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Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	cb84e43	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	7630785	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	6af02f3	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	23	<li><a href="#linkage">Linkage Types</a></li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	24	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	25	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	26	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	27	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	28	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	29	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	30	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	31	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	32	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	33	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	34	</ol>
				35	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	36	<li><a href="#typesystem">Type System</a>
				37	<ol>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	38	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	39	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	40	<ol>
Chris Lattner	7824d18	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	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	44	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	45	</ol>
				46	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	47	<li><a href="#t_derived">Derived Types</a>
				48	<ol>
Chris Lattner	9a2e3cb	2007-12-18 06:18:21 +0000	[diff] [blame]	49	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	50	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	7630785	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	53	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	54	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	55	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	56	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	57	</ol>
				58	</li>
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	59	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	60	</ol>
				61	</li>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	62	<li><a href="#constants">Constants</a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	63	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	64	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	65	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	ef9462f	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	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	69	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	70	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	71	</li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	72	<li><a href="#othervalues">Other Values</a>
				73	<ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	74	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	75	</ol>
				76	</li>
Chris Lattner	2f7c963	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	48b383b0	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	7630785	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	85	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	86	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	87	</ol>
				88	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	89	<li><a href="#binaryops">Binary Operations</a>
				90	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	91	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	92	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	93	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	94	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	95	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	96	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	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	7eb55b3	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	103	</ol>
				104	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	105	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				106	<ol>
Reid Spencer	2ab0193	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	110	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	111	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	112	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	113	</ol>
				114	</li>
Chris Lattner	ce83bff	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	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	120	</ol>
				121	</li>
Dan Gohman	b9d6660	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	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	128	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	129	<ol>
Chris Lattner	48b383b0	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	820bc75b	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	136	</ol>
				137	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	138	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	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	51b0725	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	b7344ff	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	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	151	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	152	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	153	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	154	<li><a href="#otherops">Other Operations</a>
				155	<ol>
Reid Spencer	c828a0e	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	d219570	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	160	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	161	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	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	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	164	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	165	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	166	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	167	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	168	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	169	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	170	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				171	<ol>
Reid Spencer	96a5f02	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	175	</ol>
				176	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	177	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				178	<ol>
Reid Spencer	96a5f02	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	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	182	</ol>
				183	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	184	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				185	<ol>
Reid Spencer	96a5f02	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	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	193	</ol>
				194	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	195	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				196	<ol>
Reid Spencer	96a5f02	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	b6324c1	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	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	205	</ol>
				206	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	207	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	208	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	209	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	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	5bf54c8	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	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	215	</ol>
				216	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	217	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				218	<ol>
Bill Wendling	fd2bd72	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	b9a7327	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	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	225	</ol>
				226	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	227	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	228	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	229	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	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	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	232	</ol>
				233	</li>
Bill Wendling	f85850f	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	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	251	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	252	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	253	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	254	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	255	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	256	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	257	<li><a href="#int_trap">
Bill Wendling	1431331	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	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	261	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	262	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	263	</ol>
				264	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	265	</ol>
Chris Lattner	757528b0b	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	270	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	271
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	272	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	273	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				274	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	275
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	276	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	277	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	278	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	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	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	281	representation used throughout all phases of the LLVM compilation
				282	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				287	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	289	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	290
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	291	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	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	48b383b0	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	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	300
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	301	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	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	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	311
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	312	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	314	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	315	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	316
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	317	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	318
Chris Lattner	48b383b0	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	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	323
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	324	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	325	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	326	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	327	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	328	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	329
Chris Lattner	48b383b0	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	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	333	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	334	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	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	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	337	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	338
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	339	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	340
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	341	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	342	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	343	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	344
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	345	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	346
Reid Spencer	b23b65f	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	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	350	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	351
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	352	<ol>
Reid Spencer	b23b65f	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	356	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	b23b65f	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	363
Reid Spencer	8f08d80	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	366	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	367
Reid Spencer	b23b65f	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	d79749a	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	48b383b0	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	5b95064	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	b5ebf3d	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	380	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	381	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	386	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	387
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	388	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	389	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	390	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	391	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	392	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	393
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	394	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	395
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	396	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	397	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	398	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	399	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	400	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	401
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	402	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	403
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	404	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	405	<pre>
Bill Wendling	3716c5d	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	409	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	410	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	48b383b0	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	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	414
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	415	<ol>
Chris Lattner	d79749a	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	423	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	424
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	425	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	426
John Criswell	02fdc6f	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	d79749a	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	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	432	</div>
Chris Lattner	6af02f3	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	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	451	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	452	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	455
				456	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	457	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	458
				459	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	460	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	461	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	462	%cast210 = <a
Dan Gohman	623806e	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	6af02f3	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	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	467	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	468	<a
Bill Wendling	3716c5d	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	6af02f3	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	d79749a	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	483
Chris Lattner	d79749a	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	496
				497	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	498
Rafael Espindola	6de96a1	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	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	509	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	510
Duncan Sands	35e43c1	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	6de96a1	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	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	513	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	514	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	515
Chris Lattner	184f1be	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	527	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	528
Chris Lattner	e20b470	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	534	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	535
Dale Johannesen	4188aad	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	546	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	547
Dale Johannesen	4188aad	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	552	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	553
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	561	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	562
Anton Korobeynikov	a0554d9	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	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	564
Chris Lattner	67c37d1	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	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	568	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	569
Duncan Sands	12da8ce	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	12da8ce	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	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	572	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	12da8ce	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	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	575	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4581beb	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	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	579	</dd>
				580
Chris Lattner	6af02f3	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	d79749a	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	586	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	587	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	588
Anton Korobeynikov	d61d39e	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	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	592	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	593	</p>
				594
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	595	<dl>
Anton Korobeynikov	d61d39e	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	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	601	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	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	33a9cef	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	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	610	name.
				611	</dd>
				612
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	613	</dl>
				614
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	615	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	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	92c671e	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	e288105	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	12da8ce	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	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	626	</div>
				627
				628	<!-- ======================================================================= -->
				629	<div class="doc_subsection">
Chris Lattner	0132aff	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	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	647	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	648	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	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	67c37d1	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	2c6b888	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	0132aff	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	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	674	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	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	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	680	</dl>
Chris Lattner	0132aff	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	c7f9f3d	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	67c37d1	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	c7f9f3d	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	39f3cff	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	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	726	</dl>
				727
				728	</div>
				729
				730	<!-- ======================================================================= -->
				731	<div class="doc_subsection">
Chris Lattner	bc08821	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	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	764	<!-- ======================================================================= -->
				765	<div class="doc_subsection">
Chris Lattner	6af02f3	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	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	771	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	772	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	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	5d5aede	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	4c0cf7f	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	5d5aede	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	6af02f3	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	308121c	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	25f5076	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	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	802
Chris Lattner	662c872	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	54611b4	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	308121c	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	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	814
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	815	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	816	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	817	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	818	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	819	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	820
Chris Lattner	6af02f3	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	b5ebf3d	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	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	833	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	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	7e9b05e	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	cbc4d2a	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	c7f9f3d	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	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	846	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	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	dc5cafb	2007-12-10 03:30:21 +0000	[diff] [blame]	848	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	849
Chris Lattner	67c37d1	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	6af02f3	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	a59fb10	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	6af02f3	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	662c872	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	54611b4	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	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	872	<h5>Syntax:</h5>
				873
				874	<div class="doc_code">
Chris Lattner	0ae0209	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	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	882	</div>
				883
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	884	</div>
				885
Anton Korobeynikov	a97b694	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	25b2e82	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	a97b694	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	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	899	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	900	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	901	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	902	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	903	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	904
				905	</div>
				906
				907
				908
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	909	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	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	ad0ea2d	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	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	918
Reid Spencer	cf7ebf5	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	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	921	example:</p>
				922
				923	<div class="doc_code">
				924	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	925	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	926	declare i32 @atoi(i8 zeroext)
				927	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	928	</pre>
				929	</div>
				930
Duncan Sands	ad0ea2d	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	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	933
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	934	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	935	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	936	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	940
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	941	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	945
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	946	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	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	d2597d7	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	952
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	953	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	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	1ca5c64	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	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	958	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	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	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	962	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	967
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	968	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	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	d2597d7	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	7e9b05e	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	975
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	976	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	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	d59572c	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	2abb108	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	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	990
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	991	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	992	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	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	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	995	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	996
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	997	</div>
				998
				999	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1000	<div class="doc_subsection">
Gordon Henriksen	71183b6	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	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1018	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1019	</div>
				1020
				1021	<div class="doc_text">
Devang Patel	9eb525d	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	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1031
				1032	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1033	<pre>
Devang Patel	9eb525d	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	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1039	</div>
				1040
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1041	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1042	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	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	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1046
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1047	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1048	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1049	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1050	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1051
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1052	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1053	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	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	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1056
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1057	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	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	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1061
				1062	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	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	1efabaa	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	2a1d8ba	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	1efabaa	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	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1076
Duncan Sands	2a1d8ba	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	1efabaa	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	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1086
				1087	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1088	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	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	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1092	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1093
Devang Patel	310fd4a	2009-06-12 19:45:19 +0000	[diff] [blame]	1094	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1095	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	310fd4a	2009-06-12 19:45:19 +0000	[diff] [blame]	1096	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1097
				1098	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	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	a813017	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	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1101	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1102
Devang Patel	310fd4a	2009-06-12 19:45:19 +0000	[diff] [blame]	1103	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1104	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1105	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	310fd4a	2009-06-12 19:45:19 +0000	[diff] [blame]	1106	an <tt>sspreq</tt> attribute.</dd>
				1107
				1108	<dt><tt>noredzone</tt></dt>
Dan Gohman	1b1b7e1	2009-06-15 17:37:09 +0000	[diff] [blame]	1109	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	405cf6c	2009-06-15 21:18:01 +0000	[diff] [blame]	1110	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	1b1b7e1	2009-06-15 17:37:09 +0000	[diff] [blame]	1111	</dd>
Devang Patel	310fd4a	2009-06-12 19:45:19 +0000	[diff] [blame]	1112
				1113	<dt><tt>noimplicitfloat</tt></dt>
				1114	<dd>This attributes disables implicit floating point instructions.</dd>
				1115
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1116	</dl>
				1117
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1118	</div>
				1119
				1120	<!-- ======================================================================= -->
				1121	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1122	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1123	</div>
				1124
				1125	<div class="doc_text">
				1126	<p>
				1127	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1128	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1129	LLVM and treated as a single unit, but may be separated in the .ll file if
				1130	desired. The syntax is very simple:
				1131	</p>
				1132
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1133	<div class="doc_code">
				1134	<pre>
				1135	module asm "inline asm code goes here"
				1136	module asm "more can go here"
				1137	</pre>
				1138	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1139
				1140	<p>The strings can contain any character by escaping non-printable characters.
				1141	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1142	for the number.
				1143	</p>
				1144
				1145	<p>
				1146	The inline asm code is simply printed to the machine code .s file when
				1147	assembly code is generated.
				1148	</p>
				1149	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1150
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1151	<!-- ======================================================================= -->
				1152	<div class="doc_subsection">
				1153	<a name="datalayout">Data Layout</a>
				1154	</div>
				1155
				1156	<div class="doc_text">
				1157	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	1158	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1159	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1160	<p>The <i>layout specification</i> consists of a list of specifications
				1161	separated by the minus sign character ('-'). Each specification starts with a
				1162	letter and may include other information after the letter to define some
				1163	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1164	<dl>
				1165	<dt><tt>E</tt></dt>
				1166	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1167	bits with the most significance have the lowest address location.</dd>
				1168	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1169	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1170	the bits with the least significance have the lowest address location.</dd>
				1171	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1172	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1173	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1174	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1175	too.</dd>
				1176	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1177	<dd>This specifies the alignment for an integer type of a given bit
				1178	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1179	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1180	<dd>This specifies the alignment for a vector type of a given bit
				1181	<i>size</i>.</dd>
				1182	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1183	<dd>This specifies the alignment for a floating point type of a given bit
				1184	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1185	(double).</dd>
				1186	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1187	<dd>This specifies the alignment for an aggregate type of a given bit
				1188	<i>size</i>.</dd>
Daniel Dunbar	7921a59	2009-06-08 22:17:53 +0000	[diff] [blame]	1189	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1190	<dd>This specifies the alignment for a stack object of a given bit
				1191	<i>size</i>.</dd>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1192	</dl>
				1193	<p>When constructing the data layout for a given target, LLVM starts with a
				1194	default set of specifications which are then (possibly) overriden by the
				1195	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1196	are given in this list:</p>
				1197	<ul>
				1198	<li><tt>E</tt> - big endian</li>
				1199	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1200	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1201	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1202	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1203	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1204	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1205	alignment of 64-bits</li>
				1206	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1207	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1208	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1209	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1210	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	7921a59	2009-06-08 22:17:53 +0000	[diff] [blame]	1211	<li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1212	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1213	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1214	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1215	<ol>
				1216	<li>If the type sought is an exact match for one of the specifications, that
				1217	specification is used.</li>
				1218	<li>If no match is found, and the type sought is an integer type, then the
				1219	smallest integer type that is larger than the bitwidth of the sought type is
				1220	used. If none of the specifications are larger than the bitwidth then the the
				1221	largest integer type is used. For example, given the default specifications
				1222	above, the i7 type will use the alignment of i8 (next largest) while both
				1223	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1224	<li>If no match is found, and the type sought is a vector type, then the
				1225	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	1226	as a fall back. This happens because <128 x double> can be implemented
				1227	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1228	</ol>
				1229	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1230
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1231	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1232	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1233	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1234
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1236
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1237	<p>The LLVM type system is one of the most important features of the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1238	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1239	optimizations to be performed on the intermediate representation directly,
				1240	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1241	extra analyses on the side before the transformation. A strong type
				1242	system makes it easier to read the generated code and enables novel
				1243	analyses and transformations that are not feasible to perform on normal
				1244	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1245
				1246	</div>
				1247
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1248	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1249	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1250	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1251	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1252	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1253	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1254
				1255	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1256	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1257	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1258	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1259	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1260	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1261	</tr>
				1262	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1263	<td><a href="#t_floating">floating point</a></td>
				1264	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1265	</tr>
				1266	<tr>
				1267	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1268	<td><a href="#t_integer">integer</a>,
				1269	<a href="#t_floating">floating point</a>,
				1270	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1271	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1272	<a href="#t_struct">structure</a>,
				1273	<a href="#t_array">array</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1274	<a href="#t_label">label</a>,
				1275	<a href="#t_metadata">metadata</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1276	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1277	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1278	<tr>
				1279	<td><a href="#t_primitive">primitive</a></td>
				1280	<td><a href="#t_label">label</a>,
				1281	<a href="#t_void">void</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1282	<a href="#t_floating">floating point</a>,
				1283	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1284	</tr>
				1285	<tr>
				1286	<td><a href="#t_derived">derived</a></td>
				1287	<td><a href="#t_integer">integer</a>,
				1288	<a href="#t_array">array</a>,
				1289	<a href="#t_function">function</a>,
				1290	<a href="#t_pointer">pointer</a>,
				1291	<a href="#t_struct">structure</a>,
				1292	<a href="#t_pstruct">packed structure</a>,
				1293	<a href="#t_vector">vector</a>,
				1294	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1295	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1296	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1297	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1298	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1299
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1300	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1301	most important. Values of these types are the only ones which can be
				1302	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1303	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1304	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1305
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1306	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1307	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1308
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1309	<div class="doc_text">
				1310	<p>The primitive types are the fundamental building blocks of the LLVM
				1311	system.</p>
				1312
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1313	</div>
				1314
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1315	<!-- _______________________________________________________________________ -->
				1316	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1317
				1318	<div class="doc_text">
				1319	<table>
				1320	<tbody>
				1321	<tr><th>Type</th><th>Description</th></tr>
				1322	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1323	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1324	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1325	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1326	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1327	</tbody>
				1328	</table>
				1329	</div>
				1330
				1331	<!-- _______________________________________________________________________ -->
				1332	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1333
				1334	<div class="doc_text">
				1335	<h5>Overview:</h5>
				1336	<p>The void type does not represent any value and has no size.</p>
				1337
				1338	<h5>Syntax:</h5>
				1339
				1340	<pre>
				1341	void
				1342	</pre>
				1343	</div>
				1344
				1345	<!-- _______________________________________________________________________ -->
				1346	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1347
				1348	<div class="doc_text">
				1349	<h5>Overview:</h5>
				1350	<p>The label type represents code labels.</p>
				1351
				1352	<h5>Syntax:</h5>
				1353
				1354	<pre>
				1355	label
				1356	</pre>
				1357	</div>
				1358
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	1359	<!-- _______________________________________________________________________ -->
				1360	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1361
				1362	<div class="doc_text">
				1363	<h5>Overview:</h5>
				1364	<p>The metadata type represents embedded metadata. The only derived type that
				1365	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1366	takes metadata typed parameters, but not pointer to metadata types.</p>
				1367
				1368	<h5>Syntax:</h5>
				1369
				1370	<pre>
				1371	metadata
				1372	</pre>
				1373	</div>
				1374
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1375
				1376	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1377	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1378
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1379	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1380
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1381	<p>The real power in LLVM comes from the derived types in the system.
				1382	This is what allows a programmer to represent arrays, functions,
				1383	pointers, and other useful types. Note that these derived types may be
				1384	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1385
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1386	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1387
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1388	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1389	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1390
				1391	<div class="doc_text">
				1392
				1393	<h5>Overview:</h5>
				1394	<p>The integer type is a very simple derived type that simply specifies an
				1395	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1396	2^23-1 (about 8 million) can be specified.</p>
				1397
				1398	<h5>Syntax:</h5>
				1399
				1400	<pre>
				1401	iN
				1402	</pre>
				1403
				1404	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1405	value.</p>
				1406
				1407	<h5>Examples:</h5>
				1408	<table class="layout">
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1409	<tr class="layout">
				1410	<td class="left"><tt>i1</tt></td>
				1411	<td class="left">a single-bit integer.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1412	</tr>
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1413	<tr class="layout">
				1414	<td class="left"><tt>i32</tt></td>
				1415	<td class="left">a 32-bit integer.</td>
				1416	</tr>
				1417	<tr class="layout">
				1418	<td class="left"><tt>i1942652</tt></td>
				1419	<td class="left">a really big integer of over 1 million bits.</td>
				1420	</tr>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1421	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1422
				1423	<p>Note that the code generator does not yet support large integer types
				1424	to be used as function return types. The specific limit on how large a
				1425	return type the code generator can currently handle is target-dependent;
				1426	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1427	targets.</p>
				1428
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1429	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1430
				1431	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1432	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1433
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1434	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1435
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1436	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1437
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1438	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1439	sequentially in memory. The array type requires a size (number of
				1440	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1441
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1442	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1443
				1444	<pre>
				1445	[<# elements> x <elementtype>]
				1446	</pre>
				1447
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1448	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1449	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1450
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1451	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1452	<table class="layout">
				1453	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1454	<td class="left"><tt>[40 x i32]</tt></td>
				1455	<td class="left">Array of 40 32-bit integer values.</td>
				1456	</tr>
				1457	<tr class="layout">
				1458	<td class="left"><tt>[41 x i32]</tt></td>
				1459	<td class="left">Array of 41 32-bit integer values.</td>
				1460	</tr>
				1461	<tr class="layout">
				1462	<td class="left"><tt>[4 x i8]</tt></td>
				1463	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1464	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1465	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1466	<p>Here are some examples of multidimensional arrays:</p>
				1467	<table class="layout">
				1468	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1469	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1470	<td class="left">3x4 array of 32-bit integer values.</td>
				1471	</tr>
				1472	<tr class="layout">
				1473	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1474	<td class="left">12x10 array of single precision floating point values.</td>
				1475	</tr>
				1476	<tr class="layout">
				1477	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1478	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1479	</tr>
				1480	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1481
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1482	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1483	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1484	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1485	As a special case, however, zero length arrays are recognized to be variable
				1486	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1487	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1488
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1489	<p>Note that the code generator does not yet support large aggregate types
				1490	to be used as function return types. The specific limit on how large an
				1491	aggregate return type the code generator can currently handle is
				1492	target-dependent, and also dependent on the aggregate element types.</p>
				1493
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1494	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1495
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1496	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1497	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1498	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1499
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1500	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1501
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1502	<p>The function type can be thought of as a function signature. It
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1503	consists of a return type and a list of formal parameter types. The
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1504	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	9c1f8b1	2008-03-24 20:52:42 +0000	[diff] [blame]	1505	If the return type is a struct type then all struct elements must be of first
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1506	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1507
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1508	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1509
				1510	<pre>
				1511	<returntype list> (<parameter list>)
				1512	</pre>
				1513
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1514	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	20f9a62	2004-08-12 20:16:08 +0000	[diff] [blame]	1515	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1516	which indicates that the function takes a variable number of arguments.
				1517	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1518	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1519	'<tt><returntype list></tt>' is a comma-separated list of
				1520	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1521
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1522	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1523	<table class="layout">
				1524	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1525	<td class="left"><tt>i32 (i32)</tt></td>
				1526	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1527	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1528	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1529	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1530	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1531	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1532	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1533	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1534	<tt>float</tt>.
				1535	</td>
				1536	</tr><tr class="layout">
				1537	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1538	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1539	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1540	which returns an integer. This is the signature for <tt>printf</tt> in
				1541	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1542	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1543	</tr><tr class="layout">
				1544	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1545	<td class="left">A function taking an <tt>i32</tt>, returning two
				1546	<tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1547	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1548	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1549	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1550
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1551	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1552	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1553	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1554	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1555	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1556	<p>The structure type is used to represent a collection of data members
				1557	together in memory. The packing of the field types is defined to match
				1558	the ABI of the underlying processor. The elements of a structure may
				1559	be any type that has a size.</p>
				1560	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1561	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1562	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1563	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1564	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1565	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1566	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1567	<table class="layout">
				1568	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1569	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1570	<td class="left">A triple of three <tt>i32</tt> values</td>
				1571	</tr><tr class="layout">
				1572	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1573	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1574	second element is a <a href="#t_pointer">pointer</a> to a
				1575	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1576	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1577	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1578	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1579
				1580	<p>Note that the code generator does not yet support large aggregate types
				1581	to be used as function return types. The specific limit on how large an
				1582	aggregate return type the code generator can currently handle is
				1583	target-dependent, and also dependent on the aggregate element types.</p>
				1584
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1585	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1586
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1587	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1588	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1589	</div>
				1590	<div class="doc_text">
				1591	<h5>Overview:</h5>
				1592	<p>The packed structure type is used to represent a collection of data members
				1593	together in memory. There is no padding between fields. Further, the alignment
				1594	of a packed structure is 1 byte. The elements of a packed structure may
				1595	be any type that has a size.</p>
				1596	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1597	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1598	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1599	instruction.</p>
				1600	<h5>Syntax:</h5>
				1601	<pre> < { <type list> } > <br></pre>
				1602	<h5>Examples:</h5>
				1603	<table class="layout">
				1604	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1605	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1606	<td class="left">A triple of three <tt>i32</tt> values</td>
				1607	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1608	<td class="left">
				1609	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1610	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1611	second element is a <a href="#t_pointer">pointer</a> to a
				1612	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1613	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1614	</tr>
				1615	</table>
				1616	</div>
				1617
				1618	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1619	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1620	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1621	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1622	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1623	reference to another object, which must live in memory. Pointer types may have
				1624	an optional address space attribute defining the target-specific numbered
				1625	address space where the pointed-to object resides. The default address space is
				1626	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1627
				1628	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	d1d4cff	2009-02-08 22:21:28 +0000	[diff] [blame]	1629	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1630
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1631	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1632	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1633	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1634	<table class="layout">
				1635	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1636	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1637	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1638	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1639	</tr>
				1640	<tr class="layout">
				1641	<td class="left"><tt>i32 (i32 ) </tt></td>
				1642	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1643	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1644	<tt>i32</tt>.</td>
				1645	</tr>
				1646	<tr class="layout">
				1647	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1648	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1649	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1650	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1651	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1652	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1653
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1654	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1655	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1656	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1657
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1658	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1659
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1660	<p>A vector type is a simple derived type that represents a vector
				1661	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1662	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1663	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1664	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1665	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1666	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1667
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1668	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1669
				1670	<pre>
				1671	< <# elements> x <elementtype> >
				1672	</pre>
				1673
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1674	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1675	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1676
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1677	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1678
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1679	<table class="layout">
				1680	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1681	<td class="left"><tt><4 x i32></tt></td>
				1682	<td class="left">Vector of 4 32-bit integer values.</td>
				1683	</tr>
				1684	<tr class="layout">
				1685	<td class="left"><tt><8 x float></tt></td>
				1686	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1687	</tr>
				1688	<tr class="layout">
				1689	<td class="left"><tt><2 x i64></tt></td>
				1690	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1691	</tr>
				1692	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1693
				1694	<p>Note that the code generator does not yet support large vector types
				1695	to be used as function return types. The specific limit on how large a
				1696	vector return type codegen can currently handle is target-dependent;
				1697	currently it's often a few times longer than a hardware vector register.</p>
				1698
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1699	</div>
				1700
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1701	<!-- _______________________________________________________________________ -->
				1702	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1703	<div class="doc_text">
				1704
				1705	<h5>Overview:</h5>
				1706
				1707	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	a699c4d	2007-10-14 00:34:53 +0000	[diff] [blame]	1708	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1709	In LLVM, opaque types can eventually be resolved to any type (not just a
				1710	structure type).</p>
				1711
				1712	<h5>Syntax:</h5>
				1713
				1714	<pre>
				1715	opaque
				1716	</pre>
				1717
				1718	<h5>Examples:</h5>
				1719
				1720	<table class="layout">
				1721	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1722	<td class="left"><tt>opaque</tt></td>
				1723	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1724	</tr>
				1725	</table>
				1726	</div>
				1727
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1728	<!-- ======================================================================= -->
				1729	<div class="doc_subsection">
				1730	<a name="t_uprefs">Type Up-references</a>
				1731	</div>
				1732
				1733	<div class="doc_text">
				1734	<h5>Overview:</h5>
				1735	<p>
				1736	An "up reference" allows you to refer to a lexically enclosing type without
				1737	requiring it to have a name. For instance, a structure declaration may contain a
				1738	pointer to any of the types it is lexically a member of. Example of up
				1739	references (with their equivalent as named type declarations) include:</p>
				1740
				1741	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1742	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1743	{ \2 }* %y = type { %y }*
				1744	\1* %z = type %z*
				1745	</pre>
				1746
				1747	<p>
				1748	An up reference is needed by the asmprinter for printing out cyclic types when
				1749	there is no declared name for a type in the cycle. Because the asmprinter does
				1750	not want to print out an infinite type string, it needs a syntax to handle
				1751	recursive types that have no names (all names are optional in llvm IR).
				1752	</p>
				1753
				1754	<h5>Syntax:</h5>
				1755	<pre>
				1756	\<level>
				1757	</pre>
				1758
				1759	<p>
				1760	The level is the count of the lexical type that is being referred to.
				1761	</p>
				1762
				1763	<h5>Examples:</h5>
				1764
				1765	<table class="layout">
				1766	<tr class="layout">
				1767	<td class="left"><tt>\1*</tt></td>
				1768	<td class="left">Self-referential pointer.</td>
				1769	</tr>
				1770	<tr class="layout">
				1771	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1772	<td class="left">Recursive structure where the upref refers to the out-most
				1773	structure.</td>
				1774	</tr>
				1775	</table>
				1776	</div>
				1777
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1778
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1779	<!-- *********************************************************************** -->
				1780	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1781	<!-- *********************************************************************** -->
				1782
				1783	<div class="doc_text">
				1784
				1785	<p>LLVM has several different basic types of constants. This section describes
				1786	them all and their syntax.</p>
				1787
				1788	</div>
				1789
				1790	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1791	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1792
				1793	<div class="doc_text">
				1794
				1795	<dl>
				1796	<dt><b>Boolean constants</b></dt>
				1797
				1798	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	1799	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1800	</dd>
				1801
				1802	<dt><b>Integer constants</b></dt>
				1803
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1804	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1805	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1806	integer types.
				1807	</dd>
				1808
				1809	<dt><b>Floating point constants</b></dt>
				1810
				1811	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1812	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1813	notation (see below). The assembler requires the exact decimal value of
				1814	a floating-point constant. For example, the assembler accepts 1.25 but
				1815	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1816	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1817
				1818	<dt><b>Null pointer constants</b></dt>
				1819
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1820	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1821	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1822
				1823	</dl>
				1824
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1825	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1826	of floating point constants. For example, the form '<tt>double
				1827	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1828	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1829	(and the only time that they are generated by the disassembler) is when a
				1830	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1831	decimal floating point number in a reasonable number of digits. For example,
				1832	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1833	special values are represented in their IEEE hexadecimal format so that
				1834	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1835	<p>When using the hexadecimal form, constants of types float and double are
				1836	represented using the 16-digit form shown above (which matches the IEEE754
				1837	representation for double); float values must, however, be exactly representable
				1838	as IEE754 single precision.
				1839	Hexadecimal format is always used for long
				1840	double, and there are three forms of long double. The 80-bit
				1841	format used by x86 is represented as <tt>0xK</tt>
				1842	followed by 20 hexadecimal digits.
				1843	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1844	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1845	format is represented
				1846	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1847	target uses this format. Long doubles will only work if they match
				1848	the long double format on your target. All hexadecimal formats are big-endian
				1849	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1850	</div>
				1851
				1852	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1853	<div class="doc_subsection">
				1854	<a name="aggregateconstants"> <!-- old anchor -->
				1855	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1856	</div>
				1857
				1858	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1859	<p>Complex constants are a (potentially recursive) combination of simple
				1860	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1861
				1862	<dl>
				1863	<dt><b>Structure constants</b></dt>
				1864
				1865	<dd>Structure constants are represented with notation similar to structure
				1866	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1867	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1868	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	455fc8c	2005-03-07 22:13:59 +0000	[diff] [blame]	1869	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1870	types of elements must match those specified by the type.
				1871	</dd>
				1872
				1873	<dt><b>Array constants</b></dt>
				1874
				1875	<dd>Array constants are represented with notation similar to array type
				1876	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1877	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1878	constants must have <a href="#t_array">array type</a>, and the number and
				1879	types of elements must match those specified by the type.
				1880	</dd>
				1881
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1882	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1883
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1884	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1885	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1886	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1887	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1888	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1889	match those specified by the type.
				1890	</dd>
				1891
				1892	<dt><b>Zero initialization</b></dt>
				1893
				1894	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1895	value to zero of <em>any</em> type, including scalar and aggregate types.
				1896	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1897	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1898	initializers.
				1899	</dd>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1900
				1901	<dt><b>Metadata node</b></dt>
				1902
Nick Lewycky	8e2c4f4	2009-05-30 16:08:30 +0000	[diff] [blame]	1903	<dd>A metadata node is a structure-like constant with
				1904	<a href="#t_metadata">metadata type</a>. For example:
				1905	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1906	that are meant to be interpreted as part of the instruction stream, metadata
				1907	is a place to attach additional information such as debug info.
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1908	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1909	</dl>
				1910
				1911	</div>
				1912
				1913	<!-- ======================================================================= -->
				1914	<div class="doc_subsection">
				1915	<a name="globalconstants">Global Variable and Function Addresses</a>
				1916	</div>
				1917
				1918	<div class="doc_text">
				1919
				1920	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1921	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1922	constants. These constants are explicitly referenced when the <a
				1923	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1924	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1925	file:</p>
				1926
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1927	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1928	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1929	@X = global i32 17
				1930	@Y = global i32 42
				1931	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1932	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1933	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1934
				1935	</div>
				1936
				1937	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1938	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1939	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1940	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1941	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1942	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1943
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1944	<p>Undefined values indicate to the compiler that the program is well defined
				1945	no matter what value is used, giving the compiler more freedom to optimize.
				1946	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1947	</div>
				1948
				1949	<!-- ======================================================================= -->
				1950	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1951	</div>
				1952
				1953	<div class="doc_text">
				1954
				1955	<p>Constant expressions are used to allow expressions involving other constants
				1956	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1957	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1958	that does not have side effects (e.g. load and call are not supported). The
				1959	following is the syntax for constant expressions:</p>
				1960
				1961	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1962	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1963	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1964	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1965
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1966	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1967	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1968	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1969
				1970	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1971	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1972	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1973
				1974	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1975	<dd>Truncate a floating point constant to another floating point type. The
				1976	size of CST must be larger than the size of TYPE. Both types must be
				1977	floating point.</dd>
				1978
				1979	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1980	<dd>Floating point extend a constant to another type. The size of CST must be
				1981	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1982
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1983	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1984	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1985	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1986	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1987	of the same number of elements. If the value won't fit in the integer type,
				1988	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1989
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1990	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1991	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1992	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1993	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1994	of the same number of elements. If the value won't fit in the integer type,
				1995	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1996
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1997	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1998	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1999	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2000	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2001	of the same number of elements. If the value won't fit in the floating point
				2002	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	2003
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	2004	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	2005	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	2006	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2007	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2008	of the same number of elements. If the value won't fit in the floating point
				2009	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	2010
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	2011	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2012	<dd>Convert a pointer typed constant to the corresponding integer constant
				2013	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2014	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2015
				2016	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2017	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2018	pointer type. CST must be of integer type. The CST value is zero extended,
				2019	truncated, or unchanged to make it fit in a pointer size. This one is
				2020	<i>really</i> dangerous!</dd>
				2021
				2022	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	2023	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2024	are the same as those for the <a href="#i_bitcast">bitcast
				2025	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2026
				2027	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2028
				2029	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2030	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2031	instruction, the index list may have zero or more indexes, which are required
				2032	to make sense for the type of "CSTPTR".</dd>
				2033
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2034	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2035
				2036	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2037	constants.</dd>
				2038
				2039	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2040	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2041
				2042	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2043	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2044
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	2045	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2046	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2047
				2048	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2049	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2050
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2051	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2052
				2053	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2054	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2055
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2056	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2057
				2058	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2059	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2060
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2061
				2062	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2063
				2064	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2065	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2066
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2067	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2068
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2069	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2070	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2071	binary</a> operations. The constraints on operands are the same as those for
				2072	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2073	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2074	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2075	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2076
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2077	<!-- ======================================================================= -->
				2078	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2079	</div>
				2080
				2081	<div class="doc_text">
				2082
				2083	<p>Embedded metadata provides a way to attach arbitrary data to the
				2084	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2085	two metadata primitives, strings and nodes. All metadata has the
				2086	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2087	point ('<tt>!</tt>').
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2088	</p>
				2089
				2090	<p>A metadata string is a string surrounded by double quotes. It can contain
				2091	any character by escaping non-printable characters with "\xx" where "xx" is
				2092	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2093	</p>
				2094
				2095	<p>Metadata nodes are represented with notation similar to structure constants
				2096	(a comma separated list of elements, surrounded by braces and preceeded by an
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2097	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2098	</p>
				2099
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2100	<p>A metadata node will attempt to track changes to the values it holds. In
				2101	the event that a value is deleted, it will be replaced with a typeless
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame]	2102	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2103
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2104	<p>Optimizations may rely on metadata to provide additional information about
				2105	the program that isn't available in the instructions, or that isn't easily
				2106	computable. Similarly, the code generator may expect a certain metadata format
				2107	to be used to express debugging information.</p>
				2108	</div>
				2109
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2110	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2111	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2112	<!-- *********************************************************************** -->
				2113
				2114	<!-- ======================================================================= -->
				2115	<div class="doc_subsection">
				2116	<a name="inlineasm">Inline Assembler Expressions</a>
				2117	</div>
				2118
				2119	<div class="doc_text">
				2120
				2121	<p>
				2122	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2123	Module-Level Inline Assembly</a>) through the use of a special value. This
				2124	value represents the inline assembler as a string (containing the instructions
				2125	to emit), a list of operand constraints (stored as a string), and a flag that
				2126	indicates whether or not the inline asm expression has side effects. An example
				2127	inline assembler expression is:
				2128	</p>
				2129
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2130	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2131	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2132	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2133	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2134	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2135
				2136	<p>
				2137	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2138	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2139	</p>
				2140
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2141	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2142	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2143	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2144	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2145	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2146
				2147	<p>
				2148	Inline asms with side effects not visible in the constraint list must be marked
				2149	as having side effects. This is done through the use of the
				2150	'<tt>sideeffect</tt>' keyword, like so:
				2151	</p>
				2152
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2153	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2154	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2155	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2156	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2157	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2158
				2159	<p>TODO: The format of the asm and constraints string still need to be
				2160	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	d552826	2008-10-04 18:36:02 +0000	[diff] [blame]	2161	need to be documented). This is probably best done by reference to another
				2162	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2163	</p>
				2164
				2165	</div>
				2166
				2167	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2168	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2169	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2170
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2171	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2172
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2173	<p>The LLVM instruction set consists of several different
				2174	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2175	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2176	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2177	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2178	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2179
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2180	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2181
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2182	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2183	<div class="doc_subsection"> <a name="terminators">Terminator
				2184	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2185
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2186	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2187
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2188	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2189	basic block in a program ends with a "Terminator" instruction, which
				2190	indicates which block should be executed after the current block is
				2191	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2192	value: they produce control flow, not values (the one exception being
				2193	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2194	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2195	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2196	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2197	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2198	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2199	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2200
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2201	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2202
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2203	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2204	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2205	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2206	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2207	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2208	<pre>
				2209	ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2210	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2211	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2212
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2213	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2214
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2215	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2216	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2217	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2218	returns a value and then causes control flow, and one that just causes
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2219	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2220
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2221	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2222
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2223	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2224	the return value. The type of the return value must be a
				2225	'<a href="#t_firstclass">first class</a>' type.</p>
				2226
				2227	<p>A function is not <a href="#wellformed">well formed</a> if
				2228	it it has a non-void return type and contains a '<tt>ret</tt>'
				2229	instruction with no return value or a return value with a type that
				2230	does not match its type, or if it has a void return type and contains
				2231	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2232
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2233	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2234
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2235	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2236	returns back to the calling function's context. If the caller is a "<a
John Criswell	40db33f	2004-06-25 15:16:57 +0000	[diff] [blame]	2237	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2238	the instruction after the call. If the caller was an "<a
				2239	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2240	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2241	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2242	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2243
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2244	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2245
				2246	<pre>
				2247	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2248	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2249	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2250	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2251
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2252	<p>Note that the code generator does not yet fully support large
				2253	return values. The specific sizes that are currently supported are
				2254	dependent on the target. For integers, on 32-bit targets the limit
				2255	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2256	For aggregate types, the current limits are dependent on the element
				2257	types; for example targets are often limited to 2 total integer
				2258	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2259
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2260	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2262	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2263	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2264	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2265	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2267	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2268	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2269	transfer to a different basic block in the current function. There are
				2270	two forms of this instruction, corresponding to a conditional branch
				2271	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2272	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2273	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2274	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2275	unconditional form of the '<tt>br</tt>' instruction takes a single
				2276	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2278	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2279	argument is evaluated. If the value is <tt>true</tt>, control flows
				2280	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2281	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Example:</h5>
Chris Lattner	e648c28	2009-05-09 18:11:50 +0000	[diff] [blame]	2283	<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2284	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2285	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2286	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2287	<div class="doc_subsubsection">
				2288	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2289	</div>
				2290
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2291	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2292	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2293
				2294	<pre>
				2295	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2296	</pre>
				2297
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2299
				2300	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2301	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2302	instruction, allowing a branch to occur to one of many possible
				2303	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2304
				2305
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2306	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2307
				2308	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2309	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2310	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2311	table is not allowed to contain duplicate constant entries.</p>
				2312
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2313	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2314
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2315	<p>The <tt>switch</tt> instruction specifies a table of values and
				2316	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2317	table is searched for the given value. If the value is found, control flow is
				2318	transfered to the corresponding destination; otherwise, control flow is
				2319	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2320
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2321	<h5>Implementation:</h5>
				2322
				2323	<p>Depending on properties of the target machine and the particular
				2324	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2325	ways. For example, it could be generated as a series of chained conditional
				2326	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2327
				2328	<h5>Example:</h5>
				2329
				2330	<pre>
				2331	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2332	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2333	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2334
				2335	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2336	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2337
				2338	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2339	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2340	i32 1, label %onone
				2341	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2342	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2343	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2344
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2345	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2346	<div class="doc_subsubsection">
				2347	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2348	</div>
				2349
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2350	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2351
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2352	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2353
				2354	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2355	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	6b7a008	2006-05-14 18:23:06 +0000	[diff] [blame]	2356	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2357	</pre>
				2358
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2359	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2360
				2361	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2362	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2363	'<tt>normal</tt>' label or the
				2364	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2365	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2366	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2367	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2368	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2369
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2370	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2371
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2372	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2373
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2374	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2375	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2376	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2377	convention</a> the call should use. If none is specified, the call defaults
				2378	to using C calling conventions.
				2379	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2380
				2381	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2382	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2383	and '<tt>inreg</tt>' attributes are valid here.</li>
				2384
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2385	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2386	function value being invoked. In most cases, this is a direct function
				2387	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2388	an arbitrary pointer to function value.
				2389	</li>
				2390
				2391	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2392	function to be invoked. </li>
				2393
				2394	<li>'<tt>function args</tt>': argument list whose types match the function
				2395	signature argument types. If the function signature indicates the function
				2396	accepts a variable number of arguments, the extra arguments can be
				2397	specified. </li>
				2398
				2399	<li>'<tt>normal label</tt>': the label reached when the called function
				2400	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2401
				2402	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2403	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2404
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2405	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2406	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2407	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2408	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2409
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2410	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2411
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2412	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2413	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2414	difference is that it establishes an association with a label, which is used by
				2415	the runtime library to unwind the stack.</p>
				2416
				2417	<p>This instruction is used in languages with destructors to ensure that proper
				2418	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2419	exception. Additionally, this is important for implementation of
				2420	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2421
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame]	2422	<p>For the purposes of the SSA form, the definition of the value
				2423	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2424	the edge from the current block to the "normal" label. If the callee
				2425	unwinds then no return value is available.</p>
Dan Gohman	9069d89	2009-05-22 21:47:08 +0000	[diff] [blame]	2426
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2427	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2428	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2429	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2430	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2431	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2432	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2433	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2434	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2435
				2436
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2437	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2438
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2439	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2440	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2441
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2442	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2443
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2444	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2445	<pre>
				2446	unwind
				2447	</pre>
				2448
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2449	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2450
				2451	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2452	at the first callee in the dynamic call stack which used an <a
				2453	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2454	primarily used to implement exception handling.</p>
				2455
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2456	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2457
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2458	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2459	immediately halt. The dynamic call stack is then searched for the first <a
				2460	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2461	execution continues at the "exceptional" destination block specified by the
				2462	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2463	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2464	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2465
				2466	<!-- _______________________________________________________________________ -->
				2467
				2468	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2469	Instruction</a> </div>
				2470
				2471	<div class="doc_text">
				2472
				2473	<h5>Syntax:</h5>
				2474	<pre>
				2475	unreachable
				2476	</pre>
				2477
				2478	<h5>Overview:</h5>
				2479
				2480	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2481	instruction is used to inform the optimizer that a particular portion of the
				2482	code is not reachable. This can be used to indicate that the code after a
				2483	no-return function cannot be reached, and other facts.</p>
				2484
				2485	<h5>Semantics:</h5>
				2486
				2487	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2488	</div>
				2489
				2490
				2491
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2493	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2494	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2495	<p>Binary operators are used to do most of the computation in a
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2496	program. They require two operands of the same type, execute an operation on them, and
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2497	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2498	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	81f9297	2008-04-01 18:47:32 +0000	[diff] [blame]	2499	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2501	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2502	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2503	<div class="doc_subsubsection">
				2504	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2505	</div>
				2506
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2507	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
				2511	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2512	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2513	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2514
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2515	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2516
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2517	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2518
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2519	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
				2521	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2522	href="#t_integer">integer</a> or
				2523	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2524	have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2525
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2526	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2527
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2528	<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2529
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2530	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2531	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2532	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2534	<p>Because LLVM integers use a two's complement representation, this
				2535	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2537	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2538
				2539	<pre>
				2540	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2541	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2542	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2543	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2544	<div class="doc_subsubsection">
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2545	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2546	</div>
				2547
				2548	<div class="doc_text">
				2549
				2550	<h5>Syntax:</h5>
				2551
				2552	<pre>
				2553	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2554	</pre>
				2555
				2556	<h5>Overview:</h5>
				2557
				2558	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2559
				2560	<h5>Arguments:</h5>
				2561
				2562	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2563	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2564	floating point values. Both arguments must have identical types.</p>
				2565
				2566	<h5>Semantics:</h5>
				2567
				2568	<p>The value produced is the floating point sum of the two operands.</p>
				2569
				2570	<h5>Example:</h5>
				2571
				2572	<pre>
				2573	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2574	</pre>
				2575	</div>
				2576	<!-- _______________________________________________________________________ -->
				2577	<div class="doc_subsubsection">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2578	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2579	</div>
				2580
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2581	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2582
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2583	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2584
				2585	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2586	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2587	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2588
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2589	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2591	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2592	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2593
				2594	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2595	'<tt>neg</tt>' instruction present in most other intermediate
				2596	representations.</p>
				2597
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2598	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2599
				2600	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2601	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2602	integer values. Both arguments must have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2603
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2604	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2605
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2606	<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2607
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2608	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2609	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2610	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2611
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2612	<p>Because LLVM integers use a two's complement representation, this
				2613	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2614
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2615	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2616	<pre>
				2617	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2618	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2619	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2620	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2622	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2623	<div class="doc_subsubsection">
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2624	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2625	</div>
				2626
				2627	<div class="doc_text">
				2628
				2629	<h5>Syntax:</h5>
				2630
				2631	<pre>
				2632	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2633	</pre>
				2634
				2635	<h5>Overview:</h5>
				2636
				2637	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2638	operands.</p>
				2639
				2640	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2641	'<tt>fneg</tt>' instruction present in most other intermediate
				2642	representations.</p>
				2643
				2644	<h5>Arguments:</h5>
				2645
				2646	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2647	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2648	of floating point values. Both arguments must have identical types.</p>
				2649
				2650	<h5>Semantics:</h5>
				2651
				2652	<p>The value produced is the floating point difference of the two operands.</p>
				2653
				2654	<h5>Example:</h5>
				2655	<pre>
				2656	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2657	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2658	</pre>
				2659	</div>
				2660
				2661	<!-- _______________________________________________________________________ -->
				2662	<div class="doc_subsubsection">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2663	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2664	</div>
				2665
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2666	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2667
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2668	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2669	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2670	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2671	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2672	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2673	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2674
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2675	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2676
				2677	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2678	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2679	values. Both arguments must have identical types.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2680
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2681	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2682
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2683	<p>The value produced is the integer product of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2684
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2685	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2686	the result returned is the mathematical result modulo
				2687	2<sup>n</sup>, where n is the bit width of the result.</p>
				2688	<p>Because LLVM integers use a two's complement representation, and the
				2689	result is the same width as the operands, this instruction returns the
				2690	correct result for both signed and unsigned integers. If a full product
				2691	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2692	should be sign-extended or zero-extended as appropriate to the
				2693	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2694	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2695	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2696	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2697	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2698
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2699	<!-- _______________________________________________________________________ -->
Dan Gohman	a5b9645	2009-06-04 22:49:04 +0000	[diff] [blame]	2700	<div class="doc_subsubsection">
				2701	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2702	</div>
				2703
				2704	<div class="doc_text">
				2705
				2706	<h5>Syntax:</h5>
				2707	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2708	</pre>
				2709	<h5>Overview:</h5>
				2710	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2711	operands.</p>
				2712
				2713	<h5>Arguments:</h5>
				2714
				2715	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2716	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2717	of floating point values. Both arguments must have identical types.</p>
				2718
				2719	<h5>Semantics:</h5>
				2720
				2721	<p>The value produced is the floating point product of the two operands.</p>
				2722
				2723	<h5>Example:</h5>
				2724	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2725	</pre>
				2726	</div>
				2727
				2728	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2729	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2730	</a></div>
				2731	<div class="doc_text">
				2732	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2733	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2734	</pre>
				2735	<h5>Overview:</h5>
				2736	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2737	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2738
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2739	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2740
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2741	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2742	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2743	values. Both arguments must have identical types.</p>
				2744
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2745	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2746
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2747	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2748	<p>Note that unsigned integer division and signed integer division are distinct
				2749	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2750	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2751	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2752	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2753	</pre>
				2754	</div>
				2755	<!-- _______________________________________________________________________ -->
				2756	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2757	</a> </div>
				2758	<div class="doc_text">
				2759	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2760	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2761	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2762	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2763
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2764	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2765
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2766	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2767	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2768
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2769	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2770
				2771	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2772	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2773	values. Both arguments must have identical types.</p>
				2774
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2775	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2776	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2777	<p>Note that signed integer division and unsigned integer division are distinct
				2778	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2779	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2780	undefined behavior; this is a rare case, but can occur, for example,
				2781	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2782	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2783	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2784	</pre>
				2785	</div>
				2786	<!-- _______________________________________________________________________ -->
				2787	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2788	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2789	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2790	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2791	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2792	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2793	</pre>
				2794	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2795
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2796	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2797	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2798
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2799	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2800
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2801	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2802	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2803	of floating point values. Both arguments must have identical types.</p>
				2804
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2805	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2806
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2807	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2808
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2809	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2810
				2811	<pre>
				2812	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2813	</pre>
				2814	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2815
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2816	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2817	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2818	</div>
				2819	<div class="doc_text">
				2820	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2821	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2822	</pre>
				2823	<h5>Overview:</h5>
				2824	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2825	unsigned division of its two arguments.</p>
				2826	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2827	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2828	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2829	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2830	<h5>Semantics:</h5>
				2831	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2832	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2833	<p>Note that unsigned integer remainder and signed integer remainder are
				2834	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2835	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2836	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2837	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2838	</pre>
				2839
				2840	</div>
				2841	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2842	<div class="doc_subsubsection">
				2843	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2844	</div>
				2845
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2846	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2847
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2848	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2849
				2850	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2851	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2852	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2853
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2854	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2855
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2856	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2857	signed division of its two operands. This instruction can also take
				2858	<a href="#t_vector">vector</a> versions of the values in which case
				2859	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2860
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2861	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2862
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2863	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2864	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2865	values. Both arguments must have identical types.</p>
				2866
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2867	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2868
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2869	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2870	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2871	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2872	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2873	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2874	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	db3b93b	2007-03-24 22:40:44 +0000	[diff] [blame]	2875	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2876	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2877	<p>Note that signed integer remainder and unsigned integer remainder are
				2878	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2879	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2880	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2881	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2882	(The remainder doesn't actually overflow, but this rule lets srem be
				2883	implemented using instructions that return both the result of the division
				2884	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2885	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2886	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2887	</pre>
				2888
				2889	</div>
				2890	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2891	<div class="doc_subsubsection">
				2892	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2893
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2894	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2895
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2896	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2897	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2898	</pre>
				2899	<h5>Overview:</h5>
				2900	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2901	division of its two operands.</p>
				2902	<h5>Arguments:</h5>
				2903	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2904	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2905	of floating point values. Both arguments must have identical types.</p>
				2906
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2907	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2908
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2909	<p>This instruction returns the <i>remainder</i> of a division.
				2910	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2911
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2912	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2913
				2914	<pre>
				2915	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2916	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2917	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2918
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2919	<!-- ======================================================================= -->
				2920	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2921	Operations</a> </div>
				2922	<div class="doc_text">
				2923	<p>Bitwise binary operators are used to do various forms of
				2924	bit-twiddling in a program. They are generally very efficient
				2925	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2926	instructions. They require two operands of the same type, execute an operation on them,
				2927	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2928	</div>
				2929
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2930	<!-- _______________________________________________________________________ -->
				2931	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2932	Instruction</a> </div>
				2933	<div class="doc_text">
				2934	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2935	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2936	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2937
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2938	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2939
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2940	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2941	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2942
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2943	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2944
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2945	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2946	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2947	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2948
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2949	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2950
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2951	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2952	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2953	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2954	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2955	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2956
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2957	<h5>Example:</h5><pre>
				2958	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2959	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2960	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2961	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2962	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2963	</pre>
				2964	</div>
				2965	<!-- _______________________________________________________________________ -->
				2966	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2967	Instruction</a> </div>
				2968	<div class="doc_text">
				2969	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2970	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2971	</pre>
				2972
				2973	<h5>Overview:</h5>
				2974	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2975	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2976
				2977	<h5>Arguments:</h5>
				2978	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	2979	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2980	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2981
				2982	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2983
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2984	<p>This instruction always performs a logical shift right operation. The most
				2985	significant bits of the result will be filled with zero bits after the
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2986	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	2987	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2988	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2989	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2990
				2991	<h5>Example:</h5>
				2992	<pre>
				2993	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2994	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2995	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2996	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2997	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2998	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2999	</pre>
				3000	</div>
				3001
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	3002	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3003	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				3004	Instruction</a> </div>
				3005	<div class="doc_text">
				3006
				3007	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3008	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3009	</pre>
				3010
				3011	<h5>Overview:</h5>
				3012	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3013	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3014
				3015	<h5>Arguments:</h5>
				3016	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	fecbc8c	2008-07-29 15:49:41 +0000	[diff] [blame]	3017	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3018	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3019
				3020	<h5>Semantics:</h5>
				3021	<p>This instruction always performs an arithmetic shift right operation,
				3022	The most significant bits of the result will be filled with the sign bit
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3023	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	68d4eee	2008-12-10 08:55:09 +0000	[diff] [blame]	3024	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3025	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3026	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3027
				3028	<h5>Example:</h5>
				3029	<pre>
				3030	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3031	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3032	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3033	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	3034	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	3035	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	3036	</pre>
				3037	</div>
				3038
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3039	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3040	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3041	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3042
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3043	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3044
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3045	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3046
				3047	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3048	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3049	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3050
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3051	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3052
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3053	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3054	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3055
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3056	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3057
				3058	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3059	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3060	values. Both arguments must have identical types.</p>
				3061
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3062	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3063	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3064	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3065	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3066	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3067	<tbody>
				3068	<tr>
				3069	<td>In0</td>
				3070	<td>In1</td>
				3071	<td>Out</td>
				3072	</tr>
				3073	<tr>
				3074	<td>0</td>
				3075	<td>0</td>
				3076	<td>0</td>
				3077	</tr>
				3078	<tr>
				3079	<td>0</td>
				3080	<td>1</td>
				3081	<td>0</td>
				3082	</tr>
				3083	<tr>
				3084	<td>1</td>
				3085	<td>0</td>
				3086	<td>0</td>
				3087	</tr>
				3088	<tr>
				3089	<td>1</td>
				3090	<td>1</td>
				3091	<td>1</td>
				3092	</tr>
				3093	</tbody>
				3094	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3095	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3097	<pre>
				3098	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3099	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3100	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3101	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3102	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3103	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3104	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3105	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3106	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3107	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3108	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3109	<h5>Overview:</h5>
				3110	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3111	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3113
				3114	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3115	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3116	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3117	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3118	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3119	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3120	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3121	<table border="1" cellspacing="0" cellpadding="4">
				3122	<tbody>
				3123	<tr>
				3124	<td>In0</td>
				3125	<td>In1</td>
				3126	<td>Out</td>
				3127	</tr>
				3128	<tr>
				3129	<td>0</td>
				3130	<td>0</td>
				3131	<td>0</td>
				3132	</tr>
				3133	<tr>
				3134	<td>0</td>
				3135	<td>1</td>
				3136	<td>1</td>
				3137	</tr>
				3138	<tr>
				3139	<td>1</td>
				3140	<td>0</td>
				3141	<td>1</td>
				3142	</tr>
				3143	<tr>
				3144	<td>1</td>
				3145	<td>1</td>
				3146	<td>1</td>
				3147	</tr>
				3148	</tbody>
				3149	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3150	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3151	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3152	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3153	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3154	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3155	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3156	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3157	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3158	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3159	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3160	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3161	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3162	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3163	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3164	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3165	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3166	or of its two operands. The <tt>xor</tt> is used to implement the
				3167	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3168	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3169	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3170	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3171	values. Both arguments must have identical types.</p>
				3172
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3173	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3174
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3175	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3176	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3177	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3178	<table border="1" cellspacing="0" cellpadding="4">
				3179	<tbody>
				3180	<tr>
				3181	<td>In0</td>
				3182	<td>In1</td>
				3183	<td>Out</td>
				3184	</tr>
				3185	<tr>
				3186	<td>0</td>
				3187	<td>0</td>
				3188	<td>0</td>
				3189	</tr>
				3190	<tr>
				3191	<td>0</td>
				3192	<td>1</td>
				3193	<td>1</td>
				3194	</tr>
				3195	<tr>
				3196	<td>1</td>
				3197	<td>0</td>
				3198	<td>1</td>
				3199	</tr>
				3200	<tr>
				3201	<td>1</td>
				3202	<td>1</td>
				3203	<td>0</td>
				3204	</tr>
				3205	</tbody>
				3206	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3207	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3208	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3209	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3210	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3211	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3212	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3213	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3214	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3215	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3216
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3217	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3218	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3219	<a name="vectorops">Vector Operations</a>
				3220	</div>
				3221
				3222	<div class="doc_text">
				3223
				3224	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3225	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3226	vector-specific operations needed to process vectors effectively. While LLVM
				3227	does directly support these vector operations, many sophisticated algorithms
				3228	will want to use target-specific intrinsics to take full advantage of a specific
				3229	target.</p>
				3230
				3231	</div>
				3232
				3233	<!-- _______________________________________________________________________ -->
				3234	<div class="doc_subsubsection">
				3235	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3236	</div>
				3237
				3238	<div class="doc_text">
				3239
				3240	<h5>Syntax:</h5>
				3241
				3242	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3243	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3244	</pre>
				3245
				3246	<h5>Overview:</h5>
				3247
				3248	<p>
				3249	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3250	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3251	</p>
				3252
				3253
				3254	<h5>Arguments:</h5>
				3255
				3256	<p>
				3257	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3258	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3259	an index indicating the position from which to extract the element.
				3260	The index may be a variable.</p>
				3261
				3262	<h5>Semantics:</h5>
				3263
				3264	<p>
				3265	The result is a scalar of the same type as the element type of
				3266	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3267	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3268	results are undefined.
				3269	</p>
				3270
				3271	<h5>Example:</h5>
				3272
				3273	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3274	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3275	</pre>
				3276	</div>
				3277
				3278
				3279	<!-- _______________________________________________________________________ -->
				3280	<div class="doc_subsubsection">
				3281	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3282	</div>
				3283
				3284	<div class="doc_text">
				3285
				3286	<h5>Syntax:</h5>
				3287
				3288	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3289	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3290	</pre>
				3291
				3292	<h5>Overview:</h5>
				3293
				3294	<p>
				3295	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3296	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3297	</p>
				3298
				3299
				3300	<h5>Arguments:</h5>
				3301
				3302	<p>
				3303	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3304	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3305	scalar value whose type must equal the element type of the first
				3306	operand. The third operand is an index indicating the position at
				3307	which to insert the value. The index may be a variable.</p>
				3308
				3309	<h5>Semantics:</h5>
				3310
				3311	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3312	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3313	element values are those of <tt>val</tt> except at position
				3314	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3315	exceeds the length of <tt>val</tt>, the results are undefined.
				3316	</p>
				3317
				3318	<h5>Example:</h5>
				3319
				3320	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3321	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3322	</pre>
				3323	</div>
				3324
				3325	<!-- _______________________________________________________________________ -->
				3326	<div class="doc_subsubsection">
				3327	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3328	</div>
				3329
				3330	<div class="doc_text">
				3331
				3332	<h5>Syntax:</h5>
				3333
				3334	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3335	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3336	</pre>
				3337
				3338	<h5>Overview:</h5>
				3339
				3340	<p>
				3341	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3342	from two input vectors, returning a vector with the same element type as
				3343	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3344	</p>
				3345
				3346	<h5>Arguments:</h5>
				3347
				3348	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3349	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3350	with types that match each other. The third argument is a shuffle mask whose
				3351	element type is always 'i32'. The result of the instruction is a vector whose
				3352	length is the same as the shuffle mask and whose element type is the same as
				3353	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3354	</p>
				3355
				3356	<p>
				3357	The shuffle mask operand is required to be a constant vector with either
				3358	constant integer or undef values.
				3359	</p>
				3360
				3361	<h5>Semantics:</h5>
				3362
				3363	<p>
				3364	The elements of the two input vectors are numbered from left to right across
				3365	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3366	the result vector, which element of the two input vectors the result element
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3367	gets. The element selector may be undef (meaning "don't care") and the second
				3368	operand may be undef if performing a shuffle from only one vector.
				3369	</p>
				3370
				3371	<h5>Example:</h5>
				3372
				3373	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3374	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3375	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3376	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3377	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3378	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3379	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3380	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3381	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3382	</pre>
				3383	</div>
				3384
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3385
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3386	<!-- ======================================================================= -->
				3387	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3388	<a name="aggregateops">Aggregate Operations</a>
				3389	</div>
				3390
				3391	<div class="doc_text">
				3392
				3393	<p>LLVM supports several instructions for working with aggregate values.
				3394	</p>
				3395
				3396	</div>
				3397
				3398	<!-- _______________________________________________________________________ -->
				3399	<div class="doc_subsubsection">
				3400	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3401	</div>
				3402
				3403	<div class="doc_text">
				3404
				3405	<h5>Syntax:</h5>
				3406
				3407	<pre>
				3408	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3409	</pre>
				3410
				3411	<h5>Overview:</h5>
				3412
				3413	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3414	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3415	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3416	</p>
				3417
				3418
				3419	<h5>Arguments:</h5>
				3420
				3421	<p>
				3422	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3423	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3424	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3425	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3426	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3427	</p>
				3428
				3429	<h5>Semantics:</h5>
				3430
				3431	<p>
				3432	The result is the value at the position in the aggregate specified by
				3433	the index operands.
				3434	</p>
				3435
				3436	<h5>Example:</h5>
				3437
				3438	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3439	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3440	</pre>
				3441	</div>
				3442
				3443
				3444	<!-- _______________________________________________________________________ -->
				3445	<div class="doc_subsubsection">
				3446	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3447	</div>
				3448
				3449	<div class="doc_text">
				3450
				3451	<h5>Syntax:</h5>
				3452
				3453	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3454	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3455	</pre>
				3456
				3457	<h5>Overview:</h5>
				3458
				3459	<p>
				3460	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3461	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3462	</p>
				3463
				3464
				3465	<h5>Arguments:</h5>
				3466
				3467	<p>
				3468	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3469	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3470	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3471	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3472	indicating the position at which to insert the value in a similar manner as
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3473	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3474	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3475	The value to insert must have the same type as the value identified
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3476	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3477	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3478
				3479	<h5>Semantics:</h5>
				3480
				3481	<p>
				3482	The result is an aggregate of the same type as <tt>val</tt>. Its
				3483	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3484	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3485	</p>
				3486
				3487	<h5>Example:</h5>
				3488
				3489	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3490	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3491	</pre>
				3492	</div>
				3493
				3494
				3495	<!-- ======================================================================= -->
				3496	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3497	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3498	</div>
				3499
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3500	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3501
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3502	<p>A key design point of an SSA-based representation is how it
				3503	represents memory. In LLVM, no memory locations are in SSA form, which
				3504	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3505	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3506
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3507	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3509	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3510	<div class="doc_subsubsection">
				3511	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3512	</div>
				3513
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3514	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3515
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3516	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3517
				3518	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3519	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3520	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3521
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3522	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3523
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3524	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3525	heap and returns a pointer to it. The object is always allocated in the generic
				3526	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3527
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3528	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3529
				3530	<p>The '<tt>malloc</tt>' instruction allocates
				3531	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3532	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3533	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3534	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	2ae473f	2009-06-20 13:26:06 +0000	[diff] [blame^]	3535	If a constant alignment is specified, the value result of the allocation is
				3536	guaranteed to be aligned to at least that boundary. If not specified, or if
				3537	zero, the target can choose to align the allocation on any convenient boundary
				3538	compatible with the type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3539
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3540	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3541
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3542	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3543
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3544	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3545	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3546	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3547
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3548	<h5>Example:</h5>
				3549
				3550	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3551	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3552
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3553	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3554	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3555	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3556	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3557	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3558	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3559
				3560	<p>Note that the code generator does not yet respect the
				3561	alignment value.</p>
				3562
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3563	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3564
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3565	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3566	<div class="doc_subsubsection">
				3567	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3568	</div>
				3569
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3570	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3571
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3572	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3573
				3574	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3575	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3576	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3577
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3578	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3579
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3580	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3581	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3582
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3583	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3584
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3585	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3586	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3587	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3588
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3589	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3590
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3591	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	0f103e1	2008-04-19 22:41:32 +0000	[diff] [blame]	3592	after this instruction executes. If the pointer is null, the operation
				3593	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3594
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3595	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3596
				3597	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3598	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3599	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3600	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3601	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3602
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3603	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3604	<div class="doc_subsubsection">
				3605	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3606	</div>
				3607
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3608	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3609
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3610	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3611
				3612	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3613	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3614	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3615
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3616	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3617
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3618	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3619	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3620	returns to its caller. The object is always allocated in the generic address
				3621	space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3622
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3623	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3624
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3625	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3626	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3627	appropriate type to the program. If "NumElements" is specified, it is the
				3628	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	2ae473f	2009-06-20 13:26:06 +0000	[diff] [blame^]	3629	If a constant alignment is specified, the value result of the allocation is
				3630	guaranteed to be aligned to at least that boundary. If not specified, or if
				3631	zero, the target can choose to align the allocation on any convenient boundary
				3632	compatible with the type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3633
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3634	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3635
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3636	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3637
Bill Wendling	9ee6a31	2009-05-08 20:49:29 +0000	[diff] [blame]	3638	<p>Memory is allocated; a pointer is returned. The operation is undefined if
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	3639	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3640	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3641	instruction is commonly used to represent automatic variables that must
				3642	have an address available. When the function returns (either with the <tt><a
John Criswell	c932bef	2005-05-12 16:55:34 +0000	[diff] [blame]	3643	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3644	instructions), the memory is reclaimed. Allocating zero bytes
				3645	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3646
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3647	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3648
				3649	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3650	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3651	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3652	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3653	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3654	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3655	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3656
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3657	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3658	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3659	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3660	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3661	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3662	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3663	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3664	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3665	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3666	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3667	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3668	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3669	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3670	the number or order of execution of this <tt>load</tt> with other
				3671	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3672	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3673	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3674	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3675	(that is, the alignment of the memory address). A value of 0 or an
				3676	omitted "align" argument means that the operation has the preferential
				3677	alignment for the target. It is the responsibility of the code emitter
				3678	to ensure that the alignment information is correct. Overestimating
				3679	the alignment results in an undefined behavior. Underestimating the
				3680	alignment may produce less efficient code. An alignment of 1 is always
				3681	safe.
				3682	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3683	<h5>Semantics:</h5>
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3684	<p>The location of memory pointed to is loaded. If the value being loaded
				3685	is of scalar type then the number of bytes read does not exceed the minimum
				3686	number of bytes needed to hold all bits of the type. For example, loading an
				3687	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3688	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3689	is undefined if the value was not originally written using a store of the
				3690	same type.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3691	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3692	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3693	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3694	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3695	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3696	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3697	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3698	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3699	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3700	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3701	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3702	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3703	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3704	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3705	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3706	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3707	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3708	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3709	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3710	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3711	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3712	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3713	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3714	optimizer is not allowed to modify the number or order of execution of
				3715	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3716	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3717	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3718	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3719	(that is, the alignment of the memory address). A value of 0 or an
				3720	omitted "align" argument means that the operation has the preferential
				3721	alignment for the target. It is the responsibility of the code emitter
				3722	to ensure that the alignment information is correct. Overestimating
				3723	the alignment results in an undefined behavior. Underestimating the
				3724	alignment may produce less efficient code. An alignment of 1 is always
				3725	safe.
				3726	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3727	<h5>Semantics:</h5>
				3728	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3729	at the location specified by the '<tt><pointer></tt>' operand.
				3730	If '<tt><value></tt>' is of scalar type then the number of bytes
				3731	written does not exceed the minimum number of bytes needed to hold all
				3732	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3733	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3734	size that is not an integral number of bytes, it is unspecified what
				3735	happens to the extra bits that do not belong to the type, but they will
				3736	typically be overwritten.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3737	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3738	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8830ffe	2007-10-22 05:10:05 +0000	[diff] [blame]	3739	store i32 3, i32* %ptr <i>; yields {void}</i>
				3740	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3741	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3742	</div>
				3743
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3744	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3745	<div class="doc_subsubsection">
				3746	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3747	</div>
				3748
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3749	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3750	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3751	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3752	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3753	</pre>
				3754
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3755	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3756
				3757	<p>
				3758	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3759	subelement of an aggregate data structure. It performs address calculation only
				3760	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3761
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3762	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3763
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3764	<p>The first argument is always a pointer, and forms the basis of the
				3765	calculation. The remaining arguments are indices, that indicate which of the
				3766	elements of the aggregate object are indexed. The interpretation of each index
				3767	is dependent on the type being indexed into. The first index always indexes the
				3768	pointer value given as the first argument, the second index indexes a value of
				3769	the type pointed to (not necessarily the value directly pointed to, since the
				3770	first index can be non-zero), etc. The first type indexed into must be a pointer
				3771	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3772	types being indexed into can never be pointers, since that would require loading
				3773	the pointer before continuing calculation.</p>
				3774
				3775	<p>The type of each index argument depends on the type it is indexing into.
				3776	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3777	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	1f8555a	2009-04-27 03:21:00 +0000	[diff] [blame]	3778	integers of any width are allowed (also non-constants).</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3779
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3780	<p>For example, let's consider a C code fragment and how it gets
				3781	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3782
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3783	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3784	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3785	struct RT {
				3786	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3787	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3788	char C;
				3789	};
				3790	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3791	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3792	double Y;
				3793	struct RT Z;
				3794	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3795
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3796	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3797	return &s[1].Z.B[5][13];
				3798	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3799	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3800	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3801
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3802	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3803
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3804	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3805	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3806	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3807	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3808
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3809	define i32* %foo(%ST* %s) {
				3810	entry:
				3811	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3812	ret i32* %reg
				3813	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3814	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3815	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3816
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3817	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3818
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3819	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3820	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3821	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3822	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3823	i8 }</tt>' type, another structure. The third index indexes into the second
				3824	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3825	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3826	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3827	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3828
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3829	<p>Note that it is perfectly legal to index partially through a
				3830	structure, returning a pointer to an inner element. Because of this,
				3831	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3832
				3833	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3834	define i32* %foo(%ST* %s) {
				3835	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3836	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3837	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3838	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3839	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3840	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3841	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3842	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3843
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3844	<p>Note that it is undefined to access an array out of bounds: array
				3845	and pointer indexes must always be within the defined bounds of the
				3846	array type when accessed with an instruction that dereferences the
				3847	pointer (e.g. a load or store instruction). The one exception for
				3848	this rule is zero length arrays. These arrays are defined to be
				3849	accessible as variable length arrays, which requires access beyond the
				3850	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3851
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3852	<p>The getelementptr instruction is often confusing. For some more insight
				3853	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3854	FAQ</a>.</p>
				3855
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3856	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3857
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3858	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3859	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3860	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3861	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3862	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3863	<i>; yields i8*:eptr</i>
				3864	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	0c155e6	2009-04-25 07:27:44 +0000	[diff] [blame]	3865	<i>; yields i32*:iptr</i>
Sanjiv Gupta	77abea0	2009-04-24 16:38:13 +0000	[diff] [blame]	3866	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3867	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3868	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3869
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3870	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3871	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3872	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3873	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3874	<p>The instructions in this category are the conversion instructions (casting)
				3875	which all take a single operand and a type. They perform various bit conversions
				3876	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3877	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3878
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3879	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3880	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3881	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3882	</div>
				3883	<div class="doc_text">
				3884
				3885	<h5>Syntax:</h5>
				3886	<pre>
				3887	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3888	</pre>
				3889
				3890	<h5>Overview:</h5>
				3891	<p>
				3892	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3893	</p>
				3894
				3895	<h5>Arguments:</h5>
				3896	<p>
				3897	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3898	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3899	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3900	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3901	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3902
				3903	<h5>Semantics:</h5>
				3904	<p>
				3905	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3906	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3907	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3908	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3909
				3910	<h5>Example:</h5>
				3911	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3912	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3913	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3914	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3915	</pre>
				3916	</div>
				3917
				3918	<!-- _______________________________________________________________________ -->
				3919	<div class="doc_subsubsection">
				3920	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3921	</div>
				3922	<div class="doc_text">
				3923
				3924	<h5>Syntax:</h5>
				3925	<pre>
				3926	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3927	</pre>
				3928
				3929	<h5>Overview:</h5>
				3930	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3931	<tt>ty2</tt>.</p>
				3932
				3933
				3934	<h5>Arguments:</h5>
				3935	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3936	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3937	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3938	<tt>value</tt> must be smaller than the bit size of the destination type,
				3939	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3940
				3941	<h5>Semantics:</h5>
				3942	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3943	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3944
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3945	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3946
				3947	<h5>Example:</h5>
				3948	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3949	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3950	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3951	</pre>
				3952	</div>
				3953
				3954	<!-- _______________________________________________________________________ -->
				3955	<div class="doc_subsubsection">
				3956	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3957	</div>
				3958	<div class="doc_text">
				3959
				3960	<h5>Syntax:</h5>
				3961	<pre>
				3962	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3963	</pre>
				3964
				3965	<h5>Overview:</h5>
				3966	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3967
				3968	<h5>Arguments:</h5>
				3969	<p>
				3970	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	3971	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3972	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3973	<tt>value</tt> must be smaller than the bit size of the destination type,
				3974	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3975
				3976	<h5>Semantics:</h5>
				3977	<p>
				3978	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3979	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	c87f3df	2007-05-24 19:13:27 +0000	[diff] [blame]	3980	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3981
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3982	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3983
				3984	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3985	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3986	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3987	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3988	</pre>
				3989	</div>
				3990
				3991	<!-- _______________________________________________________________________ -->
				3992	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3993	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3994	</div>
				3995
				3996	<div class="doc_text">
				3997
				3998	<h5>Syntax:</h5>
				3999
				4000	<pre>
				4001	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				4002	</pre>
				4003
				4004	<h5>Overview:</h5>
				4005	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				4006	<tt>ty2</tt>.</p>
				4007
				4008
				4009	<h5>Arguments:</h5>
				4010	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4011	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4012	cast it to. The size of <tt>value</tt> must be larger than the size of
				4013	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4014	<i>no-op cast</i>.</p>
				4015
				4016	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4017	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4018	<a href="#t_floating">floating point</a> type to a smaller
				4019	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4020	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	4021
				4022	<h5>Example:</h5>
				4023	<pre>
				4024	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4025	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4026	</pre>
				4027	</div>
				4028
				4029	<!-- _______________________________________________________________________ -->
				4030	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4031	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4032	</div>
				4033	<div class="doc_text">
				4034
				4035	<h5>Syntax:</h5>
				4036	<pre>
				4037	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4038	</pre>
				4039
				4040	<h5>Overview:</h5>
				4041	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4042	floating point value.</p>
				4043
				4044	<h5>Arguments:</h5>
				4045	<p>The '<tt>fpext</tt>' instruction takes a
				4046	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4047	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4048	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4049
				4050	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4051	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4052	<a href="#t_floating">floating point</a> type to a larger
				4053	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4054	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4055	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4056
				4057	<h5>Example:</h5>
				4058	<pre>
				4059	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4060	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4061	</pre>
				4062	</div>
				4063
				4064	<!-- _______________________________________________________________________ -->
				4065	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	4066	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4067	</div>
				4068	<div class="doc_text">
				4069
				4070	<h5>Syntax:</h5>
				4071	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4072	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4073	</pre>
				4074
				4075	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4076	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4077	unsigned integer equivalent of type <tt>ty2</tt>.
				4078	</p>
				4079
				4080	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4081	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4082	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4083	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4084	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4085	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4086
				4087	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4088	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4089	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4090	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4091	the results are undefined.</p>
				4092
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4093	<h5>Example:</h5>
				4094	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4095	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4096	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	4097	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4098	</pre>
				4099	</div>
				4100
				4101	<!-- _______________________________________________________________________ -->
				4102	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4103	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4104	</div>
				4105	<div class="doc_text">
				4106
				4107	<h5>Syntax:</h5>
				4108	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4109	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4110	</pre>
				4111
				4112	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4113	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4114	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4115	</p>
				4116
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4117	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4118	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4119	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4120	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4121	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4122	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4123
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4124	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4125	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4126	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4127	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4128	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4129
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4130	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4131	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4132	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4133	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4134	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4135	</pre>
				4136	</div>
				4137
				4138	<!-- _______________________________________________________________________ -->
				4139	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4140	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4141	</div>
				4142	<div class="doc_text">
				4143
				4144	<h5>Syntax:</h5>
				4145	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4146	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4147	</pre>
				4148
				4149	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4150	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4151	integer and converts that value to the <tt>ty2</tt> type.</p>
				4152
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4153	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4154	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4155	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4156	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4157	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4158	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4159
				4160	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4161	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4162	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4163	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4164
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4165	<h5>Example:</h5>
				4166	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4167	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4168	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4169	</pre>
				4170	</div>
				4171
				4172	<!-- _______________________________________________________________________ -->
				4173	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4174	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4175	</div>
				4176	<div class="doc_text">
				4177
				4178	<h5>Syntax:</h5>
				4179	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4180	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4181	</pre>
				4182
				4183	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4184	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4185	integer and converts that value to the <tt>ty2</tt> type.</p>
				4186
				4187	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4188	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4189	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4190	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4191	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4192	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4193
				4194	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4195	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4196	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4197	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4198
				4199	<h5>Example:</h5>
				4200	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4201	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4202	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4203	</pre>
				4204	</div>
				4205
				4206	<!-- _______________________________________________________________________ -->
				4207	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4208	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4209	</div>
				4210	<div class="doc_text">
				4211
				4212	<h5>Syntax:</h5>
				4213	<pre>
				4214	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4215	</pre>
				4216
				4217	<h5>Overview:</h5>
				4218	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4219	the integer type <tt>ty2</tt>.</p>
				4220
				4221	<h5>Arguments:</h5>
				4222	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4223	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4224	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4225
				4226	<h5>Semantics:</h5>
				4227	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4228	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4229	truncating or zero extending that value to the size of the integer type. If
				4230	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4231	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4232	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4233	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4234
				4235	<h5>Example:</h5>
				4236	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4237	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4238	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4239	</pre>
				4240	</div>
				4241
				4242	<!-- _______________________________________________________________________ -->
				4243	<div class="doc_subsubsection">
				4244	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4245	</div>
				4246	<div class="doc_text">
				4247
				4248	<h5>Syntax:</h5>
				4249	<pre>
				4250	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4251	</pre>
				4252
				4253	<h5>Overview:</h5>
				4254	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4255	a pointer type, <tt>ty2</tt>.</p>
				4256
				4257	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4258	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4259	value to cast, and a type to cast it to, which must be a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4260	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4261
				4262	<h5>Semantics:</h5>
				4263	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4264	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4265	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4266	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4267	the size of a pointer then a zero extension is done. If they are the same size,
				4268	nothing is done (<i>no-op cast</i>).</p>
				4269
				4270	<h5>Example:</h5>
				4271	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4272	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4273	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4274	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4275	</pre>
				4276	</div>
				4277
				4278	<!-- _______________________________________________________________________ -->
				4279	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4280	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4281	</div>
				4282	<div class="doc_text">
				4283
				4284	<h5>Syntax:</h5>
				4285	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4286	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4287	</pre>
				4288
				4289	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4290
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4291	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4292	<tt>ty2</tt> without changing any bits.</p>
				4293
				4294	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4295
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4296	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	c05dca9	2008-09-08 16:45:59 +0000	[diff] [blame]	4297	a non-aggregate first class value, and a type to cast it to, which must also be
				4298	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4299	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4300	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4301	type is a pointer, the destination type must also be a pointer. This
				4302	instruction supports bitwise conversion of vectors to integers and to vectors
				4303	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4304
				4305	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4306	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4307	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4308	this conversion. The conversion is done as if the <tt>value</tt> had been
				4309	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4310	converted to other pointer types with this instruction. To convert pointers to
				4311	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4312	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4313
				4314	<h5>Example:</h5>
				4315	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4316	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4317	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4318	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4319	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4320	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4321
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4322	<!-- ======================================================================= -->
				4323	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4324	<div class="doc_text">
				4325	<p>The instructions in this category are the "miscellaneous"
				4326	instructions, which defy better classification.</p>
				4327	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4328
				4329	<!-- _______________________________________________________________________ -->
				4330	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4331	</div>
				4332	<div class="doc_text">
				4333	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4334	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4335	</pre>
				4336	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4337	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4338	a vector of boolean values based on comparison
				4339	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4340	<h5>Arguments:</h5>
				4341	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4342	the condition code indicating the kind of comparison to perform. It is not
				4343	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4344	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4345	<ol>
				4346	<li><tt>eq</tt>: equal</li>
				4347	<li><tt>ne</tt>: not equal </li>
				4348	<li><tt>ugt</tt>: unsigned greater than</li>
				4349	<li><tt>uge</tt>: unsigned greater or equal</li>
				4350	<li><tt>ult</tt>: unsigned less than</li>
				4351	<li><tt>ule</tt>: unsigned less or equal</li>
				4352	<li><tt>sgt</tt>: signed greater than</li>
				4353	<li><tt>sge</tt>: signed greater or equal</li>
				4354	<li><tt>slt</tt>: signed less than</li>
				4355	<li><tt>sle</tt>: signed less or equal</li>
				4356	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4357	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4358	<a href="#t_pointer">pointer</a>
				4359	or integer <a href="#t_vector">vector</a> typed.
				4360	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4361	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4362	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4363	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4364	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4365	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4366	<ol>
				4367	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4368	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4369	</li>
				4370	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4371	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4372	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4373	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4374	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4375	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4376	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4377	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4378	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4379	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4380	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4381	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4382	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4383	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4384	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4385	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4386	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4387	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4388	</ol>
				4389	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4390	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4391	<p>If the operands are integer vectors, then they are compared
				4392	element by element. The result is an <tt>i1</tt> vector with
				4393	the same number of elements as the values being compared.
				4394	Otherwise, the result is an <tt>i1</tt>.
				4395	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4396
				4397	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4398	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4399	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4400	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4401	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4402	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4403	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4404	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4405
				4406	<p>Note that the code generator does not yet support vector types with
				4407	the <tt>icmp</tt> instruction.</p>
				4408
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4409	</div>
				4410
				4411	<!-- _______________________________________________________________________ -->
				4412	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4413	</div>
				4414	<div class="doc_text">
				4415	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4416	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4417	</pre>
				4418	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4419	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4420	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4421	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4422	<p>
				4423	If the operands are floating point scalars, then the result
				4424	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4425	</p>
				4426	<p>If the operands are floating point vectors, then the result type
				4427	is a vector of boolean with the same number of elements as the
				4428	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4429	<h5>Arguments:</h5>
				4430	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4431	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4432	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4433	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4434	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4435	<li><tt>oeq</tt>: ordered and equal</li>
				4436	<li><tt>ogt</tt>: ordered and greater than </li>
				4437	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4438	<li><tt>olt</tt>: ordered and less than </li>
				4439	<li><tt>ole</tt>: ordered and less than or equal</li>
				4440	<li><tt>one</tt>: ordered and not equal</li>
				4441	<li><tt>ord</tt>: ordered (no nans)</li>
				4442	<li><tt>ueq</tt>: unordered or equal</li>
				4443	<li><tt>ugt</tt>: unordered or greater than </li>
				4444	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4445	<li><tt>ult</tt>: unordered or less than </li>
				4446	<li><tt>ule</tt>: unordered or less than or equal</li>
				4447	<li><tt>une</tt>: unordered or not equal</li>
				4448	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4449	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4450	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4451	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4452	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4453	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4454	either a <a href="#t_floating">floating point</a> type
				4455	or a <a href="#t_vector">vector</a> of floating point type.
				4456	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4457	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4458	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4459	according to the condition code given as <tt>cond</tt>.
				4460	If the operands are vectors, then the vectors are compared
				4461	element by element.
				4462	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4463	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4464	<ol>
				4465	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4466	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4467	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4468	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4469	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4470	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4471	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4472	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4473	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4474	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4475	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4476	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4477	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4478	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4479	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4480	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4481	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4482	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4483	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4484	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4485	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4486	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4487	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4488	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4489	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4490	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4491	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4492	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4493	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4494
				4495	<h5>Example:</h5>
				4496	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4497	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4498	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4499	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4500	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4501
				4502	<p>Note that the code generator does not yet support vector types with
				4503	the <tt>fcmp</tt> instruction.</p>
				4504
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4505	</div>
				4506
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4507	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4508	<div class="doc_subsubsection">
				4509	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4510	</div>
				4511	<div class="doc_text">
				4512	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4513	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4514	</pre>
				4515	<h5>Overview:</h5>
				4516	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4517	element-wise comparison of its two integer vector operands.</p>
				4518	<h5>Arguments:</h5>
				4519	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4520	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4521	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4522	<ol>
				4523	<li><tt>eq</tt>: equal</li>
				4524	<li><tt>ne</tt>: not equal </li>
				4525	<li><tt>ugt</tt>: unsigned greater than</li>
				4526	<li><tt>uge</tt>: unsigned greater or equal</li>
				4527	<li><tt>ult</tt>: unsigned less than</li>
				4528	<li><tt>ule</tt>: unsigned less or equal</li>
				4529	<li><tt>sgt</tt>: signed greater than</li>
				4530	<li><tt>sge</tt>: signed greater or equal</li>
				4531	<li><tt>slt</tt>: signed less than</li>
				4532	<li><tt>sle</tt>: signed less or equal</li>
				4533	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4534	<p>The remaining two arguments must be <a href="#t_vector">vector</a> or
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4535	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4536	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4537	<p>The '<tt>vicmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4538	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4539	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4540	identical type as the values being compared. The most significant bit in each
				4541	element is 1 if the element-wise comparison evaluates to true, and is 0
				4542	otherwise. All other bits of the result are undefined. The condition codes
				4543	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4544	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4545
				4546	<h5>Example:</h5>
				4547	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4548	<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>
				4549	<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	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4550	</pre>
				4551	</div>
				4552
				4553	<!-- _______________________________________________________________________ -->
				4554	<div class="doc_subsubsection">
				4555	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4556	</div>
				4557	<div class="doc_text">
				4558	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4559	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4560	<h5>Overview:</h5>
				4561	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4562	element-wise comparison of its two floating point vector operands. The output
				4563	elements have the same width as the input elements.</p>
				4564	<h5>Arguments:</h5>
				4565	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4566	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4567	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4568	<ol>
				4569	<li><tt>false</tt>: no comparison, always returns false</li>
				4570	<li><tt>oeq</tt>: ordered and equal</li>
				4571	<li><tt>ogt</tt>: ordered and greater than </li>
				4572	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4573	<li><tt>olt</tt>: ordered and less than </li>
				4574	<li><tt>ole</tt>: ordered and less than or equal</li>
				4575	<li><tt>one</tt>: ordered and not equal</li>
				4576	<li><tt>ord</tt>: ordered (no nans)</li>
				4577	<li><tt>ueq</tt>: unordered or equal</li>
				4578	<li><tt>ugt</tt>: unordered or greater than </li>
				4579	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4580	<li><tt>ult</tt>: unordered or less than </li>
				4581	<li><tt>ule</tt>: unordered or less than or equal</li>
				4582	<li><tt>une</tt>: unordered or not equal</li>
				4583	<li><tt>uno</tt>: unordered (either nans)</li>
				4584	<li><tt>true</tt>: no comparison, always returns true</li>
				4585	</ol>
				4586	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4587	<a href="#t_floating">floating point</a> typed. They must also be identical
				4588	types.</p>
				4589	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4590	<p>The '<tt>vfcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4591	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4592	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4593	an identical number of elements as the values being compared, and each element
				4594	having identical with to the width of the floating point elements. The most
				4595	significant bit in each element is 1 if the element-wise comparison evaluates to
				4596	true, and is 0 otherwise. All other bits of the result are undefined. The
				4597	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4598	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4599
				4600	<h5>Example:</h5>
				4601	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4602	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4603	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4604
				4605	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4606	<result> = vfcmp ult <2 x double> < double 1, double 2 >, < double 2, double 2>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4607	</pre>
				4608	</div>
				4609
				4610	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4611	<div class="doc_subsubsection">
				4612	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4613	</div>
				4614
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4615	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4616
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4617	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4618
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4619	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4620	<h5>Overview:</h5>
				4621	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4622	the SSA graph representing the function.</p>
				4623	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4624
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4625	<p>The type of the incoming values is specified with the first type
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4626	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4627	as arguments, with one pair for each predecessor basic block of the
				4628	current block. Only values of <a href="#t_firstclass">first class</a>
				4629	type may be used as the value arguments to the PHI node. Only labels
				4630	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4631
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4632	<p>There must be no non-phi instructions between the start of a basic
				4633	block and the PHI instructions: i.e. PHI instructions must be first in
				4634	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4635
Jay Foad	1a4eea5	2009-06-03 10:20:10 +0000	[diff] [blame]	4636	<p>For the purposes of the SSA form, the use of each incoming value is
				4637	deemed to occur on the edge from the corresponding predecessor block
				4638	to the current block (but after any definition of an '<tt>invoke</tt>'
				4639	instruction's return value on the same edge).</p>
				4640
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4641	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4642
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4643	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4644	specified by the pair corresponding to the predecessor basic block that executed
				4645	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4646
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4647	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4648	<pre>
				4649	Loop: ; Infinite loop that counts from 0 on up...
				4650	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4651	%nextindvar = add i32 %indvar, 1
				4652	br label %Loop
				4653	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4654	</div>
				4655
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4656	<!-- _______________________________________________________________________ -->
				4657	<div class="doc_subsubsection">
				4658	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4659	</div>
				4660
				4661	<div class="doc_text">
				4662
				4663	<h5>Syntax:</h5>
				4664
				4665	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4666	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4667
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4668	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4669	</pre>
				4670
				4671	<h5>Overview:</h5>
				4672
				4673	<p>
				4674	The '<tt>select</tt>' instruction is used to choose one value based on a
				4675	condition, without branching.
				4676	</p>
				4677
				4678
				4679	<h5>Arguments:</h5>
				4680
				4681	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4682	The '<tt>select</tt>' instruction requires an 'i1' value or
				4683	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4684	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4685	type. If the val1/val2 are vectors and
				4686	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4687	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4688	</p>
				4689
				4690	<h5>Semantics:</h5>
				4691
				4692	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4693	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4694	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4695	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4696	<p>
				4697	If the condition is a vector of i1, then the value arguments must
				4698	be vectors of the same size, and the selection is done element
				4699	by element.
				4700	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4701
				4702	<h5>Example:</h5>
				4703
				4704	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4705	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4706	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4707
				4708	<p>Note that the code generator does not yet support conditions
				4709	with vector type.</p>
				4710
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4711	</div>
				4712
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4713
				4714	<!-- _______________________________________________________________________ -->
				4715	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4716	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4717	</div>
				4718
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4719	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4720
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4721	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4722	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4723	<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	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4724	</pre>
				4725
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4726	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4727
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4728	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4729
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4730	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4731
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4732	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4733
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4734	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4735	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4736	<p>The optional "tail" marker indicates whether the callee function accesses
				4737	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4738	function call is eligible for tail call optimization. Note that calls may
				4739	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4740	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4741	</li>
				4742	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4743	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4744	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4745	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4746	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4747
				4748	<li>
				4749	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4750	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4751	and '<tt>inreg</tt>' attributes are valid here.</p>
				4752	</li>
				4753
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4754	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4755	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4756	the type of the return value. Functions that return no value are marked
				4757	<tt><a href="#t_void">void</a></tt>.</p>
				4758	</li>
				4759	<li>
				4760	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4761	value being invoked. The argument types must match the types implied by
				4762	this signature. This type can be omitted if the function is not varargs
				4763	and if the function type does not return a pointer to a function.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4764	</li>
				4765	<li>
				4766	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4767	be invoked. In most cases, this is a direct function invocation, but
				4768	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4769	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4770	</li>
				4771	<li>
				4772	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4773	function signature argument types. All arguments must be of
				4774	<a href="#t_firstclass">first class</a> type. If the function signature
				4775	indicates the function accepts a variable number of arguments, the extra
				4776	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4777	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4778	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4779	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4780	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4781	'<tt>readnone</tt>' attributes are valid here.</p>
				4782	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4783	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4784
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4785	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4786
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4787	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4788	transfer to a specified function, with its incoming arguments bound to
				4789	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4790	instruction in the called function, control flow continues with the
				4791	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4792	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4793
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4794	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4795
				4796	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4797	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4798	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4799	%X = tail call i32 @foo() <i>; yields i32</i>
				4800	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4801	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4802
				4803	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4804	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4805	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4806	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4807	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	eefa7df	2008-10-07 10:03:45 +0000	[diff] [blame]	4808	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4809	</pre>
				4810
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4811	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4812
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4813	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4814	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4815	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4816	</div>
				4817
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4818	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4819
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4820	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4821
				4822	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4823	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4824	</pre>
				4825
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4826	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4827
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4828	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4829	the "variable argument" area of a function call. It is used to implement the
				4830	<tt>va_arg</tt> macro in C.</p>
				4831
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4832	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4833
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4834	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4835	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4836	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4837	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4838
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4839	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4840
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4841	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4842	type from the specified <tt>va_list</tt> and causes the
				4843	<tt>va_list</tt> to point to the next argument. For more information,
				4844	see the variable argument handling <a href="#int_varargs">Intrinsic
				4845	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4846
				4847	<p>It is legal for this instruction to be called in a function which does not
				4848	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4849	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4850
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4851	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4852	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4853	argument.</p>
				4854
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4855	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4856
				4857	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4858
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4859	<p>Note that the code generator does not yet fully support va_arg
				4860	on many targets. Also, it does not currently support va_arg with
				4861	aggregate types on any target.</p>
				4862
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4863	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4864
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4865	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4866	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4867	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4868
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4869	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4870
				4871	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4872	well known names and semantics and are required to follow certain restrictions.
				4873	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4874	language that does not require changing all of the transformations in LLVM when
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	4875	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4876
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4877	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4878	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4879	begin with this prefix. Intrinsic functions must always be external functions:
				4880	you cannot define the body of intrinsic functions. Intrinsic functions may
				4881	only be used in call or invoke instructions: it is illegal to take the address
				4882	of an intrinsic function. Additionally, because intrinsic functions are part
				4883	of the LLVM language, it is required if any are added that they be documented
				4884	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4885
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4886	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4887	a family of functions that perform the same operation but on different data
				4888	types. Because LLVM can represent over 8 million different integer types,
				4889	overloading is used commonly to allow an intrinsic function to operate on any
				4890	integer type. One or more of the argument types or the result type can be
				4891	overloaded to accept any integer type. Argument types may also be defined as
				4892	exactly matching a previous argument's type or the result type. This allows an
				4893	intrinsic function which accepts multiple arguments, but needs all of them to
				4894	be of the same type, to only be overloaded with respect to a single argument or
				4895	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4896
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4897	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4898	encoded into its function name, each preceded by a period. Only those types
				4899	which are overloaded result in a name suffix. Arguments whose type is matched
				4900	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4901	take an integer of any width and returns an integer of exactly the same integer
				4902	width. This leads to a family of functions such as
				4903	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4904	Only one type, the return type, is overloaded, and only one type suffix is
				4905	required. Because the argument's type is matched against the return type, it
				4906	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4907
				4908	<p>To learn how to add an intrinsic function, please see the
				4909	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4910	</p>
				4911
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4912	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4913
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4914	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4915	<div class="doc_subsection">
				4916	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4917	</div>
				4918
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4919	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4920
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4921	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4922	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4923	intrinsic functions. These functions are related to the similarly
				4924	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4925
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4926	<p>All of these functions operate on arguments that use a
				4927	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4928	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4929	transformations should be prepared to handle these functions regardless of
				4930	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4931
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4932	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4933	instruction and the variable argument handling intrinsic functions are
				4934	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4935
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4936	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4937	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4938	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4939	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4940	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4941	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4942	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4943
				4944	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4945	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4946
				4947	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4948	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4949	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4950	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4951	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4952
				4953	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4954	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4955	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4956	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4957
				4958	declare void @llvm.va_start(i8*)
				4959	declare void @llvm.va_copy(i8, i8)
				4960	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4961	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4962	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4963
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4964	</div>
				4965
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4966	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4967	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4968	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4969	</div>
				4970
				4971
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4972	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4973	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4974	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4975	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4976	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4977	<tt>*<arglist></tt> for subsequent use by <tt><a
				4978	href="#i_va_arg">va_arg</a></tt>.</p>
				4979
				4980	<h5>Arguments:</h5>
				4981
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4982	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4983
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4984	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4985
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4986	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4987	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4988	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4989	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4990	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4991	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4992
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4993	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4994
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4995	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4996	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4997	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4998	</div>
				4999
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5000	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5001	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5002	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5003	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5004
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5005	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5006	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	5007	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5008
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5009	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5010
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5011	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5012
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5013	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5014
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5015	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5016	macro available in C. In a target-dependent way, it destroys the
				5017	<tt>va_list</tt> element to which the argument points. Calls to <a
				5018	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				5019	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				5020	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	5021
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5022	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5023
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5024	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5025	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5026	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5027	</div>
				5028
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5029	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5030
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5031	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5032
				5033	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5034	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5035	</pre>
				5036
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5037	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5038
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5039	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				5040	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5041
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5042	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5043
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	5044	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	5305ea5	2005-06-22 20:38:11 +0000	[diff] [blame]	5045	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	5046
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5047
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	5048	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5049
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	5050	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				5051	macro available in C. In a target-dependent way, it copies the source
				5052	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				5053	intrinsic is necessary because the <tt><a href="#int_va_start">
				5054	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				5055	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5056
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	5057	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5058
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5059	<!-- ======================================================================= -->
				5060	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5061	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				5062	</div>
				5063
				5064	<div class="doc_text">
				5065
				5066	<p>
				5067	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5068	Collection</a> (GC) requires the implementation and generation of these
				5069	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5070	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5071	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5072	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5073	Front-ends for type-safe garbage collected languages should generate these
				5074	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				5075	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				5076	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	5077
				5078	<p>The garbage collection intrinsics only operate on objects in the generic
				5079	address space (address space zero).</p>
				5080
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5081	</div>
				5082
				5083	<!-- _______________________________________________________________________ -->
				5084	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5085	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5086	</div>
				5087
				5088	<div class="doc_text">
				5089
				5090	<h5>Syntax:</h5>
				5091
				5092	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5093	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5094	</pre>
				5095
				5096	<h5>Overview:</h5>
				5097
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	5098	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5099	the code generator, and allows some metadata to be associated with it.</p>
				5100
				5101	<h5>Arguments:</h5>
				5102
				5103	<p>The first argument specifies the address of a stack object that contains the
				5104	root pointer. The second pointer (which must be either a constant or a global
				5105	value address) contains the meta-data to be associated with the root.</p>
				5106
				5107	<h5>Semantics:</h5>
				5108
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	5109	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5110	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5111	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5112	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5113	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5114
				5115	</div>
				5116
				5117
				5118	<!-- _______________________________________________________________________ -->
				5119	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5120	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5121	</div>
				5122
				5123	<div class="doc_text">
				5124
				5125	<h5>Syntax:</h5>
				5126
				5127	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5128	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5129	</pre>
				5130
				5131	<h5>Overview:</h5>
				5132
				5133	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5134	locations, allowing garbage collector implementations that require read
				5135	barriers.</p>
				5136
				5137	<h5>Arguments:</h5>
				5138
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5139	<p>The second argument is the address to read from, which should be an address
				5140	allocated from the garbage collector. The first object is a pointer to the
				5141	start of the referenced object, if needed by the language runtime (otherwise
				5142	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5143
				5144	<h5>Semantics:</h5>
				5145
				5146	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5147	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5148	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5149	may only be used in a function which <a href="#gc">specifies a GC
				5150	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5151
				5152	</div>
				5153
				5154
				5155	<!-- _______________________________________________________________________ -->
				5156	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5157	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5158	</div>
				5159
				5160	<div class="doc_text">
				5161
				5162	<h5>Syntax:</h5>
				5163
				5164	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5165	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5166	</pre>
				5167
				5168	<h5>Overview:</h5>
				5169
				5170	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5171	locations, allowing garbage collector implementations that require write
				5172	barriers (such as generational or reference counting collectors).</p>
				5173
				5174	<h5>Arguments:</h5>
				5175
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5176	<p>The first argument is the reference to store, the second is the start of the
				5177	object to store it to, and the third is the address of the field of Obj to
				5178	store to. If the runtime does not require a pointer to the object, Obj may be
				5179	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5180
				5181	<h5>Semantics:</h5>
				5182
				5183	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5184	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5185	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5186	may only be used in a function which <a href="#gc">specifies a GC
				5187	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5188
				5189	</div>
				5190
				5191
				5192
				5193	<!-- ======================================================================= -->
				5194	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5195	<a name="int_codegen">Code Generator Intrinsics</a>
				5196	</div>
				5197
				5198	<div class="doc_text">
				5199	<p>
				5200	These intrinsics are provided by LLVM to expose special features that may only
				5201	be implemented with code generator support.
				5202	</p>
				5203
				5204	</div>
				5205
				5206	<!-- _______________________________________________________________________ -->
				5207	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5208	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5209	</div>
				5210
				5211	<div class="doc_text">
				5212
				5213	<h5>Syntax:</h5>
				5214	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5215	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5216	</pre>
				5217
				5218	<h5>Overview:</h5>
				5219
				5220	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5221	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5222	target-specific value indicating the return address of the current function
				5223	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5224	</p>
				5225
				5226	<h5>Arguments:</h5>
				5227
				5228	<p>
				5229	The argument to this intrinsic indicates which function to return the address
				5230	for. Zero indicates the calling function, one indicates its caller, etc. The
				5231	argument is <b>required</b> to be a constant integer value.
				5232	</p>
				5233
				5234	<h5>Semantics:</h5>
				5235
				5236	<p>
				5237	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5238	the return address of the specified call frame, or zero if it cannot be
				5239	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5240	for arguments other than zero, so it should only be used for debugging purposes.
				5241	</p>
				5242
				5243	<p>
				5244	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5245	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5246	source-language caller.
				5247	</p>
				5248	</div>
				5249
				5250
				5251	<!-- _______________________________________________________________________ -->
				5252	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5253	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5254	</div>
				5255
				5256	<div class="doc_text">
				5257
				5258	<h5>Syntax:</h5>
				5259	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5260	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5261	</pre>
				5262
				5263	<h5>Overview:</h5>
				5264
				5265	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5266	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5267	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5268	</p>
				5269
				5270	<h5>Arguments:</h5>
				5271
				5272	<p>
				5273	The argument to this intrinsic indicates which function to return the frame
				5274	pointer for. Zero indicates the calling function, one indicates its caller,
				5275	etc. The argument is <b>required</b> to be a constant integer value.
				5276	</p>
				5277
				5278	<h5>Semantics:</h5>
				5279
				5280	<p>
				5281	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5282	the frame address of the specified call frame, or zero if it cannot be
				5283	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5284	for arguments other than zero, so it should only be used for debugging purposes.
				5285	</p>
				5286
				5287	<p>
				5288	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5289	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5290	source-language caller.
				5291	</p>
				5292	</div>
				5293
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5294	<!-- _______________________________________________________________________ -->
				5295	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5296	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5297	</div>
				5298
				5299	<div class="doc_text">
				5300
				5301	<h5>Syntax:</h5>
				5302	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5303	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5304	</pre>
				5305
				5306	<h5>Overview:</h5>
				5307
				5308	<p>
				5309	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5310	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5311	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5312	features like scoped automatic variable sized arrays in C99.
				5313	</p>
				5314
				5315	<h5>Semantics:</h5>
				5316
				5317	<p>
				5318	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5319	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5320	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5321	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5322	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5323	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5324	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5325	</p>
				5326
				5327	</div>
				5328
				5329	<!-- _______________________________________________________________________ -->
				5330	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5331	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5332	</div>
				5333
				5334	<div class="doc_text">
				5335
				5336	<h5>Syntax:</h5>
				5337	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5338	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5339	</pre>
				5340
				5341	<h5>Overview:</h5>
				5342
				5343	<p>
				5344	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5345	the function stack to the state it was in when the corresponding <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5346	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5347	useful for implementing language features like scoped automatic variable sized
				5348	arrays in C99.
				5349	</p>
				5350
				5351	<h5>Semantics:</h5>
				5352
				5353	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5354	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5355	</p>
				5356
				5357	</div>
				5358
				5359
				5360	<!-- _______________________________________________________________________ -->
				5361	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5362	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5363	</div>
				5364
				5365	<div class="doc_text">
				5366
				5367	<h5>Syntax:</h5>
				5368	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5369	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5370	</pre>
				5371
				5372	<h5>Overview:</h5>
				5373
				5374
				5375	<p>
				5376	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5377	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5378	no
				5379	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5380	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5381	</p>
				5382
				5383	<h5>Arguments:</h5>
				5384
				5385	<p>
				5386	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5387	determining if the fetch should be for a read (0) or write (1), and
				5388	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5389	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5390	<tt>locality</tt> arguments must be constant integers.
				5391	</p>
				5392
				5393	<h5>Semantics:</h5>
				5394
				5395	<p>
				5396	This intrinsic does not modify the behavior of the program. In particular,
				5397	prefetches cannot trap and do not produce a value. On targets that support this
				5398	intrinsic, the prefetch can provide hints to the processor cache for better
				5399	performance.
				5400	</p>
				5401
				5402	</div>
				5403
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5404	<!-- _______________________________________________________________________ -->
				5405	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5406	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5407	</div>
				5408
				5409	<div class="doc_text">
				5410
				5411	<h5>Syntax:</h5>
				5412	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5413	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5414	</pre>
				5415
				5416	<h5>Overview:</h5>
				5417
				5418
				5419	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5420	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	5421	(PC) in a region of
				5422	code to simulators and other tools. The method is target specific, but it is
				5423	expected that the marker will use exported symbols to transmit the PC of the
				5424	marker.
				5425	The marker makes no guarantees that it will remain with any specific instruction
				5426	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b40261e	2006-03-24 07:16:10 +0000	[diff] [blame]	5427	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5428	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5429	</p>
				5430
				5431	<h5>Arguments:</h5>
				5432
				5433	<p>
				5434	<tt>id</tt> is a numerical id identifying the marker.
				5435	</p>
				5436
				5437	<h5>Semantics:</h5>
				5438
				5439	<p>
				5440	This intrinsic does not modify the behavior of the program. Backends that do not
				5441	support this intrinisic may ignore it.
				5442	</p>
				5443
				5444	</div>
				5445
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5446	<!-- _______________________________________________________________________ -->
				5447	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5448	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5449	</div>
				5450
				5451	<div class="doc_text">
				5452
				5453	<h5>Syntax:</h5>
				5454	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5455	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5456	</pre>
				5457
				5458	<h5>Overview:</h5>
				5459
				5460
				5461	<p>
				5462	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5463	counter register (or similar low latency, high accuracy clocks) on those targets
				5464	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5465	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5466	should only be used for small timings.
				5467	</p>
				5468
				5469	<h5>Semantics:</h5>
				5470
				5471	<p>
				5472	When directly supported, reading the cycle counter should not modify any memory.
				5473	Implementations are allowed to either return a application specific value or a
				5474	system wide value. On backends without support, this is lowered to a constant 0.
				5475	</p>
				5476
				5477	</div>
				5478
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5479	<!-- ======================================================================= -->
				5480	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5481	<a name="int_libc">Standard C Library Intrinsics</a>
				5482	</div>
				5483
				5484	<div class="doc_text">
				5485	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5486	LLVM provides intrinsics for a few important standard C library functions.
				5487	These intrinsics allow source-language front-ends to pass information about the
				5488	alignment of the pointer arguments to the code generator, providing opportunity
				5489	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5490	</p>
				5491
				5492	</div>
				5493
				5494	<!-- _______________________________________________________________________ -->
				5495	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5496	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5497	</div>
				5498
				5499	<div class="doc_text">
				5500
				5501	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5502	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5503	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5504	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5505	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5506	i8 <len>, i32 <align>)
				5507	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5508	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5509	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5510	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5511	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5512	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5513	</pre>
				5514
				5515	<h5>Overview:</h5>
				5516
				5517	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5518	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5519	location to the destination location.
				5520	</p>
				5521
				5522	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5523	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5524	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5525	</p>
				5526
				5527	<h5>Arguments:</h5>
				5528
				5529	<p>
				5530	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5531	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5532	specifying the number of bytes to copy, and the fourth argument is the alignment
				5533	of the source and destination locations.
				5534	</p>
				5535
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5536	<p>
				5537	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5538	the caller guarantees that both the source and destination pointers are aligned
				5539	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5540	</p>
				5541
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5542	<h5>Semantics:</h5>
				5543
				5544	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5545	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5546	location to the destination location, which are not allowed to overlap. It
				5547	copies "len" bytes of memory over. If the argument is known to be aligned to
				5548	some boundary, this can be specified as the fourth argument, otherwise it should
				5549	be set to 0 or 1.
				5550	</p>
				5551	</div>
				5552
				5553
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5554	<!-- _______________________________________________________________________ -->
				5555	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5556	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5557	</div>
				5558
				5559	<div class="doc_text">
				5560
				5561	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5562	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5563	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5564	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5565	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5566	i8 <len>, i32 <align>)
				5567	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5568	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5569	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5570	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5571	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5572	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5573	</pre>
				5574
				5575	<h5>Overview:</h5>
				5576
				5577	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5578	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5579	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5580	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5581	</p>
				5582
				5583	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5584	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5585	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5586	</p>
				5587
				5588	<h5>Arguments:</h5>
				5589
				5590	<p>
				5591	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5592	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5593	specifying the number of bytes to copy, and the fourth argument is the alignment
				5594	of the source and destination locations.
				5595	</p>
				5596
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5597	<p>
				5598	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5599	the caller guarantees that the source and destination pointers are aligned to
				5600	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5601	</p>
				5602
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5603	<h5>Semantics:</h5>
				5604
				5605	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5606	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5607	location to the destination location, which may overlap. It
				5608	copies "len" bytes of memory over. If the argument is known to be aligned to
				5609	some boundary, this can be specified as the fourth argument, otherwise it should
				5610	be set to 0 or 1.
				5611	</p>
				5612	</div>
				5613
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5614
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5615	<!-- _______________________________________________________________________ -->
				5616	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5617	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5618	</div>
				5619
				5620	<div class="doc_text">
				5621
				5622	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5623	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5624	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5625	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5626	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5627	i8 <len>, i32 <align>)
				5628	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5629	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5630	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5631	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5632	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5633	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5634	</pre>
				5635
				5636	<h5>Overview:</h5>
				5637
				5638	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5639	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5640	byte value.
				5641	</p>
				5642
				5643	<p>
				5644	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5645	does not return a value, and takes an extra alignment argument.
				5646	</p>
				5647
				5648	<h5>Arguments:</h5>
				5649
				5650	<p>
				5651	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5652	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5653	argument specifying the number of bytes to fill, and the fourth argument is the
				5654	known alignment of destination location.
				5655	</p>
				5656
				5657	<p>
				5658	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	5316e5d	2006-03-04 00:02:10 +0000	[diff] [blame]	5659	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5660	</p>
				5661
				5662	<h5>Semantics:</h5>
				5663
				5664	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5665	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5666	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5667	destination location. If the argument is known to be aligned to some boundary,
				5668	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5669	1.
				5670	</p>
				5671	</div>
				5672
				5673
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5674	<!-- _______________________________________________________________________ -->
				5675	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5676	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5677	</div>
				5678
				5679	<div class="doc_text">
				5680
				5681	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5682	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5683	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5684	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5685	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5686	declare float @llvm.sqrt.f32(float %Val)
				5687	declare double @llvm.sqrt.f64(double %Val)
				5688	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5689	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5690	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5691	</pre>
				5692
				5693	<h5>Overview:</h5>
				5694
				5695	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5696	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5697	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5698	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	00d7cb9	2008-01-29 07:00:44 +0000	[diff] [blame]	5699	negative numbers other than -0.0 (which allows for better optimization, because
				5700	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5701	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5702	</p>
				5703
				5704	<h5>Arguments:</h5>
				5705
				5706	<p>
				5707	The argument and return value are floating point numbers of the same type.
				5708	</p>
				5709
				5710	<h5>Semantics:</h5>
				5711
				5712	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5713	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5714	floating point number.
				5715	</p>
				5716	</div>
				5717
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5718	<!-- _______________________________________________________________________ -->
				5719	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5720	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5721	</div>
				5722
				5723	<div class="doc_text">
				5724
				5725	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5726	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5727	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5728	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5729	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5730	declare float @llvm.powi.f32(float %Val, i32 %power)
				5731	declare double @llvm.powi.f64(double %Val, i32 %power)
				5732	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5733	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5734	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5735	</pre>
				5736
				5737	<h5>Overview:</h5>
				5738
				5739	<p>
				5740	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5741	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5742	multiplications is not defined. When a vector of floating point type is
				5743	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5744	</p>
				5745
				5746	<h5>Arguments:</h5>
				5747
				5748	<p>
				5749	The second argument is an integer power, and the first is a value to raise to
				5750	that power.
				5751	</p>
				5752
				5753	<h5>Semantics:</h5>
				5754
				5755	<p>
				5756	This function returns the first value raised to the second power with an
				5757	unspecified sequence of rounding operations.</p>
				5758	</div>
				5759
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5760	<!-- _______________________________________________________________________ -->
				5761	<div class="doc_subsubsection">
				5762	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5763	</div>
				5764
				5765	<div class="doc_text">
				5766
				5767	<h5>Syntax:</h5>
				5768	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5769	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5770	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5771	<pre>
				5772	declare float @llvm.sin.f32(float %Val)
				5773	declare double @llvm.sin.f64(double %Val)
				5774	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5775	declare fp128 @llvm.sin.f128(fp128 %Val)
				5776	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5777	</pre>
				5778
				5779	<h5>Overview:</h5>
				5780
				5781	<p>
				5782	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5783	</p>
				5784
				5785	<h5>Arguments:</h5>
				5786
				5787	<p>
				5788	The argument and return value are floating point numbers of the same type.
				5789	</p>
				5790
				5791	<h5>Semantics:</h5>
				5792
				5793	<p>
				5794	This function returns the sine of the specified operand, returning the
				5795	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5796	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5797	</div>
				5798
				5799	<!-- _______________________________________________________________________ -->
				5800	<div class="doc_subsubsection">
				5801	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5802	</div>
				5803
				5804	<div class="doc_text">
				5805
				5806	<h5>Syntax:</h5>
				5807	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5808	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5809	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5810	<pre>
				5811	declare float @llvm.cos.f32(float %Val)
				5812	declare double @llvm.cos.f64(double %Val)
				5813	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5814	declare fp128 @llvm.cos.f128(fp128 %Val)
				5815	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5816	</pre>
				5817
				5818	<h5>Overview:</h5>
				5819
				5820	<p>
				5821	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5822	</p>
				5823
				5824	<h5>Arguments:</h5>
				5825
				5826	<p>
				5827	The argument and return value are floating point numbers of the same type.
				5828	</p>
				5829
				5830	<h5>Semantics:</h5>
				5831
				5832	<p>
				5833	This function returns the cosine of the specified operand, returning the
				5834	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5835	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5836	</div>
				5837
				5838	<!-- _______________________________________________________________________ -->
				5839	<div class="doc_subsubsection">
				5840	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5841	</div>
				5842
				5843	<div class="doc_text">
				5844
				5845	<h5>Syntax:</h5>
				5846	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5847	floating point or vector of floating point type. Not all targets support all
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5848	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5849	<pre>
				5850	declare float @llvm.pow.f32(float %Val, float %Power)
				5851	declare double @llvm.pow.f64(double %Val, double %Power)
				5852	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5853	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5854	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5855	</pre>
				5856
				5857	<h5>Overview:</h5>
				5858
				5859	<p>
				5860	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5861	specified (positive or negative) power.
				5862	</p>
				5863
				5864	<h5>Arguments:</h5>
				5865
				5866	<p>
				5867	The second argument is a floating point power, and the first is a value to
				5868	raise to that power.
				5869	</p>
				5870
				5871	<h5>Semantics:</h5>
				5872
				5873	<p>
				5874	This function returns the first value raised to the second power,
				5875	returning the
				5876	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	d0806a0	2007-10-17 18:05:13 +0000	[diff] [blame]	5877	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5878	</div>
				5879
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5880
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5881	<!-- ======================================================================= -->
				5882	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5883	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5884	</div>
				5885
				5886	<div class="doc_text">
				5887	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5888	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5889	These allow efficient code generation for some algorithms.
				5890	</p>
				5891
				5892	</div>
				5893
				5894	<!-- _______________________________________________________________________ -->
				5895	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5896	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5897	</div>
				5898
				5899	<div class="doc_text">
				5900
				5901	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5902	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5903	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5904	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5905	declare i16 @llvm.bswap.i16(i16 <id>)
				5906	declare i32 @llvm.bswap.i32(i32 <id>)
				5907	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5908	</pre>
				5909
				5910	<h5>Overview:</h5>
				5911
				5912	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5913	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5914	values with an even number of bytes (positive multiple of 16 bits). These are
				5915	useful for performing operations on data that is not in the target's native
				5916	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5917	</p>
				5918
				5919	<h5>Semantics:</h5>
				5920
				5921	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5922	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5923	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5924	intrinsic returns an i32 value that has the four bytes of the input i32
				5925	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5926	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5927	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5928	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5929	</p>
				5930
				5931	</div>
				5932
				5933	<!-- _______________________________________________________________________ -->
				5934	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5935	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5936	</div>
				5937
				5938	<div class="doc_text">
				5939
				5940	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5941	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5942	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5943	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5944	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5945	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5946	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5947	declare i64 @llvm.ctpop.i64(i64 <src>)
				5948	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5949	</pre>
				5950
				5951	<h5>Overview:</h5>
				5952
				5953	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5954	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5955	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5956	</p>
				5957
				5958	<h5>Arguments:</h5>
				5959
				5960	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5961	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	5962	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5963	</p>
				5964
				5965	<h5>Semantics:</h5>
				5966
				5967	<p>
				5968	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5969	</p>
				5970	</div>
				5971
				5972	<!-- _______________________________________________________________________ -->
				5973	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5974	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5975	</div>
				5976
				5977	<div class="doc_text">
				5978
				5979	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5980	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	5981	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5982	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5983	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5984	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5985	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5986	declare i64 @llvm.ctlz.i64(i64 <src>)
				5987	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5988	</pre>
				5989
				5990	<h5>Overview:</h5>
				5991
				5992	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5993	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5994	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5995	</p>
				5996
				5997	<h5>Arguments:</h5>
				5998
				5999	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	6000	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	6001	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	6002	</p>
				6003
				6004	<h5>Semantics:</h5>
				6005
				6006	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6007	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				6008	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	6009	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	6010	</p>
				6011	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	6012
				6013
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6014
				6015	<!-- _______________________________________________________________________ -->
				6016	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	6017	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6018	</div>
				6019
				6020	<div class="doc_text">
				6021
				6022	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	6023	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6024	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6025	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6026	declare i8 @llvm.cttz.i8 (i8 <src>)
				6027	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	6028	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6029	declare i64 @llvm.cttz.i64(i64 <src>)
				6030	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6031	</pre>
				6032
				6033	<h5>Overview:</h5>
				6034
				6035	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	6036	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				6037	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6038	</p>
				6039
				6040	<h5>Arguments:</h5>
				6041
				6042	<p>
				6043	The only argument is the value to be counted. The argument may be of any
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	6044	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	6045	</p>
				6046
				6047	<h5>Semantics:</h5>
				6048
				6049	<p>
				6050	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				6051	in a variable. If the src == 0 then the result is the size in bits of the type
				6052	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				6053	</p>
				6054	</div>
				6055
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	6056	<!-- _______________________________________________________________________ -->
				6057	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6058	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6059	</div>
				6060
				6061	<div class="doc_text">
				6062
				6063	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6064	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.select</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6065	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6066	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6067	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				6068	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6069	</pre>
				6070
				6071	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6072	<p>The '<tt>llvm.part.select</tt>' family of intrinsic functions selects a
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6073	range of bits from an integer value and returns them in the same bit width as
				6074	the original value.</p>
				6075
				6076	<h5>Arguments:</h5>
				6077	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				6078	any bit width but they must have the same bit width. The second and third
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	6079	arguments must be <tt>i32</tt> type since they specify only a bit index.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6080
				6081	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	6082	<p>The operation of the '<tt>llvm.part.select</tt>' intrinsic has two modes
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	6083	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				6084	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				6085	operates in forward mode.</p>
				6086	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				6087	right by <tt>%loBit</tt> bits and then ANDing it with a mask with
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6088	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				6089	<ol>
				6090	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				6091	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				6092	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				6093	to determine the number of bits to retain.</li>
				6094	<li>A mask of the retained bits is created by shifting a -1 value.</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6095	<li>The mask is ANDed with <tt>%val</tt> to produce the result.</li>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6096	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	6097	<p>In reverse mode, a similar computation is made except that the bits are
				6098	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				6099	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				6100	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				6101	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	6102	</div>
				6103
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6104	<div class="doc_subsubsection">
				6105	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				6106	</div>
				6107
				6108	<div class="doc_text">
				6109
				6110	<h5>Syntax:</h5>
				6111	<p>This is an overloaded intrinsic. You can use <tt>llvm.part.set</tt>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6112	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6113	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	6114	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				6115	declare i29 @llvm.part.set.i29.i9 (i29 %val, i9 %repl, i32 %lo, i32 %hi)
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6116	</pre>
				6117
				6118	<h5>Overview:</h5>
				6119	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6120	of bits in an integer value with another integer value. It returns the integer
				6121	with the replaced bits.</p>
				6122
				6123	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6124	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6125	any bit width, but they must have the same bit width. <tt>%val</tt> is the value
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6126	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6127	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6128	type since they specify only a bit index.</p>
				6129
				6130	<h5>Semantics:</h5>
				6131	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6132	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6133	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6134	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6135
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6136	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6137	truncating it down to the size of the replacement area or zero extending it
				6138	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6139
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6140	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6141	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6142	in <tt>%repl</tt> replaces the <tt>%lo</tt>th bit in <tt>%val</tt> and etc. up
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6143	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6144
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6145	<p>In reverse mode, a similar computation is made except that the bits are
				6146	reversed. That is, the <tt>0</tt>th bit in <tt>%repl</tt> replaces the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6147	<tt>%hi</tt> bit in <tt>%val</tt> and etc. down to the <tt>%lo</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6148
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6149	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6150
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6151	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6152	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6153	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6154	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6155	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6156	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	6157	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6158
				6159	</div>
				6160
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6161	<!-- ======================================================================= -->
				6162	<div class="doc_subsection">
				6163	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6164	</div>
				6165
				6166	<div class="doc_text">
				6167	<p>
				6168	LLVM provides intrinsics for some arithmetic with overflow operations.
				6169	</p>
				6170
				6171	</div>
				6172
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6173	<!-- _______________________________________________________________________ -->
				6174	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6175	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6176	</div>
				6177
				6178	<div class="doc_text">
				6179
				6180	<h5>Syntax:</h5>
				6181
				6182	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6183	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6184
				6185	<pre>
				6186	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6187	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6188	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6189	</pre>
				6190
				6191	<h5>Overview:</h5>
				6192
				6193	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6194	a signed addition of the two arguments, and indicate whether an overflow
				6195	occurred during the signed summation.</p>
				6196
				6197	<h5>Arguments:</h5>
				6198
				6199	<p>The arguments (%a and %b) and the first element of the result structure may
				6200	be of integer types of any bit width, but they must have the same bit width. The
				6201	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6202	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6203
				6204	<h5>Semantics:</h5>
				6205
				6206	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6207	a signed addition of the two variables. They return a structure — the
				6208	first element of which is the signed summation, and the second element of which
				6209	is a bit specifying if the signed summation resulted in an overflow.</p>
				6210
				6211	<h5>Examples:</h5>
				6212	<pre>
				6213	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6214	%sum = extractvalue {i32, i1} %res, 0
				6215	%obit = extractvalue {i32, i1} %res, 1
				6216	br i1 %obit, label %overflow, label %normal
				6217	</pre>
				6218
				6219	</div>
				6220
				6221	<!-- _______________________________________________________________________ -->
				6222	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6223	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6224	</div>
				6225
				6226	<div class="doc_text">
				6227
				6228	<h5>Syntax:</h5>
				6229
				6230	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6231	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6232
				6233	<pre>
				6234	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6235	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6236	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6237	</pre>
				6238
				6239	<h5>Overview:</h5>
				6240
				6241	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6242	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6243	during the unsigned summation.</p>
				6244
				6245	<h5>Arguments:</h5>
				6246
				6247	<p>The arguments (%a and %b) and the first element of the result structure may
				6248	be of integer types of any bit width, but they must have the same bit width. The
				6249	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6250	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6251
				6252	<h5>Semantics:</h5>
				6253
				6254	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6255	an unsigned addition of the two arguments. They return a structure — the
				6256	first element of which is the sum, and the second element of which is a bit
				6257	specifying if the unsigned summation resulted in a carry.</p>
				6258
				6259	<h5>Examples:</h5>
				6260	<pre>
				6261	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6262	%sum = extractvalue {i32, i1} %res, 0
				6263	%obit = extractvalue {i32, i1} %res, 1
				6264	br i1 %obit, label %carry, label %normal
				6265	</pre>
				6266
				6267	</div>
				6268
				6269	<!-- _______________________________________________________________________ -->
				6270	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6271	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6272	</div>
				6273
				6274	<div class="doc_text">
				6275
				6276	<h5>Syntax:</h5>
				6277
				6278	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6279	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6280
				6281	<pre>
				6282	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6283	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6284	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6285	</pre>
				6286
				6287	<h5>Overview:</h5>
				6288
				6289	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6290	a signed subtraction of the two arguments, and indicate whether an overflow
				6291	occurred during the signed subtraction.</p>
				6292
				6293	<h5>Arguments:</h5>
				6294
				6295	<p>The arguments (%a and %b) and the first element of the result structure may
				6296	be of integer types of any bit width, but they must have the same bit width. The
				6297	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6298	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6299
				6300	<h5>Semantics:</h5>
				6301
				6302	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6303	a signed subtraction of the two arguments. They return a structure — the
				6304	first element of which is the subtraction, and the second element of which is a bit
				6305	specifying if the signed subtraction resulted in an overflow.</p>
				6306
				6307	<h5>Examples:</h5>
				6308	<pre>
				6309	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6310	%sum = extractvalue {i32, i1} %res, 0
				6311	%obit = extractvalue {i32, i1} %res, 1
				6312	br i1 %obit, label %overflow, label %normal
				6313	</pre>
				6314
				6315	</div>
				6316
				6317	<!-- _______________________________________________________________________ -->
				6318	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6319	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6320	</div>
				6321
				6322	<div class="doc_text">
				6323
				6324	<h5>Syntax:</h5>
				6325
				6326	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6327	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6328
				6329	<pre>
				6330	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6331	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6332	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6333	</pre>
				6334
				6335	<h5>Overview:</h5>
				6336
				6337	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6338	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6339	occurred during the unsigned subtraction.</p>
				6340
				6341	<h5>Arguments:</h5>
				6342
				6343	<p>The arguments (%a and %b) and the first element of the result structure may
				6344	be of integer types of any bit width, but they must have the same bit width. The
				6345	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6346	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6347
				6348	<h5>Semantics:</h5>
				6349
				6350	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6351	an unsigned subtraction of the two arguments. They return a structure — the
				6352	first element of which is the subtraction, and the second element of which is a bit
				6353	specifying if the unsigned subtraction resulted in an overflow.</p>
				6354
				6355	<h5>Examples:</h5>
				6356	<pre>
				6357	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6358	%sum = extractvalue {i32, i1} %res, 0
				6359	%obit = extractvalue {i32, i1} %res, 1
				6360	br i1 %obit, label %overflow, label %normal
				6361	</pre>
				6362
				6363	</div>
				6364
				6365	<!-- _______________________________________________________________________ -->
				6366	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6367	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6368	</div>
				6369
				6370	<div class="doc_text">
				6371
				6372	<h5>Syntax:</h5>
				6373
				6374	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6375	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6376
				6377	<pre>
				6378	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6379	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6380	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6381	</pre>
				6382
				6383	<h5>Overview:</h5>
				6384
				6385	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6386	a signed multiplication of the two arguments, and indicate whether an overflow
				6387	occurred during the signed multiplication.</p>
				6388
				6389	<h5>Arguments:</h5>
				6390
				6391	<p>The arguments (%a and %b) and the first element of the result structure may
				6392	be of integer types of any bit width, but they must have the same bit width. The
				6393	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6394	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6395
				6396	<h5>Semantics:</h5>
				6397
				6398	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6399	a signed multiplication of the two arguments. They return a structure —
				6400	the first element of which is the multiplication, and the second element of
				6401	which is a bit specifying if the signed multiplication resulted in an
				6402	overflow.</p>
				6403
				6404	<h5>Examples:</h5>
				6405	<pre>
				6406	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6407	%sum = extractvalue {i32, i1} %res, 0
				6408	%obit = extractvalue {i32, i1} %res, 1
				6409	br i1 %obit, label %overflow, label %normal
				6410	</pre>
				6411
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6412	</div>
				6413
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6414	<!-- _______________________________________________________________________ -->
				6415	<div class="doc_subsubsection">
				6416	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6417	</div>
				6418
				6419	<div class="doc_text">
				6420
				6421	<h5>Syntax:</h5>
				6422
				6423	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6424	on any integer bit width.</p>
				6425
				6426	<pre>
				6427	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6428	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6429	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6430	</pre>
				6431
				6432	<h5>Overview:</h5>
				6433
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6434	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6435	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6436	occurred during the unsigned multiplication.</p>
				6437
				6438	<h5>Arguments:</h5>
				6439
				6440	<p>The arguments (%a and %b) and the first element of the result structure may
				6441	be of integer types of any bit width, but they must have the same bit width. The
				6442	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6443	and <tt>%b</tt> are the two values that will undergo unsigned
				6444	multiplication.</p>
				6445
				6446	<h5>Semantics:</h5>
				6447
				6448	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6449	an unsigned multiplication of the two arguments. They return a structure —
				6450	the first element of which is the multiplication, and the second element of
				6451	which is a bit specifying if the unsigned multiplication resulted in an
				6452	overflow.</p>
				6453
				6454	<h5>Examples:</h5>
				6455	<pre>
				6456	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6457	%sum = extractvalue {i32, i1} %res, 0
				6458	%obit = extractvalue {i32, i1} %res, 1
				6459	br i1 %obit, label %overflow, label %normal
				6460	</pre>
				6461
				6462	</div>
				6463
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6464	<!-- ======================================================================= -->
				6465	<div class="doc_subsection">
				6466	<a name="int_debugger">Debugger Intrinsics</a>
				6467	</div>
				6468
				6469	<div class="doc_text">
				6470	<p>
				6471	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6472	are described in the <a
				6473	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6474	Debugging</a> document.
				6475	</p>
				6476	</div>
				6477
				6478
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6479	<!-- ======================================================================= -->
				6480	<div class="doc_subsection">
				6481	<a name="int_eh">Exception Handling Intrinsics</a>
				6482	</div>
				6483
				6484	<div class="doc_text">
				6485	<p> The LLVM exception handling intrinsics (which all start with
				6486	<tt>llvm.eh.</tt> prefix), are described in the <a
				6487	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6488	Handling</a> document. </p>
				6489	</div>
				6490
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6491	<!-- ======================================================================= -->
				6492	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6493	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6494	</div>
				6495
				6496	<div class="doc_text">
				6497	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6498	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6499	the <tt>nest</tt> attribute, from a function. The result is a callable
				6500	function pointer lacking the nest parameter - the caller does not need
				6501	to provide a value for it. Instead, the value to use is stored in
				6502	advance in a "trampoline", a block of memory usually allocated
				6503	on the stack, which also contains code to splice the nest value into the
				6504	argument list. This is used to implement the GCC nested function address
				6505	extension.
				6506	</p>
				6507	<p>
				6508	For example, if the function is
				6509	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6510	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6511	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6512	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6513	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6514	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6515	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6516	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6517	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6518	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6519	</div>
				6520
				6521	<!-- _______________________________________________________________________ -->
				6522	<div class="doc_subsubsection">
				6523	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6524	</div>
				6525	<div class="doc_text">
				6526	<h5>Syntax:</h5>
				6527	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6528	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6529	</pre>
				6530	<h5>Overview:</h5>
				6531	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6532	This fills the memory pointed to by <tt>tramp</tt> with code
				6533	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6534	</p>
				6535	<h5>Arguments:</h5>
				6536	<p>
				6537	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6538	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6539	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	f2bcd37	2007-08-22 23:39:54 +0000	[diff] [blame]	6540	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6541	currently provides no portable way of determining them, so a front-end that
				6542	generates this intrinsic needs to have some target-specific knowledge.
				6543	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6544	</p>
				6545	<h5>Semantics:</h5>
				6546	<p>
				6547	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6548	dependent code, turning it into a function. A pointer to this function is
				6549	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6550	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6551	before being called. The new function's signature is the same as that of
				6552	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6553	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6554	of pointer type. Calling the new function is equivalent to calling
				6555	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6556	missing <tt>nest</tt> argument. If, after calling
				6557	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6558	modified, then the effect of any later call to the returned function pointer is
				6559	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6560	</p>
				6561	</div>
				6562
				6563	<!-- ======================================================================= -->
				6564	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6565	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6566	</div>
				6567
				6568	<div class="doc_text">
				6569	<p>
				6570	These intrinsic functions expand the "universal IR" of LLVM to represent
				6571	hardware constructs for atomic operations and memory synchronization. This
				6572	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	6573	is aimed at a low enough level to allow any programming models or APIs
				6574	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6575	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6576	hardware behavior. Just as hardware provides a "universal IR" for source
				6577	languages, it also provides a starting point for developing a "universal"
				6578	atomic operation and synchronization IR.
				6579	</p>
				6580	<p>
				6581	These do <em>not</em> form an API such as high-level threading libraries,
				6582	software transaction memory systems, atomic primitives, and intrinsic
				6583	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6584	application libraries. The hardware interface provided by LLVM should allow
				6585	a clean implementation of all of these APIs and parallel programming models.
				6586	No one model or paradigm should be selected above others unless the hardware
				6587	itself ubiquitously does so.
				6588
				6589	</p>
				6590	</div>
				6591
				6592	<!-- _______________________________________________________________________ -->
				6593	<div class="doc_subsubsection">
				6594	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6595	</div>
				6596	<div class="doc_text">
				6597	<h5>Syntax:</h5>
				6598	<pre>
				6599	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6600	i1 <device> )
				6601
				6602	</pre>
				6603	<h5>Overview:</h5>
				6604	<p>
				6605	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6606	specific pairs of memory access types.
				6607	</p>
				6608	<h5>Arguments:</h5>
				6609	<p>
				6610	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6611	The first four arguments enables a specific barrier as listed below. The fith
				6612	argument specifies that the barrier applies to io or device or uncached memory.
				6613
				6614	</p>
				6615	<ul>
				6616	<li><tt>ll</tt>: load-load barrier</li>
				6617	<li><tt>ls</tt>: load-store barrier</li>
				6618	<li><tt>sl</tt>: store-load barrier</li>
				6619	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6620	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6621	</ul>
				6622	<h5>Semantics:</h5>
				6623	<p>
				6624	This intrinsic causes the system to enforce some ordering constraints upon
				6625	the loads and stores of the program. This barrier does not indicate
				6626	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6627	which they occur. For any of the specified pairs of load and store operations
				6628	(f.ex. load-load, or store-load), all of the first operations preceding the
				6629	barrier will complete before any of the second operations succeeding the
				6630	barrier begin. Specifically the semantics for each pairing is as follows:
				6631	</p>
				6632	<ul>
				6633	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6634	after the barrier begins.</li>
				6635
				6636	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6637	store after the barrier begins.</li>
				6638	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6639	store after the barrier begins.</li>
				6640	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6641	load after the barrier begins.</li>
				6642	</ul>
				6643	<p>
				6644	These semantics are applied with a logical "and" behavior when more than one
				6645	is enabled in a single memory barrier intrinsic.
				6646	</p>
				6647	<p>
				6648	Backends may implement stronger barriers than those requested when they do not
				6649	support as fine grained a barrier as requested. Some architectures do not
				6650	need all types of barriers and on such architectures, these become noops.
				6651	</p>
				6652	<h5>Example:</h5>
				6653	<pre>
				6654	%ptr = malloc i32
				6655	store i32 4, %ptr
				6656
				6657	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6658	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6659	<i>; guarantee the above finishes</i>
				6660	store i32 8, %ptr <i>; before this begins</i>
				6661	</pre>
				6662	</div>
				6663
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6664	<!-- _______________________________________________________________________ -->
				6665	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6666	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6667	</div>
				6668	<div class="doc_text">
				6669	<h5>Syntax:</h5>
				6670	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6671	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6672	any integer bit width and for different address spaces. Not all targets
				6673	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6674
				6675	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6676	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6677	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6678	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6679	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6680
				6681	</pre>
				6682	<h5>Overview:</h5>
				6683	<p>
				6684	This loads a value in memory and compares it to a given value. If they are
				6685	equal, it stores a new value into the memory.
				6686	</p>
				6687	<h5>Arguments:</h5>
				6688	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6689	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6690	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6691	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6692	this integer type. While any bit width integer may be used, targets may only
				6693	lower representations they support in hardware.
				6694
				6695	</p>
				6696	<h5>Semantics:</h5>
				6697	<p>
				6698	This entire intrinsic must be executed atomically. It first loads the value
				6699	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6700	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6701	loaded value is yielded in all cases. This provides the equivalent of an
				6702	atomic compare-and-swap operation within the SSA framework.
				6703	</p>
				6704	<h5>Examples:</h5>
				6705
				6706	<pre>
				6707	%ptr = malloc i32
				6708	store i32 4, %ptr
				6709
				6710	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6711	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6712	<i>; yields {i32}:result1 = 4</i>
				6713	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6714	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6715
				6716	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6717	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6718	<i>; yields {i32}:result2 = 8</i>
				6719	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6720
				6721	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6722	</pre>
				6723	</div>
				6724
				6725	<!-- _______________________________________________________________________ -->
				6726	<div class="doc_subsubsection">
				6727	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6728	</div>
				6729	<div class="doc_text">
				6730	<h5>Syntax:</h5>
				6731
				6732	<p>
				6733	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6734	integer bit width. Not all targets support all bit widths however.</p>
				6735	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6737	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6738	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6739	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6740
				6741	</pre>
				6742	<h5>Overview:</h5>
				6743	<p>
				6744	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6745	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6746	at <tt>ptr</tt>.
				6747	</p>
				6748	<h5>Arguments:</h5>
				6749
				6750	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6751	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6752	<tt>val</tt> argument and the result must be integers of the same bit width.
				6753	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6754	integer type. The targets may only lower integer representations they
				6755	support.
				6756	</p>
				6757	<h5>Semantics:</h5>
				6758	<p>
				6759	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6760	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6761	equivalent of an atomic swap operation within the SSA framework.
				6762
				6763	</p>
				6764	<h5>Examples:</h5>
				6765	<pre>
				6766	%ptr = malloc i32
				6767	store i32 4, %ptr
				6768
				6769	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6771	<i>; yields {i32}:result1 = 4</i>
				6772	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6773	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6774
				6775	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6776	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6777	<i>; yields {i32}:result2 = 8</i>
				6778
				6779	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6780	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6781	</pre>
				6782	</div>
				6783
				6784	<!-- _______________________________________________________________________ -->
				6785	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6786	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6787
				6788	</div>
				6789	<div class="doc_text">
				6790	<h5>Syntax:</h5>
				6791	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6792	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6793	integer bit width. Not all targets support all bit widths however.</p>
				6794	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6795	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6796	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6797	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6798	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6799
				6800	</pre>
				6801	<h5>Overview:</h5>
				6802	<p>
				6803	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6804	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6805	</p>
				6806	<h5>Arguments:</h5>
				6807	<p>
				6808
				6809	The intrinsic takes two arguments, the first a pointer to an integer value
				6810	and the second an integer value. The result is also an integer value. These
				6811	integer types can have any bit width, but they must all have the same bit
				6812	width. The targets may only lower integer representations they support.
				6813	</p>
				6814	<h5>Semantics:</h5>
				6815	<p>
				6816	This intrinsic does a series of operations atomically. It first loads the
				6817	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6818	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6819	</p>
				6820
				6821	<h5>Examples:</h5>
				6822	<pre>
				6823	%ptr = malloc i32
				6824	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6825	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6826	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6827	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6828	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6829	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6830	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6831	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6832	</pre>
				6833	</div>
				6834
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6835	<!-- _______________________________________________________________________ -->
				6836	<div class="doc_subsubsection">
				6837	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6838
				6839	</div>
				6840	<div class="doc_text">
				6841	<h5>Syntax:</h5>
				6842	<p>
				6843	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6844	any integer bit width and for different address spaces. Not all targets
				6845	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6846	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6847	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6848	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6849	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6850	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6851
				6852	</pre>
				6853	<h5>Overview:</h5>
				6854	<p>
				6855	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6856	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6857	</p>
				6858	<h5>Arguments:</h5>
				6859	<p>
				6860
				6861	The intrinsic takes two arguments, the first a pointer to an integer value
				6862	and the second an integer value. The result is also an integer value. These
				6863	integer types can have any bit width, but they must all have the same bit
				6864	width. The targets may only lower integer representations they support.
				6865	</p>
				6866	<h5>Semantics:</h5>
				6867	<p>
				6868	This intrinsic does a series of operations atomically. It first loads the
				6869	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6870	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6871	</p>
				6872
				6873	<h5>Examples:</h5>
				6874	<pre>
				6875	%ptr = malloc i32
				6876	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6877	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6878	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6879	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6880	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6881	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6882	<i>; yields {i32}:result3 = 2</i>
				6883	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6884	</pre>
				6885	</div>
				6886
				6887	<!-- _______________________________________________________________________ -->
				6888	<div class="doc_subsubsection">
				6889	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6890	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6891	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6892	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6893
				6894	</div>
				6895	<div class="doc_text">
				6896	<h5>Syntax:</h5>
				6897	<p>
				6898	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6899	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6900	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6901	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6902	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6903	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6904	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6905	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6906	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6907
				6908	</pre>
				6909
				6910	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6911	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6912	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6913	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6914	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6915
				6916	</pre>
				6917
				6918	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6919	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6920	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6921	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6922	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6923
				6924	</pre>
				6925
				6926	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6927	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6928	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6929	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6930	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6931
				6932	</pre>
				6933	<h5>Overview:</h5>
				6934	<p>
				6935	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6936	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6937	at <tt>ptr</tt>.
				6938	</p>
				6939	<h5>Arguments:</h5>
				6940	<p>
				6941
				6942	These intrinsics take two arguments, the first a pointer to an integer value
				6943	and the second an integer value. The result is also an integer value. These
				6944	integer types can have any bit width, but they must all have the same bit
				6945	width. The targets may only lower integer representations they support.
				6946	</p>
				6947	<h5>Semantics:</h5>
				6948	<p>
				6949	These intrinsics does a series of operations atomically. They first load the
				6950	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6951	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6952	value stored at <tt>ptr</tt>.
				6953	</p>
				6954
				6955	<h5>Examples:</h5>
				6956	<pre>
				6957	%ptr = malloc i32
				6958	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6959	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6960	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6961	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6962	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6963	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6964	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6965	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6966	<i>; yields {i32}:result3 = FF</i>
				6967	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6968	</pre>
				6969	</div>
				6970
				6971
				6972	<!-- _______________________________________________________________________ -->
				6973	<div class="doc_subsubsection">
				6974	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6975	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6976	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6977	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6978
				6979	</div>
				6980	<div class="doc_text">
				6981	<h5>Syntax:</h5>
				6982	<p>
				6983	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6984	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6985	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6986	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6987	support all bit widths however.</p>
				6988	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6989	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6990	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6991	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6992	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6993
				6994	</pre>
				6995
				6996	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6997	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6998	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6999	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				7000	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7001
				7002	</pre>
				7003
				7004	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7005	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				7006	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				7007	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				7008	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7009
				7010	</pre>
				7011
				7012	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7013	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				7014	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				7015	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				7016	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7017
				7018	</pre>
				7019	<h5>Overview:</h5>
				7020	<p>
				7021	These intrinsics takes the signed or unsigned minimum or maximum of
				7022	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				7023	original value at <tt>ptr</tt>.
				7024	</p>
				7025	<h5>Arguments:</h5>
				7026	<p>
				7027
				7028	These intrinsics take two arguments, the first a pointer to an integer value
				7029	and the second an integer value. The result is also an integer value. These
				7030	integer types can have any bit width, but they must all have the same bit
				7031	width. The targets may only lower integer representations they support.
				7032	</p>
				7033	<h5>Semantics:</h5>
				7034	<p>
				7035	These intrinsics does a series of operations atomically. They first load the
				7036	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				7037	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				7038	the original value stored at <tt>ptr</tt>.
				7039	</p>
				7040
				7041	<h5>Examples:</h5>
				7042	<pre>
				7043	%ptr = malloc i32
				7044	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7045	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7046	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7047	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7048	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7049	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7050	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	7051	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	7052	<i>; yields {i32}:result3 = 8</i>
				7053	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				7054	</pre>
				7055	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	7056
				7057	<!-- ======================================================================= -->
				7058	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7059	<a name="int_general">General Intrinsics</a>
				7060	</div>
				7061
				7062	<div class="doc_text">
				7063	<p> This class of intrinsics is designed to be generic and has
				7064	no specific purpose. </p>
				7065	</div>
				7066
				7067	<!-- _______________________________________________________________________ -->
				7068	<div class="doc_subsubsection">
				7069	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				7070	</div>
				7071
				7072	<div class="doc_text">
				7073
				7074	<h5>Syntax:</h5>
				7075	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	7076	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7077	</pre>
				7078
				7079	<h5>Overview:</h5>
				7080
				7081	<p>
				7082	The '<tt>llvm.var.annotation</tt>' intrinsic
				7083	</p>
				7084
				7085	<h5>Arguments:</h5>
				7086
				7087	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	7088	The first argument is a pointer to a value, the second is a pointer to a
				7089	global string, the third is a pointer to a global string which is the source
				7090	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7091	</p>
				7092
				7093	<h5>Semantics:</h5>
				7094
				7095	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7096	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7097	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7098	annotations. These have no other defined use, they are ignored by code
				7099	generation and optimization.
				7100	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	7101	</div>
				7102
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7103	<!-- _______________________________________________________________________ -->
				7104	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	7105	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7106	</div>
				7107
				7108	<div class="doc_text">
				7109
				7110	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7111	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				7112	any integer bit width.
				7113	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7114	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	7115	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				7116	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7117	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7118	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7119	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7120	</pre>
				7121
				7122	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7123
				7124	<p>
				7125	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7126	</p>
				7127
				7128	<h5>Arguments:</h5>
				7129
				7130	<p>
				7131	The first argument is an integer value (result of some expression),
				7132	the second is a pointer to a global string, the third is a pointer to a global
				7133	string which is the source file name, and the last argument is the line number.
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7134	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7135	</p>
				7136
				7137	<h5>Semantics:</h5>
				7138
				7139	<p>
				7140	This intrinsic allows annotations to be put on arbitrary expressions
				7141	with arbitrary strings. This can be useful for special purpose optimizations
				7142	that want to look for these annotations. These have no other defined use, they
				7143	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	7144	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7145	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	7146
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7147	<!-- _______________________________________________________________________ -->
				7148	<div class="doc_subsubsection">
				7149	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7150	</div>
				7151
				7152	<div class="doc_text">
				7153
				7154	<h5>Syntax:</h5>
				7155	<pre>
				7156	declare void @llvm.trap()
				7157	</pre>
				7158
				7159	<h5>Overview:</h5>
				7160
				7161	<p>
				7162	The '<tt>llvm.trap</tt>' intrinsic
				7163	</p>
				7164
				7165	<h5>Arguments:</h5>
				7166
				7167	<p>
				7168	None
				7169	</p>
				7170
				7171	<h5>Semantics:</h5>
				7172
				7173	<p>
				7174	This intrinsics is lowered to the target dependent trap instruction. If the
				7175	target does not have a trap instruction, this intrinsic will be lowered to the
				7176	call of the abort() function.
				7177	</p>
				7178	</div>
				7179
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7180	<!-- _______________________________________________________________________ -->
				7181	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	7182	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7183	</div>
				7184	<div class="doc_text">
				7185	<h5>Syntax:</h5>
				7186	<pre>
				7187	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7188
				7189	</pre>
				7190	<h5>Overview:</h5>
				7191	<p>
				7192	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7193	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7194	it is placed on the stack before local variables.
				7195	</p>
				7196	<h5>Arguments:</h5>
				7197	<p>
				7198	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7199	first argument is the value loaded from the stack guard
				7200	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7201	has enough space to hold the value of the guard.
				7202	</p>
				7203	<h5>Semantics:</h5>
				7204	<p>
				7205	This intrinsic causes the prologue/epilogue inserter to force the position of
				7206	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7207	stack. This is to ensure that if a local variable on the stack is overwritten,
				7208	it will destroy the value of the guard. When the function exits, the guard on
				7209	the stack is checked against the original guard. If they're different, then
				7210	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7211	</p>
				7212	</div>
				7213
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7214	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7215	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7216	<address>
				7217	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7218	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7219	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7220	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7221
				7222	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7223	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7224	Last modified: $Date$
				7225	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7226
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7227	</body>
				7228	</html>