	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3829
				3830	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3831	define i32* %foo(%ST* %s) {
				3832	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3833	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3834	%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]	3835	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3836	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3837	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3838	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3839	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3840
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3841	<p>Note that it is undefined to access an array out of bounds: array
				3842	and pointer indexes must always be within the defined bounds of the
				3843	array type when accessed with an instruction that dereferences the
				3844	pointer (e.g. a load or store instruction). The one exception for
				3845	this rule is zero length arrays. These arrays are defined to be
				3846	accessible as variable length arrays, which requires access beyond the
				3847	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3848
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3849	<p>The getelementptr instruction is often confusing. For some more insight
				3850	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3851	FAQ</a>.</p>
				3852
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3853	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3854
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3855	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3856	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3857	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3858	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3859	%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]	3860	<i>; yields i8*:eptr</i>
				3861	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3862	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3863	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3864	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3865	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3866
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3867	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3868	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3869	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3870	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3871	<p>The instructions in this category are the conversion instructions (casting)
				3872	which all take a single operand and a type. They perform various bit conversions
				3873	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3874	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3875
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3876	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3877	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3878	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3879	</div>
				3880	<div class="doc_text">
				3881
				3882	<h5>Syntax:</h5>
				3883	<pre>
				3884	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3885	</pre>
				3886
				3887	<h5>Overview:</h5>
				3888	<p>
				3889	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3890	</p>
				3891
				3892	<h5>Arguments:</h5>
				3893	<p>
				3894	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3895	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]	3896	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]	3897	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3898	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3899
				3900	<h5>Semantics:</h5>
				3901	<p>
				3902	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]	3903	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3904	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3905	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3906
				3907	<h5>Example:</h5>
				3908	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3909	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3910	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3911	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3912	</pre>
				3913	</div>
				3914
				3915	<!-- _______________________________________________________________________ -->
				3916	<div class="doc_subsubsection">
				3917	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3918	</div>
				3919	<div class="doc_text">
				3920
				3921	<h5>Syntax:</h5>
				3922	<pre>
				3923	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3924	</pre>
				3925
				3926	<h5>Overview:</h5>
				3927	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3928	<tt>ty2</tt>.</p>
				3929
				3930
				3931	<h5>Arguments:</h5>
				3932	<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]	3933	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3934	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]	3935	<tt>value</tt> must be smaller than the bit size of the destination type,
				3936	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3937
				3938	<h5>Semantics:</h5>
				3939	<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]	3940	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]	3941
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3942	<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]	3943
				3944	<h5>Example:</h5>
				3945	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3946	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3947	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3948	</pre>
				3949	</div>
				3950
				3951	<!-- _______________________________________________________________________ -->
				3952	<div class="doc_subsubsection">
				3953	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3954	</div>
				3955	<div class="doc_text">
				3956
				3957	<h5>Syntax:</h5>
				3958	<pre>
				3959	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3960	</pre>
				3961
				3962	<h5>Overview:</h5>
				3963	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3964
				3965	<h5>Arguments:</h5>
				3966	<p>
				3967	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]	3968	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3969	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]	3970	<tt>value</tt> must be smaller than the bit size of the destination type,
				3971	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3972
				3973	<h5>Semantics:</h5>
				3974	<p>
				3975	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3976	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]	3977	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3978
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3979	<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]	3980
				3981	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3982	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3983	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3984	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3985	</pre>
				3986	</div>
				3987
				3988	<!-- _______________________________________________________________________ -->
				3989	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3990	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3991	</div>
				3992
				3993	<div class="doc_text">
				3994
				3995	<h5>Syntax:</h5>
				3996
				3997	<pre>
				3998	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3999	</pre>
				4000
				4001	<h5>Overview:</h5>
				4002	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				4003	<tt>ty2</tt>.</p>
				4004
				4005
				4006	<h5>Arguments:</h5>
				4007	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4008	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4009	cast it to. The size of <tt>value</tt> must be larger than the size of
				4010	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4011	<i>no-op cast</i>.</p>
				4012
				4013	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4014	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4015	<a href="#t_floating">floating point</a> type to a smaller
				4016	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4017	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4018
				4019	<h5>Example:</h5>
				4020	<pre>
				4021	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4022	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4023	</pre>
				4024	</div>
				4025
				4026	<!-- _______________________________________________________________________ -->
				4027	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4028	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4029	</div>
				4030	<div class="doc_text">
				4031
				4032	<h5>Syntax:</h5>
				4033	<pre>
				4034	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4035	</pre>
				4036
				4037	<h5>Overview:</h5>
				4038	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4039	floating point value.</p>
				4040
				4041	<h5>Arguments:</h5>
				4042	<p>The '<tt>fpext</tt>' instruction takes a
				4043	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4044	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4045	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4046
				4047	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4048	<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]	4049	<a href="#t_floating">floating point</a> type to a larger
				4050	<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]	4051	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]	4052	<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]	4053
				4054	<h5>Example:</h5>
				4055	<pre>
				4056	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4057	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4058	</pre>
				4059	</div>
				4060
				4061	<!-- _______________________________________________________________________ -->
				4062	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4063	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4064	</div>
				4065	<div class="doc_text">
				4066
				4067	<h5>Syntax:</h5>
				4068	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4069	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4070	</pre>
				4071
				4072	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4073	<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]	4074	unsigned integer equivalent of type <tt>ty2</tt>.
				4075	</p>
				4076
				4077	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4078	<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]	4079	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4080	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4081	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4082	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]	4083
				4084	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4085	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4086	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4087	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4088	the results are undefined.</p>
				4089
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4090	<h5>Example:</h5>
				4091	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4092	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4093	%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]	4094	%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]	4095	</pre>
				4096	</div>
				4097
				4098	<!-- _______________________________________________________________________ -->
				4099	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4100	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4101	</div>
				4102	<div class="doc_text">
				4103
				4104	<h5>Syntax:</h5>
				4105	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4106	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4107	</pre>
				4108
				4109	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4110	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4111	<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]	4112	</p>
				4113
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4114	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4115	<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]	4116	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4117	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4118	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4119	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]	4120
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4121	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4122	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4123	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4124	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4125	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4126
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4127	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4128	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4129	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4130	%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]	4131	%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]	4132	</pre>
				4133	</div>
				4134
				4135	<!-- _______________________________________________________________________ -->
				4136	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4137	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4138	</div>
				4139	<div class="doc_text">
				4140
				4141	<h5>Syntax:</h5>
				4142	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4143	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4144	</pre>
				4145
				4146	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4147	<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]	4148	integer and converts that value to the <tt>ty2</tt> type.</p>
				4149
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4150	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4151	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4152	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4153	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4154	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4155	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]	4156
				4157	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4158	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4159	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4160	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]	4161
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4162	<h5>Example:</h5>
				4163	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4164	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4165	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4166	</pre>
				4167	</div>
				4168
				4169	<!-- _______________________________________________________________________ -->
				4170	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4171	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4172	</div>
				4173	<div class="doc_text">
				4174
				4175	<h5>Syntax:</h5>
				4176	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4177	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4178	</pre>
				4179
				4180	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4181	<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]	4182	integer and converts that value to the <tt>ty2</tt> type.</p>
				4183
				4184	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4185	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4186	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4187	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4188	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4189	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]	4190
				4191	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4192	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4193	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4194	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]	4195
				4196	<h5>Example:</h5>
				4197	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4198	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4199	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4200	</pre>
				4201	</div>
				4202
				4203	<!-- _______________________________________________________________________ -->
				4204	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4205	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4206	</div>
				4207	<div class="doc_text">
				4208
				4209	<h5>Syntax:</h5>
				4210	<pre>
				4211	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4212	</pre>
				4213
				4214	<h5>Overview:</h5>
				4215	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4216	the integer type <tt>ty2</tt>.</p>
				4217
				4218	<h5>Arguments:</h5>
				4219	<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]	4220	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]	4221	<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]	4222
				4223	<h5>Semantics:</h5>
				4224	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4225	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4226	truncating or zero extending that value to the size of the integer type. If
				4227	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4228	<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]	4229	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4230	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4231
				4232	<h5>Example:</h5>
				4233	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4234	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4235	%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]	4236	</pre>
				4237	</div>
				4238
				4239	<!-- _______________________________________________________________________ -->
				4240	<div class="doc_subsubsection">
				4241	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4242	</div>
				4243	<div class="doc_text">
				4244
				4245	<h5>Syntax:</h5>
				4246	<pre>
				4247	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4248	</pre>
				4249
				4250	<h5>Overview:</h5>
				4251	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4252	a pointer type, <tt>ty2</tt>.</p>
				4253
				4254	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4255	<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]	4256	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]	4257	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4258
				4259	<h5>Semantics:</h5>
				4260	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4261	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4262	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4263	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4264	the size of a pointer then a zero extension is done. If they are the same size,
				4265	nothing is done (<i>no-op cast</i>).</p>
				4266
				4267	<h5>Example:</h5>
				4268	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4269	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4270	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4271	%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]	4272	</pre>
				4273	</div>
				4274
				4275	<!-- _______________________________________________________________________ -->
				4276	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4277	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4278	</div>
				4279	<div class="doc_text">
				4280
				4281	<h5>Syntax:</h5>
				4282	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4283	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4284	</pre>
				4285
				4286	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4287
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4288	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4289	<tt>ty2</tt> without changing any bits.</p>
				4290
				4291	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4292
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4293	<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]	4294	a non-aggregate first class value, and a type to cast it to, which must also be
				4295	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4296	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4297	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]	4298	type is a pointer, the destination type must also be a pointer. This
				4299	instruction supports bitwise conversion of vectors to integers and to vectors
				4300	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4301
				4302	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4303	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4304	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4305	this conversion. The conversion is done as if the <tt>value</tt> had been
				4306	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4307	converted to other pointer types with this instruction. To convert pointers to
				4308	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4309	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4310
				4311	<h5>Example:</h5>
				4312	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4313	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4314	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4315	%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]	4316	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4317	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4318
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4319	<!-- ======================================================================= -->
				4320	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4321	<div class="doc_text">
				4322	<p>The instructions in this category are the "miscellaneous"
				4323	instructions, which defy better classification.</p>
				4324	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4325
				4326	<!-- _______________________________________________________________________ -->
				4327	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4328	</div>
				4329	<div class="doc_text">
				4330	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4331	<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]	4332	</pre>
				4333	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4334	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4335	a vector of boolean values based on comparison
				4336	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4337	<h5>Arguments:</h5>
				4338	<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]	4339	the condition code indicating the kind of comparison to perform. It is not
				4340	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4341	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4342	<ol>
				4343	<li><tt>eq</tt>: equal</li>
				4344	<li><tt>ne</tt>: not equal </li>
				4345	<li><tt>ugt</tt>: unsigned greater than</li>
				4346	<li><tt>uge</tt>: unsigned greater or equal</li>
				4347	<li><tt>ult</tt>: unsigned less than</li>
				4348	<li><tt>ule</tt>: unsigned less or equal</li>
				4349	<li><tt>sgt</tt>: signed greater than</li>
				4350	<li><tt>sge</tt>: signed greater or equal</li>
				4351	<li><tt>slt</tt>: signed less than</li>
				4352	<li><tt>sle</tt>: signed less or equal</li>
				4353	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4354	<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]	4355	<a href="#t_pointer">pointer</a>
				4356	or integer <a href="#t_vector">vector</a> typed.
				4357	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4358	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4359	<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]	4360	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4361	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]	4362	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4363	<ol>
				4364	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4365	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4366	</li>
				4367	<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]	4368	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4369	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4370	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4371	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4372	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4373	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4374	<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]	4375	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4376	<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]	4377	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4378	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4379	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4380	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4381	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4382	<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]	4383	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4384	<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]	4385	</ol>
				4386	<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]	4387	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4388	<p>If the operands are integer vectors, then they are compared
				4389	element by element. The result is an <tt>i1</tt> vector with
				4390	the same number of elements as the values being compared.
				4391	Otherwise, the result is an <tt>i1</tt>.
				4392	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4393
				4394	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4395	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4396	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4397	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4398	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4399	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4400	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4401	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4402
				4403	<p>Note that the code generator does not yet support vector types with
				4404	the <tt>icmp</tt> instruction.</p>
				4405
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4406	</div>
				4407
				4408	<!-- _______________________________________________________________________ -->
				4409	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4410	</div>
				4411	<div class="doc_text">
				4412	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4413	<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]	4414	</pre>
				4415	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4416	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4417	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4418	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4419	<p>
				4420	If the operands are floating point scalars, then the result
				4421	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4422	</p>
				4423	<p>If the operands are floating point vectors, then the result type
				4424	is a vector of boolean with the same number of elements as the
				4425	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4426	<h5>Arguments:</h5>
				4427	<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]	4428	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]	4429	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4430	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4431	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4432	<li><tt>oeq</tt>: ordered and equal</li>
				4433	<li><tt>ogt</tt>: ordered and greater than </li>
				4434	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4435	<li><tt>olt</tt>: ordered and less than </li>
				4436	<li><tt>ole</tt>: ordered and less than or equal</li>
				4437	<li><tt>one</tt>: ordered and not equal</li>
				4438	<li><tt>ord</tt>: ordered (no nans)</li>
				4439	<li><tt>ueq</tt>: unordered or equal</li>
				4440	<li><tt>ugt</tt>: unordered or greater than </li>
				4441	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4442	<li><tt>ult</tt>: unordered or less than </li>
				4443	<li><tt>ule</tt>: unordered or less than or equal</li>
				4444	<li><tt>une</tt>: unordered or not equal</li>
				4445	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4446	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4447	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4448	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4449	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4450	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4451	either a <a href="#t_floating">floating point</a> type
				4452	or a <a href="#t_vector">vector</a> of floating point type.
				4453	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4454	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4455	<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]	4456	according to the condition code given as <tt>cond</tt>.
				4457	If the operands are vectors, then the vectors are compared
				4458	element by element.
				4459	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4460	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]	4461	<ol>
				4462	<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]	4463	<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]	4464	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4465	<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]	4466	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4467	<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]	4468	<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]	4469	<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]	4470	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4471	<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]	4472	<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]	4473	<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]	4474	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4475	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4476	<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]	4477	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4478	<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]	4479	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4480	<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]	4481	<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]	4482	<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]	4483	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4484	<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]	4485	<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]	4486	<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]	4487	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4488	<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]	4489	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4490	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4491
				4492	<h5>Example:</h5>
				4493	<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]	4494	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4495	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4496	<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]	4497	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4498
				4499	<p>Note that the code generator does not yet support vector types with
				4500	the <tt>fcmp</tt> instruction.</p>
				4501
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4502	</div>
				4503
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4504	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4505	<div class="doc_subsubsection">
				4506	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4507	</div>
				4508	<div class="doc_text">
				4509	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4510	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4511	</pre>
				4512	<h5>Overview:</h5>
				4513	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4514	element-wise comparison of its two integer vector operands.</p>
				4515	<h5>Arguments:</h5>
				4516	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4517	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]	4518	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4519	<ol>
				4520	<li><tt>eq</tt>: equal</li>
				4521	<li><tt>ne</tt>: not equal </li>
				4522	<li><tt>ugt</tt>: unsigned greater than</li>
				4523	<li><tt>uge</tt>: unsigned greater or equal</li>
				4524	<li><tt>ult</tt>: unsigned less than</li>
				4525	<li><tt>ule</tt>: unsigned less or equal</li>
				4526	<li><tt>sgt</tt>: signed greater than</li>
				4527	<li><tt>sge</tt>: signed greater or equal</li>
				4528	<li><tt>slt</tt>: signed less than</li>
				4529	<li><tt>sle</tt>: signed less or equal</li>
				4530	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4531	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4532	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4533	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4534	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4535	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4536	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4537	identical type as the values being compared. The most significant bit in each
				4538	element is 1 if the element-wise comparison evaluates to true, and is 0
				4539	otherwise. All other bits of the result are undefined. The condition codes
				4540	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4541	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4542
				4543	<h5>Example:</h5>
				4544	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4545	<result> = vicmp eq <2 x i32> < i32 4, i32 0>, < i32 5, i32 0> <i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4546	<result> = vicmp ult <2 x i8 > < i8 1, i8 2>, < i8 2, i8 2 > <i>; yields: result=<2 x i8> < i8 -1, i8 0 ></i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4547	</pre>
				4548	</div>
				4549
				4550	<!-- _______________________________________________________________________ -->
				4551	<div class="doc_subsubsection">
				4552	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4553	</div>
				4554	<div class="doc_text">
				4555	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4556	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4557	<h5>Overview:</h5>
				4558	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4559	element-wise comparison of its two floating point vector operands. The output
				4560	elements have the same width as the input elements.</p>
				4561	<h5>Arguments:</h5>
				4562	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4563	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]	4564	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4565	<ol>
				4566	<li><tt>false</tt>: no comparison, always returns false</li>
				4567	<li><tt>oeq</tt>: ordered and equal</li>
				4568	<li><tt>ogt</tt>: ordered and greater than </li>
				4569	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4570	<li><tt>olt</tt>: ordered and less than </li>
				4571	<li><tt>ole</tt>: ordered and less than or equal</li>
				4572	<li><tt>one</tt>: ordered and not equal</li>
				4573	<li><tt>ord</tt>: ordered (no nans)</li>
				4574	<li><tt>ueq</tt>: unordered or equal</li>
				4575	<li><tt>ugt</tt>: unordered or greater than </li>
				4576	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4577	<li><tt>ult</tt>: unordered or less than </li>
				4578	<li><tt>ule</tt>: unordered or less than or equal</li>
				4579	<li><tt>une</tt>: unordered or not equal</li>
				4580	<li><tt>uno</tt>: unordered (either nans)</li>
				4581	<li><tt>true</tt>: no comparison, always returns true</li>
				4582	</ol>
				4583	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4584	<a href="#t_floating">floating point</a> typed. They must also be identical
				4585	types.</p>
				4586	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4587	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4588	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4589	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4590	an identical number of elements as the values being compared, and each element
				4591	having identical with to the width of the floating point elements. The most
				4592	significant bit in each element is 1 if the element-wise comparison evaluates to
				4593	true, and is 0 otherwise. All other bits of the result are undefined. The
				4594	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4595	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4596
				4597	<h5>Example:</h5>
				4598	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4599	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4600	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4601
				4602	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4603	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4604	</pre>
				4605	</div>
				4606
				4607	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4608	<div class="doc_subsubsection">
				4609	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4610	</div>
				4611
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4612	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4613
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4614	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4615
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4616	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4617	<h5>Overview:</h5>
				4618	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4619	the SSA graph representing the function.</p>
				4620	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4621
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4622	<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]	4623	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4624	as arguments, with one pair for each predecessor basic block of the
				4625	current block. Only values of <a href="#t_firstclass">first class</a>
				4626	type may be used as the value arguments to the PHI node. Only labels
				4627	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4628
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4629	<p>There must be no non-phi instructions between the start of a basic
				4630	block and the PHI instructions: i.e. PHI instructions must be first in
				4631	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4632
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4633	<p>For the purposes of the SSA form, the use of each incoming value is
				4634	deemed to occur on the edge from the corresponding predecessor block
				4635	to the current block (but after any definition of an '<tt>invoke</tt>'
				4636	instruction's return value on the same edge).</p>
				4637
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4638	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4639
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4640	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4641	specified by the pair corresponding to the predecessor basic block that executed
				4642	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4643
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4644	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4645	<pre>
				4646	Loop: ; Infinite loop that counts from 0 on up...
				4647	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4648	%nextindvar = add i32 %indvar, 1
				4649	br label %Loop
				4650	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4651	</div>
				4652
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4653	<!-- _______________________________________________________________________ -->
				4654	<div class="doc_subsubsection">
				4655	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4656	</div>
				4657
				4658	<div class="doc_text">
				4659
				4660	<h5>Syntax:</h5>
				4661
				4662	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4663	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4664
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4665	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4666	</pre>
				4667
				4668	<h5>Overview:</h5>
				4669
				4670	<p>
				4671	The '<tt>select</tt>' instruction is used to choose one value based on a
				4672	condition, without branching.
				4673	</p>
				4674
				4675
				4676	<h5>Arguments:</h5>
				4677
				4678	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4679	The '<tt>select</tt>' instruction requires an 'i1' value or
				4680	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4681	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]	4682	type. If the val1/val2 are vectors and
				4683	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4684	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4685	</p>
				4686
				4687	<h5>Semantics:</h5>
				4688
				4689	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4690	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]	4691	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4692	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4693	<p>
				4694	If the condition is a vector of i1, then the value arguments must
				4695	be vectors of the same size, and the selection is done element
				4696	by element.
				4697	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4698
				4699	<h5>Example:</h5>
				4700
				4701	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4702	%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]	4703	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4704
				4705	<p>Note that the code generator does not yet support conditions
				4706	with vector type.</p>
				4707
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4708	</div>
				4709
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4710
				4711	<!-- _______________________________________________________________________ -->
				4712	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4713	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4714	</div>
				4715
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4716	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4717
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4718	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4719	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4720	<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]	4721	</pre>
				4722
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4723	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4724
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4725	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4726
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4727	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4728
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4729	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4730
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4731	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4732	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4733	<p>The optional "tail" marker indicates whether the callee function accesses
				4734	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]	4735	function call is eligible for tail call optimization. Note that calls may
				4736	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4737	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4738	</li>
				4739	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4740	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4741	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]	4742	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4743	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4744
				4745	<li>
				4746	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4747	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4748	and '<tt>inreg</tt>' attributes are valid here.</p>
				4749	</li>
				4750
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4751	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4752	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4753	the type of the return value. Functions that return no value are marked
				4754	<tt><a href="#t_void">void</a></tt>.</p>
				4755	</li>
				4756	<li>
				4757	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4758	value being invoked. The argument types must match the types implied by
				4759	this signature. This type can be omitted if the function is not varargs
				4760	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]	4761	</li>
				4762	<li>
				4763	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4764	be invoked. In most cases, this is a direct function invocation, but
				4765	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]	4766	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4767	</li>
				4768	<li>
				4769	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4770	function signature argument types. All arguments must be of
				4771	<a href="#t_firstclass">first class</a> type. If the function signature
				4772	indicates the function accepts a variable number of arguments, the extra
				4773	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4774	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4775	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4776	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4777	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4778	'<tt>readnone</tt>' attributes are valid here.</p>
				4779	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4780	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4781
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4782	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4783
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4784	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4785	transfer to a specified function, with its incoming arguments bound to
				4786	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4787	instruction in the called function, control flow continues with the
				4788	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4789	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4790
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4791	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4792
				4793	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4794	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4795	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4796	%X = tail call i32 @foo() <i>; yields i32</i>
				4797	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4798	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4799
				4800	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4801	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4802	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4803	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4804	%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]	4805	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4806	</pre>
				4807
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4808	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4809
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4810	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4811	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4812	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4813	</div>
				4814
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4815	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4816
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4817	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4818
				4819	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4820	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4821	</pre>
				4822
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4823	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4824
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4825	<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]	4826	the "variable argument" area of a function call. It is used to implement the
				4827	<tt>va_arg</tt> macro in C.</p>
				4828
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4829	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4830
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4831	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4832	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4833	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]	4834	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4835
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4836	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4837
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4838	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4839	type from the specified <tt>va_list</tt> and causes the
				4840	<tt>va_list</tt> to point to the next argument. For more information,
				4841	see the variable argument handling <a href="#int_varargs">Intrinsic
				4842	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4843
				4844	<p>It is legal for this instruction to be called in a function which does not
				4845	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4846	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4847
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4848	<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]	4849	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4850	argument.</p>
				4851
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4852	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4853
				4854	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4855
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4856	<p>Note that the code generator does not yet fully support va_arg
				4857	on many targets. Also, it does not currently support va_arg with
				4858	aggregate types on any target.</p>
				4859
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4860	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4861
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4862	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4863	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4864	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4865
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4866	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4867
				4868	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4869	well known names and semantics and are required to follow certain restrictions.
				4870	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4871	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]	4872	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]	4873
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4874	<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]	4875	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4876	begin with this prefix. Intrinsic functions must always be external functions:
				4877	you cannot define the body of intrinsic functions. Intrinsic functions may
				4878	only be used in call or invoke instructions: it is illegal to take the address
				4879	of an intrinsic function. Additionally, because intrinsic functions are part
				4880	of the LLVM language, it is required if any are added that they be documented
				4881	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4882
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4883	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4884	a family of functions that perform the same operation but on different data
				4885	types. Because LLVM can represent over 8 million different integer types,
				4886	overloading is used commonly to allow an intrinsic function to operate on any
				4887	integer type. One or more of the argument types or the result type can be
				4888	overloaded to accept any integer type. Argument types may also be defined as
				4889	exactly matching a previous argument's type or the result type. This allows an
				4890	intrinsic function which accepts multiple arguments, but needs all of them to
				4891	be of the same type, to only be overloaded with respect to a single argument or
				4892	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4893
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4894	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4895	encoded into its function name, each preceded by a period. Only those types
				4896	which are overloaded result in a name suffix. Arguments whose type is matched
				4897	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4898	take an integer of any width and returns an integer of exactly the same integer
				4899	width. This leads to a family of functions such as
				4900	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4901	Only one type, the return type, is overloaded, and only one type suffix is
				4902	required. Because the argument's type is matched against the return type, it
				4903	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4904
				4905	<p>To learn how to add an intrinsic function, please see the
				4906	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4907	</p>
				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_subsection">
				4913	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				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
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4918	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4919	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]	4920	intrinsic functions. These functions are related to the similarly
				4921	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4922
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4923	<p>All of these functions operate on arguments that use a
				4924	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4925	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4926	transformations should be prepared to handle these functions regardless of
				4927	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4928
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4929	<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]	4930	instruction and the variable argument handling intrinsic functions are
				4931	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4932
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4933	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4934	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4935	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4936	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4937	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4938	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4939	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4940
				4941	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4942	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4943
				4944	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4945	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4946	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4947	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4948	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4949
				4950	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4951	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4952	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4953	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4954
				4955	declare void @llvm.va_start(i8*)
				4956	declare void @llvm.va_copy(i8, i8)
				4957	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4958	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4959	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4960
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4961	</div>
				4962
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4963	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4964	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4965	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4966	</div>
				4967
				4968
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4969	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4970	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4971	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4972	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4973	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4974	<tt>*<arglist></tt> for subsequent use by <tt><a
				4975	href="#i_va_arg">va_arg</a></tt>.</p>
				4976
				4977	<h5>Arguments:</h5>
				4978
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4979	<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]	4980
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4981	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4982
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4983	<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]	4984	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4985	<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]	4986	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4987	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]	4988	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]	4989
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4990	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4991
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4992	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4993	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4994	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4995	</div>
				4996
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4997	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4998	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4999	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5000	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5001
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5002	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5003	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]	5004	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]	5005
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5006	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5007
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5008	<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]	5009
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5010	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5011
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5012	<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]	5013	macro available in C. In a target-dependent way, it destroys the
				5014	<tt>va_list</tt> element to which the argument points. Calls to <a
				5015	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				5016	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				5017	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5018
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5019	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5020
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5021	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5022	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5023	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5024	</div>
				5025
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5026	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5027
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5028	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5029
				5030	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5031	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5032	</pre>
				5033
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5034	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5035
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5036	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				5037	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5038
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5039	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5040
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	5041	<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]	5042	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]	5043
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5044
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5045	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5046
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5047	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				5048	macro available in C. In a target-dependent way, it copies the source
				5049	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				5050	intrinsic is necessary because the <tt><a href="#int_va_start">
				5051	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				5052	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5053
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5054	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5055
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5056	<!-- ======================================================================= -->
				5057	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5058	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				5059	</div>
				5060
				5061	<div class="doc_text">
				5062
				5063	<p>
				5064	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5065	Collection</a> (GC) requires the implementation and generation of these
				5066	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5067	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]	5068	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5069	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]	5070	Front-ends for type-safe garbage collected languages should generate these
				5071	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				5072	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				5073	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	5074
				5075	<p>The garbage collection intrinsics only operate on objects in the generic
				5076	address space (address space zero).</p>
				5077
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5078	</div>
				5079
				5080	<!-- _______________________________________________________________________ -->
				5081	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5082	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5083	</div>
				5084
				5085	<div class="doc_text">
				5086
				5087	<h5>Syntax:</h5>
				5088
				5089	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5090	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5091	</pre>
				5092
				5093	<h5>Overview:</h5>
				5094
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	5095	<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]	5096	the code generator, and allows some metadata to be associated with it.</p>
				5097
				5098	<h5>Arguments:</h5>
				5099
				5100	<p>The first argument specifies the address of a stack object that contains the
				5101	root pointer. The second pointer (which must be either a constant or a global
				5102	value address) contains the meta-data to be associated with the root.</p>
				5103
				5104	<h5>Semantics:</h5>
				5105
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	5106	<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]	5107	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5108	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5109	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5110	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5111
				5112	</div>
				5113
				5114
				5115	<!-- _______________________________________________________________________ -->
				5116	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5117	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5118	</div>
				5119
				5120	<div class="doc_text">
				5121
				5122	<h5>Syntax:</h5>
				5123
				5124	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5125	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5126	</pre>
				5127
				5128	<h5>Overview:</h5>
				5129
				5130	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5131	locations, allowing garbage collector implementations that require read
				5132	barriers.</p>
				5133
				5134	<h5>Arguments:</h5>
				5135
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5136	<p>The second argument is the address to read from, which should be an address
				5137	allocated from the garbage collector. The first object is a pointer to the
				5138	start of the referenced object, if needed by the language runtime (otherwise
				5139	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5140
				5141	<h5>Semantics:</h5>
				5142
				5143	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5144	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5145	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5146	may only be used in a function which <a href="#gc">specifies a GC
				5147	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5148
				5149	</div>
				5150
				5151
				5152	<!-- _______________________________________________________________________ -->
				5153	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5154	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5155	</div>
				5156
				5157	<div class="doc_text">
				5158
				5159	<h5>Syntax:</h5>
				5160
				5161	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5162	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5163	</pre>
				5164
				5165	<h5>Overview:</h5>
				5166
				5167	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5168	locations, allowing garbage collector implementations that require write
				5169	barriers (such as generational or reference counting collectors).</p>
				5170
				5171	<h5>Arguments:</h5>
				5172
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5173	<p>The first argument is the reference to store, the second is the start of the
				5174	object to store it to, and the third is the address of the field of Obj to
				5175	store to. If the runtime does not require a pointer to the object, Obj may be
				5176	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5177
				5178	<h5>Semantics:</h5>
				5179
				5180	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5181	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5182	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5183	may only be used in a function which <a href="#gc">specifies a GC
				5184	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5185
				5186	</div>
				5187
				5188
				5189
				5190	<!-- ======================================================================= -->
				5191	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5192	<a name="int_codegen">Code Generator Intrinsics</a>
				5193	</div>
				5194
				5195	<div class="doc_text">
				5196	<p>
				5197	These intrinsics are provided by LLVM to expose special features that may only
				5198	be implemented with code generator support.
				5199	</p>
				5200
				5201	</div>
				5202
				5203	<!-- _______________________________________________________________________ -->
				5204	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5205	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5206	</div>
				5207
				5208	<div class="doc_text">
				5209
				5210	<h5>Syntax:</h5>
				5211	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5212	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5213	</pre>
				5214
				5215	<h5>Overview:</h5>
				5216
				5217	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5218	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5219	target-specific value indicating the return address of the current function
				5220	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5221	</p>
				5222
				5223	<h5>Arguments:</h5>
				5224
				5225	<p>
				5226	The argument to this intrinsic indicates which function to return the address
				5227	for. Zero indicates the calling function, one indicates its caller, etc. The
				5228	argument is <b>required</b> to be a constant integer value.
				5229	</p>
				5230
				5231	<h5>Semantics:</h5>
				5232
				5233	<p>
				5234	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5235	the return address of the specified call frame, or zero if it cannot be
				5236	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5237	for arguments other than zero, so it should only be used for debugging purposes.
				5238	</p>
				5239
				5240	<p>
				5241	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5242	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]	5243	source-language caller.
				5244	</p>
				5245	</div>
				5246
				5247
				5248	<!-- _______________________________________________________________________ -->
				5249	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5250	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5251	</div>
				5252
				5253	<div class="doc_text">
				5254
				5255	<h5>Syntax:</h5>
				5256	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5257	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5258	</pre>
				5259
				5260	<h5>Overview:</h5>
				5261
				5262	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5263	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5264	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5265	</p>
				5266
				5267	<h5>Arguments:</h5>
				5268
				5269	<p>
				5270	The argument to this intrinsic indicates which function to return the frame
				5271	pointer for. Zero indicates the calling function, one indicates its caller,
				5272	etc. The argument is <b>required</b> to be a constant integer value.
				5273	</p>
				5274
				5275	<h5>Semantics:</h5>
				5276
				5277	<p>
				5278	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5279	the frame address of the specified call frame, or zero if it cannot be
				5280	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5281	for arguments other than zero, so it should only be used for debugging purposes.
				5282	</p>
				5283
				5284	<p>
				5285	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5286	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]	5287	source-language caller.
				5288	</p>
				5289	</div>
				5290
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +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_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +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 i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5301	</pre>
				5302
				5303	<h5>Overview:</h5>
				5304
				5305	<p>
				5306	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]	5307	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5308	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5309	features like scoped automatic variable sized arrays in C99.
				5310	</p>
				5311
				5312	<h5>Semantics:</h5>
				5313
				5314	<p>
				5315	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]	5316	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5317	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5318	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5319	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5320	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5321	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5322	</p>
				5323
				5324	</div>
				5325
				5326	<!-- _______________________________________________________________________ -->
				5327	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5328	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5329	</div>
				5330
				5331	<div class="doc_text">
				5332
				5333	<h5>Syntax:</h5>
				5334	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5335	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5336	</pre>
				5337
				5338	<h5>Overview:</h5>
				5339
				5340	<p>
				5341	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5342	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]	5343	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5344	useful for implementing language features like scoped automatic variable sized
				5345	arrays in C99.
				5346	</p>
				5347
				5348	<h5>Semantics:</h5>
				5349
				5350	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5351	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]	5352	</p>
				5353
				5354	</div>
				5355
				5356
				5357	<!-- _______________________________________________________________________ -->
				5358	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5359	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5360	</div>
				5361
				5362	<div class="doc_text">
				5363
				5364	<h5>Syntax:</h5>
				5365	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5366	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5367	</pre>
				5368
				5369	<h5>Overview:</h5>
				5370
				5371
				5372	<p>
				5373	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]	5374	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5375	no
				5376	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5377	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5378	</p>
				5379
				5380	<h5>Arguments:</h5>
				5381
				5382	<p>
				5383	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5384	determining if the fetch should be for a read (0) or write (1), and
				5385	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5386	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]	5387	<tt>locality</tt> arguments must be constant integers.
				5388	</p>
				5389
				5390	<h5>Semantics:</h5>
				5391
				5392	<p>
				5393	This intrinsic does not modify the behavior of the program. In particular,
				5394	prefetches cannot trap and do not produce a value. On targets that support this
				5395	intrinsic, the prefetch can provide hints to the processor cache for better
				5396	performance.
				5397	</p>
				5398
				5399	</div>
				5400
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5401	<!-- _______________________________________________________________________ -->
				5402	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5403	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5404	</div>
				5405
				5406	<div class="doc_text">
				5407
				5408	<h5>Syntax:</h5>
				5409	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5410	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5411	</pre>
				5412
				5413	<h5>Overview:</h5>
				5414
				5415
				5416	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5417	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]	5418	(PC) in a region of
				5419	code to simulators and other tools. The method is target specific, but it is
				5420	expected that the marker will use exported symbols to transmit the PC of the
				5421	marker.
				5422	The marker makes no guarantees that it will remain with any specific instruction
				5423	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]	5424	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5425	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5426	</p>
				5427
				5428	<h5>Arguments:</h5>
				5429
				5430	<p>
				5431	<tt>id</tt> is a numerical id identifying the marker.
				5432	</p>
				5433
				5434	<h5>Semantics:</h5>
				5435
				5436	<p>
				5437	This intrinsic does not modify the behavior of the program. Backends that do not
				5438	support this intrinisic may ignore it.
				5439	</p>
				5440
				5441	</div>
				5442
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5443	<!-- _______________________________________________________________________ -->
				5444	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5445	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5446	</div>
				5447
				5448	<div class="doc_text">
				5449
				5450	<h5>Syntax:</h5>
				5451	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5452	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5453	</pre>
				5454
				5455	<h5>Overview:</h5>
				5456
				5457
				5458	<p>
				5459	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5460	counter register (or similar low latency, high accuracy clocks) on those targets
				5461	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5462	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5463	should only be used for small timings.
				5464	</p>
				5465
				5466	<h5>Semantics:</h5>
				5467
				5468	<p>
				5469	When directly supported, reading the cycle counter should not modify any memory.
				5470	Implementations are allowed to either return a application specific value or a
				5471	system wide value. On backends without support, this is lowered to a constant 0.
				5472	</p>
				5473
				5474	</div>
				5475
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5476	<!-- ======================================================================= -->
				5477	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5478	<a name="int_libc">Standard C Library Intrinsics</a>
				5479	</div>
				5480
				5481	<div class="doc_text">
				5482	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5483	LLVM provides intrinsics for a few important standard C library functions.
				5484	These intrinsics allow source-language front-ends to pass information about the
				5485	alignment of the pointer arguments to the code generator, providing opportunity
				5486	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5487	</p>
				5488
				5489	</div>
				5490
				5491	<!-- _______________________________________________________________________ -->
				5492	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5493	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5494	</div>
				5495
				5496	<div class="doc_text">
				5497
				5498	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5499	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5500	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5501	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5502	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5503	i8 <len>, i32 <align>)
				5504	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5505	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5506	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5507	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5508	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5509	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5510	</pre>
				5511
				5512	<h5>Overview:</h5>
				5513
				5514	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5515	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]	5516	location to the destination location.
				5517	</p>
				5518
				5519	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5520	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5521	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5522	</p>
				5523
				5524	<h5>Arguments:</h5>
				5525
				5526	<p>
				5527	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]	5528	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5529	specifying the number of bytes to copy, and the fourth argument is the alignment
				5530	of the source and destination locations.
				5531	</p>
				5532
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5533	<p>
				5534	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]	5535	the caller guarantees that both the source and destination pointers are aligned
				5536	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5537	</p>
				5538
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5539	<h5>Semantics:</h5>
				5540
				5541	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5542	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]	5543	location to the destination location, which are not allowed to overlap. It
				5544	copies "len" bytes of memory over. If the argument is known to be aligned to
				5545	some boundary, this can be specified as the fourth argument, otherwise it should
				5546	be set to 0 or 1.
				5547	</p>
				5548	</div>
				5549
				5550
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5551	<!-- _______________________________________________________________________ -->
				5552	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5553	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5554	</div>
				5555
				5556	<div class="doc_text">
				5557
				5558	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5559	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5560	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5561	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5562	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5563	i8 <len>, i32 <align>)
				5564	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5565	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5566	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5567	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5568	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5569	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5570	</pre>
				5571
				5572	<h5>Overview:</h5>
				5573
				5574	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5575	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5576	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5577	'<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]	5578	</p>
				5579
				5580	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5581	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5582	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5583	</p>
				5584
				5585	<h5>Arguments:</h5>
				5586
				5587	<p>
				5588	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]	5589	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5590	specifying the number of bytes to copy, and the fourth argument is the alignment
				5591	of the source and destination locations.
				5592	</p>
				5593
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5594	<p>
				5595	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]	5596	the caller guarantees that the source and destination pointers are aligned to
				5597	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5598	</p>
				5599
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5600	<h5>Semantics:</h5>
				5601
				5602	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5603	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]	5604	location to the destination location, which may overlap. It
				5605	copies "len" bytes of memory over. If the argument is known to be aligned to
				5606	some boundary, this can be specified as the fourth argument, otherwise it should
				5607	be set to 0 or 1.
				5608	</p>
				5609	</div>
				5610
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5611
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5612	<!-- _______________________________________________________________________ -->
				5613	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5614	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5615	</div>
				5616
				5617	<div class="doc_text">
				5618
				5619	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5620	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5621	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5622	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5623	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5624	i8 <len>, i32 <align>)
				5625	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5626	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5627	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5628	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5629	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5630	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5631	</pre>
				5632
				5633	<h5>Overview:</h5>
				5634
				5635	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5636	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]	5637	byte value.
				5638	</p>
				5639
				5640	<p>
				5641	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5642	does not return a value, and takes an extra alignment argument.
				5643	</p>
				5644
				5645	<h5>Arguments:</h5>
				5646
				5647	<p>
				5648	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]	5649	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5650	argument specifying the number of bytes to fill, and the fourth argument is the
				5651	known alignment of destination location.
				5652	</p>
				5653
				5654	<p>
				5655	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]	5656	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5657	</p>
				5658
				5659	<h5>Semantics:</h5>
				5660
				5661	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5662	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5663	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5664	destination location. If the argument is known to be aligned to some boundary,
				5665	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5666	1.
				5667	</p>
				5668	</div>
				5669
				5670
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5671	<!-- _______________________________________________________________________ -->
				5672	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5673	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5674	</div>
				5675
				5676	<div class="doc_text">
				5677
				5678	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5679	<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]	5680	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]	5681	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5682	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5683	declare float @llvm.sqrt.f32(float %Val)
				5684	declare double @llvm.sqrt.f64(double %Val)
				5685	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5686	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5687	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5688	</pre>
				5689
				5690	<h5>Overview:</h5>
				5691
				5692	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5693	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]	5694	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]	5695	<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]	5696	negative numbers other than -0.0 (which allows for better optimization, because
				5697	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5698	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5699	</p>
				5700
				5701	<h5>Arguments:</h5>
				5702
				5703	<p>
				5704	The argument and return value are floating point numbers of the same type.
				5705	</p>
				5706
				5707	<h5>Semantics:</h5>
				5708
				5709	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5710	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]	5711	floating point number.
				5712	</p>
				5713	</div>
				5714
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5715	<!-- _______________________________________________________________________ -->
				5716	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5717	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5718	</div>
				5719
				5720	<div class="doc_text">
				5721
				5722	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5723	<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]	5724	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]	5725	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5726	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5727	declare float @llvm.powi.f32(float %Val, i32 %power)
				5728	declare double @llvm.powi.f64(double %Val, i32 %power)
				5729	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5730	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5731	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5732	</pre>
				5733
				5734	<h5>Overview:</h5>
				5735
				5736	<p>
				5737	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5738	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5739	multiplications is not defined. When a vector of floating point type is
				5740	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5741	</p>
				5742
				5743	<h5>Arguments:</h5>
				5744
				5745	<p>
				5746	The second argument is an integer power, and the first is a value to raise to
				5747	that power.
				5748	</p>
				5749
				5750	<h5>Semantics:</h5>
				5751
				5752	<p>
				5753	This function returns the first value raised to the second power with an
				5754	unspecified sequence of rounding operations.</p>
				5755	</div>
				5756
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5757	<!-- _______________________________________________________________________ -->
				5758	<div class="doc_subsubsection">
				5759	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5760	</div>
				5761
				5762	<div class="doc_text">
				5763
				5764	<h5>Syntax:</h5>
				5765	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5766	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]	5767	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5768	<pre>
				5769	declare float @llvm.sin.f32(float %Val)
				5770	declare double @llvm.sin.f64(double %Val)
				5771	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5772	declare fp128 @llvm.sin.f128(fp128 %Val)
				5773	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5774	</pre>
				5775
				5776	<h5>Overview:</h5>
				5777
				5778	<p>
				5779	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5780	</p>
				5781
				5782	<h5>Arguments:</h5>
				5783
				5784	<p>
				5785	The argument and return value are floating point numbers of the same type.
				5786	</p>
				5787
				5788	<h5>Semantics:</h5>
				5789
				5790	<p>
				5791	This function returns the sine of the specified operand, returning the
				5792	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]	5793	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5794	</div>
				5795
				5796	<!-- _______________________________________________________________________ -->
				5797	<div class="doc_subsubsection">
				5798	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5799	</div>
				5800
				5801	<div class="doc_text">
				5802
				5803	<h5>Syntax:</h5>
				5804	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5805	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]	5806	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5807	<pre>
				5808	declare float @llvm.cos.f32(float %Val)
				5809	declare double @llvm.cos.f64(double %Val)
				5810	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5811	declare fp128 @llvm.cos.f128(fp128 %Val)
				5812	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5813	</pre>
				5814
				5815	<h5>Overview:</h5>
				5816
				5817	<p>
				5818	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5819	</p>
				5820
				5821	<h5>Arguments:</h5>
				5822
				5823	<p>
				5824	The argument and return value are floating point numbers of the same type.
				5825	</p>
				5826
				5827	<h5>Semantics:</h5>
				5828
				5829	<p>
				5830	This function returns the cosine of the specified operand, returning the
				5831	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]	5832	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5833	</div>
				5834
				5835	<!-- _______________________________________________________________________ -->
				5836	<div class="doc_subsubsection">
				5837	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5838	</div>
				5839
				5840	<div class="doc_text">
				5841
				5842	<h5>Syntax:</h5>
				5843	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5844	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]	5845	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5846	<pre>
				5847	declare float @llvm.pow.f32(float %Val, float %Power)
				5848	declare double @llvm.pow.f64(double %Val, double %Power)
				5849	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5850	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5851	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5852	</pre>
				5853
				5854	<h5>Overview:</h5>
				5855
				5856	<p>
				5857	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5858	specified (positive or negative) power.
				5859	</p>
				5860
				5861	<h5>Arguments:</h5>
				5862
				5863	<p>
				5864	The second argument is a floating point power, and the first is a value to
				5865	raise to that power.
				5866	</p>
				5867
				5868	<h5>Semantics:</h5>
				5869
				5870	<p>
				5871	This function returns the first value raised to the second power,
				5872	returning the
				5873	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]	5874	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5875	</div>
				5876
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5877
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5878	<!-- ======================================================================= -->
				5879	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5880	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5881	</div>
				5882
				5883	<div class="doc_text">
				5884	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5885	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5886	These allow efficient code generation for some algorithms.
				5887	</p>
				5888
				5889	</div>
				5890
				5891	<!-- _______________________________________________________________________ -->
				5892	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5893	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5894	</div>
				5895
				5896	<div class="doc_text">
				5897
				5898	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5899	<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]	5900	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]	5901	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5902	declare i16 @llvm.bswap.i16(i16 <id>)
				5903	declare i32 @llvm.bswap.i32(i32 <id>)
				5904	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5905	</pre>
				5906
				5907	<h5>Overview:</h5>
				5908
				5909	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5910	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]	5911	values with an even number of bytes (positive multiple of 16 bits). These are
				5912	useful for performing operations on data that is not in the target's native
				5913	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5914	</p>
				5915
				5916	<h5>Semantics:</h5>
				5917
				5918	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5919	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]	5920	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5921	intrinsic returns an i32 value that has the four bytes of the input i32
				5922	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]	5923	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5924	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5925	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5926	</p>
				5927
				5928	</div>
				5929
				5930	<!-- _______________________________________________________________________ -->
				5931	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5932	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5933	</div>
				5934
				5935	<div class="doc_text">
				5936
				5937	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5938	<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]	5939	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5940	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5941	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5942	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5943	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5944	declare i64 @llvm.ctpop.i64(i64 <src>)
				5945	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5946	</pre>
				5947
				5948	<h5>Overview:</h5>
				5949
				5950	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5951	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5952	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5953	</p>
				5954
				5955	<h5>Arguments:</h5>
				5956
				5957	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5958	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]	5959	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5960	</p>
				5961
				5962	<h5>Semantics:</h5>
				5963
				5964	<p>
				5965	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5966	</p>
				5967	</div>
				5968
				5969	<!-- _______________________________________________________________________ -->
				5970	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5971	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5972	</div>
				5973
				5974	<div class="doc_text">
				5975
				5976	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5977	<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]	5978	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5979	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5980	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5981	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5982	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5983	declare i64 @llvm.ctlz.i64(i64 <src>)
				5984	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5985	</pre>
				5986
				5987	<h5>Overview:</h5>
				5988
				5989	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5990	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5991	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5992	</p>
				5993
				5994	<h5>Arguments:</h5>
				5995
				5996	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5997	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]	5998	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5999	</p>
				6000
				6001	<h5>Semantics:</h5>
				6002
				6003	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6004	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				6005	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]	6006	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	6007	</p>
				6008	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	6009
				6010
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6011
				6012	<!-- _______________________________________________________________________ -->
				6013	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	6014	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6015	</div>
				6016
				6017	<div class="doc_text">
				6018
				6019	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	6020	<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]	6021	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6022	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6023	declare i8 @llvm.cttz.i8 (i8 <src>)
				6024	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	6025	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6026	declare i64 @llvm.cttz.i64(i64 <src>)
				6027	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6028	</pre>
				6029
				6030	<h5>Overview:</h5>
				6031
				6032	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	6033	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				6034	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6035	</p>
				6036
				6037	<h5>Arguments:</h5>
				6038
				6039	<p>
				6040	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]	6041	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6042	</p>
				6043
				6044	<h5>Semantics:</h5>
				6045
				6046	<p>
				6047	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				6048	in a variable. If the src == 0 then the result is the size in bits of the type
				6049	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				6050	</p>
				6051	</div>
				6052
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	6053	<!-- _______________________________________________________________________ -->
				6054	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6055	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6056	</div>
				6057
				6058	<div class="doc_text">
				6059
				6060	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6061	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6062	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6063	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6064	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				6065	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6066	</pre>
				6067
				6068	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6069	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6070	range of bits from an integer value and returns them in the same bit width as
				6071	the original value.</p>
				6072
				6073	<h5>Arguments:</h5>
				6074	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				6075	any bit width but they must have the same bit width. The second and third
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	6076	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6077
				6078	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6079	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	6080	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				6081	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				6082	operates in forward mode.</p>
				6083	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				6084	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6085	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				6086	<ol>
				6087	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				6088	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				6089	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				6090	to determine the number of bits to retain.</li>
				6091	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6092	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6093	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	6094	<p>In reverse mode, a similar computation is made except that the bits are
				6095	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				6096	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				6097	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				6098	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6099	</div>
				6100
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6101	<div class="doc_subsubsection">
				6102	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				6103	</div>
				6104
				6105	<div class="doc_text">
				6106
				6107	<h5>Syntax:</h5>
				6108	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6109	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6110	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6111	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6112	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6113	</pre>
				6114
				6115	<h5>Overview:</h5>
				6116	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6117	of bits in an integer value with another integer value. It returns the integer
				6118	with the replaced bits.</p>
				6119
				6120	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6121	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6122	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6123	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6124	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6125	type since they specify only a bit index.</p>
				6126
				6127	<h5>Semantics:</h5>
				6128	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6129	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6130	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6131	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6132
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6133	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6134	truncating it down to the size of the replacement area or zero extending it
				6135	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6136
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6137	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6138	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6139	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6140	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6141
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6142	<p>In reverse mode, a similar computation is made except that the bits are
				6143	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6144	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6145
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6146	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6147
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6148	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6149	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6150	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6151	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6152	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6153	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	6154	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6155
				6156	</div>
				6157
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6158	<!-- ======================================================================= -->
				6159	<div class="doc_subsection">
				6160	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6161	</div>
				6162
				6163	<div class="doc_text">
				6164	<p>
				6165	LLVM provides intrinsics for some arithmetic with overflow operations.
				6166	</p>
				6167
				6168	</div>
				6169
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6170	<!-- _______________________________________________________________________ -->
				6171	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6172	<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]	6173	</div>
				6174
				6175	<div class="doc_text">
				6176
				6177	<h5>Syntax:</h5>
				6178
				6179	<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]	6180	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6181
				6182	<pre>
				6183	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6184	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6185	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6186	</pre>
				6187
				6188	<h5>Overview:</h5>
				6189
				6190	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6191	a signed addition of the two arguments, and indicate whether an overflow
				6192	occurred during the signed summation.</p>
				6193
				6194	<h5>Arguments:</h5>
				6195
				6196	<p>The arguments (%a and %b) and the first element of the result structure may
				6197	be of integer types of any bit width, but they must have the same bit width. The
				6198	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6199	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6200
				6201	<h5>Semantics:</h5>
				6202
				6203	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6204	a signed addition of the two variables. They return a structure — the
				6205	first element of which is the signed summation, and the second element of which
				6206	is a bit specifying if the signed summation resulted in an overflow.</p>
				6207
				6208	<h5>Examples:</h5>
				6209	<pre>
				6210	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6211	%sum = extractvalue {i32, i1} %res, 0
				6212	%obit = extractvalue {i32, i1} %res, 1
				6213	br i1 %obit, label %overflow, label %normal
				6214	</pre>
				6215
				6216	</div>
				6217
				6218	<!-- _______________________________________________________________________ -->
				6219	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6220	<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]	6221	</div>
				6222
				6223	<div class="doc_text">
				6224
				6225	<h5>Syntax:</h5>
				6226
				6227	<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]	6228	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6229
				6230	<pre>
				6231	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6232	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6233	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6234	</pre>
				6235
				6236	<h5>Overview:</h5>
				6237
				6238	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6239	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6240	during the unsigned summation.</p>
				6241
				6242	<h5>Arguments:</h5>
				6243
				6244	<p>The arguments (%a and %b) and the first element of the result structure may
				6245	be of integer types of any bit width, but they must have the same bit width. The
				6246	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6247	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6248
				6249	<h5>Semantics:</h5>
				6250
				6251	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6252	an unsigned addition of the two arguments. They return a structure — the
				6253	first element of which is the sum, and the second element of which is a bit
				6254	specifying if the unsigned summation resulted in a carry.</p>
				6255
				6256	<h5>Examples:</h5>
				6257	<pre>
				6258	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6259	%sum = extractvalue {i32, i1} %res, 0
				6260	%obit = extractvalue {i32, i1} %res, 1
				6261	br i1 %obit, label %carry, label %normal
				6262	</pre>
				6263
				6264	</div>
				6265
				6266	<!-- _______________________________________________________________________ -->
				6267	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6268	<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]	6269	</div>
				6270
				6271	<div class="doc_text">
				6272
				6273	<h5>Syntax:</h5>
				6274
				6275	<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]	6276	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6277
				6278	<pre>
				6279	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6280	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6281	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6282	</pre>
				6283
				6284	<h5>Overview:</h5>
				6285
				6286	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6287	a signed subtraction of the two arguments, and indicate whether an overflow
				6288	occurred during the signed subtraction.</p>
				6289
				6290	<h5>Arguments:</h5>
				6291
				6292	<p>The arguments (%a and %b) and the first element of the result structure may
				6293	be of integer types of any bit width, but they must have the same bit width. The
				6294	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6295	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6296
				6297	<h5>Semantics:</h5>
				6298
				6299	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6300	a signed subtraction of the two arguments. They return a structure — the
				6301	first element of which is the subtraction, and the second element of which is a bit
				6302	specifying if the signed subtraction resulted in an overflow.</p>
				6303
				6304	<h5>Examples:</h5>
				6305	<pre>
				6306	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6307	%sum = extractvalue {i32, i1} %res, 0
				6308	%obit = extractvalue {i32, i1} %res, 1
				6309	br i1 %obit, label %overflow, label %normal
				6310	</pre>
				6311
				6312	</div>
				6313
				6314	<!-- _______________________________________________________________________ -->
				6315	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6316	<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]	6317	</div>
				6318
				6319	<div class="doc_text">
				6320
				6321	<h5>Syntax:</h5>
				6322
				6323	<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]	6324	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6325
				6326	<pre>
				6327	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6328	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6329	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6330	</pre>
				6331
				6332	<h5>Overview:</h5>
				6333
				6334	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6335	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6336	occurred during the unsigned subtraction.</p>
				6337
				6338	<h5>Arguments:</h5>
				6339
				6340	<p>The arguments (%a and %b) and the first element of the result structure may
				6341	be of integer types of any bit width, but they must have the same bit width. The
				6342	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6343	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6344
				6345	<h5>Semantics:</h5>
				6346
				6347	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6348	an unsigned subtraction of the two arguments. They return a structure — the
				6349	first element of which is the subtraction, and the second element of which is a bit
				6350	specifying if the unsigned subtraction resulted in an overflow.</p>
				6351
				6352	<h5>Examples:</h5>
				6353	<pre>
				6354	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6355	%sum = extractvalue {i32, i1} %res, 0
				6356	%obit = extractvalue {i32, i1} %res, 1
				6357	br i1 %obit, label %overflow, label %normal
				6358	</pre>
				6359
				6360	</div>
				6361
				6362	<!-- _______________________________________________________________________ -->
				6363	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6364	<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]	6365	</div>
				6366
				6367	<div class="doc_text">
				6368
				6369	<h5>Syntax:</h5>
				6370
				6371	<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]	6372	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6373
				6374	<pre>
				6375	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6376	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6377	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6378	</pre>
				6379
				6380	<h5>Overview:</h5>
				6381
				6382	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6383	a signed multiplication of the two arguments, and indicate whether an overflow
				6384	occurred during the signed multiplication.</p>
				6385
				6386	<h5>Arguments:</h5>
				6387
				6388	<p>The arguments (%a and %b) and the first element of the result structure may
				6389	be of integer types of any bit width, but they must have the same bit width. The
				6390	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6391	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6392
				6393	<h5>Semantics:</h5>
				6394
				6395	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6396	a signed multiplication of the two arguments. They return a structure —
				6397	the first element of which is the multiplication, and the second element of
				6398	which is a bit specifying if the signed multiplication resulted in an
				6399	overflow.</p>
				6400
				6401	<h5>Examples:</h5>
				6402	<pre>
				6403	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6404	%sum = extractvalue {i32, i1} %res, 0
				6405	%obit = extractvalue {i32, i1} %res, 1
				6406	br i1 %obit, label %overflow, label %normal
				6407	</pre>
				6408
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6409	</div>
				6410
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6411	<!-- _______________________________________________________________________ -->
				6412	<div class="doc_subsubsection">
				6413	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6414	</div>
				6415
				6416	<div class="doc_text">
				6417
				6418	<h5>Syntax:</h5>
				6419
				6420	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6421	on any integer bit width.</p>
				6422
				6423	<pre>
				6424	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6425	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6426	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6427	</pre>
				6428
				6429	<h5>Overview:</h5>
				6430
				6431	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6432	actively being fixed, but it should not currently be used!</i></p>
				6433
				6434	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6435	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6436	occurred during the unsigned multiplication.</p>
				6437
				6438	<h5>Arguments:</h5>
				6439
				6440	<p>The arguments (%a and %b) and the first element of the result structure may
				6441	be of integer types of any bit width, but they must have the same bit width. The
				6442	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6443	and <tt>%b</tt> are the two values that will undergo unsigned
				6444	multiplication.</p>
				6445
				6446	<h5>Semantics:</h5>
				6447
				6448	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6449	an unsigned multiplication of the two arguments. They return a structure —
				6450	the first element of which is the multiplication, and the second element of
				6451	which is a bit specifying if the unsigned multiplication resulted in an
				6452	overflow.</p>
				6453
				6454	<h5>Examples:</h5>
				6455	<pre>
				6456	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6457	%sum = extractvalue {i32, i1} %res, 0
				6458	%obit = extractvalue {i32, i1} %res, 1
				6459	br i1 %obit, label %overflow, label %normal
				6460	</pre>
				6461
				6462	</div>
				6463
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6464	<!-- ======================================================================= -->
				6465	<div class="doc_subsection">
				6466	<a name="int_debugger">Debugger Intrinsics</a>
				6467	</div>
				6468
				6469	<div class="doc_text">
				6470	<p>
				6471	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6472	are described in the <a
				6473	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6474	Debugging</a> document.
				6475	</p>
				6476	</div>
				6477
				6478
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6479	<!-- ======================================================================= -->
				6480	<div class="doc_subsection">
				6481	<a name="int_eh">Exception Handling Intrinsics</a>
				6482	</div>
				6483
				6484	<div class="doc_text">
				6485	<p> The LLVM exception handling intrinsics (which all start with
				6486	<tt>llvm.eh.</tt> prefix), are described in the <a
				6487	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6488	Handling</a> document. </p>
				6489	</div>
				6490
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6491	<!-- ======================================================================= -->
				6492	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6493	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6494	</div>
				6495
				6496	<div class="doc_text">
				6497	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6498	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6499	the <tt>nest</tt> attribute, from a function. The result is a callable
				6500	function pointer lacking the nest parameter - the caller does not need
				6501	to provide a value for it. Instead, the value to use is stored in
				6502	advance in a "trampoline", a block of memory usually allocated
				6503	on the stack, which also contains code to splice the nest value into the
				6504	argument list. This is used to implement the GCC nested function address
				6505	extension.
				6506	</p>
				6507	<p>
				6508	For example, if the function is
				6509	<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]	6510	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]	6511	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6512	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6513	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6514	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6515	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6516	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6517	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6518	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]	6519	</div>
				6520
				6521	<!-- _______________________________________________________________________ -->
				6522	<div class="doc_subsubsection">
				6523	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6524	</div>
				6525	<div class="doc_text">
				6526	<h5>Syntax:</h5>
				6527	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6528	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6529	</pre>
				6530	<h5>Overview:</h5>
				6531	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6532	This fills the memory pointed to by <tt>tramp</tt> with code
				6533	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6534	</p>
				6535	<h5>Arguments:</h5>
				6536	<p>
				6537	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6538	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6539	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]	6540	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6541	currently provides no portable way of determining them, so a front-end that
				6542	generates this intrinsic needs to have some target-specific knowledge.
				6543	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]	6544	</p>
				6545	<h5>Semantics:</h5>
				6546	<p>
				6547	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]	6548	dependent code, turning it into a function. A pointer to this function is
				6549	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6550	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6551	before being called. The new function's signature is the same as that of
				6552	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6553	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6554	of pointer type. Calling the new function is equivalent to calling
				6555	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6556	missing <tt>nest</tt> argument. If, after calling
				6557	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6558	modified, then the effect of any later call to the returned function pointer is
				6559	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6560	</p>
				6561	</div>
				6562
				6563	<!-- ======================================================================= -->
				6564	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6565	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6566	</div>
				6567
				6568	<div class="doc_text">
				6569	<p>
				6570	These intrinsic functions expand the "universal IR" of LLVM to represent
				6571	hardware constructs for atomic operations and memory synchronization. This
				6572	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]	6573	is aimed at a low enough level to allow any programming models or APIs
				6574	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6575	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6576	hardware behavior. Just as hardware provides a "universal IR" for source
				6577	languages, it also provides a starting point for developing a "universal"
				6578	atomic operation and synchronization IR.
				6579	</p>
				6580	<p>
				6581	These do <em>not</em> form an API such as high-level threading libraries,
				6582	software transaction memory systems, atomic primitives, and intrinsic
				6583	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6584	application libraries. The hardware interface provided by LLVM should allow
				6585	a clean implementation of all of these APIs and parallel programming models.
				6586	No one model or paradigm should be selected above others unless the hardware
				6587	itself ubiquitously does so.
				6588
				6589	</p>
				6590	</div>
				6591
				6592	<!-- _______________________________________________________________________ -->
				6593	<div class="doc_subsubsection">
				6594	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6595	</div>
				6596	<div class="doc_text">
				6597	<h5>Syntax:</h5>
				6598	<pre>
				6599	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6600	i1 <device> )
				6601
				6602	</pre>
				6603	<h5>Overview:</h5>
				6604	<p>
				6605	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6606	specific pairs of memory access types.
				6607	</p>
				6608	<h5>Arguments:</h5>
				6609	<p>
				6610	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6611	The first four arguments enables a specific barrier as listed below. The fith
				6612	argument specifies that the barrier applies to io or device or uncached memory.
				6613
				6614	</p>
				6615	<ul>
				6616	<li><tt>ll</tt>: load-load barrier</li>
				6617	<li><tt>ls</tt>: load-store barrier</li>
				6618	<li><tt>sl</tt>: store-load barrier</li>
				6619	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6620	<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]	6621	</ul>
				6622	<h5>Semantics:</h5>
				6623	<p>
				6624	This intrinsic causes the system to enforce some ordering constraints upon
				6625	the loads and stores of the program. This barrier does not indicate
				6626	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6627	which they occur. For any of the specified pairs of load and store operations
				6628	(f.ex. load-load, or store-load), all of the first operations preceding the
				6629	barrier will complete before any of the second operations succeeding the
				6630	barrier begin. Specifically the semantics for each pairing is as follows:
				6631	</p>
				6632	<ul>
				6633	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6634	after the barrier begins.</li>
				6635
				6636	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6637	store after the barrier begins.</li>
				6638	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6639	store after the barrier begins.</li>
				6640	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6641	load after the barrier begins.</li>
				6642	</ul>
				6643	<p>
				6644	These semantics are applied with a logical "and" behavior when more than one
				6645	is enabled in a single memory barrier intrinsic.
				6646	</p>
				6647	<p>
				6648	Backends may implement stronger barriers than those requested when they do not
				6649	support as fine grained a barrier as requested. Some architectures do not
				6650	need all types of barriers and on such architectures, these become noops.
				6651	</p>
				6652	<h5>Example:</h5>
				6653	<pre>
				6654	%ptr = malloc i32
				6655	store i32 4, %ptr
				6656
				6657	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6658	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6659	<i>; guarantee the above finishes</i>
				6660	store i32 8, %ptr <i>; before this begins</i>
				6661	</pre>
				6662	</div>
				6663
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6664	<!-- _______________________________________________________________________ -->
				6665	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6666	<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]	6667	</div>
				6668	<div class="doc_text">
				6669	<h5>Syntax:</h5>
				6670	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6671	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6672	any integer bit width and for different address spaces. Not all targets
				6673	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6674
				6675	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6676	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6677	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6678	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6679	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]	6680
				6681	</pre>
				6682	<h5>Overview:</h5>
				6683	<p>
				6684	This loads a value in memory and compares it to a given value. If they are
				6685	equal, it stores a new value into the memory.
				6686	</p>
				6687	<h5>Arguments:</h5>
				6688	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6689	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]	6690	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6691	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6692	this integer type. While any bit width integer may be used, targets may only
				6693	lower representations they support in hardware.
				6694
				6695	</p>
				6696	<h5>Semantics:</h5>
				6697	<p>
				6698	This entire intrinsic must be executed atomically. It first loads the value
				6699	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6700	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6701	loaded value is yielded in all cases. This provides the equivalent of an
				6702	atomic compare-and-swap operation within the SSA framework.
				6703	</p>
				6704	<h5>Examples:</h5>
				6705
				6706	<pre>
				6707	%ptr = malloc i32
				6708	store i32 4, %ptr
				6709
				6710	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6711	%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]	6712	<i>; yields {i32}:result1 = 4</i>
				6713	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6714	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6715
				6716	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6717	%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]	6718	<i>; yields {i32}:result2 = 8</i>
				6719	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6720
				6721	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6722	</pre>
				6723	</div>
				6724
				6725	<!-- _______________________________________________________________________ -->
				6726	<div class="doc_subsubsection">
				6727	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6728	</div>
				6729	<div class="doc_text">
				6730	<h5>Syntax:</h5>
				6731
				6732	<p>
				6733	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6734	integer bit width. Not all targets support all bit widths however.</p>
				6735	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6737	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6738	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6739	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6740
				6741	</pre>
				6742	<h5>Overview:</h5>
				6743	<p>
				6744	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6745	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6746	at <tt>ptr</tt>.
				6747	</p>
				6748	<h5>Arguments:</h5>
				6749
				6750	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6751	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6752	<tt>val</tt> argument and the result must be integers of the same bit width.
				6753	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6754	integer type. The targets may only lower integer representations they
				6755	support.
				6756	</p>
				6757	<h5>Semantics:</h5>
				6758	<p>
				6759	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6760	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6761	equivalent of an atomic swap operation within the SSA framework.
				6762
				6763	</p>
				6764	<h5>Examples:</h5>
				6765	<pre>
				6766	%ptr = malloc i32
				6767	store i32 4, %ptr
				6768
				6769	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6771	<i>; yields {i32}:result1 = 4</i>
				6772	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6773	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6774
				6775	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6776	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6777	<i>; yields {i32}:result2 = 8</i>
				6778
				6779	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6780	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6781	</pre>
				6782	</div>
				6783
				6784	<!-- _______________________________________________________________________ -->
				6785	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6786	<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]	6787
				6788	</div>
				6789	<div class="doc_text">
				6790	<h5>Syntax:</h5>
				6791	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6792	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]	6793	integer bit width. Not all targets support all bit widths however.</p>
				6794	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6795	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6796	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6797	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6798	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6799
				6800	</pre>
				6801	<h5>Overview:</h5>
				6802	<p>
				6803	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6804	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6805	</p>
				6806	<h5>Arguments:</h5>
				6807	<p>
				6808
				6809	The intrinsic takes two arguments, the first a pointer to an integer value
				6810	and the second an integer value. The result is also an integer value. These
				6811	integer types can have any bit width, but they must all have the same bit
				6812	width. The targets may only lower integer representations they support.
				6813	</p>
				6814	<h5>Semantics:</h5>
				6815	<p>
				6816	This intrinsic does a series of operations atomically. It first loads the
				6817	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6818	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6819	</p>
				6820
				6821	<h5>Examples:</h5>
				6822	<pre>
				6823	%ptr = malloc i32
				6824	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6825	%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]	6826	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6827	%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]	6828	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6829	%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]	6830	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6831	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6832	</pre>
				6833	</div>
				6834
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6835	<!-- _______________________________________________________________________ -->
				6836	<div class="doc_subsubsection">
				6837	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6838
				6839	</div>
				6840	<div class="doc_text">
				6841	<h5>Syntax:</h5>
				6842	<p>
				6843	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]	6844	any integer bit width and for different address spaces. Not all targets
				6845	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6846	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6847	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6848	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6849	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6850	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]	6851
				6852	</pre>
				6853	<h5>Overview:</h5>
				6854	<p>
				6855	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6856	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6857	</p>
				6858	<h5>Arguments:</h5>
				6859	<p>
				6860
				6861	The intrinsic takes two arguments, the first a pointer to an integer value
				6862	and the second an integer value. The result is also an integer value. These
				6863	integer types can have any bit width, but they must all have the same bit
				6864	width. The targets may only lower integer representations they support.
				6865	</p>
				6866	<h5>Semantics:</h5>
				6867	<p>
				6868	This intrinsic does a series of operations atomically. It first loads the
				6869	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6870	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6871	</p>
				6872
				6873	<h5>Examples:</h5>
				6874	<pre>
				6875	%ptr = malloc i32
				6876	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6877	%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]	6878	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6879	%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]	6880	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6881	%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]	6882	<i>; yields {i32}:result3 = 2</i>
				6883	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6884	</pre>
				6885	</div>
				6886
				6887	<!-- _______________________________________________________________________ -->
				6888	<div class="doc_subsubsection">
				6889	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6890	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6891	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6892	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6893
				6894	</div>
				6895	<div class="doc_text">
				6896	<h5>Syntax:</h5>
				6897	<p>
				6898	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6899	<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]	6900	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6901	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6902	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6903	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6904	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6905	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6906	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]	6907
				6908	</pre>
				6909
				6910	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6911	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6912	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6913	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6914	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]	6915
				6916	</pre>
				6917
				6918	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6919	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6920	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6921	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6922	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]	6923
				6924	</pre>
				6925
				6926	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6927	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6928	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6929	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6930	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]	6931
				6932	</pre>
				6933	<h5>Overview:</h5>
				6934	<p>
				6935	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6936	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6937	at <tt>ptr</tt>.
				6938	</p>
				6939	<h5>Arguments:</h5>
				6940	<p>
				6941
				6942	These intrinsics take two arguments, the first a pointer to an integer value
				6943	and the second an integer value. The result is also an integer value. These
				6944	integer types can have any bit width, but they must all have the same bit
				6945	width. The targets may only lower integer representations they support.
				6946	</p>
				6947	<h5>Semantics:</h5>
				6948	<p>
				6949	These intrinsics does a series of operations atomically. They first load the
				6950	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6951	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6952	value stored at <tt>ptr</tt>.
				6953	</p>
				6954
				6955	<h5>Examples:</h5>
				6956	<pre>
				6957	%ptr = malloc i32
				6958	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6959	%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]	6960	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6961	%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]	6962	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6963	%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]	6964	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6965	%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]	6966	<i>; yields {i32}:result3 = FF</i>
				6967	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6968	</pre>
				6969	</div>
				6970
				6971
				6972	<!-- _______________________________________________________________________ -->
				6973	<div class="doc_subsubsection">
				6974	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6975	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6976	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6977	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6978
				6979	</div>
				6980	<div class="doc_text">
				6981	<h5>Syntax:</h5>
				6982	<p>
				6983	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6984	<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]	6985	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6986	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6987	support all bit widths however.</p>
				6988	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6989	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6990	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6991	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6992	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]	6993
				6994	</pre>
				6995
				6996	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6997	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6998	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6999	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				7000	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]	7001
				7002	</pre>
				7003
				7004	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7005	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				7006	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				7007	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				7008	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]	7009
				7010	</pre>
				7011
				7012	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7013	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				7014	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				7015	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				7016	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]	7017
				7018	</pre>
				7019	<h5>Overview:</h5>
				7020	<p>
				7021	These intrinsics takes the signed or unsigned minimum or maximum of
				7022	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				7023	original value at <tt>ptr</tt>.
				7024	</p>
				7025	<h5>Arguments:</h5>
				7026	<p>
				7027
				7028	These intrinsics take two arguments, the first a pointer to an integer value
				7029	and the second an integer value. The result is also an integer value. These
				7030	integer types can have any bit width, but they must all have the same bit
				7031	width. The targets may only lower integer representations they support.
				7032	</p>
				7033	<h5>Semantics:</h5>
				7034	<p>
				7035	These intrinsics does a series of operations atomically. They first load the
				7036	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				7037	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				7038	the original value stored at <tt>ptr</tt>.
				7039	</p>
				7040
				7041	<h5>Examples:</h5>
				7042	<pre>
				7043	%ptr = malloc i32
				7044	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7045	%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]	7046	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7047	%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]	7048	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7049	%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]	7050	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7051	%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]	7052	<i>; yields {i32}:result3 = 8</i>
				7053	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				7054	</pre>
				7055	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	7056
				7057	<!-- ======================================================================= -->
				7058	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7059	<a name="int_general">General Intrinsics</a>
				7060	</div>
				7061
				7062	<div class="doc_text">
				7063	<p> This class of intrinsics is designed to be generic and has
				7064	no specific purpose. </p>
				7065	</div>
				7066
				7067	<!-- _______________________________________________________________________ -->
				7068	<div class="doc_subsubsection">
				7069	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				7070	</div>
				7071
				7072	<div class="doc_text">
				7073
				7074	<h5>Syntax:</h5>
				7075	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7076	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]	7077	</pre>
				7078
				7079	<h5>Overview:</h5>
				7080
				7081	<p>
				7082	The '<tt>llvm.var.annotation</tt>' intrinsic
				7083	</p>
				7084
				7085	<h5>Arguments:</h5>
				7086
				7087	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7088	The first argument is a pointer to a value, the second is a pointer to a
				7089	global string, the third is a pointer to a global string which is the source
				7090	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7091	</p>
				7092
				7093	<h5>Semantics:</h5>
				7094
				7095	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7096	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7097	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]	7098	annotations. These have no other defined use, they are ignored by code
				7099	generation and optimization.
				7100	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7101	</div>
				7102
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7103	<!-- _______________________________________________________________________ -->
				7104	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	7105	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7106	</div>
				7107
				7108	<div class="doc_text">
				7109
				7110	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7111	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7112	any integer bit width.
				7113	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7114	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	7115	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7116	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7117	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7118	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7119	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]	7120	</pre>
				7121
				7122	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7123
				7124	<p>
				7125	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7126	</p>
				7127
				7128	<h5>Arguments:</h5>
				7129
				7130	<p>
				7131	The first argument is an integer value (result of some expression),
				7132	the second is a pointer to a global string, the third is a pointer to a global
				7133	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]	7134	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7135	</p>
				7136
				7137	<h5>Semantics:</h5>
				7138
				7139	<p>
				7140	This intrinsic allows annotations to be put on arbitrary expressions
				7141	with arbitrary strings. This can be useful for special purpose optimizations
				7142	that want to look for these annotations. These have no other defined use, they
				7143	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	7144	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7145	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	7146
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7147	<!-- _______________________________________________________________________ -->
				7148	<div class="doc_subsubsection">
				7149	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7150	</div>
				7151
				7152	<div class="doc_text">
				7153
				7154	<h5>Syntax:</h5>
				7155	<pre>
				7156	declare void @llvm.trap()
				7157	</pre>
				7158
				7159	<h5>Overview:</h5>
				7160
				7161	<p>
				7162	The '<tt>llvm.trap</tt>' intrinsic
				7163	</p>
				7164
				7165	<h5>Arguments:</h5>
				7166
				7167	<p>
				7168	None
				7169	</p>
				7170
				7171	<h5>Semantics:</h5>
				7172
				7173	<p>
				7174	This intrinsics is lowered to the target dependent trap instruction. If the
				7175	target does not have a trap instruction, this intrinsic will be lowered to the
				7176	call of the abort() function.
				7177	</p>
				7178	</div>
				7179
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7180	<!-- _______________________________________________________________________ -->
				7181	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7182	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7183	</div>
				7184	<div class="doc_text">
				7185	<h5>Syntax:</h5>
				7186	<pre>
				7187	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7188
				7189	</pre>
				7190	<h5>Overview:</h5>
				7191	<p>
				7192	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7193	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7194	it is placed on the stack before local variables.
				7195	</p>
				7196	<h5>Arguments:</h5>
				7197	<p>
				7198	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7199	first argument is the value loaded from the stack guard
				7200	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7201	has enough space to hold the value of the guard.
				7202	</p>
				7203	<h5>Semantics:</h5>
				7204	<p>
				7205	This intrinsic causes the prologue/epilogue inserter to force the position of
				7206	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7207	stack. This is to ensure that if a local variable on the stack is overwritten,
				7208	it will destroy the value of the guard. When the function exits, the guard on
				7209	the stack is checked against the original guard. If they're different, then
				7210	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7211	</p>
				7212	</div>
				7213
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7214	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7215	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7216	<address>
				7217	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7218	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]	7219	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7220	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]	7221
				7222	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7223	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7224	Last modified: $Date$
				7225	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7226
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7227	</body>
				7228	</html>