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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
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1094	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1095	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1096	have an <tt>ssp</tt> attribute.</p></dd>
				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
				1103	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				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
				1106	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1107	</dl>
				1108
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1109	</div>
				1110
				1111	<!-- ======================================================================= -->
				1112	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1113	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1114	</div>
				1115
				1116	<div class="doc_text">
				1117	<p>
				1118	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1119	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1120	LLVM and treated as a single unit, but may be separated in the .ll file if
				1121	desired. The syntax is very simple:
				1122	</p>
				1123
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1124	<div class="doc_code">
				1125	<pre>
				1126	module asm "inline asm code goes here"
				1127	module asm "more can go here"
				1128	</pre>
				1129	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1130
				1131	<p>The strings can contain any character by escaping non-printable characters.
				1132	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1133	for the number.
				1134	</p>
				1135
				1136	<p>
				1137	The inline asm code is simply printed to the machine code .s file when
				1138	assembly code is generated.
				1139	</p>
				1140	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1141
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1142	<!-- ======================================================================= -->
				1143	<div class="doc_subsection">
				1144	<a name="datalayout">Data Layout</a>
				1145	</div>
				1146
				1147	<div class="doc_text">
				1148	<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]	1149	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1150	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1151	<p>The <i>layout specification</i> consists of a list of specifications
				1152	separated by the minus sign character ('-'). Each specification starts with a
				1153	letter and may include other information after the letter to define some
				1154	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1155	<dl>
				1156	<dt><tt>E</tt></dt>
				1157	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1158	bits with the most significance have the lowest address location.</dd>
				1159	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1160	<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]	1161	the bits with the least significance have the lowest address location.</dd>
				1162	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1163	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1164	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1165	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1166	too.</dd>
				1167	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1168	<dd>This specifies the alignment for an integer type of a given bit
				1169	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1170	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the alignment for a vector type of a given bit
				1172	<i>size</i>.</dd>
				1173	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1174	<dd>This specifies the alignment for a floating point type of a given bit
				1175	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1176	(double).</dd>
				1177	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1178	<dd>This specifies the alignment for an aggregate type of a given bit
				1179	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame^]	1180	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1181	<dd>This specifies the alignment for a stack object of a given bit
				1182	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1183	</dl>
				1184	<p>When constructing the data layout for a given target, LLVM starts with a
				1185	default set of specifications which are then (possibly) overriden by the
				1186	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1187	are given in this list:</p>
				1188	<ul>
				1189	<li><tt>E</tt> - big endian</li>
				1190	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1191	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1192	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1193	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1194	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1195	<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]	1196	alignment of 64-bits</li>
				1197	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1198	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1199	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1200	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1201	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame^]	1202	<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]	1203	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1204	<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]	1205	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1206	<ol>
				1207	<li>If the type sought is an exact match for one of the specifications, that
				1208	specification is used.</li>
				1209	<li>If no match is found, and the type sought is an integer type, then the
				1210	smallest integer type that is larger than the bitwidth of the sought type is
				1211	used. If none of the specifications are larger than the bitwidth then the the
				1212	largest integer type is used. For example, given the default specifications
				1213	above, the i7 type will use the alignment of i8 (next largest) while both
				1214	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1215	<li>If no match is found, and the type sought is a vector type, then the
				1216	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]	1217	as a fall back. This happens because <128 x double> can be implemented
				1218	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1219	</ol>
				1220	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1221
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1222	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1223	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1224	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1225
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1226	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1227
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1228	<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]	1229	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1230	optimizations to be performed on the intermediate representation directly,
				1231	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1232	extra analyses on the side before the transformation. A strong type
				1233	system makes it easier to read the generated code and enables novel
				1234	analyses and transformations that are not feasible to perform on normal
				1235	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1236
				1237	</div>
				1238
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1239	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1240	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1242	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1243	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1244	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1245
				1246	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1247	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1248	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1250	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1251	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1252	</tr>
				1253	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1254	<td><a href="#t_floating">floating point</a></td>
				1255	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	</tr>
				1257	<tr>
				1258	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1259	<td><a href="#t_integer">integer</a>,
				1260	<a href="#t_floating">floating point</a>,
				1261	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1262	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1263	<a href="#t_struct">structure</a>,
				1264	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1265	<a href="#t_label">label</a>,
				1266	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1267	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1268	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1269	<tr>
				1270	<td><a href="#t_primitive">primitive</a></td>
				1271	<td><a href="#t_label">label</a>,
				1272	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1273	<a href="#t_floating">floating point</a>,
				1274	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1275	</tr>
				1276	<tr>
				1277	<td><a href="#t_derived">derived</a></td>
				1278	<td><a href="#t_integer">integer</a>,
				1279	<a href="#t_array">array</a>,
				1280	<a href="#t_function">function</a>,
				1281	<a href="#t_pointer">pointer</a>,
				1282	<a href="#t_struct">structure</a>,
				1283	<a href="#t_pstruct">packed structure</a>,
				1284	<a href="#t_vector">vector</a>,
				1285	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1286	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1287	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1288	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1289	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1290
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1291	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1292	most important. Values of these types are the only ones which can be
				1293	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1294	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1295	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1296
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1297	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1298	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1299
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1300	<div class="doc_text">
				1301	<p>The primitive types are the fundamental building blocks of the LLVM
				1302	system.</p>
				1303
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1304	</div>
				1305
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1306	<!-- _______________________________________________________________________ -->
				1307	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1308
				1309	<div class="doc_text">
				1310	<table>
				1311	<tbody>
				1312	<tr><th>Type</th><th>Description</th></tr>
				1313	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1314	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1315	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1316	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1317	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1318	</tbody>
				1319	</table>
				1320	</div>
				1321
				1322	<!-- _______________________________________________________________________ -->
				1323	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1324
				1325	<div class="doc_text">
				1326	<h5>Overview:</h5>
				1327	<p>The void type does not represent any value and has no size.</p>
				1328
				1329	<h5>Syntax:</h5>
				1330
				1331	<pre>
				1332	void
				1333	</pre>
				1334	</div>
				1335
				1336	<!-- _______________________________________________________________________ -->
				1337	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1338
				1339	<div class="doc_text">
				1340	<h5>Overview:</h5>
				1341	<p>The label type represents code labels.</p>
				1342
				1343	<h5>Syntax:</h5>
				1344
				1345	<pre>
				1346	label
				1347	</pre>
				1348	</div>
				1349
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1350	<!-- _______________________________________________________________________ -->
				1351	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1352
				1353	<div class="doc_text">
				1354	<h5>Overview:</h5>
				1355	<p>The metadata type represents embedded metadata. The only derived type that
				1356	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1357	takes metadata typed parameters, but not pointer to metadata types.</p>
				1358
				1359	<h5>Syntax:</h5>
				1360
				1361	<pre>
				1362	metadata
				1363	</pre>
				1364	</div>
				1365
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1366
				1367	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1368	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1369
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1370	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1371
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1372	<p>The real power in LLVM comes from the derived types in the system.
				1373	This is what allows a programmer to represent arrays, functions,
				1374	pointers, and other useful types. Note that these derived types may be
				1375	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]	1376
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1377	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1378
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1379	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1380	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1381
				1382	<div class="doc_text">
				1383
				1384	<h5>Overview:</h5>
				1385	<p>The integer type is a very simple derived type that simply specifies an
				1386	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1387	2^23-1 (about 8 million) can be specified.</p>
				1388
				1389	<h5>Syntax:</h5>
				1390
				1391	<pre>
				1392	iN
				1393	</pre>
				1394
				1395	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1396	value.</p>
				1397
				1398	<h5>Examples:</h5>
				1399	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1400	<tr class="layout">
				1401	<td class="left"><tt>i1</tt></td>
				1402	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1403	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1404	<tr class="layout">
				1405	<td class="left"><tt>i32</tt></td>
				1406	<td class="left">a 32-bit integer.</td>
				1407	</tr>
				1408	<tr class="layout">
				1409	<td class="left"><tt>i1942652</tt></td>
				1410	<td class="left">a really big integer of over 1 million bits.</td>
				1411	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1412	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1413
				1414	<p>Note that the code generator does not yet support large integer types
				1415	to be used as function return types. The specific limit on how large a
				1416	return type the code generator can currently handle is target-dependent;
				1417	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1418	targets.</p>
				1419
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1420	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1421
				1422	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1423	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1424
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1425	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1426
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1427	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1428
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1429	<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]	1430	sequentially in memory. The array type requires a size (number of
				1431	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1432
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1433	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1434
				1435	<pre>
				1436	[<# elements> x <elementtype>]
				1437	</pre>
				1438
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1439	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1440	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1441
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1442	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1443	<table class="layout">
				1444	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1445	<td class="left"><tt>[40 x i32]</tt></td>
				1446	<td class="left">Array of 40 32-bit integer values.</td>
				1447	</tr>
				1448	<tr class="layout">
				1449	<td class="left"><tt>[41 x i32]</tt></td>
				1450	<td class="left">Array of 41 32-bit integer values.</td>
				1451	</tr>
				1452	<tr class="layout">
				1453	<td class="left"><tt>[4 x i8]</tt></td>
				1454	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1455	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1456	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1457	<p>Here are some examples of multidimensional arrays:</p>
				1458	<table class="layout">
				1459	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1460	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1461	<td class="left">3x4 array of 32-bit integer values.</td>
				1462	</tr>
				1463	<tr class="layout">
				1464	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1465	<td class="left">12x10 array of single precision floating point values.</td>
				1466	</tr>
				1467	<tr class="layout">
				1468	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1469	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1470	</tr>
				1471	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1472
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1473	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1474	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]	1475	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1476	As a special case, however, zero length arrays are recognized to be variable
				1477	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1478	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1479
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1480	<p>Note that the code generator does not yet support large aggregate types
				1481	to be used as function return types. The specific limit on how large an
				1482	aggregate return type the code generator can currently handle is
				1483	target-dependent, and also dependent on the aggregate element types.</p>
				1484
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1485	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1486
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1487	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1488	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1489	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1490
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1491	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1492
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1493	<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]	1494	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]	1495	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]	1496	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]	1497	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1498
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1499	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1500
				1501	<pre>
				1502	<returntype list> (<parameter list>)
				1503	</pre>
				1504
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1505	<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]	1506	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1507	which indicates that the function takes a variable number of arguments.
				1508	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1509	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1510	'<tt><returntype list></tt>' is a comma-separated list of
				1511	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1512
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1513	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1514	<table class="layout">
				1515	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1516	<td class="left"><tt>i32 (i32)</tt></td>
				1517	<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]	1518	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1519	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1520	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1521	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1522	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1523	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1524	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1525	<tt>float</tt>.
				1526	</td>
				1527	</tr><tr class="layout">
				1528	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1529	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1530	<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]	1531	which returns an integer. This is the signature for <tt>printf</tt> in
				1532	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1533	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1534	</tr><tr class="layout">
				1535	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1536	<td class="left">A function taking an <tt>i32</tt>, returning two
				1537	<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]	1538	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1539	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1540	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1541
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1542	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1543	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1544	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1545	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1546	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1547	<p>The structure type is used to represent a collection of data members
				1548	together in memory. The packing of the field types is defined to match
				1549	the ABI of the underlying processor. The elements of a structure may
				1550	be any type that has a size.</p>
				1551	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1552	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1553	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1554	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1555	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1556	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1557	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1558	<table class="layout">
				1559	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1560	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1561	<td class="left">A triple of three <tt>i32</tt> values</td>
				1562	</tr><tr class="layout">
				1563	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1564	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1565	second element is a <a href="#t_pointer">pointer</a> to a
				1566	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1567	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1568	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1569	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1570
				1571	<p>Note that the code generator does not yet support large aggregate types
				1572	to be used as function return types. The specific limit on how large an
				1573	aggregate return type the code generator can currently handle is
				1574	target-dependent, and also dependent on the aggregate element types.</p>
				1575
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1576	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1577
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1578	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1579	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1580	</div>
				1581	<div class="doc_text">
				1582	<h5>Overview:</h5>
				1583	<p>The packed structure type is used to represent a collection of data members
				1584	together in memory. There is no padding between fields. Further, the alignment
				1585	of a packed structure is 1 byte. The elements of a packed structure may
				1586	be any type that has a size.</p>
				1587	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1588	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1589	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1590	instruction.</p>
				1591	<h5>Syntax:</h5>
				1592	<pre> < { <type list> } > <br></pre>
				1593	<h5>Examples:</h5>
				1594	<table class="layout">
				1595	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1596	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1597	<td class="left">A triple of three <tt>i32</tt> values</td>
				1598	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1599	<td class="left">
				1600	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1601	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1602	second element is a <a href="#t_pointer">pointer</a> to a
				1603	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1604	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1605	</tr>
				1606	</table>
				1607	</div>
				1608
				1609	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1610	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1611	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1612	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1613	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1614	reference to another object, which must live in memory. Pointer types may have
				1615	an optional address space attribute defining the target-specific numbered
				1616	address space where the pointed-to object resides. The default address space is
				1617	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1618
				1619	<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]	1620	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]	1621
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1622	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1623	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1624	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1625	<table class="layout">
				1626	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1627	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1628	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1629	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1630	</tr>
				1631	<tr class="layout">
				1632	<td class="left"><tt>i32 (i32 ) </tt></td>
				1633	<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]	1634	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]	1635	<tt>i32</tt>.</td>
				1636	</tr>
				1637	<tr class="layout">
				1638	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1639	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1640	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1641	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1642	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1643	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1644
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1645	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1646	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1647	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1648
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1649	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1650
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1651	<p>A vector type is a simple derived type that represents a vector
				1652	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1653	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1654	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1655	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1656	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1657	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1658
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1659	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1660
				1661	<pre>
				1662	< <# elements> x <elementtype> >
				1663	</pre>
				1664
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1665	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1666	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1667
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1668	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1669
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1670	<table class="layout">
				1671	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1672	<td class="left"><tt><4 x i32></tt></td>
				1673	<td class="left">Vector of 4 32-bit integer values.</td>
				1674	</tr>
				1675	<tr class="layout">
				1676	<td class="left"><tt><8 x float></tt></td>
				1677	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1678	</tr>
				1679	<tr class="layout">
				1680	<td class="left"><tt><2 x i64></tt></td>
				1681	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1682	</tr>
				1683	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1684
				1685	<p>Note that the code generator does not yet support large vector types
				1686	to be used as function return types. The specific limit on how large a
				1687	vector return type codegen can currently handle is target-dependent;
				1688	currently it's often a few times longer than a hardware vector register.</p>
				1689
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1690	</div>
				1691
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1692	<!-- _______________________________________________________________________ -->
				1693	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1694	<div class="doc_text">
				1695
				1696	<h5>Overview:</h5>
				1697
				1698	<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]	1699	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]	1700	In LLVM, opaque types can eventually be resolved to any type (not just a
				1701	structure type).</p>
				1702
				1703	<h5>Syntax:</h5>
				1704
				1705	<pre>
				1706	opaque
				1707	</pre>
				1708
				1709	<h5>Examples:</h5>
				1710
				1711	<table class="layout">
				1712	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1713	<td class="left"><tt>opaque</tt></td>
				1714	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1715	</tr>
				1716	</table>
				1717	</div>
				1718
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1719	<!-- ======================================================================= -->
				1720	<div class="doc_subsection">
				1721	<a name="t_uprefs">Type Up-references</a>
				1722	</div>
				1723
				1724	<div class="doc_text">
				1725	<h5>Overview:</h5>
				1726	<p>
				1727	An "up reference" allows you to refer to a lexically enclosing type without
				1728	requiring it to have a name. For instance, a structure declaration may contain a
				1729	pointer to any of the types it is lexically a member of. Example of up
				1730	references (with their equivalent as named type declarations) include:</p>
				1731
				1732	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1733	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1734	{ \2 }* %y = type { %y }*
				1735	\1* %z = type %z*
				1736	</pre>
				1737
				1738	<p>
				1739	An up reference is needed by the asmprinter for printing out cyclic types when
				1740	there is no declared name for a type in the cycle. Because the asmprinter does
				1741	not want to print out an infinite type string, it needs a syntax to handle
				1742	recursive types that have no names (all names are optional in llvm IR).
				1743	</p>
				1744
				1745	<h5>Syntax:</h5>
				1746	<pre>
				1747	\<level>
				1748	</pre>
				1749
				1750	<p>
				1751	The level is the count of the lexical type that is being referred to.
				1752	</p>
				1753
				1754	<h5>Examples:</h5>
				1755
				1756	<table class="layout">
				1757	<tr class="layout">
				1758	<td class="left"><tt>\1*</tt></td>
				1759	<td class="left">Self-referential pointer.</td>
				1760	</tr>
				1761	<tr class="layout">
				1762	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1763	<td class="left">Recursive structure where the upref refers to the out-most
				1764	structure.</td>
				1765	</tr>
				1766	</table>
				1767	</div>
				1768
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1769
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1770	<!-- *********************************************************************** -->
				1771	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1772	<!-- *********************************************************************** -->
				1773
				1774	<div class="doc_text">
				1775
				1776	<p>LLVM has several different basic types of constants. This section describes
				1777	them all and their syntax.</p>
				1778
				1779	</div>
				1780
				1781	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1782	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1783
				1784	<div class="doc_text">
				1785
				1786	<dl>
				1787	<dt><b>Boolean constants</b></dt>
				1788
				1789	<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]	1790	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1791	</dd>
				1792
				1793	<dt><b>Integer constants</b></dt>
				1794
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1795	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1796	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1797	integer types.
				1798	</dd>
				1799
				1800	<dt><b>Floating point constants</b></dt>
				1801
				1802	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1803	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1804	notation (see below). The assembler requires the exact decimal value of
				1805	a floating-point constant. For example, the assembler accepts 1.25 but
				1806	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1807	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]	1808
				1809	<dt><b>Null pointer constants</b></dt>
				1810
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1811	<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]	1812	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1813
				1814	</dl>
				1815
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1816	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1817	of floating point constants. For example, the form '<tt>double
				1818	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1819	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]	1820	(and the only time that they are generated by the disassembler) is when a
				1821	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]	1822	decimal floating point number in a reasonable number of digits. For example,
				1823	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1824	special values are represented in their IEEE hexadecimal format so that
				1825	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]	1826	<p>When using the hexadecimal form, constants of types float and double are
				1827	represented using the 16-digit form shown above (which matches the IEEE754
				1828	representation for double); float values must, however, be exactly representable
				1829	as IEE754 single precision.
				1830	Hexadecimal format is always used for long
				1831	double, and there are three forms of long double. The 80-bit
				1832	format used by x86 is represented as <tt>0xK</tt>
				1833	followed by 20 hexadecimal digits.
				1834	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1835	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1836	format is represented
				1837	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1838	target uses this format. Long doubles will only work if they match
				1839	the long double format on your target. All hexadecimal formats are big-endian
				1840	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1841	</div>
				1842
				1843	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1844	<div class="doc_subsection">
				1845	<a name="aggregateconstants"> <!-- old anchor -->
				1846	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1847	</div>
				1848
				1849	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1850	<p>Complex constants are a (potentially recursive) combination of simple
				1851	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1852
				1853	<dl>
				1854	<dt><b>Structure constants</b></dt>
				1855
				1856	<dd>Structure constants are represented with notation similar to structure
				1857	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1858	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1859	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]	1860	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]	1861	types of elements must match those specified by the type.
				1862	</dd>
				1863
				1864	<dt><b>Array constants</b></dt>
				1865
				1866	<dd>Array constants are represented with notation similar to array type
				1867	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1868	(<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]	1869	constants must have <a href="#t_array">array type</a>, and the number and
				1870	types of elements must match those specified by the type.
				1871	</dd>
				1872
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1873	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1874
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1875	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1876	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1877	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1878	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1879	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]	1880	match those specified by the type.
				1881	</dd>
				1882
				1883	<dt><b>Zero initialization</b></dt>
				1884
				1885	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1886	value to zero of <em>any</em> type, including scalar and aggregate types.
				1887	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]	1888	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1889	initializers.
				1890	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1891
				1892	<dt><b>Metadata node</b></dt>
				1893
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1894	<dd>A metadata node is a structure-like constant with
				1895	<a href="#t_metadata">metadata type</a>. For example:
				1896	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1897	that are meant to be interpreted as part of the instruction stream, metadata
				1898	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1899	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1900	</dl>
				1901
				1902	</div>
				1903
				1904	<!-- ======================================================================= -->
				1905	<div class="doc_subsection">
				1906	<a name="globalconstants">Global Variable and Function Addresses</a>
				1907	</div>
				1908
				1909	<div class="doc_text">
				1910
				1911	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1912	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1913	constants. These constants are explicitly referenced when the <a
				1914	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]	1915	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1916	file:</p>
				1917
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1918	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1919	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1920	@X = global i32 17
				1921	@Y = global i32 42
				1922	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1923	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1924	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1925
				1926	</div>
				1927
				1928	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1929	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1930	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1931	<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]	1932	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]	1933	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1934
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1935	<p>Undefined values indicate to the compiler that the program is well defined
				1936	no matter what value is used, giving the compiler more freedom to optimize.
				1937	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1938	</div>
				1939
				1940	<!-- ======================================================================= -->
				1941	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1942	</div>
				1943
				1944	<div class="doc_text">
				1945
				1946	<p>Constant expressions are used to allow expressions involving other constants
				1947	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1948	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]	1949	that does not have side effects (e.g. load and call are not supported). The
				1950	following is the syntax for constant expressions:</p>
				1951
				1952	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1953	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1954	<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]	1955	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1956
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1957	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1958	<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]	1959	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]	1960
				1961	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1962	<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]	1963	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]	1964
				1965	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1966	<dd>Truncate a floating point constant to another floating point type. The
				1967	size of CST must be larger than the size of TYPE. Both types must be
				1968	floating point.</dd>
				1969
				1970	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1971	<dd>Floating point extend a constant to another type. The size of CST must be
				1972	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1973
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	1974	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1975	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1976	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1977	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1978	of the same number of elements. If the value won't fit in the integer type,
				1979	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1980
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1981	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1982	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1983	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1984	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1985	of the same number of elements. If the value won't fit in the integer type,
				1986	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1987
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1988	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1989	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1990	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1991	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1992	of the same number of elements. If the value won't fit in the floating point
				1993	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1994
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	1995	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1996	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	1997	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1998	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1999	of the same number of elements. If the value won't fit in the floating point
				2000	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2001
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2002	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2003	<dd>Convert a pointer typed constant to the corresponding integer constant
				2004	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2005	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2006
				2007	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2008	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2009	pointer type. CST must be of integer type. The CST value is zero extended,
				2010	truncated, or unchanged to make it fit in a pointer size. This one is
				2011	<i>really</i> dangerous!</dd>
				2012
				2013	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2014	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2015	are the same as those for the <a href="#i_bitcast">bitcast
				2016	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2017
				2018	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2019
				2020	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2021	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2022	instruction, the index list may have zero or more indexes, which are required
				2023	to make sense for the type of "CSTPTR".</dd>
				2024
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2025	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2026
				2027	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2028	constants.</dd>
				2029
				2030	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2031	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2032
				2033	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2034	<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]	2035
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	2036	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2037	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2038
				2039	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2040	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2041
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2042	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2043
				2044	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2045	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2046
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2047	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2048
				2049	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2050	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2051
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2052
				2053	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2054
				2055	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2056	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2057
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2058	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2059
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2060	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2061	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]	2062	binary</a> operations. The constraints on operands are the same as those for
				2063	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2064	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2065	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2066	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2067
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2068	<!-- ======================================================================= -->
				2069	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2070	</div>
				2071
				2072	<div class="doc_text">
				2073
				2074	<p>Embedded metadata provides a way to attach arbitrary data to the
				2075	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2076	two metadata primitives, strings and nodes. All metadata has the
				2077	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2078	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2079	</p>
				2080
				2081	<p>A metadata string is a string surrounded by double quotes. It can contain
				2082	any character by escaping non-printable characters with "\xx" where "xx" is
				2083	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2084	</p>
				2085
				2086	<p>Metadata nodes are represented with notation similar to structure constants
				2087	(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]	2088	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2089	</p>
				2090
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2091	<p>A metadata node will attempt to track changes to the values it holds. In
				2092	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]	2093	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2094
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2095	<p>Optimizations may rely on metadata to provide additional information about
				2096	the program that isn't available in the instructions, or that isn't easily
				2097	computable. Similarly, the code generator may expect a certain metadata format
				2098	to be used to express debugging information.</p>
				2099	</div>
				2100
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2101	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2102	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2103	<!-- *********************************************************************** -->
				2104
				2105	<!-- ======================================================================= -->
				2106	<div class="doc_subsection">
				2107	<a name="inlineasm">Inline Assembler Expressions</a>
				2108	</div>
				2109
				2110	<div class="doc_text">
				2111
				2112	<p>
				2113	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2114	Module-Level Inline Assembly</a>) through the use of a special value. This
				2115	value represents the inline assembler as a string (containing the instructions
				2116	to emit), a list of operand constraints (stored as a string), and a flag that
				2117	indicates whether or not the inline asm expression has side effects. An example
				2118	inline assembler expression is:
				2119	</p>
				2120
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2121	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2122	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2123	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2124	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2125	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2126
				2127	<p>
				2128	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2129	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2130	</p>
				2131
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2132	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2133	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2134	%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]	2135	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2136	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2137
				2138	<p>
				2139	Inline asms with side effects not visible in the constraint list must be marked
				2140	as having side effects. This is done through the use of the
				2141	'<tt>sideeffect</tt>' keyword, like so:
				2142	</p>
				2143
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2144	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2145	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2146	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2147	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2148	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2149
				2150	<p>TODO: The format of the asm and constraints string still need to be
				2151	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]	2152	need to be documented). This is probably best done by reference to another
				2153	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2154	</p>
				2155
				2156	</div>
				2157
				2158	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2159	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2160	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2161
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2162	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2163
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2164	<p>The LLVM instruction set consists of several different
				2165	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2166	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2167	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2168	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2169	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2170
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2171	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2172
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2173	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2174	<div class="doc_subsection"> <a name="terminators">Terminator
				2175	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2176
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2177	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2178
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2179	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2180	basic block in a program ends with a "Terminator" instruction, which
				2181	indicates which block should be executed after the current block is
				2182	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2183	value: they produce control flow, not values (the one exception being
				2184	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2185	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2186	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2187	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2188	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2189	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2190	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2191
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2192	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2193
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2194	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2196	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2197	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2198	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2199	<pre>
				2200	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]	2201	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2202	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2203
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2204	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2205
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2206	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2207	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2208	<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]	2209	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]	2210	control flow to occur.</p>
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>Arguments:</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 optionally accepts a single argument,
				2215	the return value. The type of the return value must be a
				2216	'<a href="#t_firstclass">first class</a>' type.</p>
				2217
				2218	<p>A function is not <a href="#wellformed">well formed</a> if
				2219	it it has a non-void return type and contains a '<tt>ret</tt>'
				2220	instruction with no return value or a return value with a type that
				2221	does not match its type, or if it has a void return type and contains
				2222	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2223
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2224	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2225
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2226	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2227	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]	2228	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2229	the instruction after the call. If the caller was an "<a
				2230	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2231	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2232	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]	2233	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2234
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2235	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2236
				2237	<pre>
				2238	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2239	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2240	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]	2241	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2242
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2243	<p>Note that the code generator does not yet fully support large
				2244	return values. The specific sizes that are currently supported are
				2245	dependent on the target. For integers, on 32-bit targets the limit
				2246	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2247	For aggregate types, the current limits are dependent on the element
				2248	types; for example targets are often limited to 2 total integer
				2249	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2250
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2251	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2252	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2253	<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]	2254	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2255	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2256	<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]	2257	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2258	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2259	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2260	transfer to a different basic block in the current function. There are
				2261	two forms of this instruction, corresponding to a conditional branch
				2262	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2263	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2264	<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]	2265	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2266	unconditional form of the '<tt>br</tt>' instruction takes a single
				2267	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2268	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2269	<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]	2270	argument is evaluated. If the value is <tt>true</tt>, control flows
				2271	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2272	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2273	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2274	<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]	2275	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]	2276	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2278	<div class="doc_subsubsection">
				2279	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2280	</div>
				2281
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2282	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2283	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2284
				2285	<pre>
				2286	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2287	</pre>
				2288
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2289	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2290
				2291	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2292	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2293	instruction, allowing a branch to occur to one of many possible
				2294	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2295
				2296
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2297	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2298
				2299	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2300	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2301	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2302	table is not allowed to contain duplicate constant entries.</p>
				2303
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2304	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2305
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2306	<p>The <tt>switch</tt> instruction specifies a table of values and
				2307	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2308	table is searched for the given value. If the value is found, control flow is
				2309	transfered to the corresponding destination; otherwise, control flow is
				2310	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2311
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2312	<h5>Implementation:</h5>
				2313
				2314	<p>Depending on properties of the target machine and the particular
				2315	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2316	ways. For example, it could be generated as a series of chained conditional
				2317	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2318
				2319	<h5>Example:</h5>
				2320
				2321	<pre>
				2322	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2323	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2324	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2325
				2326	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2327	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2328
				2329	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2330	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2331	i32 1, label %onone
				2332	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2333	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2334	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2335
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2336	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2337	<div class="doc_subsubsection">
				2338	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2339	</div>
				2340
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2341	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2342
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2343	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2344
				2345	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2346	<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]	2347	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2348	</pre>
				2349
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2350	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2351
				2352	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2353	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2354	'<tt>normal</tt>' label or the
				2355	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2356	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2357	"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]	2358	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2359	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2360
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2361	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2362
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2363	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2364
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2365	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2366	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2367	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2368	convention</a> the call should use. If none is specified, the call defaults
				2369	to using C calling conventions.
				2370	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2371
				2372	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2373	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2374	and '<tt>inreg</tt>' attributes are valid here.</li>
				2375
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2376	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2377	function value being invoked. In most cases, this is a direct function
				2378	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2379	an arbitrary pointer to function value.
				2380	</li>
				2381
				2382	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2383	function to be invoked. </li>
				2384
				2385	<li>'<tt>function args</tt>': argument list whose types match the function
				2386	signature argument types. If the function signature indicates the function
				2387	accepts a variable number of arguments, the extra arguments can be
				2388	specified. </li>
				2389
				2390	<li>'<tt>normal label</tt>': the label reached when the called function
				2391	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2392
				2393	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2394	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2395
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2396	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2397	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2398	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2399	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2400
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2401	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2402
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2403	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2404	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2405	difference is that it establishes an association with a label, which is used by
				2406	the runtime library to unwind the stack.</p>
				2407
				2408	<p>This instruction is used in languages with destructors to ensure that proper
				2409	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2410	exception. Additionally, this is important for implementation of
				2411	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2412
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2413	<p>For the purposes of the SSA form, the definition of the value
				2414	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2415	the edge from the current block to the "normal" label. If the callee
				2416	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2417
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2418	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2419	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2420	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2421	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2422	%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]	2423	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2424	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2425	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2426
				2427
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2428	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2429
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2430	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2431	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2432
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2433	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2434
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2435	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2436	<pre>
				2437	unwind
				2438	</pre>
				2439
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2440	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2441
				2442	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2443	at the first callee in the dynamic call stack which used an <a
				2444	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2445	primarily used to implement exception handling.</p>
				2446
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2447	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2448
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2449	<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]	2450	immediately halt. The dynamic call stack is then searched for the first <a
				2451	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2452	execution continues at the "exceptional" destination block specified by the
				2453	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2454	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2455	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2456
				2457	<!-- _______________________________________________________________________ -->
				2458
				2459	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2460	Instruction</a> </div>
				2461
				2462	<div class="doc_text">
				2463
				2464	<h5>Syntax:</h5>
				2465	<pre>
				2466	unreachable
				2467	</pre>
				2468
				2469	<h5>Overview:</h5>
				2470
				2471	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2472	instruction is used to inform the optimizer that a particular portion of the
				2473	code is not reachable. This can be used to indicate that the code after a
				2474	no-return function cannot be reached, and other facts.</p>
				2475
				2476	<h5>Semantics:</h5>
				2477
				2478	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2479	</div>
				2480
				2481
				2482
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2483	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2484	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2485	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2486	<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]	2487	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]	2488	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2489	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]	2490	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2491	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2492	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2493	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2494	<div class="doc_subsubsection">
				2495	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2496	</div>
				2497
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2498	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2499
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2500	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2501
				2502	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2503	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2504	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2505
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2506	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2507
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2508	<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]	2509
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2510	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2511
				2512	<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]	2513	href="#t_integer">integer</a> or
				2514	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2515	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2516
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2517	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2519	<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]	2520
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2521	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2522	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2523	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2524
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2525	<p>Because LLVM integers use a two's complement representation, this
				2526	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2527
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2528	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2529
				2530	<pre>
				2531	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2532	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2533	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2534	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2535	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2536	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2537	</div>
				2538
				2539	<div class="doc_text">
				2540
				2541	<h5>Syntax:</h5>
				2542
				2543	<pre>
				2544	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2545	</pre>
				2546
				2547	<h5>Overview:</h5>
				2548
				2549	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2550
				2551	<h5>Arguments:</h5>
				2552
				2553	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2554	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2555	floating point values. Both arguments must have identical types.</p>
				2556
				2557	<h5>Semantics:</h5>
				2558
				2559	<p>The value produced is the floating point sum of the two operands.</p>
				2560
				2561	<h5>Example:</h5>
				2562
				2563	<pre>
				2564	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2565	</pre>
				2566	</div>
				2567	<!-- _______________________________________________________________________ -->
				2568	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2569	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2570	</div>
				2571
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2572	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2573
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2574	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2575
				2576	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2577	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2578	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2579
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2580	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2581
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2582	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2583	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2584
				2585	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2586	'<tt>neg</tt>' instruction present in most other intermediate
				2587	representations.</p>
				2588
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2589	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
				2591	<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]	2592	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2593	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2594
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2595	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2596
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2597	<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]	2598
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2599	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2600	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2601	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2602
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2603	<p>Because LLVM integers use a two's complement representation, this
				2604	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2606	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2607	<pre>
				2608	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2609	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2610	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2611	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2612
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2613	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2614	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2615	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2616	</div>
				2617
				2618	<div class="doc_text">
				2619
				2620	<h5>Syntax:</h5>
				2621
				2622	<pre>
				2623	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2624	</pre>
				2625
				2626	<h5>Overview:</h5>
				2627
				2628	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2629	operands.</p>
				2630
				2631	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2632	'<tt>fneg</tt>' instruction present in most other intermediate
				2633	representations.</p>
				2634
				2635	<h5>Arguments:</h5>
				2636
				2637	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2638	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2639	of floating point values. Both arguments must have identical types.</p>
				2640
				2641	<h5>Semantics:</h5>
				2642
				2643	<p>The value produced is the floating point difference of the two operands.</p>
				2644
				2645	<h5>Example:</h5>
				2646	<pre>
				2647	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2648	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2649	</pre>
				2650	</div>
				2651
				2652	<!-- _______________________________________________________________________ -->
				2653	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2654	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2655	</div>
				2656
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2657	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2658
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2659	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2660	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2661	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2662	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2663	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2664	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2665
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2666	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2667
				2668	<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]	2669	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2670	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2671
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2672	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2673
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2674	<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]	2675
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2676	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2677	the result returned is the mathematical result modulo
				2678	2<sup>n</sup>, where n is the bit width of the result.</p>
				2679	<p>Because LLVM integers use a two's complement representation, and the
				2680	result is the same width as the operands, this instruction returns the
				2681	correct result for both signed and unsigned integers. If a full product
				2682	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2683	should be sign-extended or zero-extended as appropriate to the
				2684	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2685	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2686	<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]	2687	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2688	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2689
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2690	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2691	<div class="doc_subsubsection">
				2692	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2693	</div>
				2694
				2695	<div class="doc_text">
				2696
				2697	<h5>Syntax:</h5>
				2698	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2699	</pre>
				2700	<h5>Overview:</h5>
				2701	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2702	operands.</p>
				2703
				2704	<h5>Arguments:</h5>
				2705
				2706	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2707	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2708	of floating point values. Both arguments must have identical types.</p>
				2709
				2710	<h5>Semantics:</h5>
				2711
				2712	<p>The value produced is the floating point product of the two operands.</p>
				2713
				2714	<h5>Example:</h5>
				2715	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2716	</pre>
				2717	</div>
				2718
				2719	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2720	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2721	</a></div>
				2722	<div class="doc_text">
				2723	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2724	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2725	</pre>
				2726	<h5>Overview:</h5>
				2727	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2728	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2729
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2730	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2731
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2732	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2733	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2734	values. Both arguments must have identical types.</p>
				2735
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2736	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2737
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2738	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2739	<p>Note that unsigned integer division and signed integer division are distinct
				2740	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2741	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2742	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2743	<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]	2744	</pre>
				2745	</div>
				2746	<!-- _______________________________________________________________________ -->
				2747	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2748	</a> </div>
				2749	<div class="doc_text">
				2750	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2751	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2752	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2753	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2754
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2755	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2756
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2757	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2758	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2759
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2760	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2761
				2762	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2763	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2764	values. Both arguments must have identical types.</p>
				2765
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2766	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2767	<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]	2768	<p>Note that signed integer division and unsigned integer division are distinct
				2769	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2770	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2771	undefined behavior; this is a rare case, but can occur, for example,
				2772	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2773	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2774	<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]	2775	</pre>
				2776	</div>
				2777	<!-- _______________________________________________________________________ -->
				2778	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2779	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2780	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2781	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2782	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2783	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2784	</pre>
				2785	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2786
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2787	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2788	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2789
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2790	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2791
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2792	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2793	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2794	of floating point values. Both arguments must have identical types.</p>
				2795
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2796	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2797
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2798	<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]	2799
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2800	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2801
				2802	<pre>
				2803	<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]	2804	</pre>
				2805	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2806
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2807	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2808	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2809	</div>
				2810	<div class="doc_text">
				2811	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2812	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2813	</pre>
				2814	<h5>Overview:</h5>
				2815	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2816	unsigned division of its two arguments.</p>
				2817	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2818	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2819	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2820	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2821	<h5>Semantics:</h5>
				2822	<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]	2823	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2824	<p>Note that unsigned integer remainder and signed integer remainder are
				2825	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2826	<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]	2827	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2828	<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]	2829	</pre>
				2830
				2831	</div>
				2832	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2833	<div class="doc_subsubsection">
				2834	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2835	</div>
				2836
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2837	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2838
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2839	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2840
				2841	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2842	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2843	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2844
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2845	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2846
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2847	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2848	signed division of its two operands. This instruction can also take
				2849	<a href="#t_vector">vector</a> versions of the values in which case
				2850	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2851
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2852	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2853
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2854	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2855	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2856	values. Both arguments must have identical types.</p>
				2857
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2858	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2859
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2860	<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]	2861	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2862	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]	2863	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2864	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]	2865	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]	2866	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2867	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2868	<p>Note that signed integer remainder and unsigned integer remainder are
				2869	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2870	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2871	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2872	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2873	(The remainder doesn't actually overflow, but this rule lets srem be
				2874	implemented using instructions that return both the result of the division
				2875	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2876	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2877	<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]	2878	</pre>
				2879
				2880	</div>
				2881	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2882	<div class="doc_subsubsection">
				2883	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2884
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2885	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2886
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2887	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2888	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2889	</pre>
				2890	<h5>Overview:</h5>
				2891	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2892	division of its two operands.</p>
				2893	<h5>Arguments:</h5>
				2894	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2895	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2896	of floating point values. Both arguments must have identical types.</p>
				2897
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2898	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2899
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2900	<p>This instruction returns the <i>remainder</i> of a division.
				2901	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2902
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2903	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2904
				2905	<pre>
				2906	<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]	2907	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2908	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2909
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2910	<!-- ======================================================================= -->
				2911	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2912	Operations</a> </div>
				2913	<div class="doc_text">
				2914	<p>Bitwise binary operators are used to do various forms of
				2915	bit-twiddling in a program. They are generally very efficient
				2916	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2917	instructions. They require two operands of the same type, execute an operation on them,
				2918	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]	2919	</div>
				2920
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2921	<!-- _______________________________________________________________________ -->
				2922	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2923	Instruction</a> </div>
				2924	<div class="doc_text">
				2925	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2926	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2927	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2928
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2929	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2930
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2931	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2932	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2933
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2934	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2935
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2936	<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]	2937	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]	2938	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2939
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2940	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2941
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2942	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2943	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]	2944	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2945	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2946	corresponding shift amount in <tt>op2</tt>.</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>Example:</h5><pre>
				2949	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2950	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2951	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2952	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2953	<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]	2954	</pre>
				2955	</div>
				2956	<!-- _______________________________________________________________________ -->
				2957	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2958	Instruction</a> </div>
				2959	<div class="doc_text">
				2960	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2961	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2962	</pre>
				2963
				2964	<h5>Overview:</h5>
				2965	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2966	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]	2967
				2968	<h5>Arguments:</h5>
				2969	<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]	2970	<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]	2971	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2972
				2973	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2974
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2975	<p>This instruction always performs a logical shift right operation. The most
				2976	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]	2977	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]	2978	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2979	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2980	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2981
				2982	<h5>Example:</h5>
				2983	<pre>
				2984	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2985	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2986	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2987	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2988	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2989	<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]	2990	</pre>
				2991	</div>
				2992
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2993	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2994	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2995	Instruction</a> </div>
				2996	<div class="doc_text">
				2997
				2998	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2999	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3000	</pre>
				3001
				3002	<h5>Overview:</h5>
				3003	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3004	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]	3005
				3006	<h5>Arguments:</h5>
				3007	<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]	3008	<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]	3009	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3010
				3011	<h5>Semantics:</h5>
				3012	<p>This instruction always performs an arithmetic shift right operation,
				3013	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]	3014	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]	3015	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3016	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3017	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3018
				3019	<h5>Example:</h5>
				3020	<pre>
				3021	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3022	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3023	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3024	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3025	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3026	<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]	3027	</pre>
				3028	</div>
				3029
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3030	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3031	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3032	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3033
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3034	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3035
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3036	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3037
				3038	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3039	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3040	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3041
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3042	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3043
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3044	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3045	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3046
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3047	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3048
				3049	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3050	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3051	values. Both arguments must have identical types.</p>
				3052
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3053	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3054	<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]	3055	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3056	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3057	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3058	<tbody>
				3059	<tr>
				3060	<td>In0</td>
				3061	<td>In1</td>
				3062	<td>Out</td>
				3063	</tr>
				3064	<tr>
				3065	<td>0</td>
				3066	<td>0</td>
				3067	<td>0</td>
				3068	</tr>
				3069	<tr>
				3070	<td>0</td>
				3071	<td>1</td>
				3072	<td>0</td>
				3073	</tr>
				3074	<tr>
				3075	<td>1</td>
				3076	<td>0</td>
				3077	<td>0</td>
				3078	</tr>
				3079	<tr>
				3080	<td>1</td>
				3081	<td>1</td>
				3082	<td>1</td>
				3083	</tr>
				3084	</tbody>
				3085	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3086	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3087	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3088	<pre>
				3089	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3090	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3091	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3092	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3093	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3094	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3095	<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]	3096	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3097	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3098	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3099	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3100	<h5>Overview:</h5>
				3101	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3102	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3103	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3104
				3105	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3106	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3107	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3108	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3109	<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]	3110	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3111	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3112	<table border="1" cellspacing="0" cellpadding="4">
				3113	<tbody>
				3114	<tr>
				3115	<td>In0</td>
				3116	<td>In1</td>
				3117	<td>Out</td>
				3118	</tr>
				3119	<tr>
				3120	<td>0</td>
				3121	<td>0</td>
				3122	<td>0</td>
				3123	</tr>
				3124	<tr>
				3125	<td>0</td>
				3126	<td>1</td>
				3127	<td>1</td>
				3128	</tr>
				3129	<tr>
				3130	<td>1</td>
				3131	<td>0</td>
				3132	<td>1</td>
				3133	</tr>
				3134	<tr>
				3135	<td>1</td>
				3136	<td>1</td>
				3137	<td>1</td>
				3138	</tr>
				3139	</tbody>
				3140	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3141	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3142	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3143	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3144	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3145	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3146	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3147	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3148	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3149	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3150	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3151	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3152	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3153	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3154	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3156	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3157	or of its two operands. The <tt>xor</tt> is used to implement the
				3158	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3159	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3160	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3161	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3162	values. Both arguments must have identical types.</p>
				3163
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3164	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3165
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3166	<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]	3167	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3168	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3169	<table border="1" cellspacing="0" cellpadding="4">
				3170	<tbody>
				3171	<tr>
				3172	<td>In0</td>
				3173	<td>In1</td>
				3174	<td>Out</td>
				3175	</tr>
				3176	<tr>
				3177	<td>0</td>
				3178	<td>0</td>
				3179	<td>0</td>
				3180	</tr>
				3181	<tr>
				3182	<td>0</td>
				3183	<td>1</td>
				3184	<td>1</td>
				3185	</tr>
				3186	<tr>
				3187	<td>1</td>
				3188	<td>0</td>
				3189	<td>1</td>
				3190	</tr>
				3191	<tr>
				3192	<td>1</td>
				3193	<td>1</td>
				3194	<td>0</td>
				3195	</tr>
				3196	</tbody>
				3197	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3198	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3199	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3200	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3201	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3202	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3203	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3204	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3205	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3206	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3207
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3208	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3209	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3210	<a name="vectorops">Vector Operations</a>
				3211	</div>
				3212
				3213	<div class="doc_text">
				3214
				3215	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3216	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3217	vector-specific operations needed to process vectors effectively. While LLVM
				3218	does directly support these vector operations, many sophisticated algorithms
				3219	will want to use target-specific intrinsics to take full advantage of a specific
				3220	target.</p>
				3221
				3222	</div>
				3223
				3224	<!-- _______________________________________________________________________ -->
				3225	<div class="doc_subsubsection">
				3226	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3227	</div>
				3228
				3229	<div class="doc_text">
				3230
				3231	<h5>Syntax:</h5>
				3232
				3233	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3234	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3235	</pre>
				3236
				3237	<h5>Overview:</h5>
				3238
				3239	<p>
				3240	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3241	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3242	</p>
				3243
				3244
				3245	<h5>Arguments:</h5>
				3246
				3247	<p>
				3248	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3249	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]	3250	an index indicating the position from which to extract the element.
				3251	The index may be a variable.</p>
				3252
				3253	<h5>Semantics:</h5>
				3254
				3255	<p>
				3256	The result is a scalar of the same type as the element type of
				3257	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3258	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3259	results are undefined.
				3260	</p>
				3261
				3262	<h5>Example:</h5>
				3263
				3264	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3265	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3266	</pre>
				3267	</div>
				3268
				3269
				3270	<!-- _______________________________________________________________________ -->
				3271	<div class="doc_subsubsection">
				3272	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3273	</div>
				3274
				3275	<div class="doc_text">
				3276
				3277	<h5>Syntax:</h5>
				3278
				3279	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3280	<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]	3281	</pre>
				3282
				3283	<h5>Overview:</h5>
				3284
				3285	<p>
				3286	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3287	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3288	</p>
				3289
				3290
				3291	<h5>Arguments:</h5>
				3292
				3293	<p>
				3294	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3295	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]	3296	scalar value whose type must equal the element type of the first
				3297	operand. The third operand is an index indicating the position at
				3298	which to insert the value. The index may be a variable.</p>
				3299
				3300	<h5>Semantics:</h5>
				3301
				3302	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3303	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]	3304	element values are those of <tt>val</tt> except at position
				3305	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3306	exceeds the length of <tt>val</tt>, the results are undefined.
				3307	</p>
				3308
				3309	<h5>Example:</h5>
				3310
				3311	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3312	%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]	3313	</pre>
				3314	</div>
				3315
				3316	<!-- _______________________________________________________________________ -->
				3317	<div class="doc_subsubsection">
				3318	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3319	</div>
				3320
				3321	<div class="doc_text">
				3322
				3323	<h5>Syntax:</h5>
				3324
				3325	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3326	<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]	3327	</pre>
				3328
				3329	<h5>Overview:</h5>
				3330
				3331	<p>
				3332	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3333	from two input vectors, returning a vector with the same element type as
				3334	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3335	</p>
				3336
				3337	<h5>Arguments:</h5>
				3338
				3339	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3340	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3341	with types that match each other. The third argument is a shuffle mask whose
				3342	element type is always 'i32'. The result of the instruction is a vector whose
				3343	length is the same as the shuffle mask and whose element type is the same as
				3344	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3345	</p>
				3346
				3347	<p>
				3348	The shuffle mask operand is required to be a constant vector with either
				3349	constant integer or undef values.
				3350	</p>
				3351
				3352	<h5>Semantics:</h5>
				3353
				3354	<p>
				3355	The elements of the two input vectors are numbered from left to right across
				3356	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]	3357	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]	3358	gets. The element selector may be undef (meaning "don't care") and the second
				3359	operand may be undef if performing a shuffle from only one vector.
				3360	</p>
				3361
				3362	<h5>Example:</h5>
				3363
				3364	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3365	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3366	<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]	3367	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3368	<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]	3369	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3370	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3371	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3372	<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]	3373	</pre>
				3374	</div>
				3375
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3376
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3377	<!-- ======================================================================= -->
				3378	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3379	<a name="aggregateops">Aggregate Operations</a>
				3380	</div>
				3381
				3382	<div class="doc_text">
				3383
				3384	<p>LLVM supports several instructions for working with aggregate values.
				3385	</p>
				3386
				3387	</div>
				3388
				3389	<!-- _______________________________________________________________________ -->
				3390	<div class="doc_subsubsection">
				3391	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3392	</div>
				3393
				3394	<div class="doc_text">
				3395
				3396	<h5>Syntax:</h5>
				3397
				3398	<pre>
				3399	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3400	</pre>
				3401
				3402	<h5>Overview:</h5>
				3403
				3404	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3405	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3406	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3407	</p>
				3408
				3409
				3410	<h5>Arguments:</h5>
				3411
				3412	<p>
				3413	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3414	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]	3415	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3416	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3417	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3418	</p>
				3419
				3420	<h5>Semantics:</h5>
				3421
				3422	<p>
				3423	The result is the value at the position in the aggregate specified by
				3424	the index operands.
				3425	</p>
				3426
				3427	<h5>Example:</h5>
				3428
				3429	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3430	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3431	</pre>
				3432	</div>
				3433
				3434
				3435	<!-- _______________________________________________________________________ -->
				3436	<div class="doc_subsubsection">
				3437	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3438	</div>
				3439
				3440	<div class="doc_text">
				3441
				3442	<h5>Syntax:</h5>
				3443
				3444	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3445	<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]	3446	</pre>
				3447
				3448	<h5>Overview:</h5>
				3449
				3450	<p>
				3451	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3452	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3453	</p>
				3454
				3455
				3456	<h5>Arguments:</h5>
				3457
				3458	<p>
				3459	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3460	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3461	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3462	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3463	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]	3464	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3465	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3466	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]	3467	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3468	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3469
				3470	<h5>Semantics:</h5>
				3471
				3472	<p>
				3473	The result is an aggregate of the same type as <tt>val</tt>. Its
				3474	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]	3475	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3476	</p>
				3477
				3478	<h5>Example:</h5>
				3479
				3480	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3481	%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]	3482	</pre>
				3483	</div>
				3484
				3485
				3486	<!-- ======================================================================= -->
				3487	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3488	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3489	</div>
				3490
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3491	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3492
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3493	<p>A key design point of an SSA-based representation is how it
				3494	represents memory. In LLVM, no memory locations are in SSA form, which
				3495	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3496	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3497
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3498	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3499
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3500	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3501	<div class="doc_subsubsection">
				3502	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3503	</div>
				3504
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3505	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3506
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3507	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3508
				3509	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3510	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3511	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3512
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3513	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3514
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3515	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3516	heap and returns a pointer to it. The object is always allocated in the generic
				3517	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3518
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3519	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3520
				3521	<p>The '<tt>malloc</tt>' instruction allocates
				3522	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3523	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]	3524	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3525	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3526	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]	3527	be aligned to at least that boundary. If not specified, or if zero, the target can
				3528	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3529
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3530	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3531
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3532	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3534	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3535	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3536	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3537
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3538	<h5>Example:</h5>
				3539
				3540	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3541	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3542
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3543	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3544	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3545	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3546	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3547	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3548	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3549
				3550	<p>Note that the code generator does not yet respect the
				3551	alignment value.</p>
				3552
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3553	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3554
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3555	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3556	<div class="doc_subsubsection">
				3557	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3558	</div>
				3559
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3560	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3561
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3562	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3563
				3564	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3565	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3566	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3567
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3568	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3569
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3570	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3571	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3572
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3573	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3574
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3575	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3576	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3577	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3578
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3579	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3581	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	e0db56d	2008-04-19 22:41:32 +0000	[diff] [blame]	3582	after this instruction executes. If the pointer is null, the operation
				3583	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3584
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3585	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3586
				3587	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3588	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3589	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3590	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3591	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3592
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3593	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3594	<div class="doc_subsubsection">
				3595	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3596	</div>
				3597
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3598	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3599
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3600	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3601
				3602	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3603	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3604	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3605
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3606	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3607
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3608	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3609	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3610	returns to its caller. The object is always allocated in the generic address
				3611	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3612
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3613	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3614
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3615	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3616	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3617	appropriate type to the program. If "NumElements" is specified, it is the
				3618	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3619	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]	3620	to be aligned to at least that boundary. If not specified, or if zero, the target
				3621	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3622
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3623	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3624
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3625	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3626
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3627	<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]	3628	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3629	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3630	instruction is commonly used to represent automatic variables that must
				3631	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]	3632	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]	3633	instructions), the memory is reclaimed. Allocating zero bytes
				3634	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3635
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3636	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3637
				3638	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3639	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3640	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3641	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3642	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3643	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3644	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3645
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3646	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3647	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3648	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3649	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3650	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3651	<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]	3652	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3653	<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]	3654	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3655	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3656	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3657	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]	3658	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]	3659	the number or order of execution of this <tt>load</tt> with other
				3660	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3661	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3662	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3663	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3664	(that is, the alignment of the memory address). A value of 0 or an
				3665	omitted "align" argument means that the operation has the preferential
				3666	alignment for the target. It is the responsibility of the code emitter
				3667	to ensure that the alignment information is correct. Overestimating
				3668	the alignment results in an undefined behavior. Underestimating the
				3669	alignment may produce less efficient code. An alignment of 1 is always
				3670	safe.
				3671	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3672	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3673	<p>The location of memory pointed to is loaded. If the value being loaded
				3674	is of scalar type then the number of bytes read does not exceed the minimum
				3675	number of bytes needed to hold all bits of the type. For example, loading an
				3676	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3677	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3678	is undefined if the value was not originally written using a store of the
				3679	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3680	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3681	<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]	3682	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3683	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3684	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3685	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3686	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3687	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3688	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3689	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3690	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3691	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3692	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3693	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3694	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3695	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3696	<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]	3697	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3698	<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]	3699	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]	3700	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3701	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3702	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]	3703	optimizer is not allowed to modify the number or order of execution of
				3704	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3705	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3706	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3707	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3708	(that is, the alignment of the memory address). A value of 0 or an
				3709	omitted "align" argument means that the operation has the preferential
				3710	alignment for the target. It is the responsibility of the code emitter
				3711	to ensure that the alignment information is correct. Overestimating
				3712	the alignment results in an undefined behavior. Underestimating the
				3713	alignment may produce less efficient code. An alignment of 1 is always
				3714	safe.
				3715	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3716	<h5>Semantics:</h5>
				3717	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3718	at the location specified by the '<tt><pointer></tt>' operand.
				3719	If '<tt><value></tt>' is of scalar type then the number of bytes
				3720	written does not exceed the minimum number of bytes needed to hold all
				3721	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3722	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3723	size that is not an integral number of bytes, it is unspecified what
				3724	happens to the extra bits that do not belong to the type, but they will
				3725	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3726	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3727	<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]	3728	store i32 3, i32* %ptr <i>; yields {void}</i>
				3729	%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]	3730	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3731	</div>
				3732
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3733	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3734	<div class="doc_subsubsection">
				3735	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3736	</div>
				3737
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3738	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3739	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3740	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3741	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3742	</pre>
				3743
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3744	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3745
				3746	<p>
				3747	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]	3748	subelement of an aggregate data structure. It performs address calculation only
				3749	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3750
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3751	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3752
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3753	<p>The first argument is always a pointer, and forms the basis of the
				3754	calculation. The remaining arguments are indices, that indicate which of the
				3755	elements of the aggregate object are indexed. The interpretation of each index
				3756	is dependent on the type being indexed into. The first index always indexes the
				3757	pointer value given as the first argument, the second index indexes a value of
				3758	the type pointed to (not necessarily the value directly pointed to, since the
				3759	first index can be non-zero), etc. The first type indexed into must be a pointer
				3760	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3761	types being indexed into can never be pointers, since that would require loading
				3762	the pointer before continuing calculation.</p>
				3763
				3764	<p>The type of each index argument depends on the type it is indexing into.
				3765	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3766	<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]	3767	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3768
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3769	<p>For example, let's consider a C code fragment and how it gets
				3770	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3771
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3772	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3773	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3774	struct RT {
				3775	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3776	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3777	char C;
				3778	};
				3779	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3780	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3781	double Y;
				3782	struct RT Z;
				3783	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3784
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3785	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3786	return &s[1].Z.B[5][13];
				3787	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3788	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3789	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3790
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3791	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3792
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3793	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3794	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3795	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3796	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3797
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3798	define i32* %foo(%ST* %s) {
				3799	entry:
				3800	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3801	ret i32* %reg
				3802	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3803	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3804	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3805
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3806	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3807
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3808	<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]	3809	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]	3810	}</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]	3811	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3812	i8 }</tt>' type, another structure. The third index indexes into the second
				3813	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]	3814	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3815	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3816	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]	3817
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3818	<p>Note that it is perfectly legal to index partially through a
				3819	structure, returning a pointer to an inner element. Because of this,
				3820	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3821
				3822	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3823	define i32* %foo(%ST* %s) {
				3824	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3825	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3826	%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]	3827	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3828	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3829	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3830	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3831	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3832
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3833	<p>Note that it is undefined to access an array out of bounds: array
				3834	and pointer indexes must always be within the defined bounds of the
				3835	array type when accessed with an instruction that dereferences the
				3836	pointer (e.g. a load or store instruction). The one exception for
				3837	this rule is zero length arrays. These arrays are defined to be
				3838	accessible as variable length arrays, which requires access beyond the
				3839	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3840
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3841	<p>The getelementptr instruction is often confusing. For some more insight
				3842	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3843	FAQ</a>.</p>
				3844
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3845	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3846
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3847	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3848	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3849	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3850	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3851	%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]	3852	<i>; yields i8*:eptr</i>
				3853	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3854	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3855	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3856	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3857	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3858
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3859	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3860	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3861	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3862	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3863	<p>The instructions in this category are the conversion instructions (casting)
				3864	which all take a single operand and a type. They perform various bit conversions
				3865	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3866	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3867
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3868	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3869	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3870	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3871	</div>
				3872	<div class="doc_text">
				3873
				3874	<h5>Syntax:</h5>
				3875	<pre>
				3876	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3877	</pre>
				3878
				3879	<h5>Overview:</h5>
				3880	<p>
				3881	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3882	</p>
				3883
				3884	<h5>Arguments:</h5>
				3885	<p>
				3886	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3887	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]	3888	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]	3889	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3890	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3891
				3892	<h5>Semantics:</h5>
				3893	<p>
				3894	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]	3895	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3896	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3897	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3898
				3899	<h5>Example:</h5>
				3900	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3901	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3902	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3903	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3904	</pre>
				3905	</div>
				3906
				3907	<!-- _______________________________________________________________________ -->
				3908	<div class="doc_subsubsection">
				3909	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3910	</div>
				3911	<div class="doc_text">
				3912
				3913	<h5>Syntax:</h5>
				3914	<pre>
				3915	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3916	</pre>
				3917
				3918	<h5>Overview:</h5>
				3919	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3920	<tt>ty2</tt>.</p>
				3921
				3922
				3923	<h5>Arguments:</h5>
				3924	<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]	3925	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3926	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]	3927	<tt>value</tt> must be smaller than the bit size of the destination type,
				3928	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3929
				3930	<h5>Semantics:</h5>
				3931	<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]	3932	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]	3933
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3934	<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]	3935
				3936	<h5>Example:</h5>
				3937	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3938	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3939	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3940	</pre>
				3941	</div>
				3942
				3943	<!-- _______________________________________________________________________ -->
				3944	<div class="doc_subsubsection">
				3945	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3946	</div>
				3947	<div class="doc_text">
				3948
				3949	<h5>Syntax:</h5>
				3950	<pre>
				3951	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3952	</pre>
				3953
				3954	<h5>Overview:</h5>
				3955	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3956
				3957	<h5>Arguments:</h5>
				3958	<p>
				3959	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]	3960	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3961	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]	3962	<tt>value</tt> must be smaller than the bit size of the destination type,
				3963	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3964
				3965	<h5>Semantics:</h5>
				3966	<p>
				3967	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3968	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]	3969	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3970
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3971	<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]	3972
				3973	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3974	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3975	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3976	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3977	</pre>
				3978	</div>
				3979
				3980	<!-- _______________________________________________________________________ -->
				3981	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	3982	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3983	</div>
				3984
				3985	<div class="doc_text">
				3986
				3987	<h5>Syntax:</h5>
				3988
				3989	<pre>
				3990	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3991	</pre>
				3992
				3993	<h5>Overview:</h5>
				3994	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3995	<tt>ty2</tt>.</p>
				3996
				3997
				3998	<h5>Arguments:</h5>
				3999	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4000	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4001	cast it to. The size of <tt>value</tt> must be larger than the size of
				4002	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4003	<i>no-op cast</i>.</p>
				4004
				4005	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4006	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4007	<a href="#t_floating">floating point</a> type to a smaller
				4008	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4009	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4010
				4011	<h5>Example:</h5>
				4012	<pre>
				4013	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4014	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4015	</pre>
				4016	</div>
				4017
				4018	<!-- _______________________________________________________________________ -->
				4019	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4020	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4021	</div>
				4022	<div class="doc_text">
				4023
				4024	<h5>Syntax:</h5>
				4025	<pre>
				4026	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4027	</pre>
				4028
				4029	<h5>Overview:</h5>
				4030	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4031	floating point value.</p>
				4032
				4033	<h5>Arguments:</h5>
				4034	<p>The '<tt>fpext</tt>' instruction takes a
				4035	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4036	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4037	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4038
				4039	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4040	<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]	4041	<a href="#t_floating">floating point</a> type to a larger
				4042	<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]	4043	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]	4044	<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]	4045
				4046	<h5>Example:</h5>
				4047	<pre>
				4048	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4049	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4050	</pre>
				4051	</div>
				4052
				4053	<!-- _______________________________________________________________________ -->
				4054	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4055	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4056	</div>
				4057	<div class="doc_text">
				4058
				4059	<h5>Syntax:</h5>
				4060	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4061	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4062	</pre>
				4063
				4064	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4065	<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]	4066	unsigned integer equivalent of type <tt>ty2</tt>.
				4067	</p>
				4068
				4069	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4070	<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]	4071	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4072	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4073	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4074	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]	4075
				4076	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4077	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4078	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4079	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4080	the results are undefined.</p>
				4081
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4082	<h5>Example:</h5>
				4083	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4084	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4085	%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]	4086	%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]	4087	</pre>
				4088	</div>
				4089
				4090	<!-- _______________________________________________________________________ -->
				4091	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4092	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4093	</div>
				4094	<div class="doc_text">
				4095
				4096	<h5>Syntax:</h5>
				4097	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4098	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4099	</pre>
				4100
				4101	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4102	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4103	<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]	4104	</p>
				4105
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4106	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4107	<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]	4108	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4109	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4110	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4111	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]	4112
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4113	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4114	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4115	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4116	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4117	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4118
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4119	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4120	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4121	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4122	%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]	4123	%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]	4124	</pre>
				4125	</div>
				4126
				4127	<!-- _______________________________________________________________________ -->
				4128	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4129	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4130	</div>
				4131	<div class="doc_text">
				4132
				4133	<h5>Syntax:</h5>
				4134	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4135	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4136	</pre>
				4137
				4138	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4139	<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]	4140	integer and converts that value to the <tt>ty2</tt> type.</p>
				4141
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4142	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4143	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4144	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4145	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4146	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4147	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]	4148
				4149	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4150	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4151	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4152	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]	4153
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4154	<h5>Example:</h5>
				4155	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4156	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4157	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4158	</pre>
				4159	</div>
				4160
				4161	<!-- _______________________________________________________________________ -->
				4162	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4163	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4164	</div>
				4165	<div class="doc_text">
				4166
				4167	<h5>Syntax:</h5>
				4168	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4169	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4170	</pre>
				4171
				4172	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4173	<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]	4174	integer and converts that value to the <tt>ty2</tt> type.</p>
				4175
				4176	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4177	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4178	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4179	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4180	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4181	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]	4182
				4183	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4184	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4185	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4186	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]	4187
				4188	<h5>Example:</h5>
				4189	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4190	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4191	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4192	</pre>
				4193	</div>
				4194
				4195	<!-- _______________________________________________________________________ -->
				4196	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4197	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4198	</div>
				4199	<div class="doc_text">
				4200
				4201	<h5>Syntax:</h5>
				4202	<pre>
				4203	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4204	</pre>
				4205
				4206	<h5>Overview:</h5>
				4207	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4208	the integer type <tt>ty2</tt>.</p>
				4209
				4210	<h5>Arguments:</h5>
				4211	<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]	4212	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]	4213	<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]	4214
				4215	<h5>Semantics:</h5>
				4216	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4217	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4218	truncating or zero extending that value to the size of the integer type. If
				4219	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4220	<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]	4221	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4222	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4223
				4224	<h5>Example:</h5>
				4225	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4226	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4227	%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]	4228	</pre>
				4229	</div>
				4230
				4231	<!-- _______________________________________________________________________ -->
				4232	<div class="doc_subsubsection">
				4233	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4234	</div>
				4235	<div class="doc_text">
				4236
				4237	<h5>Syntax:</h5>
				4238	<pre>
				4239	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4240	</pre>
				4241
				4242	<h5>Overview:</h5>
				4243	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4244	a pointer type, <tt>ty2</tt>.</p>
				4245
				4246	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4247	<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]	4248	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]	4249	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4250
				4251	<h5>Semantics:</h5>
				4252	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4253	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4254	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4255	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4256	the size of a pointer then a zero extension is done. If they are the same size,
				4257	nothing is done (<i>no-op cast</i>).</p>
				4258
				4259	<h5>Example:</h5>
				4260	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4261	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4262	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4263	%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]	4264	</pre>
				4265	</div>
				4266
				4267	<!-- _______________________________________________________________________ -->
				4268	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4269	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4270	</div>
				4271	<div class="doc_text">
				4272
				4273	<h5>Syntax:</h5>
				4274	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4275	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4276	</pre>
				4277
				4278	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4279
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4280	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4281	<tt>ty2</tt> without changing any bits.</p>
				4282
				4283	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4284
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4285	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	4286	a non-aggregate first class value, and a type to cast it to, which must also be
				4287	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4288	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4289	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]	4290	type is a pointer, the destination type must also be a pointer. This
				4291	instruction supports bitwise conversion of vectors to integers and to vectors
				4292	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4293
				4294	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4295	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4296	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4297	this conversion. The conversion is done as if the <tt>value</tt> had been
				4298	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4299	converted to other pointer types with this instruction. To convert pointers to
				4300	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4301	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4302
				4303	<h5>Example:</h5>
				4304	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4305	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4306	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4307	%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]	4308	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4309	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4310
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4311	<!-- ======================================================================= -->
				4312	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4313	<div class="doc_text">
				4314	<p>The instructions in this category are the "miscellaneous"
				4315	instructions, which defy better classification.</p>
				4316	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4317
				4318	<!-- _______________________________________________________________________ -->
				4319	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4320	</div>
				4321	<div class="doc_text">
				4322	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4323	<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]	4324	</pre>
				4325	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4326	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4327	a vector of boolean values based on comparison
				4328	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4329	<h5>Arguments:</h5>
				4330	<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]	4331	the condition code indicating the kind of comparison to perform. It is not
				4332	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4333	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4334	<ol>
				4335	<li><tt>eq</tt>: equal</li>
				4336	<li><tt>ne</tt>: not equal </li>
				4337	<li><tt>ugt</tt>: unsigned greater than</li>
				4338	<li><tt>uge</tt>: unsigned greater or equal</li>
				4339	<li><tt>ult</tt>: unsigned less than</li>
				4340	<li><tt>ule</tt>: unsigned less or equal</li>
				4341	<li><tt>sgt</tt>: signed greater than</li>
				4342	<li><tt>sge</tt>: signed greater or equal</li>
				4343	<li><tt>slt</tt>: signed less than</li>
				4344	<li><tt>sle</tt>: signed less or equal</li>
				4345	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4346	<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]	4347	<a href="#t_pointer">pointer</a>
				4348	or integer <a href="#t_vector">vector</a> typed.
				4349	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4350	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4351	<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]	4352	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4353	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]	4354	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4355	<ol>
				4356	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4357	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4358	</li>
				4359	<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]	4360	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4361	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4362	<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]	4363	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4364	<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]	4365	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4366	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4367	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4368	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4369	<li><tt>sgt</tt>: interprets the operands as signed 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>sge</tt>: interprets the operands as signed 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>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4374	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4375	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4376	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4377	</ol>
				4378	<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]	4379	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4380	<p>If the operands are integer vectors, then they are compared
				4381	element by element. The result is an <tt>i1</tt> vector with
				4382	the same number of elements as the values being compared.
				4383	Otherwise, the result is an <tt>i1</tt>.
				4384	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4385
				4386	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4387	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4388	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4389	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4390	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4391	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4392	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4393	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4394
				4395	<p>Note that the code generator does not yet support vector types with
				4396	the <tt>icmp</tt> instruction.</p>
				4397
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4398	</div>
				4399
				4400	<!-- _______________________________________________________________________ -->
				4401	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4402	</div>
				4403	<div class="doc_text">
				4404	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4405	<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]	4406	</pre>
				4407	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4408	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4409	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4410	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4411	<p>
				4412	If the operands are floating point scalars, then the result
				4413	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4414	</p>
				4415	<p>If the operands are floating point vectors, then the result type
				4416	is a vector of boolean with the same number of elements as the
				4417	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4418	<h5>Arguments:</h5>
				4419	<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]	4420	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]	4421	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4422	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4423	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4424	<li><tt>oeq</tt>: ordered and equal</li>
				4425	<li><tt>ogt</tt>: ordered and greater than </li>
				4426	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4427	<li><tt>olt</tt>: ordered and less than </li>
				4428	<li><tt>ole</tt>: ordered and less than or equal</li>
				4429	<li><tt>one</tt>: ordered and not equal</li>
				4430	<li><tt>ord</tt>: ordered (no nans)</li>
				4431	<li><tt>ueq</tt>: unordered or equal</li>
				4432	<li><tt>ugt</tt>: unordered or greater than </li>
				4433	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4434	<li><tt>ult</tt>: unordered or less than </li>
				4435	<li><tt>ule</tt>: unordered or less than or equal</li>
				4436	<li><tt>une</tt>: unordered or not equal</li>
				4437	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4438	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4439	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4440	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4441	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4442	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4443	either a <a href="#t_floating">floating point</a> type
				4444	or a <a href="#t_vector">vector</a> of floating point type.
				4445	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4446	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4447	<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]	4448	according to the condition code given as <tt>cond</tt>.
				4449	If the operands are vectors, then the vectors are compared
				4450	element by element.
				4451	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4452	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]	4453	<ol>
				4454	<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]	4455	<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]	4456	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4457	<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]	4458	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4459	<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]	4460	<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]	4461	<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]	4462	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4463	<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]	4464	<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]	4465	<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]	4466	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4467	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4468	<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]	4469	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4470	<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]	4471	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4472	<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]	4473	<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]	4474	<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]	4475	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4476	<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]	4477	<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]	4478	<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]	4479	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4480	<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]	4481	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4482	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4483
				4484	<h5>Example:</h5>
				4485	<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]	4486	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4487	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4488	<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]	4489	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4490
				4491	<p>Note that the code generator does not yet support vector types with
				4492	the <tt>fcmp</tt> instruction.</p>
				4493
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4494	</div>
				4495
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4496	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4497	<div class="doc_subsubsection">
				4498	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4499	</div>
				4500	<div class="doc_text">
				4501	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4502	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4503	</pre>
				4504	<h5>Overview:</h5>
				4505	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4506	element-wise comparison of its two integer vector operands.</p>
				4507	<h5>Arguments:</h5>
				4508	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4509	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]	4510	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4511	<ol>
				4512	<li><tt>eq</tt>: equal</li>
				4513	<li><tt>ne</tt>: not equal </li>
				4514	<li><tt>ugt</tt>: unsigned greater than</li>
				4515	<li><tt>uge</tt>: unsigned greater or equal</li>
				4516	<li><tt>ult</tt>: unsigned less than</li>
				4517	<li><tt>ule</tt>: unsigned less or equal</li>
				4518	<li><tt>sgt</tt>: signed greater than</li>
				4519	<li><tt>sge</tt>: signed greater or equal</li>
				4520	<li><tt>slt</tt>: signed less than</li>
				4521	<li><tt>sle</tt>: signed less or equal</li>
				4522	</ol>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4523	<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]	4524	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4525	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4526	<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]	4527	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4528	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4529	identical type as the values being compared. The most significant bit in each
				4530	element is 1 if the element-wise comparison evaluates to true, and is 0
				4531	otherwise. All other bits of the result are undefined. The condition codes
				4532	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4533	instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4534
				4535	<h5>Example:</h5>
				4536	<pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4537	<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>
				4538	<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]	4539	</pre>
				4540	</div>
				4541
				4542	<!-- _______________________________________________________________________ -->
				4543	<div class="doc_subsubsection">
				4544	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4545	</div>
				4546	<div class="doc_text">
				4547	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4548	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4549	<h5>Overview:</h5>
				4550	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4551	element-wise comparison of its two floating point vector operands. The output
				4552	elements have the same width as the input elements.</p>
				4553	<h5>Arguments:</h5>
				4554	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4555	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]	4556	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4557	<ol>
				4558	<li><tt>false</tt>: no comparison, always returns false</li>
				4559	<li><tt>oeq</tt>: ordered and equal</li>
				4560	<li><tt>ogt</tt>: ordered and greater than </li>
				4561	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4562	<li><tt>olt</tt>: ordered and less than </li>
				4563	<li><tt>ole</tt>: ordered and less than or equal</li>
				4564	<li><tt>one</tt>: ordered and not equal</li>
				4565	<li><tt>ord</tt>: ordered (no nans)</li>
				4566	<li><tt>ueq</tt>: unordered or equal</li>
				4567	<li><tt>ugt</tt>: unordered or greater than </li>
				4568	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4569	<li><tt>ult</tt>: unordered or less than </li>
				4570	<li><tt>ule</tt>: unordered or less than or equal</li>
				4571	<li><tt>une</tt>: unordered or not equal</li>
				4572	<li><tt>uno</tt>: unordered (either nans)</li>
				4573	<li><tt>true</tt>: no comparison, always returns true</li>
				4574	</ol>
				4575	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4576	<a href="#t_floating">floating point</a> typed. They must also be identical
				4577	types.</p>
				4578	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4579	<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]	4580	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4581	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4582	an identical number of elements as the values being compared, and each element
				4583	having identical with to the width of the floating point elements. The most
				4584	significant bit in each element is 1 if the element-wise comparison evaluates to
				4585	true, and is 0 otherwise. All other bits of the result are undefined. The
				4586	condition codes are evaluated identically to the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4587	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4588
				4589	<h5>Example:</h5>
				4590	<pre>
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	4591	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4592	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4593
				4594	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4595	<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]	4596	</pre>
				4597	</div>
				4598
				4599	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4600	<div class="doc_subsubsection">
				4601	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4602	</div>
				4603
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4604	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4605
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4606	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4607
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4608	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4609	<h5>Overview:</h5>
				4610	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4611	the SSA graph representing the function.</p>
				4612	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4613
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4614	<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]	4615	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4616	as arguments, with one pair for each predecessor basic block of the
				4617	current block. Only values of <a href="#t_firstclass">first class</a>
				4618	type may be used as the value arguments to the PHI node. Only labels
				4619	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4620
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4621	<p>There must be no non-phi instructions between the start of a basic
				4622	block and the PHI instructions: i.e. PHI instructions must be first in
				4623	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4624
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4625	<p>For the purposes of the SSA form, the use of each incoming value is
				4626	deemed to occur on the edge from the corresponding predecessor block
				4627	to the current block (but after any definition of an '<tt>invoke</tt>'
				4628	instruction's return value on the same edge).</p>
				4629
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4630	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4631
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4632	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4633	specified by the pair corresponding to the predecessor basic block that executed
				4634	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4635
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4636	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4637	<pre>
				4638	Loop: ; Infinite loop that counts from 0 on up...
				4639	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4640	%nextindvar = add i32 %indvar, 1
				4641	br label %Loop
				4642	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4643	</div>
				4644
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4645	<!-- _______________________________________________________________________ -->
				4646	<div class="doc_subsubsection">
				4647	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4648	</div>
				4649
				4650	<div class="doc_text">
				4651
				4652	<h5>Syntax:</h5>
				4653
				4654	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4655	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4656
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4657	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4658	</pre>
				4659
				4660	<h5>Overview:</h5>
				4661
				4662	<p>
				4663	The '<tt>select</tt>' instruction is used to choose one value based on a
				4664	condition, without branching.
				4665	</p>
				4666
				4667
				4668	<h5>Arguments:</h5>
				4669
				4670	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4671	The '<tt>select</tt>' instruction requires an 'i1' value or
				4672	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4673	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]	4674	type. If the val1/val2 are vectors and
				4675	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4676	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4677	</p>
				4678
				4679	<h5>Semantics:</h5>
				4680
				4681	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4682	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]	4683	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4684	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4685	<p>
				4686	If the condition is a vector of i1, then the value arguments must
				4687	be vectors of the same size, and the selection is done element
				4688	by element.
				4689	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4690
				4691	<h5>Example:</h5>
				4692
				4693	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4694	%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]	4695	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4696
				4697	<p>Note that the code generator does not yet support conditions
				4698	with vector type.</p>
				4699
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4700	</div>
				4701
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4702
				4703	<!-- _______________________________________________________________________ -->
				4704	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4705	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4706	</div>
				4707
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4708	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4709
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4710	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4711	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4712	<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]	4713	</pre>
				4714
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4715	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4716
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4717	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4718
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4719	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4720
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4721	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4722
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4723	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4724	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4725	<p>The optional "tail" marker indicates whether the callee function accesses
				4726	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]	4727	function call is eligible for tail call optimization. Note that calls may
				4728	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4729	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4730	</li>
				4731	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4732	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4733	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]	4734	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4735	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4736
				4737	<li>
				4738	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4739	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4740	and '<tt>inreg</tt>' attributes are valid here.</p>
				4741	</li>
				4742
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4743	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4744	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4745	the type of the return value. Functions that return no value are marked
				4746	<tt><a href="#t_void">void</a></tt>.</p>
				4747	</li>
				4748	<li>
				4749	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4750	value being invoked. The argument types must match the types implied by
				4751	this signature. This type can be omitted if the function is not varargs
				4752	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]	4753	</li>
				4754	<li>
				4755	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4756	be invoked. In most cases, this is a direct function invocation, but
				4757	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]	4758	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4759	</li>
				4760	<li>
				4761	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4762	function signature argument types. All arguments must be of
				4763	<a href="#t_firstclass">first class</a> type. If the function signature
				4764	indicates the function accepts a variable number of arguments, the extra
				4765	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4766	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4767	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4768	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4769	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4770	'<tt>readnone</tt>' attributes are valid here.</p>
				4771	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4772	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4773
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4774	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4775
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4776	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4777	transfer to a specified function, with its incoming arguments bound to
				4778	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4779	instruction in the called function, control flow continues with the
				4780	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4781	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4782
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4783	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4784
				4785	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4786	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4787	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4788	%X = tail call i32 @foo() <i>; yields i32</i>
				4789	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4790	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4791
				4792	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4793	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4794	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4795	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4796	%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]	4797	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4798	</pre>
				4799
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4800	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4801
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4802	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4803	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4804	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4805	</div>
				4806
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4807	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4808
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4809	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4810
				4811	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4812	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4813	</pre>
				4814
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4815	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4816
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4817	<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]	4818	the "variable argument" area of a function call. It is used to implement the
				4819	<tt>va_arg</tt> macro in C.</p>
				4820
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4821	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4822
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4823	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4824	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4825	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]	4826	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4827
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4828	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4829
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4830	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4831	type from the specified <tt>va_list</tt> and causes the
				4832	<tt>va_list</tt> to point to the next argument. For more information,
				4833	see the variable argument handling <a href="#int_varargs">Intrinsic
				4834	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4835
				4836	<p>It is legal for this instruction to be called in a function which does not
				4837	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4838	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4839
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4840	<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]	4841	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4842	argument.</p>
				4843
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4844	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4845
				4846	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4847
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4848	<p>Note that the code generator does not yet fully support va_arg
				4849	on many targets. Also, it does not currently support va_arg with
				4850	aggregate types on any target.</p>
				4851
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4852	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4853
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4854	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4855	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4856	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4857
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4858	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4859
				4860	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4861	well known names and semantics and are required to follow certain restrictions.
				4862	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4863	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]	4864	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]	4865
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4866	<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]	4867	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4868	begin with this prefix. Intrinsic functions must always be external functions:
				4869	you cannot define the body of intrinsic functions. Intrinsic functions may
				4870	only be used in call or invoke instructions: it is illegal to take the address
				4871	of an intrinsic function. Additionally, because intrinsic functions are part
				4872	of the LLVM language, it is required if any are added that they be documented
				4873	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4874
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4875	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4876	a family of functions that perform the same operation but on different data
				4877	types. Because LLVM can represent over 8 million different integer types,
				4878	overloading is used commonly to allow an intrinsic function to operate on any
				4879	integer type. One or more of the argument types or the result type can be
				4880	overloaded to accept any integer type. Argument types may also be defined as
				4881	exactly matching a previous argument's type or the result type. This allows an
				4882	intrinsic function which accepts multiple arguments, but needs all of them to
				4883	be of the same type, to only be overloaded with respect to a single argument or
				4884	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4885
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4886	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4887	encoded into its function name, each preceded by a period. Only those types
				4888	which are overloaded result in a name suffix. Arguments whose type is matched
				4889	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4890	take an integer of any width and returns an integer of exactly the same integer
				4891	width. This leads to a family of functions such as
				4892	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4893	Only one type, the return type, is overloaded, and only one type suffix is
				4894	required. Because the argument's type is matched against the return type, it
				4895	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4896
				4897	<p>To learn how to add an intrinsic function, please see the
				4898	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4899	</p>
				4900
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4901	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4902
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4903	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4904	<div class="doc_subsection">
				4905	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4906	</div>
				4907
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4908	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4909
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4910	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4911	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]	4912	intrinsic functions. These functions are related to the similarly
				4913	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4914
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4915	<p>All of these functions operate on arguments that use a
				4916	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4917	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4918	transformations should be prepared to handle these functions regardless of
				4919	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4920
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4921	<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]	4922	instruction and the variable argument handling intrinsic functions are
				4923	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4924
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4925	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4926	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4927	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4928	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4929	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4930	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4931	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4932
				4933	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4934	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4935
				4936	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4937	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4938	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4939	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4940	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4941
				4942	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4943	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4944	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4945	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4946
				4947	declare void @llvm.va_start(i8*)
				4948	declare void @llvm.va_copy(i8, i8)
				4949	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4950	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4951	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4952
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4953	</div>
				4954
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4955	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4956	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4957	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4958	</div>
				4959
				4960
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4961	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4962	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4963	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4964	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4965	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4966	<tt>*<arglist></tt> for subsequent use by <tt><a
				4967	href="#i_va_arg">va_arg</a></tt>.</p>
				4968
				4969	<h5>Arguments:</h5>
				4970
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4971	<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]	4972
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4973	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4974
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4975	<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]	4976	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4977	<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]	4978	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4979	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]	4980	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]	4981
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4982	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4983
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4984	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4985	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4986	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4987	</div>
				4988
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4989	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4990	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4991	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4992	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4993
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4994	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4995	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]	4996	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]	4997
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4998	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4999
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5000	<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]	5001
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5002	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5003
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5004	<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]	5005	macro available in C. In a target-dependent way, it destroys the
				5006	<tt>va_list</tt> element to which the argument points. Calls to <a
				5007	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				5008	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				5009	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	5010
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5011	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5012
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5013	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5014	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5015	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5016	</div>
				5017
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5018	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5019
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5020	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5021
				5022	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5023	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5024	</pre>
				5025
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5026	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5027
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5028	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				5029	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5030
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5031	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5032
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	5033	<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]	5034	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]	5035
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5036
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	5037	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5038
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	5039	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				5040	macro available in C. In a target-dependent way, it copies the source
				5041	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				5042	intrinsic is necessary because the <tt><a href="#int_va_start">
				5043	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				5044	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5045
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	5046	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5047
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5048	<!-- ======================================================================= -->
				5049	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5050	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				5051	</div>
				5052
				5053	<div class="doc_text">
				5054
				5055	<p>
				5056	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5057	Collection</a> (GC) requires the implementation and generation of these
				5058	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5059	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]	5060	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5061	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]	5062	Front-ends for type-safe garbage collected languages should generate these
				5063	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				5064	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				5065	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	5066
				5067	<p>The garbage collection intrinsics only operate on objects in the generic
				5068	address space (address space zero).</p>
				5069
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5070	</div>
				5071
				5072	<!-- _______________________________________________________________________ -->
				5073	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5074	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5075	</div>
				5076
				5077	<div class="doc_text">
				5078
				5079	<h5>Syntax:</h5>
				5080
				5081	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5082	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5083	</pre>
				5084
				5085	<h5>Overview:</h5>
				5086
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	5087	<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]	5088	the code generator, and allows some metadata to be associated with it.</p>
				5089
				5090	<h5>Arguments:</h5>
				5091
				5092	<p>The first argument specifies the address of a stack object that contains the
				5093	root pointer. The second pointer (which must be either a constant or a global
				5094	value address) contains the meta-data to be associated with the root.</p>
				5095
				5096	<h5>Semantics:</h5>
				5097
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	5098	<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]	5099	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5100	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5101	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5102	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5103
				5104	</div>
				5105
				5106
				5107	<!-- _______________________________________________________________________ -->
				5108	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5109	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5110	</div>
				5111
				5112	<div class="doc_text">
				5113
				5114	<h5>Syntax:</h5>
				5115
				5116	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5117	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5118	</pre>
				5119
				5120	<h5>Overview:</h5>
				5121
				5122	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5123	locations, allowing garbage collector implementations that require read
				5124	barriers.</p>
				5125
				5126	<h5>Arguments:</h5>
				5127
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5128	<p>The second argument is the address to read from, which should be an address
				5129	allocated from the garbage collector. The first object is a pointer to the
				5130	start of the referenced object, if needed by the language runtime (otherwise
				5131	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5132
				5133	<h5>Semantics:</h5>
				5134
				5135	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5136	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5137	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5138	may only be used in a function which <a href="#gc">specifies a GC
				5139	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5140
				5141	</div>
				5142
				5143
				5144	<!-- _______________________________________________________________________ -->
				5145	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5146	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5147	</div>
				5148
				5149	<div class="doc_text">
				5150
				5151	<h5>Syntax:</h5>
				5152
				5153	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5154	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5155	</pre>
				5156
				5157	<h5>Overview:</h5>
				5158
				5159	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5160	locations, allowing garbage collector implementations that require write
				5161	barriers (such as generational or reference counting collectors).</p>
				5162
				5163	<h5>Arguments:</h5>
				5164
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5165	<p>The first argument is the reference to store, the second is the start of the
				5166	object to store it to, and the third is the address of the field of Obj to
				5167	store to. If the runtime does not require a pointer to the object, Obj may be
				5168	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5169
				5170	<h5>Semantics:</h5>
				5171
				5172	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5173	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5174	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5175	may only be used in a function which <a href="#gc">specifies a GC
				5176	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5177
				5178	</div>
				5179
				5180
				5181
				5182	<!-- ======================================================================= -->
				5183	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5184	<a name="int_codegen">Code Generator Intrinsics</a>
				5185	</div>
				5186
				5187	<div class="doc_text">
				5188	<p>
				5189	These intrinsics are provided by LLVM to expose special features that may only
				5190	be implemented with code generator support.
				5191	</p>
				5192
				5193	</div>
				5194
				5195	<!-- _______________________________________________________________________ -->
				5196	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5197	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5198	</div>
				5199
				5200	<div class="doc_text">
				5201
				5202	<h5>Syntax:</h5>
				5203	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5204	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5205	</pre>
				5206
				5207	<h5>Overview:</h5>
				5208
				5209	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5210	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5211	target-specific value indicating the return address of the current function
				5212	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5213	</p>
				5214
				5215	<h5>Arguments:</h5>
				5216
				5217	<p>
				5218	The argument to this intrinsic indicates which function to return the address
				5219	for. Zero indicates the calling function, one indicates its caller, etc. The
				5220	argument is <b>required</b> to be a constant integer value.
				5221	</p>
				5222
				5223	<h5>Semantics:</h5>
				5224
				5225	<p>
				5226	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5227	the return address of the specified call frame, or zero if it cannot be
				5228	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5229	for arguments other than zero, so it should only be used for debugging purposes.
				5230	</p>
				5231
				5232	<p>
				5233	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5234	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]	5235	source-language caller.
				5236	</p>
				5237	</div>
				5238
				5239
				5240	<!-- _______________________________________________________________________ -->
				5241	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5242	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5243	</div>
				5244
				5245	<div class="doc_text">
				5246
				5247	<h5>Syntax:</h5>
				5248	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5249	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5250	</pre>
				5251
				5252	<h5>Overview:</h5>
				5253
				5254	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5255	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5256	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5257	</p>
				5258
				5259	<h5>Arguments:</h5>
				5260
				5261	<p>
				5262	The argument to this intrinsic indicates which function to return the frame
				5263	pointer for. Zero indicates the calling function, one indicates its caller,
				5264	etc. The argument is <b>required</b> to be a constant integer value.
				5265	</p>
				5266
				5267	<h5>Semantics:</h5>
				5268
				5269	<p>
				5270	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5271	the frame address of the specified call frame, or zero if it cannot be
				5272	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5273	for arguments other than zero, so it should only be used for debugging purposes.
				5274	</p>
				5275
				5276	<p>
				5277	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5278	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]	5279	source-language caller.
				5280	</p>
				5281	</div>
				5282
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5283	<!-- _______________________________________________________________________ -->
				5284	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5285	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5286	</div>
				5287
				5288	<div class="doc_text">
				5289
				5290	<h5>Syntax:</h5>
				5291	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5292	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5293	</pre>
				5294
				5295	<h5>Overview:</h5>
				5296
				5297	<p>
				5298	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]	5299	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5300	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5301	features like scoped automatic variable sized arrays in C99.
				5302	</p>
				5303
				5304	<h5>Semantics:</h5>
				5305
				5306	<p>
				5307	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]	5308	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5309	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5310	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5311	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5312	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5313	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5314	</p>
				5315
				5316	</div>
				5317
				5318	<!-- _______________________________________________________________________ -->
				5319	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5320	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5321	</div>
				5322
				5323	<div class="doc_text">
				5324
				5325	<h5>Syntax:</h5>
				5326	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5327	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5328	</pre>
				5329
				5330	<h5>Overview:</h5>
				5331
				5332	<p>
				5333	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5334	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]	5335	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5336	useful for implementing language features like scoped automatic variable sized
				5337	arrays in C99.
				5338	</p>
				5339
				5340	<h5>Semantics:</h5>
				5341
				5342	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5343	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]	5344	</p>
				5345
				5346	</div>
				5347
				5348
				5349	<!-- _______________________________________________________________________ -->
				5350	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5351	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5352	</div>
				5353
				5354	<div class="doc_text">
				5355
				5356	<h5>Syntax:</h5>
				5357	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5358	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5359	</pre>
				5360
				5361	<h5>Overview:</h5>
				5362
				5363
				5364	<p>
				5365	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]	5366	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5367	no
				5368	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5369	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5370	</p>
				5371
				5372	<h5>Arguments:</h5>
				5373
				5374	<p>
				5375	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5376	determining if the fetch should be for a read (0) or write (1), and
				5377	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5378	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]	5379	<tt>locality</tt> arguments must be constant integers.
				5380	</p>
				5381
				5382	<h5>Semantics:</h5>
				5383
				5384	<p>
				5385	This intrinsic does not modify the behavior of the program. In particular,
				5386	prefetches cannot trap and do not produce a value. On targets that support this
				5387	intrinsic, the prefetch can provide hints to the processor cache for better
				5388	performance.
				5389	</p>
				5390
				5391	</div>
				5392
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5393	<!-- _______________________________________________________________________ -->
				5394	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5395	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5396	</div>
				5397
				5398	<div class="doc_text">
				5399
				5400	<h5>Syntax:</h5>
				5401	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5402	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5403	</pre>
				5404
				5405	<h5>Overview:</h5>
				5406
				5407
				5408	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5409	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]	5410	(PC) in a region of
				5411	code to simulators and other tools. The method is target specific, but it is
				5412	expected that the marker will use exported symbols to transmit the PC of the
				5413	marker.
				5414	The marker makes no guarantees that it will remain with any specific instruction
				5415	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]	5416	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5417	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5418	</p>
				5419
				5420	<h5>Arguments:</h5>
				5421
				5422	<p>
				5423	<tt>id</tt> is a numerical id identifying the marker.
				5424	</p>
				5425
				5426	<h5>Semantics:</h5>
				5427
				5428	<p>
				5429	This intrinsic does not modify the behavior of the program. Backends that do not
				5430	support this intrinisic may ignore it.
				5431	</p>
				5432
				5433	</div>
				5434
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5435	<!-- _______________________________________________________________________ -->
				5436	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5437	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5438	</div>
				5439
				5440	<div class="doc_text">
				5441
				5442	<h5>Syntax:</h5>
				5443	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5444	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5445	</pre>
				5446
				5447	<h5>Overview:</h5>
				5448
				5449
				5450	<p>
				5451	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5452	counter register (or similar low latency, high accuracy clocks) on those targets
				5453	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5454	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5455	should only be used for small timings.
				5456	</p>
				5457
				5458	<h5>Semantics:</h5>
				5459
				5460	<p>
				5461	When directly supported, reading the cycle counter should not modify any memory.
				5462	Implementations are allowed to either return a application specific value or a
				5463	system wide value. On backends without support, this is lowered to a constant 0.
				5464	</p>
				5465
				5466	</div>
				5467
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5468	<!-- ======================================================================= -->
				5469	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5470	<a name="int_libc">Standard C Library Intrinsics</a>
				5471	</div>
				5472
				5473	<div class="doc_text">
				5474	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5475	LLVM provides intrinsics for a few important standard C library functions.
				5476	These intrinsics allow source-language front-ends to pass information about the
				5477	alignment of the pointer arguments to the code generator, providing opportunity
				5478	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5479	</p>
				5480
				5481	</div>
				5482
				5483	<!-- _______________________________________________________________________ -->
				5484	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5485	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5486	</div>
				5487
				5488	<div class="doc_text">
				5489
				5490	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5491	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5492	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5493	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5494	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5495	i8 <len>, i32 <align>)
				5496	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5497	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5498	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5499	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5500	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5501	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5502	</pre>
				5503
				5504	<h5>Overview:</h5>
				5505
				5506	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5507	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]	5508	location to the destination location.
				5509	</p>
				5510
				5511	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5512	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5513	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5514	</p>
				5515
				5516	<h5>Arguments:</h5>
				5517
				5518	<p>
				5519	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]	5520	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5521	specifying the number of bytes to copy, and the fourth argument is the alignment
				5522	of the source and destination locations.
				5523	</p>
				5524
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5525	<p>
				5526	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]	5527	the caller guarantees that both the source and destination pointers are aligned
				5528	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5529	</p>
				5530
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5531	<h5>Semantics:</h5>
				5532
				5533	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5534	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]	5535	location to the destination location, which are not allowed to overlap. It
				5536	copies "len" bytes of memory over. If the argument is known to be aligned to
				5537	some boundary, this can be specified as the fourth argument, otherwise it should
				5538	be set to 0 or 1.
				5539	</p>
				5540	</div>
				5541
				5542
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5543	<!-- _______________________________________________________________________ -->
				5544	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5545	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5546	</div>
				5547
				5548	<div class="doc_text">
				5549
				5550	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5551	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5552	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5553	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5554	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5555	i8 <len>, i32 <align>)
				5556	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5557	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5558	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5559	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5560	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5561	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5562	</pre>
				5563
				5564	<h5>Overview:</h5>
				5565
				5566	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5567	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5568	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5569	'<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]	5570	</p>
				5571
				5572	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5573	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5574	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5575	</p>
				5576
				5577	<h5>Arguments:</h5>
				5578
				5579	<p>
				5580	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]	5581	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5582	specifying the number of bytes to copy, and the fourth argument is the alignment
				5583	of the source and destination locations.
				5584	</p>
				5585
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5586	<p>
				5587	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]	5588	the caller guarantees that the source and destination pointers are aligned to
				5589	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5590	</p>
				5591
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5592	<h5>Semantics:</h5>
				5593
				5594	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5595	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]	5596	location to the destination location, which may overlap. It
				5597	copies "len" bytes of memory over. If the argument is known to be aligned to
				5598	some boundary, this can be specified as the fourth argument, otherwise it should
				5599	be set to 0 or 1.
				5600	</p>
				5601	</div>
				5602
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5603
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5604	<!-- _______________________________________________________________________ -->
				5605	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5606	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5607	</div>
				5608
				5609	<div class="doc_text">
				5610
				5611	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5612	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5613	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5614	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5615	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5616	i8 <len>, i32 <align>)
				5617	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5618	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5619	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5620	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5621	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5622	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5623	</pre>
				5624
				5625	<h5>Overview:</h5>
				5626
				5627	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5628	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]	5629	byte value.
				5630	</p>
				5631
				5632	<p>
				5633	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5634	does not return a value, and takes an extra alignment argument.
				5635	</p>
				5636
				5637	<h5>Arguments:</h5>
				5638
				5639	<p>
				5640	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]	5641	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5642	argument specifying the number of bytes to fill, and the fourth argument is the
				5643	known alignment of destination location.
				5644	</p>
				5645
				5646	<p>
				5647	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]	5648	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5649	</p>
				5650
				5651	<h5>Semantics:</h5>
				5652
				5653	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5654	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5655	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5656	destination location. If the argument is known to be aligned to some boundary,
				5657	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5658	1.
				5659	</p>
				5660	</div>
				5661
				5662
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5663	<!-- _______________________________________________________________________ -->
				5664	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5665	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5666	</div>
				5667
				5668	<div class="doc_text">
				5669
				5670	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5671	<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]	5672	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]	5673	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5674	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5675	declare float @llvm.sqrt.f32(float %Val)
				5676	declare double @llvm.sqrt.f64(double %Val)
				5677	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5678	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5679	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5680	</pre>
				5681
				5682	<h5>Overview:</h5>
				5683
				5684	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5685	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]	5686	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]	5687	<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]	5688	negative numbers other than -0.0 (which allows for better optimization, because
				5689	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5690	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5691	</p>
				5692
				5693	<h5>Arguments:</h5>
				5694
				5695	<p>
				5696	The argument and return value are floating point numbers of the same type.
				5697	</p>
				5698
				5699	<h5>Semantics:</h5>
				5700
				5701	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5702	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]	5703	floating point number.
				5704	</p>
				5705	</div>
				5706
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5707	<!-- _______________________________________________________________________ -->
				5708	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5709	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5710	</div>
				5711
				5712	<div class="doc_text">
				5713
				5714	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5715	<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]	5716	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]	5717	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5718	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5719	declare float @llvm.powi.f32(float %Val, i32 %power)
				5720	declare double @llvm.powi.f64(double %Val, i32 %power)
				5721	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5722	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5723	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5724	</pre>
				5725
				5726	<h5>Overview:</h5>
				5727
				5728	<p>
				5729	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5730	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5731	multiplications is not defined. When a vector of floating point type is
				5732	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5733	</p>
				5734
				5735	<h5>Arguments:</h5>
				5736
				5737	<p>
				5738	The second argument is an integer power, and the first is a value to raise to
				5739	that power.
				5740	</p>
				5741
				5742	<h5>Semantics:</h5>
				5743
				5744	<p>
				5745	This function returns the first value raised to the second power with an
				5746	unspecified sequence of rounding operations.</p>
				5747	</div>
				5748
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5749	<!-- _______________________________________________________________________ -->
				5750	<div class="doc_subsubsection">
				5751	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5752	</div>
				5753
				5754	<div class="doc_text">
				5755
				5756	<h5>Syntax:</h5>
				5757	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5758	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]	5759	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5760	<pre>
				5761	declare float @llvm.sin.f32(float %Val)
				5762	declare double @llvm.sin.f64(double %Val)
				5763	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5764	declare fp128 @llvm.sin.f128(fp128 %Val)
				5765	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5766	</pre>
				5767
				5768	<h5>Overview:</h5>
				5769
				5770	<p>
				5771	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5772	</p>
				5773
				5774	<h5>Arguments:</h5>
				5775
				5776	<p>
				5777	The argument and return value are floating point numbers of the same type.
				5778	</p>
				5779
				5780	<h5>Semantics:</h5>
				5781
				5782	<p>
				5783	This function returns the sine of the specified operand, returning the
				5784	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]	5785	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5786	</div>
				5787
				5788	<!-- _______________________________________________________________________ -->
				5789	<div class="doc_subsubsection">
				5790	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5791	</div>
				5792
				5793	<div class="doc_text">
				5794
				5795	<h5>Syntax:</h5>
				5796	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5797	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]	5798	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5799	<pre>
				5800	declare float @llvm.cos.f32(float %Val)
				5801	declare double @llvm.cos.f64(double %Val)
				5802	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5803	declare fp128 @llvm.cos.f128(fp128 %Val)
				5804	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5805	</pre>
				5806
				5807	<h5>Overview:</h5>
				5808
				5809	<p>
				5810	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5811	</p>
				5812
				5813	<h5>Arguments:</h5>
				5814
				5815	<p>
				5816	The argument and return value are floating point numbers of the same type.
				5817	</p>
				5818
				5819	<h5>Semantics:</h5>
				5820
				5821	<p>
				5822	This function returns the cosine of the specified operand, returning the
				5823	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]	5824	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5825	</div>
				5826
				5827	<!-- _______________________________________________________________________ -->
				5828	<div class="doc_subsubsection">
				5829	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5830	</div>
				5831
				5832	<div class="doc_text">
				5833
				5834	<h5>Syntax:</h5>
				5835	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5836	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]	5837	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5838	<pre>
				5839	declare float @llvm.pow.f32(float %Val, float %Power)
				5840	declare double @llvm.pow.f64(double %Val, double %Power)
				5841	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5842	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5843	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5844	</pre>
				5845
				5846	<h5>Overview:</h5>
				5847
				5848	<p>
				5849	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5850	specified (positive or negative) power.
				5851	</p>
				5852
				5853	<h5>Arguments:</h5>
				5854
				5855	<p>
				5856	The second argument is a floating point power, and the first is a value to
				5857	raise to that power.
				5858	</p>
				5859
				5860	<h5>Semantics:</h5>
				5861
				5862	<p>
				5863	This function returns the first value raised to the second power,
				5864	returning the
				5865	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]	5866	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5867	</div>
				5868
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5869
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5870	<!-- ======================================================================= -->
				5871	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5872	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5873	</div>
				5874
				5875	<div class="doc_text">
				5876	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5877	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5878	These allow efficient code generation for some algorithms.
				5879	</p>
				5880
				5881	</div>
				5882
				5883	<!-- _______________________________________________________________________ -->
				5884	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5885	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5886	</div>
				5887
				5888	<div class="doc_text">
				5889
				5890	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5891	<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]	5892	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]	5893	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5894	declare i16 @llvm.bswap.i16(i16 <id>)
				5895	declare i32 @llvm.bswap.i32(i32 <id>)
				5896	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5897	</pre>
				5898
				5899	<h5>Overview:</h5>
				5900
				5901	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5902	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]	5903	values with an even number of bytes (positive multiple of 16 bits). These are
				5904	useful for performing operations on data that is not in the target's native
				5905	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5906	</p>
				5907
				5908	<h5>Semantics:</h5>
				5909
				5910	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5911	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]	5912	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5913	intrinsic returns an i32 value that has the four bytes of the input i32
				5914	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]	5915	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5916	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5917	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5918	</p>
				5919
				5920	</div>
				5921
				5922	<!-- _______________________________________________________________________ -->
				5923	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5924	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5925	</div>
				5926
				5927	<div class="doc_text">
				5928
				5929	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5930	<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]	5931	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5932	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5933	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5934	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5935	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5936	declare i64 @llvm.ctpop.i64(i64 <src>)
				5937	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5938	</pre>
				5939
				5940	<h5>Overview:</h5>
				5941
				5942	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5943	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5944	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5945	</p>
				5946
				5947	<h5>Arguments:</h5>
				5948
				5949	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5950	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]	5951	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5952	</p>
				5953
				5954	<h5>Semantics:</h5>
				5955
				5956	<p>
				5957	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5958	</p>
				5959	</div>
				5960
				5961	<!-- _______________________________________________________________________ -->
				5962	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5963	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5964	</div>
				5965
				5966	<div class="doc_text">
				5967
				5968	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5969	<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]	5970	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5971	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5972	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5973	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5974	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5975	declare i64 @llvm.ctlz.i64(i64 <src>)
				5976	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5977	</pre>
				5978
				5979	<h5>Overview:</h5>
				5980
				5981	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5982	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5983	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5984	</p>
				5985
				5986	<h5>Arguments:</h5>
				5987
				5988	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5989	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]	5990	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5991	</p>
				5992
				5993	<h5>Semantics:</h5>
				5994
				5995	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5996	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5997	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]	5998	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5999	</p>
				6000	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	6001
				6002
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6003
				6004	<!-- _______________________________________________________________________ -->
				6005	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	6006	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6007	</div>
				6008
				6009	<div class="doc_text">
				6010
				6011	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	6012	<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]	6013	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6014	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6015	declare i8 @llvm.cttz.i8 (i8 <src>)
				6016	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	6017	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6018	declare i64 @llvm.cttz.i64(i64 <src>)
				6019	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6020	</pre>
				6021
				6022	<h5>Overview:</h5>
				6023
				6024	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	6025	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				6026	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6027	</p>
				6028
				6029	<h5>Arguments:</h5>
				6030
				6031	<p>
				6032	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]	6033	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	6034	</p>
				6035
				6036	<h5>Semantics:</h5>
				6037
				6038	<p>
				6039	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				6040	in a variable. If the src == 0 then the result is the size in bits of the type
				6041	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				6042	</p>
				6043	</div>
				6044
Reid Spencer	497d93e	2007-04-01 08:27:01 +0000	[diff] [blame]	6045	<!-- _______________________________________________________________________ -->
				6046	<div class="doc_subsubsection">
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6047	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6048	</div>
				6049
				6050	<div class="doc_text">
				6051
				6052	<h5>Syntax:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6053	<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]	6054	on any integer bit width.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6055	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6056	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				6057	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6058	</pre>
				6059
				6060	<h5>Overview:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6061	<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]	6062	range of bits from an integer value and returns them in the same bit width as
				6063	the original value.</p>
				6064
				6065	<h5>Arguments:</h5>
				6066	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				6067	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]	6068	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]	6069
				6070	<h5>Semantics:</h5>
Reid Spencer	beacf66	2007-04-10 02:51:31 +0000	[diff] [blame]	6071	<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]	6072	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				6073	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				6074	operates in forward mode.</p>
				6075	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				6076	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]	6077	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				6078	<ol>
				6079	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				6080	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				6081	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				6082	to determine the number of bits to retain.</li>
				6083	<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]	6084	<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]	6085	</ol>
Reid Spencer	d6a85b5	2007-05-14 16:14:57 +0000	[diff] [blame]	6086	<p>In reverse mode, a similar computation is made except that the bits are
				6087	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				6088	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				6089	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				6090	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	a13ba7d	2007-04-01 19:00:37 +0000	[diff] [blame]	6091	</div>
				6092
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6093	<div class="doc_subsubsection">
				6094	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				6095	</div>
				6096
				6097	<div class="doc_text">
				6098
				6099	<h5>Syntax:</h5>
				6100	<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]	6101	on any integer bit width.</p>
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6102	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	6103	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6104	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]	6105	</pre>
				6106
				6107	<h5>Overview:</h5>
				6108	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6109	of bits in an integer value with another integer value. It returns the integer
				6110	with the replaced bits.</p>
				6111
				6112	<h5>Arguments:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6113	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6114	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]	6115	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6116	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6117	type since they specify only a bit index.</p>
				6118
				6119	<h5>Semantics:</h5>
				6120	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6121	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6122	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6123	operates in forward mode.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6124
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6125	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6126	truncating it down to the size of the replacement area or zero extending it
				6127	up to that size.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6128
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6129	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6130	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6131	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]	6132	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6133
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6134	<p>In reverse mode, a similar computation is made except that the bits are
				6135	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]	6136	<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]	6137
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6138	<h5>Examples:</h5>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6139
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6140	<pre>
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6141	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	c6749c4	2007-05-14 16:50:20 +0000	[diff] [blame]	6142	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6143	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6144	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	f0dbf64	2007-04-12 01:03:03 +0000	[diff] [blame]	6145	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	6146	</pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6147
				6148	</div>
				6149
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6150	<!-- ======================================================================= -->
				6151	<div class="doc_subsection">
				6152	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6153	</div>
				6154
				6155	<div class="doc_text">
				6156	<p>
				6157	LLVM provides intrinsics for some arithmetic with overflow operations.
				6158	</p>
				6159
				6160	</div>
				6161
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6162	<!-- _______________________________________________________________________ -->
				6163	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6164	<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]	6165	</div>
				6166
				6167	<div class="doc_text">
				6168
				6169	<h5>Syntax:</h5>
				6170
				6171	<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]	6172	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6173
				6174	<pre>
				6175	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6176	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6177	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6178	</pre>
				6179
				6180	<h5>Overview:</h5>
				6181
				6182	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6183	a signed addition of the two arguments, and indicate whether an overflow
				6184	occurred during the signed summation.</p>
				6185
				6186	<h5>Arguments:</h5>
				6187
				6188	<p>The arguments (%a and %b) and the first element of the result structure may
				6189	be of integer types of any bit width, but they must have the same bit width. The
				6190	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6191	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6192
				6193	<h5>Semantics:</h5>
				6194
				6195	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6196	a signed addition of the two variables. They return a structure — the
				6197	first element of which is the signed summation, and the second element of which
				6198	is a bit specifying if the signed summation resulted in an overflow.</p>
				6199
				6200	<h5>Examples:</h5>
				6201	<pre>
				6202	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6203	%sum = extractvalue {i32, i1} %res, 0
				6204	%obit = extractvalue {i32, i1} %res, 1
				6205	br i1 %obit, label %overflow, label %normal
				6206	</pre>
				6207
				6208	</div>
				6209
				6210	<!-- _______________________________________________________________________ -->
				6211	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6212	<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]	6213	</div>
				6214
				6215	<div class="doc_text">
				6216
				6217	<h5>Syntax:</h5>
				6218
				6219	<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]	6220	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6221
				6222	<pre>
				6223	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6224	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6225	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6226	</pre>
				6227
				6228	<h5>Overview:</h5>
				6229
				6230	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6231	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6232	during the unsigned summation.</p>
				6233
				6234	<h5>Arguments:</h5>
				6235
				6236	<p>The arguments (%a and %b) and the first element of the result structure may
				6237	be of integer types of any bit width, but they must have the same bit width. The
				6238	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6239	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6240
				6241	<h5>Semantics:</h5>
				6242
				6243	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6244	an unsigned addition of the two arguments. They return a structure — the
				6245	first element of which is the sum, and the second element of which is a bit
				6246	specifying if the unsigned summation resulted in a carry.</p>
				6247
				6248	<h5>Examples:</h5>
				6249	<pre>
				6250	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6251	%sum = extractvalue {i32, i1} %res, 0
				6252	%obit = extractvalue {i32, i1} %res, 1
				6253	br i1 %obit, label %carry, label %normal
				6254	</pre>
				6255
				6256	</div>
				6257
				6258	<!-- _______________________________________________________________________ -->
				6259	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6260	<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]	6261	</div>
				6262
				6263	<div class="doc_text">
				6264
				6265	<h5>Syntax:</h5>
				6266
				6267	<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]	6268	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6269
				6270	<pre>
				6271	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6272	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6273	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6274	</pre>
				6275
				6276	<h5>Overview:</h5>
				6277
				6278	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6279	a signed subtraction of the two arguments, and indicate whether an overflow
				6280	occurred during the signed subtraction.</p>
				6281
				6282	<h5>Arguments:</h5>
				6283
				6284	<p>The arguments (%a and %b) and the first element of the result structure may
				6285	be of integer types of any bit width, but they must have the same bit width. The
				6286	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6287	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6288
				6289	<h5>Semantics:</h5>
				6290
				6291	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6292	a signed subtraction of the two arguments. They return a structure — the
				6293	first element of which is the subtraction, and the second element of which is a bit
				6294	specifying if the signed subtraction resulted in an overflow.</p>
				6295
				6296	<h5>Examples:</h5>
				6297	<pre>
				6298	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6299	%sum = extractvalue {i32, i1} %res, 0
				6300	%obit = extractvalue {i32, i1} %res, 1
				6301	br i1 %obit, label %overflow, label %normal
				6302	</pre>
				6303
				6304	</div>
				6305
				6306	<!-- _______________________________________________________________________ -->
				6307	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6308	<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]	6309	</div>
				6310
				6311	<div class="doc_text">
				6312
				6313	<h5>Syntax:</h5>
				6314
				6315	<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]	6316	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6317
				6318	<pre>
				6319	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6320	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6321	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6322	</pre>
				6323
				6324	<h5>Overview:</h5>
				6325
				6326	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6327	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6328	occurred during the unsigned subtraction.</p>
				6329
				6330	<h5>Arguments:</h5>
				6331
				6332	<p>The arguments (%a and %b) and the first element of the result structure may
				6333	be of integer types of any bit width, but they must have the same bit width. The
				6334	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6335	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6336
				6337	<h5>Semantics:</h5>
				6338
				6339	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6340	an unsigned subtraction of the two arguments. They return a structure — the
				6341	first element of which is the subtraction, and the second element of which is a bit
				6342	specifying if the unsigned subtraction resulted in an overflow.</p>
				6343
				6344	<h5>Examples:</h5>
				6345	<pre>
				6346	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6347	%sum = extractvalue {i32, i1} %res, 0
				6348	%obit = extractvalue {i32, i1} %res, 1
				6349	br i1 %obit, label %overflow, label %normal
				6350	</pre>
				6351
				6352	</div>
				6353
				6354	<!-- _______________________________________________________________________ -->
				6355	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6356	<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]	6357	</div>
				6358
				6359	<div class="doc_text">
				6360
				6361	<h5>Syntax:</h5>
				6362
				6363	<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]	6364	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6365
				6366	<pre>
				6367	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6368	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6369	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6370	</pre>
				6371
				6372	<h5>Overview:</h5>
				6373
				6374	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6375	a signed multiplication of the two arguments, and indicate whether an overflow
				6376	occurred during the signed multiplication.</p>
				6377
				6378	<h5>Arguments:</h5>
				6379
				6380	<p>The arguments (%a and %b) and the first element of the result structure may
				6381	be of integer types of any bit width, but they must have the same bit width. The
				6382	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6383	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6384
				6385	<h5>Semantics:</h5>
				6386
				6387	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6388	a signed multiplication of the two arguments. They return a structure —
				6389	the first element of which is the multiplication, and the second element of
				6390	which is a bit specifying if the signed multiplication resulted in an
				6391	overflow.</p>
				6392
				6393	<h5>Examples:</h5>
				6394	<pre>
				6395	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6396	%sum = extractvalue {i32, i1} %res, 0
				6397	%obit = extractvalue {i32, i1} %res, 1
				6398	br i1 %obit, label %overflow, label %normal
				6399	</pre>
				6400
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6401	</div>
				6402
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6403	<!-- _______________________________________________________________________ -->
				6404	<div class="doc_subsubsection">
				6405	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6406	</div>
				6407
				6408	<div class="doc_text">
				6409
				6410	<h5>Syntax:</h5>
				6411
				6412	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6413	on any integer bit width.</p>
				6414
				6415	<pre>
				6416	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6417	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6418	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6419	</pre>
				6420
				6421	<h5>Overview:</h5>
				6422
				6423	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6424	actively being fixed, but it should not currently be used!</i></p>
				6425
				6426	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6427	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6428	occurred during the unsigned multiplication.</p>
				6429
				6430	<h5>Arguments:</h5>
				6431
				6432	<p>The arguments (%a and %b) and the first element of the result structure may
				6433	be of integer types of any bit width, but they must have the same bit width. The
				6434	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6435	and <tt>%b</tt> are the two values that will undergo unsigned
				6436	multiplication.</p>
				6437
				6438	<h5>Semantics:</h5>
				6439
				6440	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6441	an unsigned multiplication of the two arguments. They return a structure —
				6442	the first element of which is the multiplication, and the second element of
				6443	which is a bit specifying if the unsigned multiplication resulted in an
				6444	overflow.</p>
				6445
				6446	<h5>Examples:</h5>
				6447	<pre>
				6448	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6449	%sum = extractvalue {i32, i1} %res, 0
				6450	%obit = extractvalue {i32, i1} %res, 1
				6451	br i1 %obit, label %overflow, label %normal
				6452	</pre>
				6453
				6454	</div>
				6455
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6456	<!-- ======================================================================= -->
				6457	<div class="doc_subsection">
				6458	<a name="int_debugger">Debugger Intrinsics</a>
				6459	</div>
				6460
				6461	<div class="doc_text">
				6462	<p>
				6463	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6464	are described in the <a
				6465	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6466	Debugging</a> document.
				6467	</p>
				6468	</div>
				6469
				6470
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6471	<!-- ======================================================================= -->
				6472	<div class="doc_subsection">
				6473	<a name="int_eh">Exception Handling Intrinsics</a>
				6474	</div>
				6475
				6476	<div class="doc_text">
				6477	<p> The LLVM exception handling intrinsics (which all start with
				6478	<tt>llvm.eh.</tt> prefix), are described in the <a
				6479	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6480	Handling</a> document. </p>
				6481	</div>
				6482
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6483	<!-- ======================================================================= -->
				6484	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6485	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6486	</div>
				6487
				6488	<div class="doc_text">
				6489	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6490	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6491	the <tt>nest</tt> attribute, from a function. The result is a callable
				6492	function pointer lacking the nest parameter - the caller does not need
				6493	to provide a value for it. Instead, the value to use is stored in
				6494	advance in a "trampoline", a block of memory usually allocated
				6495	on the stack, which also contains code to splice the nest value into the
				6496	argument list. This is used to implement the GCC nested function address
				6497	extension.
				6498	</p>
				6499	<p>
				6500	For example, if the function is
				6501	<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]	6502	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]	6503	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6504	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6505	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6506	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6507	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6508	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6509	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6510	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]	6511	</div>
				6512
				6513	<!-- _______________________________________________________________________ -->
				6514	<div class="doc_subsubsection">
				6515	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6516	</div>
				6517	<div class="doc_text">
				6518	<h5>Syntax:</h5>
				6519	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6520	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6521	</pre>
				6522	<h5>Overview:</h5>
				6523	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6524	This fills the memory pointed to by <tt>tramp</tt> with code
				6525	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6526	</p>
				6527	<h5>Arguments:</h5>
				6528	<p>
				6529	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6530	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6531	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]	6532	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6533	currently provides no portable way of determining them, so a front-end that
				6534	generates this intrinsic needs to have some target-specific knowledge.
				6535	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]	6536	</p>
				6537	<h5>Semantics:</h5>
				6538	<p>
				6539	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]	6540	dependent code, turning it into a function. A pointer to this function is
				6541	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6542	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6543	before being called. The new function's signature is the same as that of
				6544	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6545	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6546	of pointer type. Calling the new function is equivalent to calling
				6547	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6548	missing <tt>nest</tt> argument. If, after calling
				6549	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6550	modified, then the effect of any later call to the returned function pointer is
				6551	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6552	</p>
				6553	</div>
				6554
				6555	<!-- ======================================================================= -->
				6556	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6557	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6558	</div>
				6559
				6560	<div class="doc_text">
				6561	<p>
				6562	These intrinsic functions expand the "universal IR" of LLVM to represent
				6563	hardware constructs for atomic operations and memory synchronization. This
				6564	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]	6565	is aimed at a low enough level to allow any programming models or APIs
				6566	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6567	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6568	hardware behavior. Just as hardware provides a "universal IR" for source
				6569	languages, it also provides a starting point for developing a "universal"
				6570	atomic operation and synchronization IR.
				6571	</p>
				6572	<p>
				6573	These do <em>not</em> form an API such as high-level threading libraries,
				6574	software transaction memory systems, atomic primitives, and intrinsic
				6575	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6576	application libraries. The hardware interface provided by LLVM should allow
				6577	a clean implementation of all of these APIs and parallel programming models.
				6578	No one model or paradigm should be selected above others unless the hardware
				6579	itself ubiquitously does so.
				6580
				6581	</p>
				6582	</div>
				6583
				6584	<!-- _______________________________________________________________________ -->
				6585	<div class="doc_subsubsection">
				6586	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6587	</div>
				6588	<div class="doc_text">
				6589	<h5>Syntax:</h5>
				6590	<pre>
				6591	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6592	i1 <device> )
				6593
				6594	</pre>
				6595	<h5>Overview:</h5>
				6596	<p>
				6597	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6598	specific pairs of memory access types.
				6599	</p>
				6600	<h5>Arguments:</h5>
				6601	<p>
				6602	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6603	The first four arguments enables a specific barrier as listed below. The fith
				6604	argument specifies that the barrier applies to io or device or uncached memory.
				6605
				6606	</p>
				6607	<ul>
				6608	<li><tt>ll</tt>: load-load barrier</li>
				6609	<li><tt>ls</tt>: load-store barrier</li>
				6610	<li><tt>sl</tt>: store-load barrier</li>
				6611	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6612	<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]	6613	</ul>
				6614	<h5>Semantics:</h5>
				6615	<p>
				6616	This intrinsic causes the system to enforce some ordering constraints upon
				6617	the loads and stores of the program. This barrier does not indicate
				6618	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6619	which they occur. For any of the specified pairs of load and store operations
				6620	(f.ex. load-load, or store-load), all of the first operations preceding the
				6621	barrier will complete before any of the second operations succeeding the
				6622	barrier begin. Specifically the semantics for each pairing is as follows:
				6623	</p>
				6624	<ul>
				6625	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6626	after the barrier begins.</li>
				6627
				6628	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6629	store after the barrier begins.</li>
				6630	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6631	store after the barrier begins.</li>
				6632	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6633	load after the barrier begins.</li>
				6634	</ul>
				6635	<p>
				6636	These semantics are applied with a logical "and" behavior when more than one
				6637	is enabled in a single memory barrier intrinsic.
				6638	</p>
				6639	<p>
				6640	Backends may implement stronger barriers than those requested when they do not
				6641	support as fine grained a barrier as requested. Some architectures do not
				6642	need all types of barriers and on such architectures, these become noops.
				6643	</p>
				6644	<h5>Example:</h5>
				6645	<pre>
				6646	%ptr = malloc i32
				6647	store i32 4, %ptr
				6648
				6649	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6650	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6651	<i>; guarantee the above finishes</i>
				6652	store i32 8, %ptr <i>; before this begins</i>
				6653	</pre>
				6654	</div>
				6655
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6656	<!-- _______________________________________________________________________ -->
				6657	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6658	<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]	6659	</div>
				6660	<div class="doc_text">
				6661	<h5>Syntax:</h5>
				6662	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6663	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6664	any integer bit width and for different address spaces. Not all targets
				6665	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6666
				6667	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6668	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6669	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6670	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6671	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]	6672
				6673	</pre>
				6674	<h5>Overview:</h5>
				6675	<p>
				6676	This loads a value in memory and compares it to a given value. If they are
				6677	equal, it stores a new value into the memory.
				6678	</p>
				6679	<h5>Arguments:</h5>
				6680	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6681	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]	6682	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6683	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6684	this integer type. While any bit width integer may be used, targets may only
				6685	lower representations they support in hardware.
				6686
				6687	</p>
				6688	<h5>Semantics:</h5>
				6689	<p>
				6690	This entire intrinsic must be executed atomically. It first loads the value
				6691	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6692	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6693	loaded value is yielded in all cases. This provides the equivalent of an
				6694	atomic compare-and-swap operation within the SSA framework.
				6695	</p>
				6696	<h5>Examples:</h5>
				6697
				6698	<pre>
				6699	%ptr = malloc i32
				6700	store i32 4, %ptr
				6701
				6702	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6703	%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]	6704	<i>; yields {i32}:result1 = 4</i>
				6705	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6706	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6707
				6708	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6709	%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]	6710	<i>; yields {i32}:result2 = 8</i>
				6711	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6712
				6713	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6714	</pre>
				6715	</div>
				6716
				6717	<!-- _______________________________________________________________________ -->
				6718	<div class="doc_subsubsection">
				6719	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6720	</div>
				6721	<div class="doc_text">
				6722	<h5>Syntax:</h5>
				6723
				6724	<p>
				6725	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6726	integer bit width. Not all targets support all bit widths however.</p>
				6727	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6728	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6729	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6730	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6731	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6732
				6733	</pre>
				6734	<h5>Overview:</h5>
				6735	<p>
				6736	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6737	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6738	at <tt>ptr</tt>.
				6739	</p>
				6740	<h5>Arguments:</h5>
				6741
				6742	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6743	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6744	<tt>val</tt> argument and the result must be integers of the same bit width.
				6745	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6746	integer type. The targets may only lower integer representations they
				6747	support.
				6748	</p>
				6749	<h5>Semantics:</h5>
				6750	<p>
				6751	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6752	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6753	equivalent of an atomic swap operation within the SSA framework.
				6754
				6755	</p>
				6756	<h5>Examples:</h5>
				6757	<pre>
				6758	%ptr = malloc i32
				6759	store i32 4, %ptr
				6760
				6761	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6762	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6763	<i>; yields {i32}:result1 = 4</i>
				6764	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6765	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6766
				6767	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6768	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6769	<i>; yields {i32}:result2 = 8</i>
				6770
				6771	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6772	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6773	</pre>
				6774	</div>
				6775
				6776	<!-- _______________________________________________________________________ -->
				6777	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6778	<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]	6779
				6780	</div>
				6781	<div class="doc_text">
				6782	<h5>Syntax:</h5>
				6783	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6784	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]	6785	integer bit width. Not all targets support all bit widths however.</p>
				6786	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6787	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6788	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6789	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6790	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6791
				6792	</pre>
				6793	<h5>Overview:</h5>
				6794	<p>
				6795	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6796	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6797	</p>
				6798	<h5>Arguments:</h5>
				6799	<p>
				6800
				6801	The intrinsic takes two arguments, the first a pointer to an integer value
				6802	and the second an integer value. The result is also an integer value. These
				6803	integer types can have any bit width, but they must all have the same bit
				6804	width. The targets may only lower integer representations they support.
				6805	</p>
				6806	<h5>Semantics:</h5>
				6807	<p>
				6808	This intrinsic does a series of operations atomically. It first loads the
				6809	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6810	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6811	</p>
				6812
				6813	<h5>Examples:</h5>
				6814	<pre>
				6815	%ptr = malloc i32
				6816	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6817	%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]	6818	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6819	%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]	6820	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6821	%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]	6822	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6823	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6824	</pre>
				6825	</div>
				6826
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6827	<!-- _______________________________________________________________________ -->
				6828	<div class="doc_subsubsection">
				6829	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6830
				6831	</div>
				6832	<div class="doc_text">
				6833	<h5>Syntax:</h5>
				6834	<p>
				6835	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]	6836	any integer bit width and for different address spaces. Not all targets
				6837	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6838	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6839	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6840	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6841	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6842	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]	6843
				6844	</pre>
				6845	<h5>Overview:</h5>
				6846	<p>
				6847	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6848	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6849	</p>
				6850	<h5>Arguments:</h5>
				6851	<p>
				6852
				6853	The intrinsic takes two arguments, the first a pointer to an integer value
				6854	and the second an integer value. The result is also an integer value. These
				6855	integer types can have any bit width, but they must all have the same bit
				6856	width. The targets may only lower integer representations they support.
				6857	</p>
				6858	<h5>Semantics:</h5>
				6859	<p>
				6860	This intrinsic does a series of operations atomically. It first loads the
				6861	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6862	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6863	</p>
				6864
				6865	<h5>Examples:</h5>
				6866	<pre>
				6867	%ptr = malloc i32
				6868	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6869	%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]	6870	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6871	%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]	6872	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6873	%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]	6874	<i>; yields {i32}:result3 = 2</i>
				6875	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6876	</pre>
				6877	</div>
				6878
				6879	<!-- _______________________________________________________________________ -->
				6880	<div class="doc_subsubsection">
				6881	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6882	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6883	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6884	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6885
				6886	</div>
				6887	<div class="doc_text">
				6888	<h5>Syntax:</h5>
				6889	<p>
				6890	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6891	<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]	6892	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6893	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6894	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6895	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6896	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6897	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6898	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]	6899
				6900	</pre>
				6901
				6902	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6903	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6904	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6905	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6906	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]	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.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6912	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6913	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6914	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]	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.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6920	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6921	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6922	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]	6923
				6924	</pre>
				6925	<h5>Overview:</h5>
				6926	<p>
				6927	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6928	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6929	at <tt>ptr</tt>.
				6930	</p>
				6931	<h5>Arguments:</h5>
				6932	<p>
				6933
				6934	These intrinsics take two arguments, the first a pointer to an integer value
				6935	and the second an integer value. The result is also an integer value. These
				6936	integer types can have any bit width, but they must all have the same bit
				6937	width. The targets may only lower integer representations they support.
				6938	</p>
				6939	<h5>Semantics:</h5>
				6940	<p>
				6941	These intrinsics does a series of operations atomically. They first load the
				6942	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6943	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6944	value stored at <tt>ptr</tt>.
				6945	</p>
				6946
				6947	<h5>Examples:</h5>
				6948	<pre>
				6949	%ptr = malloc i32
				6950	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6951	%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]	6952	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6953	%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]	6954	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6955	%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]	6956	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6957	%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]	6958	<i>; yields {i32}:result3 = FF</i>
				6959	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6960	</pre>
				6961	</div>
				6962
				6963
				6964	<!-- _______________________________________________________________________ -->
				6965	<div class="doc_subsubsection">
				6966	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6967	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6968	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6969	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6970
				6971	</div>
				6972	<div class="doc_text">
				6973	<h5>Syntax:</h5>
				6974	<p>
				6975	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6976	<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]	6977	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6978	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6979	support all bit widths however.</p>
				6980	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6981	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6982	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6983	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6984	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]	6985
				6986	</pre>
				6987
				6988	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6989	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6990	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6991	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6992	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]	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.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6998	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6999	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				7000	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]	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.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				7006	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				7007	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				7008	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]	7009
				7010	</pre>
				7011	<h5>Overview:</h5>
				7012	<p>
				7013	These intrinsics takes the signed or unsigned minimum or maximum of
				7014	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				7015	original value at <tt>ptr</tt>.
				7016	</p>
				7017	<h5>Arguments:</h5>
				7018	<p>
				7019
				7020	These intrinsics take two arguments, the first a pointer to an integer value
				7021	and the second an integer value. The result is also an integer value. These
				7022	integer types can have any bit width, but they must all have the same bit
				7023	width. The targets may only lower integer representations they support.
				7024	</p>
				7025	<h5>Semantics:</h5>
				7026	<p>
				7027	These intrinsics does a series of operations atomically. They first load the
				7028	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				7029	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				7030	the original value stored at <tt>ptr</tt>.
				7031	</p>
				7032
				7033	<h5>Examples:</h5>
				7034	<pre>
				7035	%ptr = malloc i32
				7036	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7037	%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]	7038	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7039	%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]	7040	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7041	%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]	7042	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	7043	%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]	7044	<i>; yields {i32}:result3 = 8</i>
				7045	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				7046	</pre>
				7047	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	7048
				7049	<!-- ======================================================================= -->
				7050	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7051	<a name="int_general">General Intrinsics</a>
				7052	</div>
				7053
				7054	<div class="doc_text">
				7055	<p> This class of intrinsics is designed to be generic and has
				7056	no specific purpose. </p>
				7057	</div>
				7058
				7059	<!-- _______________________________________________________________________ -->
				7060	<div class="doc_subsubsection">
				7061	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				7062	</div>
				7063
				7064	<div class="doc_text">
				7065
				7066	<h5>Syntax:</h5>
				7067	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7068	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]	7069	</pre>
				7070
				7071	<h5>Overview:</h5>
				7072
				7073	<p>
				7074	The '<tt>llvm.var.annotation</tt>' intrinsic
				7075	</p>
				7076
				7077	<h5>Arguments:</h5>
				7078
				7079	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	7080	The first argument is a pointer to a value, the second is a pointer to a
				7081	global string, the third is a pointer to a global string which is the source
				7082	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7083	</p>
				7084
				7085	<h5>Semantics:</h5>
				7086
				7087	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7088	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7089	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]	7090	annotations. These have no other defined use, they are ignored by code
				7091	generation and optimization.
				7092	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	7093	</div>
				7094
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7095	<!-- _______________________________________________________________________ -->
				7096	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	7097	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7098	</div>
				7099
				7100	<div class="doc_text">
				7101
				7102	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7103	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7104	any integer bit width.
				7105	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7106	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	7107	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7108	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7109	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7110	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7111	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]	7112	</pre>
				7113
				7114	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	7115
				7116	<p>
				7117	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7118	</p>
				7119
				7120	<h5>Arguments:</h5>
				7121
				7122	<p>
				7123	The first argument is an integer value (result of some expression),
				7124	the second is a pointer to a global string, the third is a pointer to a global
				7125	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]	7126	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7127	</p>
				7128
				7129	<h5>Semantics:</h5>
				7130
				7131	<p>
				7132	This intrinsic allows annotations to be put on arbitrary expressions
				7133	with arbitrary strings. This can be useful for special purpose optimizations
				7134	that want to look for these annotations. These have no other defined use, they
				7135	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	7136	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	7137	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	7138
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	7139	<!-- _______________________________________________________________________ -->
				7140	<div class="doc_subsubsection">
				7141	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7142	</div>
				7143
				7144	<div class="doc_text">
				7145
				7146	<h5>Syntax:</h5>
				7147	<pre>
				7148	declare void @llvm.trap()
				7149	</pre>
				7150
				7151	<h5>Overview:</h5>
				7152
				7153	<p>
				7154	The '<tt>llvm.trap</tt>' intrinsic
				7155	</p>
				7156
				7157	<h5>Arguments:</h5>
				7158
				7159	<p>
				7160	None
				7161	</p>
				7162
				7163	<h5>Semantics:</h5>
				7164
				7165	<p>
				7166	This intrinsics is lowered to the target dependent trap instruction. If the
				7167	target does not have a trap instruction, this intrinsic will be lowered to the
				7168	call of the abort() function.
				7169	</p>
				7170	</div>
				7171
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7172	<!-- _______________________________________________________________________ -->
				7173	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	7174	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	7175	</div>
				7176	<div class="doc_text">
				7177	<h5>Syntax:</h5>
				7178	<pre>
				7179	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7180
				7181	</pre>
				7182	<h5>Overview:</h5>
				7183	<p>
				7184	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7185	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7186	it is placed on the stack before local variables.
				7187	</p>
				7188	<h5>Arguments:</h5>
				7189	<p>
				7190	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7191	first argument is the value loaded from the stack guard
				7192	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7193	has enough space to hold the value of the guard.
				7194	</p>
				7195	<h5>Semantics:</h5>
				7196	<p>
				7197	This intrinsic causes the prologue/epilogue inserter to force the position of
				7198	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7199	stack. This is to ensure that if a local variable on the stack is overwritten,
				7200	it will destroy the value of the guard. When the function exits, the guard on
				7201	the stack is checked against the original guard. If they're different, then
				7202	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7203	</p>
				7204	</div>
				7205
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7206	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7207	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7208	<address>
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Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7213
				7214	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7215	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7216	Last modified: $Date$
				7217	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7218
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7219	</body>
				7220	</html>