Blame - llvm/docs/LangRef.html - toolchain/llvm-project

blob: f0ec684265982f0e5b3fb3993b69f1ff1809c1f7 [file] [log] [blame]

Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
				2	"http://www.w3.org/TR/html4/strict.dtd">
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>
				92	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
				93	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	94	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				95	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				96	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	97	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				98	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				99	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	100	</ol>
				101	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	102	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				103	<ol>
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	104	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				105	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				106	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	107	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	108	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	109	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	110	</ol>
				111	</li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	112	<li><a href="#vectorops">Vector Operations</a>
				113	<ol>
				114	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				115	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				116	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	117	</ol>
				118	</li>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	119	<li><a href="#aggregateops">Aggregate Operations</a>
				120	<ol>
				121	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				122	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				123	</ol>
				124	</li>
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	125	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	126	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	127	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				128	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				129	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	130	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				131	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				132	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	133	</ol>
				134	</li>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	135	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	136	<ol>
				137	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				138	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				139	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				140	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				141	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	142	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				143	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				144	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				145	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	146	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				147	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	148	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	149	</ol>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	150	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	151	<li><a href="#otherops">Other Operations</a>
				152	<ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	153	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				154	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	155	<li><a href="#i_vicmp">'<tt>vicmp</tt>' Instruction</a></li>
				156	<li><a href="#i_vfcmp">'<tt>vfcmp</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	157	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	158	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	159	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	160	<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]	161	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	162	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	163	</ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	164	</li>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	165	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	166	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	167	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				168	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	169	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				170	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				171	<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]	172	</ol>
				173	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	174	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				175	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	176	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				177	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				178	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	179	</ol>
				180	</li>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	181	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				182	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	183	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				184	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				185	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				186	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				187	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				188	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				189	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	aa1c3c1	2004-04-09 16:43:20 +0000	[diff] [blame]	190	</ol>
				191	</li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	192	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				193	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	194	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				195	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				196	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				197	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				198	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	199	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				200	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				201	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	202	</ol>
				203	</li>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	204	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	205	<ol>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	206	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	207	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				208	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				209	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	210	<li><a href="#int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic </a></li>
				211	<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]	212	</ol>
				213	</li>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	214	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				215	<ol>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	216	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				217	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				218	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				219	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				220	<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]	221	<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]	222	</ol>
				223	</li>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	224	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	225	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	226	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	227	<ol>
				228	<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]	229	</ol>
				230	</li>
Bill Wendling	f85850f	2008-11-18 22:10:53 +0000	[diff] [blame]	231	<li><a href="#int_atomics">Atomic intrinsics</a>
				232	<ol>
				233	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				234	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				235	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				236	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				237	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				238	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				239	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				240	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				241	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				242	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				243	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				244	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				245	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				246	</ol>
				247	</li>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	248	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	249	<ol>
Reid Spencer	5b2cb0f	2007-07-20 19:59:11 +0000	[diff] [blame]	250	<li><a href="#int_var_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	251	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	252	<li><a href="#int_annotation">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	253	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	254	<li><a href="#int_trap">
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	255	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				256	<li><a href="#int_stackprotector">
				257	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	258	</ol>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	259	</li>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	260	</ol>
				261	</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	262	</ol>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	263
				264	<div class="doc_author">
				265	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				266	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	267	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	268
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	269	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	270	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				271	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	272
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	273	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	274	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	6e03f9a	2008-08-05 22:29:16 +0000	[diff] [blame]	275	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	276	type safety, low-level operations, flexibility, and the capability of
				277	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	278	representation used throughout all phases of the LLVM compilation
				279	strategy.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	280	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	281
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	282	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	283	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				284	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	285
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	286	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	287
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	288	<p>The LLVM code representation is designed to be used in three
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	289	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]	290	representation (suitable for fast loading by a Just-In-Time compiler),
				291	and as a human readable assembly language representation. This allows
				292	LLVM to provide a powerful intermediate representation for efficient
				293	compiler transformations and analysis, while providing a natural means
				294	to debug and visualize the transformations. The three different forms
				295	of LLVM are all equivalent. This document describes the human readable
				296	representation and notation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	297
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	298	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	299	while being expressive, typed, and extensible at the same time. It
				300	aims to be a "universal IR" of sorts, by being at a low enough level
				301	that high-level ideas may be cleanly mapped to it (similar to how
				302	microprocessors are "universal IR's", allowing many source languages to
				303	be mapped to them). By providing type information, LLVM can be used as
				304	the target of optimizations: for example, through pointer analysis, it
				305	can be proven that a C automatic variable is never accessed outside of
				306	the current function... allowing it to be promoted to a simple SSA
				307	value instead of a memory location.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	308
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	309	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	310
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	311	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	312	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	313
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	314	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	315
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	316	<p>It is important to note that this document describes 'well formed'
				317	LLVM assembly language. There is a difference between what the parser
				318	accepts and what is considered 'well formed'. For example, the
				319	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	320
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	321	<div class="doc_code">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	322	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	323	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	324	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	325	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	327	<p>...because the definition of <tt>%x</tt> does not dominate all of
				328	its uses. The LLVM infrastructure provides a verification pass that may
				329	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]	330	automatically run by the parser after parsing input assembly and by
Gabor Greif	a54634a	2007-07-06 22:07:22 +0000	[diff] [blame]	331	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	332	by the verifier pass indicate bugs in transformation passes or input to
				333	the parser.</p>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	334	</div>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	335
Chris Lattner	87a3dbe	2007-10-03 17:34:29 +0000	[diff] [blame]	336	<!-- Describe the typesetting conventions here. -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	337
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	338	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	339	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	340	<!-- *********************************************************************** -->
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	341
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	342	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	343
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	344	<p>LLVM identifiers come in two basic types: global and local. Global
				345	identifiers (functions, global variables) begin with the @ character. Local
				346	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	347	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	348
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	349	<ol>
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	350	<li>Named values are represented as a string of characters with their prefix.
				351	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				352	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]	353	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	0f8155a	2008-10-14 23:51:43 +0000	[diff] [blame]	354	with quotes. Special characters may be escaped using "\xx" where xx is the
				355	ASCII code for the character in hexadecimal. In this way, any character can
				356	be used in a name value, even quotes themselves.
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	357
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	358	<li>Unnamed values are represented as an unsigned numeric value with their
				359	prefix. For example, %12, @2, %44.</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	360
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	361	<li>Constants, which are described in a <a href="#constants">section about
				362	constants</a>, below.</li>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	363	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	364
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	365	<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]	366	don't need to worry about name clashes with reserved words, and the set of
				367	reserved words may be expanded in the future without penalty. Additionally,
				368	unnamed identifiers allow a compiler to quickly come up with a temporary
				369	variable without having to avoid symbol table conflicts.</p>
				370
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	371	<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]	372	languages. There are keywords for different opcodes
				373	('<tt><a href="#i_add">add</a></tt>',
				374	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				375	'<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]	376	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]	377	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	b23b65f	2007-08-07 14:34:28 +0000	[diff] [blame]	378	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	379
				380	<p>Here is an example of LLVM code to multiply the integer variable
				381	'<tt>%X</tt>' by 8:</p>
				382
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	383	<p>The easy way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	384
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	385	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	386	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	387	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	388	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	389	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	390
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	391	<p>After strength reduction:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	392
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	393	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	394	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	395	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	396	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	397	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	398
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	399	<p>And the hard way:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	400
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	401	<div class="doc_code">
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	402	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	403	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				404	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				405	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	406	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	407	</div>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	408
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	409	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				410	important lexical features of LLVM:</p>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	411
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	412	<ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	413
				414	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				415	line.</li>
				416
				417	<li>Unnamed temporaries are created when the result of a computation is not
				418	assigned to a named value.</li>
				419
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	420	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	421
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	422	</ol>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	423
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	424	<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]	425	demonstrating instructions, we will follow an instruction with a comment that
				426	defines the type and name of value produced. Comments are shown in italic
				427	text.</p>
				428
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	429	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	430
				431	<!-- *********************************************************************** -->
				432	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				433	<!-- *********************************************************************** -->
				434
				435	<!-- ======================================================================= -->
				436	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				437	</div>
				438
				439	<div class="doc_text">
				440
				441	<p>LLVM programs are composed of "Module"s, each of which is a
				442	translation unit of the input programs. Each module consists of
				443	functions, global variables, and symbol table entries. Modules may be
				444	combined together with the LLVM linker, which merges function (and
				445	global variable) definitions, resolves forward declarations, and merges
				446	symbol table entries. Here is an example of the "hello world" module:</p>
				447
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	448	<div class="doc_code">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	449	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	450	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				451	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]	452
				453	<i>; External declaration of the puts function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	454	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	455
				456	<i>; Definition of main function</i>
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	457	define i32 @main() { <i>; i32()* </i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	458	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	459	%cast210 = <a
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	460	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]	461
				462	<i>; Call puts function to write out the string to stdout...</i>
				463	<a
Chris Lattner	2b0bf4f	2007-06-12 17:00:26 +0000	[diff] [blame]	464	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	465	<a
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	466	href="#i_ret">ret</a> i32 0<br>}<br>
				467	</pre>
				468	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	469
				470	<p>This example is made up of a <a href="#globalvars">global variable</a>
				471	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				472	function, and a <a href="#functionstructure">function definition</a>
				473	for "<tt>main</tt>".</p>
				474
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	475	<p>In general, a module is made up of a list of global values,
				476	where both functions and global variables are global values. Global values are
				477	represented by a pointer to a memory location (in this case, a pointer to an
				478	array of char, and a pointer to a function), and have one of the following <a
				479	href="#linkage">linkage types</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	480
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	481	</div>
				482
				483	<!-- ======================================================================= -->
				484	<div class="doc_subsection">
				485	<a name="linkage">Linkage Types</a>
				486	</div>
				487
				488	<div class="doc_text">
				489
				490	<p>
				491	All Global Variables and Functions have one of the following types of linkage:
				492	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	493
				494	<dl>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	495
Rafael Espindola	6de96a1	2009-01-15 20:18:42 +0000	[diff] [blame]	496	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				497
				498	<dd>Global values with private linkage are only directly accessible by
				499	objects in the current module. In particular, linking code into a module with
				500	an private global value may cause the private to be renamed as necessary to
				501	avoid collisions. Because the symbol is private to the module, all
				502	references can be updated. This doesn't show up in any symbol table in the
				503	object file.
				504	</dd>
				505
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	506	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	507
Duncan Sands	35e43c1	2009-01-16 09:29:46 +0000	[diff] [blame]	508	<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]	509	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]	510	'<tt>static</tt>' keyword in C.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	511	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	512
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	513	<dt><tt><b><a name="available_externally">available_externally</a></b></tt>:
				514	</dt>
				515
				516	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				517	into the object file corresponding to the LLVM module. They exist to
				518	allow inlining and other optimizations to take place given knowledge of the
				519	definition of the global, which is known to be somewhere outside the module.
				520	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				521	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				522	type is only allowed on definitions, not declarations.</dd>
				523
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	524	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	525
Chris Lattner	e20b470	2007-01-14 06:51:48 +0000	[diff] [blame]	526	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				527	the same name when linkage occurs. This is typically used to implement
				528	inline functions, templates, or other code which must be generated in each
				529	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				530	allowed to be discarded.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	531	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	532
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	533	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				534
				535	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				536	linkage, except that unreferenced <tt>common</tt> globals may not be
				537	discarded. This is used for globals that may be emitted in multiple
				538	translation units, but that are not guaranteed to be emitted into every
				539	translation unit that uses them. One example of this is tentative
				540	definitions in C, such as "<tt>int X;</tt>" at global scope.
				541	</dd>
				542
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	543	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	544
Dale Johannesen	4188aad	2008-05-23 23:13:41 +0000	[diff] [blame]	545	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				546	that some targets may choose to emit different assembly sequences for them
				547	for target-dependent reasons. This is used for globals that are declared
				548	"weak" in C source code.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	549	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	550
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	551	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	552
				553	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				554	pointer to array type. When two global variables with appending linkage are
				555	linked together, the two global arrays are appended together. This is the
				556	LLVM, typesafe, equivalent of having the system linker append together
				557	"sections" with identical names when .o files are linked.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	558	</dd>
Chris Lattner	d79749a	2004-12-09 16:36:40 +0000	[diff] [blame]	559
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	560	<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]	561
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	562	<dd>The semantics of this linkage follow the ELF object file model: the
				563	symbol is weak until linked, if not linked, the symbol becomes null instead
				564	of being an undefined reference.
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	565	</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	566
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	567	<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]	568	<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]	569	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	570	functions with different semantics. Other languages, such as <tt>C++</tt>,
				571	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	184f1be	2009-04-13 05:44:34 +0000	[diff] [blame]	572	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4581beb	2009-03-11 20:14:15 +0000	[diff] [blame]	573	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				574	be merged with equivalent globals. These linkage types are otherwise the
				575	same as their non-<tt>odr</tt> versions.
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	576	</dd>
				577
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	578	<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]	579
				580	<dd>If none of the above identifiers are used, the global is externally
				581	visible, meaning that it participates in linkage and can be used to resolve
				582	external symbol references.
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	583	</dd>
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	584	</dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	585
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	586	<p>
				587	The next two types of linkage are targeted for Microsoft Windows platform
				588	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	589	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	590	</p>
				591
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	592	<dl>
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	593	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				594
				595	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				596	or variable via a global pointer to a pointer that is set up by the DLL
				597	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	598	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	d61d39e	2006-09-14 18:23:27 +0000	[diff] [blame]	599	</dd>
				600
				601	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				602
				603	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				604	pointer to a pointer in a DLL, so that it can be referenced with the
				605	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	33a9cef	2009-01-12 21:35:55 +0000	[diff] [blame]	606	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]	607	name.
				608	</dd>
				609
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	610	</dl>
				611
Dan Gohman	8ef4498	2008-11-24 17:18:39 +0000	[diff] [blame]	612	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	613	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				614	variable and was linked with this one, one of the two would be renamed,
				615	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				616	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	92c671e	2007-01-05 00:59:10 +0000	[diff] [blame]	617	outside of the current module.</p>
				618	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	e288105	2009-03-11 08:08:06 +0000	[diff] [blame]	619	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				620	or <tt>extern_weak</tt>.</p>
Duncan Sands	12da8ce	2009-03-07 15:45:40 +0000	[diff] [blame]	621	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				622	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	623	</div>
				624
				625	<!-- ======================================================================= -->
				626	<div class="doc_subsection">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	627	<a name="callingconv">Calling Conventions</a>
				628	</div>
				629
				630	<div class="doc_text">
				631
				632	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				633	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				634	specified for the call. The calling convention of any pair of dynamic
				635	caller/callee must match, or the behavior of the program is undefined. The
				636	following calling conventions are supported by LLVM, and more may be added in
				637	the future:</p>
				638
				639	<dl>
				640	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				641
				642	<dd>This calling convention (the default if no other calling convention is
				643	specified) matches the target C calling conventions. This calling convention
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	644	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	72ba499	2006-12-31 21:30:18 +0000	[diff] [blame]	645	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	646	</dd>
				647
				648	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				649
				650	<dd>This calling convention attempts to make calls as fast as possible
				651	(e.g. by passing things in registers). This calling convention allows the
				652	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]	653	without having to conform to an externally specified ABI (Application Binary
				654	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	2c6b888	2008-05-14 09:17:12 +0000	[diff] [blame]	655	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				656	supported. This calling convention does not support varargs and requires the
				657	prototype of all callees to exactly match the prototype of the function
				658	definition.
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	659	</dd>
				660
				661	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				662
				663	<dd>This calling convention attempts to make code in the caller as efficient
				664	as possible under the assumption that the call is not commonly executed. As
				665	such, these calls often preserve all registers so that the call does not break
				666	any live ranges in the caller side. This calling convention does not support
				667	varargs and requires the prototype of all callees to exactly match the
				668	prototype of the function definition.
				669	</dd>
				670
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	671	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	672
				673	<dd>Any calling convention may be specified by number, allowing
				674	target-specific calling conventions to be used. Target specific calling
				675	conventions start at 64.
				676	</dd>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	677	</dl>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	678
				679	<p>More calling conventions can be added/defined on an as-needed basis, to
				680	support pascal conventions or any other well-known target-independent
				681	convention.</p>
				682
				683	</div>
				684
				685	<!-- ======================================================================= -->
				686	<div class="doc_subsection">
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	687	<a name="visibility">Visibility Styles</a>
				688	</div>
				689
				690	<div class="doc_text">
				691
				692	<p>
				693	All Global Variables and Functions have one of the following visibility styles:
				694	</p>
				695
				696	<dl>
				697	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				698
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	699	<dd>On targets that use the ELF object file format, default visibility means
				700	that the declaration is visible to other
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	701	modules and, in shared libraries, means that the declared entity may be
				702	overridden. On Darwin, default visibility means that the declaration is
				703	visible to other modules. Default visibility corresponds to "external
				704	linkage" in the language.
				705	</dd>
				706
				707	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				708
				709	<dd>Two declarations of an object with hidden visibility refer to the same
				710	object if they are in the same shared object. Usually, hidden visibility
				711	indicates that the symbol will not be placed into the dynamic symbol table,
				712	so no other module (executable or shared library) can reference it
				713	directly.
				714	</dd>
				715
Anton Korobeynikov	39f3cff	2007-04-29 18:35:00 +0000	[diff] [blame]	716	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				717
				718	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				719	the dynamic symbol table, but that references within the defining module will
				720	bind to the local symbol. That is, the symbol cannot be overridden by another
				721	module.
				722	</dd>
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	723	</dl>
				724
				725	</div>
				726
				727	<!-- ======================================================================= -->
				728	<div class="doc_subsection">
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	729	<a name="namedtypes">Named Types</a>
				730	</div>
				731
				732	<div class="doc_text">
				733
				734	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				735	it easier to read the IR and make the IR more condensed (particularly when
				736	recursive types are involved). An example of a name specification is:
				737	</p>
				738
				739	<div class="doc_code">
				740	<pre>
				741	%mytype = type { %mytype*, i32 }
				742	</pre>
				743	</div>
				744
				745	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				746	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				747	expected with the syntax "%mytype".</p>
				748
				749	<p>Note that type names are aliases for the structural type that they indicate,
				750	and that you can therefore specify multiple names for the same type. This often
				751	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				752	structural typing, the name is not part of the type. When printing out LLVM IR,
				753	the printer will pick <em>one name</em> to render all types of a particular
				754	shape. This means that if you have code where two different source types end up
				755	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				756	unexpected type. This is an important design point and isn't going to
				757	change.</p>
				758
				759	</div>
				760
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	761	<!-- ======================================================================= -->
				762	<div class="doc_subsection">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	763	<a name="globalvars">Global Variables</a>
				764	</div>
				765
				766	<div class="doc_text">
				767
Chris Lattner	5d5aede	2005-02-12 19:30:21 +0000	[diff] [blame]	768	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	769	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	770	an explicit section to be placed in, and may have an optional explicit alignment
				771	specified. A variable may be defined as "thread_local", which means that it
				772	will not be shared by threads (each thread will have a separated copy of the
				773	variable). A variable may be defined as a global "constant," which indicates
				774	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]	775	optimization, allowing the global data to be placed in the read-only section of
				776	an executable, etc). Note that variables that need runtime initialization
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	777	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]	778
				779	<p>
				780	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				781	constant, even if the final definition of the global is not. This capability
				782	can be used to enable slightly better optimization of the program, but requires
				783	the language definition to guarantee that optimizations based on the
				784	'constantness' are valid for the translation units that do not include the
				785	definition.
				786	</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	787
				788	<p>As SSA values, global variables define pointer values that are in
				789	scope (i.e. they dominate) all basic blocks in the program. Global
				790	variables always define a pointer to their "content" type because they
				791	describe a region of memory, and all memory objects in LLVM are
				792	accessed through pointers.</p>
				793
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	794	<p>A global variable may be declared to reside in a target-specifc numbered
				795	address space. For targets that support them, address spaces may affect how
				796	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	25f5076	2007-12-12 08:44:39 +0000	[diff] [blame]	797	the variable. The default address space is zero. The address space qualifier
				798	must precede any other attributes.</p>
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	799
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	800	<p>LLVM allows an explicit section to be specified for globals. If the target
				801	supports it, it will emit globals to the section specified.</p>
				802
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	803	<p>An explicit alignment may be specified for a global. If not present, or if
				804	the alignment is set to zero, the alignment of the global is set by the target
				805	to whatever it feels convenient. If an explicit alignment is specified, the
				806	global is forced to have at least that much alignment. All alignments must be
				807	a power of 2.</p>
				808
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	809	<p>For example, the following defines a global in a numbered address space with
				810	an initializer, section, and alignment:</p>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	811
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	812	<div class="doc_code">
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	813	<pre>
Dan Gohman	aaa679b	2009-01-11 00:40:00 +0000	[diff] [blame]	814	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	815	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	816	</div>
Chris Lattner	5760c50	2007-01-14 00:27:09 +0000	[diff] [blame]	817
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	818	</div>
				819
				820
				821	<!-- ======================================================================= -->
				822	<div class="doc_subsection">
				823	<a name="functionstructure">Functions</a>
				824	</div>
				825
				826	<div class="doc_text">
				827
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	828	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				829	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	c7f9f3d	2007-01-23 12:35:46 +0000	[diff] [blame]	830	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	831	<a href="#callingconv">calling convention</a>, a return type, an optional
				832	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				833	name, a (possibly empty) argument list (each with optional
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	834	<a href="#paramattrs">parameter attributes</a>), optional
				835	<a href="#fnattrs">function attributes</a>, an optional section,
				836	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	cbc4d2a	2008-10-04 18:10:21 +0000	[diff] [blame]	837	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]	838
				839	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				840	optional <a href="#linkage">linkage type</a>, an optional
				841	<a href="#visibility">visibility style</a>, an optional
				842	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	843	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	844	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]	845	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	846
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	847	<p>A function definition contains a list of basic blocks, forming the CFG
				848	(Control Flow Graph) for
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	849	the function. Each basic block may optionally start with a label (giving the
				850	basic block a symbol table entry), contains a list of instructions, and ends
				851	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				852	function return).</p>
				853
Chris Lattner	a59fb10	2007-06-08 16:52:14 +0000	[diff] [blame]	854	<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]	855	executed on entrance to the function, and it is not allowed to have predecessor
				856	basic blocks (i.e. there can not be any branches to the entry block of a
				857	function). Because the block can have no predecessors, it also cannot have any
				858	<a href="#i_phi">PHI nodes</a>.</p>
				859
Chris Lattner	662c872	2005-11-12 00:45:07 +0000	[diff] [blame]	860	<p>LLVM allows an explicit section to be specified for functions. If the target
				861	supports it, it will emit functions to the section specified.</p>
				862
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	863	<p>An explicit alignment may be specified for a function. If not present, or if
				864	the alignment is set to zero, the alignment of the function is set by the target
				865	to whatever it feels convenient. If an explicit alignment is specified, the
				866	function is forced to have at least that much alignment. All alignments must be
				867	a power of 2.</p>
				868
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	869	<h5>Syntax:</h5>
				870
				871	<div class="doc_code">
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	872	<tt>
				873	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				874	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				875	<ResultType> @<FunctionName> ([argument list])
				876	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				877	[<a href="#gc">gc</a>] { ... }
				878	</tt>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	879	</div>
				880
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	881	</div>
				882
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	883
				884	<!-- ======================================================================= -->
				885	<div class="doc_subsection">
				886	<a name="aliasstructure">Aliases</a>
				887	</div>
				888	<div class="doc_text">
				889	<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]	890	function, global variable, another alias or bitcast of global value). Aliases
				891	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	892	optional <a href="#visibility">visibility style</a>.</p>
				893
				894	<h5>Syntax:</h5>
				895
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	896	<div class="doc_code">
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	897	<pre>
Duncan Sands	7e99a94	2008-09-12 20:48:21 +0000	[diff] [blame]	898	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	899	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	900	</div>
Anton Korobeynikov	a97b694	2007-04-25 14:27:10 +0000	[diff] [blame]	901
				902	</div>
				903
				904
				905
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	906	<!-- ======================================================================= -->
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	907	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				908	<div class="doc_text">
				909	<p>The return type and each parameter of a function type may have a set of
				910	<i>parameter attributes</i> associated with them. Parameter attributes are
				911	used to communicate additional information about the result or parameters of
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	912	a function. Parameter attributes are considered to be part of the function,
				913	not of the function type, so functions with different parameter attributes
				914	can have the same function type.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	915
Reid Spencer	cf7ebf5	2007-01-15 18:27:39 +0000	[diff] [blame]	916	<p>Parameter attributes are simple keywords that follow the type specified. If
				917	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	918	example:</p>
				919
				920	<div class="doc_code">
				921	<pre>
Nick Lewycky	dac78d8	2009-02-15 23:06:14 +0000	[diff] [blame]	922	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	923	declare i32 @atoi(i8 zeroext)
				924	declare signext i8 @returns_signed_char()
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	925	</pre>
				926	</div>
				927
Duncan Sands	ad0ea2d	2007-11-27 13:23:08 +0000	[diff] [blame]	928	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				929	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	930
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	931	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	932	<dl>
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	933	<dt><tt>zeroext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	934	<dd>This indicates to the code generator that the parameter or return value
				935	should be zero-extended to a 32-bit value by the caller (for a parameter)
				936	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	937
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	938	<dt><tt>signext</tt></dt>
Chris Lattner	d2597d7	2008-10-04 18:33:34 +0000	[diff] [blame]	939	<dd>This indicates to the code generator that the parameter or return value
				940	should be sign-extended to a 32-bit value by the caller (for a parameter)
				941	or the callee (for a return value).</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	942
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	943	<dt><tt>inreg</tt></dt>
Dale Johannesen	c50ada2	2008-09-25 20:47:45 +0000	[diff] [blame]	944	<dd>This indicates that this parameter or return value should be treated
				945	in a special target-dependent fashion during while emitting code for a
				946	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]	947	to memory, though some targets use it to distinguish between two different
				948	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	949
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	950	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	352ab9b	2008-01-15 04:34:22 +0000	[diff] [blame]	951	<dd>This indicates that the pointer parameter should really be passed by
				952	value to the function. The attribute implies that a hidden copy of the
				953	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]	954	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]	955	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	956	value, but is also valid on pointers to scalars. The copy is considered to
				957	belong to the caller not the callee (for example,
				958	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	959	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	08aa906	2009-02-05 05:42:28 +0000	[diff] [blame]	960	values. The byval attribute also supports specifying an alignment with the
				961	align attribute. This has a target-specific effect on the code generator
				962	that usually indicates a desired alignment for the synthesized stack
				963	slot.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	964
Anton Korobeynikov	e816685	2007-01-28 14:30:45 +0000	[diff] [blame]	965	<dt><tt>sret</tt></dt>
Duncan Sands	fa4b673	2008-02-18 04:19:38 +0000	[diff] [blame]	966	<dd>This indicates that the pointer parameter specifies the address of a
				967	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]	968	This pointer must be guaranteed by the caller to be valid: loads and stores
				969	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]	970	be applied to the first parameter. This is not a valid attribute for
				971	return values. </dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	972
Zhou Sheng	2444a9a	2007-06-05 05:28:26 +0000	[diff] [blame]	973	<dt><tt>noalias</tt></dt>
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	974	<dd>This indicates that the pointer does not alias any global or any other
				975	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	d59572c	2008-11-24 05:00:44 +0000	[diff] [blame]	976	case. On a function return value, <tt>noalias</tt> additionally indicates
				977	that the pointer does not alias any other pointers visible to the
Nick Lewycky	2abb108	2008-12-19 06:39:12 +0000	[diff] [blame]	978	caller. For further details, please see the discussion of the NoAlias
				979	response in
				980	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				981	analysis</a>.</dd>
				982
				983	<dt><tt>nocapture</tt></dt>
				984	<dd>This indicates that the callee does not make any copies of the pointer
				985	that outlive the callee itself. This is not a valid attribute for return
				986	values.</dd>
Chris Lattner	5cee13f	2008-01-11 06:20:47 +0000	[diff] [blame]	987
Duncan Sands	27e9159	2007-07-27 19:57:41 +0000	[diff] [blame]	988	<dt><tt>nest</tt></dt>
Duncan Sands	825bde4	2008-07-08 09:27:25 +0000	[diff] [blame]	989	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	990	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				991	attribute for return values.</dd>
Anton Korobeynikov	a0554d9	2007-01-12 19:20:47 +0000	[diff] [blame]	992	</dl>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	993
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	994	</div>
				995
				996	<!-- ======================================================================= -->
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	997	<div class="doc_subsection">
Gordon Henriksen	71183b6	2007-12-10 03:18:06 +0000	[diff] [blame]	998	<a name="gc">Garbage Collector Names</a>
				999	</div>
				1000
				1001	<div class="doc_text">
				1002	<p>Each function may specify a garbage collector name, which is simply a
				1003	string.</p>
				1004
				1005	<div class="doc_code"><pre
				1006	>define void @f() gc "name" { ...</pre></div>
				1007
				1008	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1009	collector which will cause the compiler to alter its output in order to support
				1010	the named garbage collection algorithm.</p>
				1011	</div>
				1012
				1013	<!-- ======================================================================= -->
				1014	<div class="doc_subsection">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1015	<a name="fnattrs">Function Attributes</a>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1016	</div>
				1017
				1018	<div class="doc_text">
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1019
				1020	<p>Function attributes are set to communicate additional information about
				1021	a function. Function attributes are considered to be part of the function,
				1022	not of the function type, so functions with different parameter attributes
				1023	can have the same function type.</p>
				1024
				1025	<p>Function attributes are simple keywords that follow the type specified. If
				1026	multiple attributes are needed, they are space separated. For
				1027	example:</p>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1028
				1029	<div class="doc_code">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1030	<pre>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1031	define void @f() noinline { ... }
				1032	define void @f() alwaysinline { ... }
				1033	define void @f() alwaysinline optsize { ... }
				1034	define void @f() optsize
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1035	</pre>
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1036	</div>
				1037
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1038	<dl>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1039	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1040	<dd>This attribute indicates that the inliner should attempt to inline this
				1041	function into callers whenever possible, ignoring any active inlining size
				1042	threshold for this caller.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1043
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1044	<dt><tt>noinline</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1045	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	0625c28	2008-10-05 17:14:59 +0000	[diff] [blame]	1046	in any situation. This attribute may not be used together with the
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1047	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1048
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1049	<dt><tt>optsize</tt></dt>
Devang Patel	e974390	2008-09-29 18:34:44 +0000	[diff] [blame]	1050	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1051	make choices that keep the code size of this function low, and otherwise do
				1052	optimizations specifically to reduce code size.</dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1053
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1054	<dt><tt>noreturn</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1055	<dd>This function attribute indicates that the function never returns normally.
				1056	This produces undefined behavior at runtime if the function ever does
				1057	dynamically return.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1058
				1059	<dt><tt>nounwind</tt></dt>
Chris Lattner	fbf60a4	2008-10-04 18:23:17 +0000	[diff] [blame]	1060	<dd>This function attribute indicates that the function never returns with an
				1061	unwind or exceptional control flow. If the function does unwind, its runtime
				1062	behavior is undefined.</dd>
				1063
				1064	<dt><tt>readnone</tt></dt>
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1065	<dd>This attribute indicates that the function computes its result (or decides to
				1066	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1067	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1068	registers, etc) visible to caller functions. It does not write through any
				1069	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1070	never changes any state visible to callers. This means that it cannot unwind
				1071	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1072	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	9eb525d	2008-09-26 23:51:19 +0000	[diff] [blame]	1073
Duncan Sands	2a1d8ba	2008-10-06 08:14:18 +0000	[diff] [blame]	1074	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1075	<dd>This attribute indicates that the function does not write through any
				1076	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1077	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1078	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	1efabaa	2009-05-06 06:49:50 +0000	[diff] [blame]	1079	be set in the caller. A readonly function always returns the same value (or
				1080	unwinds an exception identically) when called with the same set of arguments
				1081	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1082	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1083
				1084	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1085	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1086	protector. It is in the form of a "canary"—a random value placed on the
				1087	stack before the local variables that's checked upon return from the function to
				1088	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]	1089	needs stack protectors or not.
Bill Wendling	a813017	2008-11-13 01:02:51 +0000	[diff] [blame]	1090
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1091	<p>If a function that has an <tt>ssp</tt> attribute is inlined into a function
				1092	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
				1093	have an <tt>ssp</tt> attribute.</p></dd>
				1094
				1095	<dt><tt>sspreq</tt></dt>
Bill Wendling	6e41add	2008-11-26 19:19:05 +0000	[diff] [blame]	1096	<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]	1097	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]	1098	function attribute.
Bill Wendling	0f5541e	2008-11-26 19:07:40 +0000	[diff] [blame]	1099
				1100	<p>If a function that has an <tt>sspreq</tt> attribute is inlined into a
				1101	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1102	an <tt>ssp</tt> attribute, then the resulting function will have
				1103	an <tt>sspreq</tt> attribute.</p></dd>
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1104	</dl>
				1105
Devang Patel	caacdba	2008-09-04 23:05:13 +0000	[diff] [blame]	1106	</div>
				1107
				1108	<!-- ======================================================================= -->
				1109	<div class="doc_subsection">
Chris Lattner	9356489	2006-04-08 04:40:53 +0000	[diff] [blame]	1110	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1111	</div>
				1112
				1113	<div class="doc_text">
				1114	<p>
				1115	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1116	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1117	LLVM and treated as a single unit, but may be separated in the .ll file if
				1118	desired. The syntax is very simple:
				1119	</p>
				1120
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1121	<div class="doc_code">
				1122	<pre>
				1123	module asm "inline asm code goes here"
				1124	module asm "more can go here"
				1125	</pre>
				1126	</div>
Chris Lattner	91c15c4	2006-01-23 23:23:47 +0000	[diff] [blame]	1127
				1128	<p>The strings can contain any character by escaping non-printable characters.
				1129	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1130	for the number.
				1131	</p>
				1132
				1133	<p>
				1134	The inline asm code is simply printed to the machine code .s file when
				1135	assembly code is generated.
				1136	</p>
				1137	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1138
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1139	<!-- ======================================================================= -->
				1140	<div class="doc_subsection">
				1141	<a name="datalayout">Data Layout</a>
				1142	</div>
				1143
				1144	<div class="doc_text">
				1145	<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]	1146	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1147	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1148	<p>The <i>layout specification</i> consists of a list of specifications
				1149	separated by the minus sign character ('-'). Each specification starts with a
				1150	letter and may include other information after the letter to define some
				1151	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1152	<dl>
				1153	<dt><tt>E</tt></dt>
				1154	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1155	bits with the most significance have the lowest address location.</dd>
				1156	<dt><tt>e</tt></dt>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1157	<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]	1158	the bits with the least significance have the lowest address location.</dd>
				1159	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1160	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1161	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1162	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1163	too.</dd>
				1164	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1165	<dd>This specifies the alignment for an integer type of a given bit
				1166	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1167	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1168	<dd>This specifies the alignment for a vector type of a given bit
				1169	<i>size</i>.</dd>
				1170	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1171	<dd>This specifies the alignment for a floating point type of a given bit
				1172	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1173	(double).</dd>
				1174	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1175	<dd>This specifies the alignment for an aggregate type of a given bit
				1176	<i>size</i>.</dd>
				1177	</dl>
				1178	<p>When constructing the data layout for a given target, LLVM starts with a
				1179	default set of specifications which are then (possibly) overriden by the
				1180	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1181	are given in this list:</p>
				1182	<ul>
				1183	<li><tt>E</tt> - big endian</li>
				1184	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1185	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1186	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1187	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1188	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1189	<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]	1190	alignment of 64-bits</li>
				1191	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1192	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1193	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1194	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1195	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
				1196	</ul>
Chris Lattner	1ca5c64	2008-08-05 18:21:08 +0000	[diff] [blame]	1197	<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]	1198	following rules:</p>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1199	<ol>
				1200	<li>If the type sought is an exact match for one of the specifications, that
				1201	specification is used.</li>
				1202	<li>If no match is found, and the type sought is an integer type, then the
				1203	smallest integer type that is larger than the bitwidth of the sought type is
				1204	used. If none of the specifications are larger than the bitwidth then the the
				1205	largest integer type is used. For example, given the default specifications
				1206	above, the i7 type will use the alignment of i8 (next largest) while both
				1207	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1208	<li>If no match is found, and the type sought is a vector type, then the
				1209	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]	1210	as a fall back. This happens because <128 x double> can be implemented
				1211	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	1212	</ol>
				1213	</div>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1214
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1215	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1216	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1217	<!-- *********************************************************************** -->
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1218
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1219	<div class="doc_text">
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1220
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1221	<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]	1222	intermediate representation. Being typed enables a number of
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	1223	optimizations to be performed on the intermediate representation directly,
				1224	without having to do
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1225	extra analyses on the side before the transformation. A strong type
				1226	system makes it easier to read the generated code and enables novel
				1227	analyses and transformations that are not feasible to perform on normal
				1228	three address code representations.</p>
Chris Lattner	6af02f3	2004-12-09 16:11:40 +0000	[diff] [blame]	1229
				1230	</div>
				1231
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1232	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1233	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1234	Classifications</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1235	<div class="doc_text">
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1236	<p>The types fall into a few useful
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1237	classifications:</p>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1238
				1239	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1240	<tbody>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1241	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1242	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1243	<td><a href="#t_integer">integer</a></td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1244	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1245	</tr>
				1246	<tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1247	<td><a href="#t_floating">floating point</a></td>
				1248	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1249	</tr>
				1250	<tr>
				1251	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1252	<td><a href="#t_integer">integer</a>,
				1253	<a href="#t_floating">floating point</a>,
				1254	<a href="#t_pointer">pointer</a>,
Dan Gohman	08783a88	2008-06-18 18:42:13 +0000	[diff] [blame]	1255	<a href="#t_vector">vector</a>,
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	1256	<a href="#t_struct">structure</a>,
				1257	<a href="#t_array">array</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame^]	1258	<a href="#t_label">label</a>,
				1259	<a href="#t_metadata">metadata</a>.
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1260	</td>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1261	</tr>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1262	<tr>
				1263	<td><a href="#t_primitive">primitive</a></td>
				1264	<td><a href="#t_label">label</a>,
				1265	<a href="#t_void">void</a>,
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame^]	1266	<a href="#t_floating">floating point</a>,
				1267	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1268	</tr>
				1269	<tr>
				1270	<td><a href="#t_derived">derived</a></td>
				1271	<td><a href="#t_integer">integer</a>,
				1272	<a href="#t_array">array</a>,
				1273	<a href="#t_function">function</a>,
				1274	<a href="#t_pointer">pointer</a>,
				1275	<a href="#t_struct">structure</a>,
				1276	<a href="#t_pstruct">packed structure</a>,
				1277	<a href="#t_vector">vector</a>,
				1278	<a href="#t_opaque">opaque</a>.
Dan Gohman	93bf60d	2008-10-14 16:32:04 +0000	[diff] [blame]	1279	</td>
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1280	</tr>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1281	</tbody>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1282	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1283
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1284	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1285	most important. Values of these types are the only ones which can be
				1286	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	1287	instructions.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1288	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1289
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1290	<!-- ======================================================================= -->
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1291	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1292
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1293	<div class="doc_text">
				1294	<p>The primitive types are the fundamental building blocks of the LLVM
				1295	system.</p>
				1296
Chris Lattner	43542b3	2008-01-04 04:34:14 +0000	[diff] [blame]	1297	</div>
				1298
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1299	<!-- _______________________________________________________________________ -->
				1300	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1301
				1302	<div class="doc_text">
				1303	<table>
				1304	<tbody>
				1305	<tr><th>Type</th><th>Description</th></tr>
				1306	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1307	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1308	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1309	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1310	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1311	</tbody>
				1312	</table>
				1313	</div>
				1314
				1315	<!-- _______________________________________________________________________ -->
				1316	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1317
				1318	<div class="doc_text">
				1319	<h5>Overview:</h5>
				1320	<p>The void type does not represent any value and has no size.</p>
				1321
				1322	<h5>Syntax:</h5>
				1323
				1324	<pre>
				1325	void
				1326	</pre>
				1327	</div>
				1328
				1329	<!-- _______________________________________________________________________ -->
				1330	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1331
				1332	<div class="doc_text">
				1333	<h5>Overview:</h5>
				1334	<p>The label type represents code labels.</p>
				1335
				1336	<h5>Syntax:</h5>
				1337
				1338	<pre>
				1339	label
				1340	</pre>
				1341	</div>
				1342
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame^]	1343	<!-- _______________________________________________________________________ -->
				1344	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1345
				1346	<div class="doc_text">
				1347	<h5>Overview:</h5>
				1348	<p>The metadata type represents embedded metadata. The only derived type that
				1349	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1350	takes metadata typed parameters, but not pointer to metadata types.</p>
				1351
				1352	<h5>Syntax:</h5>
				1353
				1354	<pre>
				1355	metadata
				1356	</pre>
				1357	</div>
				1358
Chris Lattner	7824d18	2008-01-04 04:32:38 +0000	[diff] [blame]	1359
				1360	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1361	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1362
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1363	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1364
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1365	<p>The real power in LLVM comes from the derived types in the system.
				1366	This is what allows a programmer to represent arrays, functions,
				1367	pointers, and other useful types. Note that these derived types may be
				1368	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]	1369
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1370	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1371
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1372	<!-- _______________________________________________________________________ -->
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1373	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1374
				1375	<div class="doc_text">
				1376
				1377	<h5>Overview:</h5>
				1378	<p>The integer type is a very simple derived type that simply specifies an
				1379	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1380	2^23-1 (about 8 million) can be specified.</p>
				1381
				1382	<h5>Syntax:</h5>
				1383
				1384	<pre>
				1385	iN
				1386	</pre>
				1387
				1388	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1389	value.</p>
				1390
				1391	<h5>Examples:</h5>
				1392	<table class="layout">
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1393	<tr class="layout">
				1394	<td class="left"><tt>i1</tt></td>
				1395	<td class="left">a single-bit integer.</td>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1396	</tr>
Nick Lewycky	aab930a	2009-05-24 02:46:06 +0000	[diff] [blame]	1397	<tr class="layout">
				1398	<td class="left"><tt>i32</tt></td>
				1399	<td class="left">a 32-bit integer.</td>
				1400	</tr>
				1401	<tr class="layout">
				1402	<td class="left"><tt>i1942652</tt></td>
				1403	<td class="left">a really big integer of over 1 million bits.</td>
				1404	</tr>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1405	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1406
				1407	<p>Note that the code generator does not yet support large integer types
				1408	to be used as function return types. The specific limit on how large a
				1409	return type the code generator can currently handle is target-dependent;
				1410	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1411	targets.</p>
				1412
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1413	</div>
Reid Spencer	138249b	2007-05-16 18:44:01 +0000	[diff] [blame]	1414
				1415	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1416	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1417
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1418	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1419
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1420	<h5>Overview:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1421
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1422	<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]	1423	sequentially in memory. The array type requires a size (number of
				1424	elements) and an underlying data type.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1425
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1426	<h5>Syntax:</h5>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1427
				1428	<pre>
				1429	[<# elements> x <elementtype>]
				1430	</pre>
				1431
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	1432	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1433	be any type with a size.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1434
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1435	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1436	<table class="layout">
				1437	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1438	<td class="left"><tt>[40 x i32]</tt></td>
				1439	<td class="left">Array of 40 32-bit integer values.</td>
				1440	</tr>
				1441	<tr class="layout">
				1442	<td class="left"><tt>[41 x i32]</tt></td>
				1443	<td class="left">Array of 41 32-bit integer values.</td>
				1444	</tr>
				1445	<tr class="layout">
				1446	<td class="left"><tt>[4 x i8]</tt></td>
				1447	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1448	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1449	</table>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1450	<p>Here are some examples of multidimensional arrays:</p>
				1451	<table class="layout">
				1452	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1453	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1454	<td class="left">3x4 array of 32-bit integer values.</td>
				1455	</tr>
				1456	<tr class="layout">
				1457	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1458	<td class="left">12x10 array of single precision floating point values.</td>
				1459	</tr>
				1460	<tr class="layout">
				1461	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1462	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1463	</tr>
				1464	</table>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1465
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1466	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1467	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]	1468	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1469	As a special case, however, zero length arrays are recognized to be variable
				1470	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1471	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	1472
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1473	<p>Note that the code generator does not yet support large aggregate types
				1474	to be used as function return types. The specific limit on how large an
				1475	aggregate return type the code generator can currently handle is
				1476	target-dependent, and also dependent on the aggregate element types.</p>
				1477
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1478	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1479
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1480	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1481	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1482	<div class="doc_text">
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1483
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1484	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1485
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1486	<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]	1487	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]	1488	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]	1489	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]	1490	class types, and the struct must have at least one element.</p>
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1491
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1492	<h5>Syntax:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1493
				1494	<pre>
				1495	<returntype list> (<parameter list>)
				1496	</pre>
				1497
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	1498	<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]	1499	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	1500	which indicates that the function takes a variable number of arguments.
				1501	Variable argument functions can access their arguments with the <a
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	1502	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1503	'<tt><returntype list></tt>' is a comma-separated list of
				1504	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	1505
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1506	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1507	<table class="layout">
				1508	<tr class="layout">
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1509	<td class="left"><tt>i32 (i32)</tt></td>
				1510	<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]	1511	</td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1512	</tr><tr class="layout">
Reid Spencer	314e1cb	2007-07-19 23:13:04 +0000	[diff] [blame]	1513	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	655dcc6	2006-12-31 07:20:23 +0000	[diff] [blame]	1514	</tt></td>
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1515	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1516	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1517	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	58c0871	2006-12-31 07:18:34 +0000	[diff] [blame]	1518	<tt>float</tt>.
				1519	</td>
				1520	</tr><tr class="layout">
				1521	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1522	<td class="left">A vararg function that takes at least one
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1523	<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]	1524	which returns an integer. This is the signature for <tt>printf</tt> in
				1525	LLVM.
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1526	</td>
Devang Patel	e3dfc1c	2008-03-24 05:35:41 +0000	[diff] [blame]	1527	</tr><tr class="layout">
				1528	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	c9813bd	2008-11-27 06:41:20 +0000	[diff] [blame]	1529	<td class="left">A function taking an <tt>i32</tt>, returning two
				1530	<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]	1531	</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1532	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1533	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	1534
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1535	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1536	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1537	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1538	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1539	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1540	<p>The structure type is used to represent a collection of data members
				1541	together in memory. The packing of the field types is defined to match
				1542	the ABI of the underlying processor. The elements of a structure may
				1543	be any type that has a size.</p>
				1544	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1545	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1546	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1547	instruction.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1548	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1549	<pre> { <type list> }<br></pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1550	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1551	<table class="layout">
				1552	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1553	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1554	<td class="left">A triple of three <tt>i32</tt> values</td>
				1555	</tr><tr class="layout">
				1556	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1557	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1558	second element is a <a href="#t_pointer">pointer</a> to a
				1559	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1560	an <tt>i32</tt>.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1561	</tr>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1562	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1563
				1564	<p>Note that the code generator does not yet support large aggregate types
				1565	to be used as function return types. The specific limit on how large an
				1566	aggregate return type the code generator can currently handle is
				1567	target-dependent, and also dependent on the aggregate element types.</p>
				1568
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1569	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1570
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	1571	<!-- _______________________________________________________________________ -->
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1572	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1573	</div>
				1574	<div class="doc_text">
				1575	<h5>Overview:</h5>
				1576	<p>The packed structure type is used to represent a collection of data members
				1577	together in memory. There is no padding between fields. Further, the alignment
				1578	of a packed structure is 1 byte. The elements of a packed structure may
				1579	be any type that has a size.</p>
				1580	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1581	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1582	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1583	instruction.</p>
				1584	<h5>Syntax:</h5>
				1585	<pre> < { <type list> } > <br></pre>
				1586	<h5>Examples:</h5>
				1587	<table class="layout">
				1588	<tr class="layout">
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1589	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1590	<td class="left">A triple of three <tt>i32</tt> values</td>
				1591	</tr><tr class="layout">
Bill Wendling	b175fa4	2008-09-07 10:26:33 +0000	[diff] [blame]	1592	<td class="left">
				1593	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1594	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1595	second element is a <a href="#t_pointer">pointer</a> to a
				1596	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1597	an <tt>i32</tt>.</td>
Andrew Lenharth	8df88e2	2006-12-08 17:13:00 +0000	[diff] [blame]	1598	</tr>
				1599	</table>
				1600	</div>
				1601
				1602	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1603	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1604	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1605	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1606	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	308121c	2007-12-11 09:31:00 +0000	[diff] [blame]	1607	reference to another object, which must live in memory. Pointer types may have
				1608	an optional address space attribute defining the target-specific numbered
				1609	address space where the pointed-to object resides. The default address space is
				1610	zero.</p>
Chris Lattner	4a67c91	2009-02-08 19:53:29 +0000	[diff] [blame]	1611
				1612	<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]	1613	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]	1614
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1615	<h5>Syntax:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	1616	<pre> <type> *<br></pre>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	1617	<h5>Examples:</h5>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1618	<table class="layout">
				1619	<tr class="layout">
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	1620	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1621	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1622	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1623	</tr>
				1624	<tr class="layout">
				1625	<td class="left"><tt>i32 (i32 ) </tt></td>
				1626	<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]	1627	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]	1628	<tt>i32</tt>.</td>
				1629	</tr>
				1630	<tr class="layout">
				1631	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1632	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1633	that resides in address space #5.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1634	</tr>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1635	</table>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1636	</div>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1637
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1638	<!-- _______________________________________________________________________ -->
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1639	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1640	<div class="doc_text">
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1641
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1642	<h5>Overview:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1643
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1644	<p>A vector type is a simple derived type that represents a vector
				1645	of elements. Vector types are used when multiple primitive data
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1646	are operated in parallel using a single instruction (SIMD).
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1647	A vector type requires a size (number of
Chris Lattner	330ce69	2005-11-10 01:44:22 +0000	[diff] [blame]	1648	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1649	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1650	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1651
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1652	<h5>Syntax:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1653
				1654	<pre>
				1655	< <# elements> x <elementtype> >
				1656	</pre>
				1657
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1658	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	1659	be any integer or floating point type.</p>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1660
Chris Lattner	c8cb695	2004-08-12 19:12:28 +0000	[diff] [blame]	1661	<h5>Examples:</h5>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1662
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1663	<table class="layout">
				1664	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1665	<td class="left"><tt><4 x i32></tt></td>
				1666	<td class="left">Vector of 4 32-bit integer values.</td>
				1667	</tr>
				1668	<tr class="layout">
				1669	<td class="left"><tt><8 x float></tt></td>
				1670	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1671	</tr>
				1672	<tr class="layout">
				1673	<td class="left"><tt><2 x i64></tt></td>
				1674	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	c3c4c4f	2004-11-01 08:19:36 +0000	[diff] [blame]	1675	</tr>
				1676	</table>
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	1677
				1678	<p>Note that the code generator does not yet support large vector types
				1679	to be used as function return types. The specific limit on how large a
				1680	vector return type codegen can currently handle is target-dependent;
				1681	currently it's often a few times longer than a hardware vector register.</p>
				1682
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	1683	</div>
				1684
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1685	<!-- _______________________________________________________________________ -->
				1686	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1687	<div class="doc_text">
				1688
				1689	<h5>Overview:</h5>
				1690
				1691	<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]	1692	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]	1693	In LLVM, opaque types can eventually be resolved to any type (not just a
				1694	structure type).</p>
				1695
				1696	<h5>Syntax:</h5>
				1697
				1698	<pre>
				1699	opaque
				1700	</pre>
				1701
				1702	<h5>Examples:</h5>
				1703
				1704	<table class="layout">
				1705	<tr class="layout">
Chris Lattner	747359f	2007-12-19 05:04:11 +0000	[diff] [blame]	1706	<td class="left"><tt>opaque</tt></td>
				1707	<td class="left">An opaque type.</td>
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1708	</tr>
				1709	</table>
				1710	</div>
				1711
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1712	<!-- ======================================================================= -->
				1713	<div class="doc_subsection">
				1714	<a name="t_uprefs">Type Up-references</a>
				1715	</div>
				1716
				1717	<div class="doc_text">
				1718	<h5>Overview:</h5>
				1719	<p>
				1720	An "up reference" allows you to refer to a lexically enclosing type without
				1721	requiring it to have a name. For instance, a structure declaration may contain a
				1722	pointer to any of the types it is lexically a member of. Example of up
				1723	references (with their equivalent as named type declarations) include:</p>
				1724
				1725	<pre>
Chris Lattner	bf1d545	2009-02-09 10:00:56 +0000	[diff] [blame]	1726	{ \2 * } %x = type { %x* }
Chris Lattner	cf7a584	2009-02-02 07:32:36 +0000	[diff] [blame]	1727	{ \2 }* %y = type { %y }*
				1728	\1* %z = type %z*
				1729	</pre>
				1730
				1731	<p>
				1732	An up reference is needed by the asmprinter for printing out cyclic types when
				1733	there is no declared name for a type in the cycle. Because the asmprinter does
				1734	not want to print out an infinite type string, it needs a syntax to handle
				1735	recursive types that have no names (all names are optional in llvm IR).
				1736	</p>
				1737
				1738	<h5>Syntax:</h5>
				1739	<pre>
				1740	\<level>
				1741	</pre>
				1742
				1743	<p>
				1744	The level is the count of the lexical type that is being referred to.
				1745	</p>
				1746
				1747	<h5>Examples:</h5>
				1748
				1749	<table class="layout">
				1750	<tr class="layout">
				1751	<td class="left"><tt>\1*</tt></td>
				1752	<td class="left">Self-referential pointer.</td>
				1753	</tr>
				1754	<tr class="layout">
				1755	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1756	<td class="left">Recursive structure where the upref refers to the out-most
				1757	structure.</td>
				1758	</tr>
				1759	</table>
				1760	</div>
				1761
Chris Lattner	37b6b09	2005-04-25 17:34:15 +0000	[diff] [blame]	1762
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1763	<!-- *********************************************************************** -->
				1764	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1765	<!-- *********************************************************************** -->
				1766
				1767	<div class="doc_text">
				1768
				1769	<p>LLVM has several different basic types of constants. This section describes
				1770	them all and their syntax.</p>
				1771
				1772	</div>
				1773
				1774	<!-- ======================================================================= -->
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1775	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1776
				1777	<div class="doc_text">
				1778
				1779	<dl>
				1780	<dt><b>Boolean constants</b></dt>
				1781
				1782	<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]	1783	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1784	</dd>
				1785
				1786	<dt><b>Integer constants</b></dt>
				1787
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1788	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	3e628eb9	2007-01-04 16:43:23 +0000	[diff] [blame]	1789	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1790	integer types.
				1791	</dd>
				1792
				1793	<dt><b>Floating point constants</b></dt>
				1794
				1795	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1796	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	1797	notation (see below). The assembler requires the exact decimal value of
				1798	a floating-point constant. For example, the assembler accepts 1.25 but
				1799	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1800	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]	1801
				1802	<dt><b>Null pointer constants</b></dt>
				1803
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1804	<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]	1805	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1806
				1807	</dl>
				1808
Dale Johannesen	cd4a301	2009-02-11 22:14:51 +0000	[diff] [blame]	1809	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1810	of floating point constants. For example, the form '<tt>double
				1811	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1812	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]	1813	(and the only time that they are generated by the disassembler) is when a
				1814	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]	1815	decimal floating point number in a reasonable number of digits. For example,
				1816	NaN's, infinities, and other
Reid Spencer	8f08d80	2004-12-09 18:02:53 +0000	[diff] [blame]	1817	special values are represented in their IEEE hexadecimal format so that
				1818	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]	1819	<p>When using the hexadecimal form, constants of types float and double are
				1820	represented using the 16-digit form shown above (which matches the IEEE754
				1821	representation for double); float values must, however, be exactly representable
				1822	as IEE754 single precision.
				1823	Hexadecimal format is always used for long
				1824	double, and there are three forms of long double. The 80-bit
				1825	format used by x86 is represented as <tt>0xK</tt>
				1826	followed by 20 hexadecimal digits.
				1827	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1828	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1829	format is represented
				1830	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1831	target uses this format. Long doubles will only work if they match
				1832	the long double format on your target. All hexadecimal formats are big-endian
				1833	(sign bit at the left).</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1834	</div>
				1835
				1836	<!-- ======================================================================= -->
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1837	<div class="doc_subsection">
				1838	<a name="aggregateconstants"> <!-- old anchor -->
				1839	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1840	</div>
				1841
				1842	<div class="doc_text">
Chris Lattner	361bfcd	2009-02-28 18:32:25 +0000	[diff] [blame]	1843	<p>Complex constants are a (potentially recursive) combination of simple
				1844	constants and smaller complex constants.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1845
				1846	<dl>
				1847	<dt><b>Structure constants</b></dt>
				1848
				1849	<dd>Structure constants are represented with notation similar to structure
				1850	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	bea1117	2007-12-25 20:34:52 +0000	[diff] [blame]	1851	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1852	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]	1853	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]	1854	types of elements must match those specified by the type.
				1855	</dd>
				1856
				1857	<dt><b>Array constants</b></dt>
				1858
				1859	<dd>Array constants are represented with notation similar to array type
				1860	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1861	(<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]	1862	constants must have <a href="#t_array">array type</a>, and the number and
				1863	types of elements must match those specified by the type.
				1864	</dd>
				1865
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1866	<dt><b>Vector constants</b></dt>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1867
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1868	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1869	definitions (a comma separated list of elements, surrounded by
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	1870	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	1871	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	1872	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]	1873	match those specified by the type.
				1874	</dd>
				1875
				1876	<dt><b>Zero initialization</b></dt>
				1877
				1878	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1879	value to zero of <em>any</em> type, including scalar and aggregate types.
				1880	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]	1881	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1882	initializers.
				1883	</dd>
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1884
				1885	<dt><b>Metadata node</b></dt>
				1886
				1887	<dd>A metadata node is a structure-like constant with the type of an empty
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame^]	1888	struct. For example: "<tt>metadata !{ i32 0, metadata !"test" }</tt>".
				1889	Unlike other constants that are meant to be interpreted as part of the
				1890	instruction stream, metadata is a place to attach additional information such
				1891	as debug info.
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	1892	</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1893	</dl>
				1894
				1895	</div>
				1896
				1897	<!-- ======================================================================= -->
				1898	<div class="doc_subsection">
				1899	<a name="globalconstants">Global Variable and Function Addresses</a>
				1900	</div>
				1901
				1902	<div class="doc_text">
				1903
				1904	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1905	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	1906	constants. These constants are explicitly referenced when the <a
				1907	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]	1908	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1909	file:</p>
				1910
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1911	<div class="doc_code">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1912	<pre>
Chris Lattner	00538a1	2007-06-06 18:28:13 +0000	[diff] [blame]	1913	@X = global i32 17
				1914	@Y = global i32 42
				1915	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1916	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	1917	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1918
				1919	</div>
				1920
				1921	<!-- ======================================================================= -->
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1922	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1923	<div class="doc_text">
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1924	<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]	1925	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]	1926	a constant is permitted.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1927
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	1928	<p>Undefined values indicate to the compiler that the program is well defined
				1929	no matter what value is used, giving the compiler more freedom to optimize.
				1930	</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1931	</div>
				1932
				1933	<!-- ======================================================================= -->
				1934	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1935	</div>
				1936
				1937	<div class="doc_text">
				1938
				1939	<p>Constant expressions are used to allow expressions involving other constants
				1940	to be used as constants. Constant expressions may be of any <a
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	1941	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]	1942	that does not have side effects (e.g. load and call are not supported). The
				1943	following is the syntax for constant expressions:</p>
				1944
				1945	<dl>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1946	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1947	<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]	1948	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	1949
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1950	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1951	<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]	1952	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]	1953
				1954	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1955	<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]	1956	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]	1957
				1958	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1959	<dd>Truncate a floating point constant to another floating point type. The
				1960	size of CST must be larger than the size of TYPE. Both types must be
				1961	floating point.</dd>
				1962
				1963	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				1964	<dd>Floating point extend a constant to another type. The size of CST must be
				1965	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				1966
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	1967	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1968	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1969	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1970	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1971	of the same number of elements. If the value won't fit in the integer type,
				1972	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1973
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1974	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1975	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1976	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				1977	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				1978	of the same number of elements. If the value won't fit in the integer type,
				1979	the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1980
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1981	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1982	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1983	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1984	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1985	of the same number of elements. If the value won't fit in the floating point
				1986	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1987
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	1988	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1989	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	1990	constant. TYPE must be a scalar or vector floating point type. CST must be of
				1991	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				1992	of the same number of elements. If the value won't fit in the floating point
				1993	type, the results are undefined.</dd>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	1994
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	1995	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				1996	<dd>Convert a pointer typed constant to the corresponding integer constant
				1997	TYPE must be an integer type. CST must be of pointer type. The CST value is
				1998	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				1999
				2000	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2001	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2002	pointer type. CST must be of integer type. The CST value is zero extended,
				2003	truncated, or unchanged to make it fit in a pointer size. This one is
				2004	<i>really</i> dangerous!</dd>
				2005
				2006	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	789dee3	2009-02-28 18:27:03 +0000	[diff] [blame]	2007	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2008	are the same as those for the <a href="#i_bitcast">bitcast
				2009	instruction</a>.</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2010
				2011	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2012
				2013	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2014	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2015	instruction, the index list may have zero or more indexes, which are required
				2016	to make sense for the type of "CSTPTR".</dd>
				2017
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2018	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2019
				2020	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2021	constants.</dd>
				2022
				2023	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2024	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2025
				2026	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2027	<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]	2028
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	2029	<dt><b><tt>vicmp COND ( VAL1, VAL2 )</tt></b></dt>
				2030	<dd>Performs the <a href="#i_vicmp">vicmp operation</a> on constants.</dd>
				2031
				2032	<dt><b><tt>vfcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2033	<dd>Performs the <a href="#i_vfcmp">vfcmp operation</a> on constants.</dd>
				2034
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2035	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2036
				2037	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2038	operation</a> on constants.</dd>
Robert Bocchino	7e97a6d	2006-01-10 19:31:34 +0000	[diff] [blame]	2039
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2040	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2041
				2042	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2043	operation</a> on constants.</dd>
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	2044
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2045
				2046	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2047
				2048	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	9965ee7	2006-12-04 19:23:19 +0000	[diff] [blame]	2049	operation</a> on constants.</dd>
Chris Lattner	016a0e5	2006-04-08 00:13:41 +0000	[diff] [blame]	2050
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2051	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2052
Reid Spencer	641f5c9	2004-12-09 18:13:12 +0000	[diff] [blame]	2053	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2054	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]	2055	binary</a> operations. The constraints on operands are the same as those for
				2056	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2057	values are allowed).</dd>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2058	</dl>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2059	</div>
Chris Lattner	b165261	2004-03-08 16:49:10 +0000	[diff] [blame]	2060
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2061	<!-- ======================================================================= -->
				2062	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2063	</div>
				2064
				2065	<div class="doc_text">
				2066
				2067	<p>Embedded metadata provides a way to attach arbitrary data to the
				2068	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	adbc284	2009-05-30 05:06:04 +0000	[diff] [blame^]	2069	two metadata primitives, strings and nodes. All metadata has the
				2070	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2071	point ('<tt>!</tt>').
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2072	</p>
				2073
				2074	<p>A metadata string is a string surrounded by double quotes. It can contain
				2075	any character by escaping non-printable characters with "\xx" where "xx" is
				2076	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2077	</p>
				2078
				2079	<p>Metadata nodes are represented with notation similar to structure constants
				2080	(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^]	2081	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2082	</p>
				2083
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2084	<p>A metadata node will attempt to track changes to the values it holds. In
				2085	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^]	2086	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	b8f9b7a	2009-05-10 20:57:05 +0000	[diff] [blame]	2087
Nick Lewycky	49f8919	2009-04-04 07:22:01 +0000	[diff] [blame]	2088	<p>Optimizations may rely on metadata to provide additional information about
				2089	the program that isn't available in the instructions, or that isn't easily
				2090	computable. Similarly, the code generator may expect a certain metadata format
				2091	to be used to express debugging information.</p>
				2092	</div>
				2093
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2094	<!-- *********************************************************************** -->
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2095	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2096	<!-- *********************************************************************** -->
				2097
				2098	<!-- ======================================================================= -->
				2099	<div class="doc_subsection">
				2100	<a name="inlineasm">Inline Assembler Expressions</a>
				2101	</div>
				2102
				2103	<div class="doc_text">
				2104
				2105	<p>
				2106	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2107	Module-Level Inline Assembly</a>) through the use of a special value. This
				2108	value represents the inline assembler as a string (containing the instructions
				2109	to emit), a list of operand constraints (stored as a string), and a flag that
				2110	indicates whether or not the inline asm expression has side effects. An example
				2111	inline assembler expression is:
				2112	</p>
				2113
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2114	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2115	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2116	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2117	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2118	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2119
				2120	<p>
				2121	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2122	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2123	</p>
				2124
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2125	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2126	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2127	%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]	2128	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2129	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2130
				2131	<p>
				2132	Inline asms with side effects not visible in the constraint list must be marked
				2133	as having side effects. This is done through the use of the
				2134	'<tt>sideeffect</tt>' keyword, like so:
				2135	</p>
				2136
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2137	<div class="doc_code">
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2138	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2139	call void asm sideeffect "eieio", ""()
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2140	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	2141	</div>
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2142
				2143	<p>TODO: The format of the asm and constraints string still need to be
				2144	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]	2145	need to be documented). This is probably best done by reference to another
				2146	document that covers inline asm from a holistic perspective.
Chris Lattner	98f013c	2006-01-25 23:47:57 +0000	[diff] [blame]	2147	</p>
				2148
				2149	</div>
				2150
				2151	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2152	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2153	<!-- *********************************************************************** -->
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2154
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2155	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2156
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2157	<p>The LLVM instruction set consists of several different
				2158	classifications of instructions: <a href="#terminators">terminator
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	2159	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2160	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2161	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2162	instructions</a>.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2163
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2164	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2165
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2166	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2167	<div class="doc_subsection"> <a name="terminators">Terminator
				2168	Instructions</a> </div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2169
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2170	<div class="doc_text">
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2171
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2172	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2173	basic block in a program ends with a "Terminator" instruction, which
				2174	indicates which block should be executed after the current block is
				2175	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2176	value: they produce control flow, not values (the one exception being
				2177	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	2178	<p>There are six different terminator instructions: the '<a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2179	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2180	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2181	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2182	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2183	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2184
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2185	</div>
Chris Lattner	74d3f82	2004-12-09 17:30:23 +0000	[diff] [blame]	2186
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2187	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2188	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2189	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2190	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2191	<h5>Syntax:</h5>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2192	<pre>
				2193	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]	2194	ret void <i>; Return from void function</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2195	</pre>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2196
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2197	<h5>Overview:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2198
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2199	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2200	optionally a value) from a function back to the caller.</p>
John Criswell	417228d	2004-04-09 16:48:45 +0000	[diff] [blame]	2201	<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]	2202	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]	2203	control flow to occur.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2204
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2205	<h5>Arguments:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2206
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	2207	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2208	the return value. The type of the return value must be a
				2209	'<a href="#t_firstclass">first class</a>' type.</p>
				2210
				2211	<p>A function is not <a href="#wellformed">well formed</a> if
				2212	it it has a non-void return type and contains a '<tt>ret</tt>'
				2213	instruction with no return value or a return value with a type that
				2214	does not match its type, or if it has a void return type and contains
				2215	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2216
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2217	<h5>Semantics:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2218
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2219	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2220	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]	2221	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2222	the instruction after the call. If the caller was an "<a
				2223	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2224	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2225	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]	2226	return value.</p>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2227
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2228	<h5>Example:</h5>
Chris Lattner	da508ac	2008-04-23 04:59:35 +0000	[diff] [blame]	2229
				2230	<pre>
				2231	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	2232	ret void <i>; Return from a void function</i>
Bill Wendling	050ee8f	2009-02-28 22:12:54 +0000	[diff] [blame]	2233	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]	2234	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2235
Dan Gohman	142ccc0	2009-01-24 15:58:40 +0000	[diff] [blame]	2236	<p>Note that the code generator does not yet fully support large
				2237	return values. The specific sizes that are currently supported are
				2238	dependent on the target. For integers, on 32-bit targets the limit
				2239	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2240	For aggregate types, the current limits are dependent on the element
				2241	types; for example targets are often limited to 2 total integer
				2242	elements and 2 total floating-point elements.</p>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	2243
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2244	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2245	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2246	<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]	2247	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2248	<h5>Syntax:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2249	<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]	2250	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2251	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2252	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2253	transfer to a different basic block in the current function. There are
				2254	two forms of this instruction, corresponding to a conditional branch
				2255	and an unconditional branch.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2256	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2257	<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]	2258	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	50c723a	2007-02-19 23:54:10 +0000	[diff] [blame]	2259	unconditional form of the '<tt>br</tt>' instruction takes a single
				2260	'<tt>label</tt>' value as a target.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2261	<h5>Semantics:</h5>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2262	<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]	2263	argument is evaluated. If the value is <tt>true</tt>, control flows
				2264	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2265	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	<h5>Example:</h5>
Chris Lattner	e648c28	2009-05-09 18:11:50 +0000	[diff] [blame]	2267	<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]	2268	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]	2269	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2270	<!-- _______________________________________________________________________ -->
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2271	<div class="doc_subsubsection">
				2272	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2273	</div>
				2274
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2275	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2276	<h5>Syntax:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2277
				2278	<pre>
				2279	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2280	</pre>
				2281
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	<h5>Overview:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2283
				2284	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2285	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2286	instruction, allowing a branch to occur to one of many possible
				2287	destinations.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2288
				2289
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2290	<h5>Arguments:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2291
				2292	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2293	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2294	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2295	table is not allowed to contain duplicate constant entries.</p>
				2296
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2297	<h5>Semantics:</h5>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2298
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2299	<p>The <tt>switch</tt> instruction specifies a table of values and
				2300	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2301	table is searched for the given value. If the value is found, control flow is
				2302	transfered to the corresponding destination; otherwise, control flow is
				2303	transfered to the default destination.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2304
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2305	<h5>Implementation:</h5>
				2306
				2307	<p>Depending on properties of the target machine and the particular
				2308	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	bcbb18c	2004-06-25 16:05:06 +0000	[diff] [blame]	2309	ways. For example, it could be generated as a series of chained conditional
				2310	branches or with a lookup table.</p>
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2311
				2312	<h5>Example:</h5>
				2313
				2314	<pre>
				2315	<i>; Emulate a conditional br instruction</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	2316	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2317	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2318
				2319	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2320	switch i32 0, label %dest [ ]
Chris Lattner	cf96c6c	2004-02-24 04:54:45 +0000	[diff] [blame]	2321
				2322	<i>; Implement a jump table:</i>
Dan Gohman	623806e	2009-01-04 23:44:43 +0000	[diff] [blame]	2323	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2324	i32 1, label %onone
				2325	i32 2, label %ontwo ]
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2326	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2327	</div>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2328
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2329	<!-- _______________________________________________________________________ -->
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2330	<div class="doc_subsubsection">
				2331	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2332	</div>
				2333
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2334	<div class="doc_text">
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2335
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2336	<h5>Syntax:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2337
				2338	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2339	<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]	2340	to label <normal label> unwind label <exception label>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2341	</pre>
				2342
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	2343	<h5>Overview:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2344
				2345	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2346	function, with the possibility of control flow transfer to either the
John Criswell	02fdc6f	2005-05-12 16:52:32 +0000	[diff] [blame]	2347	'<tt>normal</tt>' label or the
				2348	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2349	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2350	"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]	2351	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	2352	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2353
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2354	<h5>Arguments:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2355
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2356	<p>This instruction requires several arguments:</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2357
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2358	<ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2359	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	2360	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2361	convention</a> the call should use. If none is specified, the call defaults
				2362	to using C calling conventions.
				2363	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2364
				2365	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2366	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2367	and '<tt>inreg</tt>' attributes are valid here.</li>
				2368
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2369	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2370	function value being invoked. In most cases, this is a direct function
				2371	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2372	an arbitrary pointer to function value.
				2373	</li>
				2374
				2375	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2376	function to be invoked. </li>
				2377
				2378	<li>'<tt>function args</tt>': argument list whose types match the function
				2379	signature argument types. If the function signature indicates the function
				2380	accepts a variable number of arguments, the extra arguments can be
				2381	specified. </li>
				2382
				2383	<li>'<tt>normal label</tt>': the label reached when the called function
				2384	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2385
				2386	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2387	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2388
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	2389	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	2390	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2391	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2392	</ol>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2393
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2394	<h5>Semantics:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2395
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2396	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2397	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2398	difference is that it establishes an association with a label, which is used by
				2399	the runtime library to unwind the stack.</p>
				2400
				2401	<p>This instruction is used in languages with destructors to ensure that proper
				2402	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2403	exception. Additionally, this is important for implementation of
				2404	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2405
Dan Gohman	9069d89	2009-05-22 21:47:08 +0000	[diff] [blame]	2406	<p>It is not valid to reference the return value of an invoke call from
				2407	anywhere not dominated by the normal label, since an unwind does not
				2408	provide a return value.</p>
				2409
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2410	<h5>Example:</h5>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	2411	<pre>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2412	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2413	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	084ab47	2008-03-16 07:18:12 +0000	[diff] [blame]	2414	%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]	2415	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2416	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2417	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2418
				2419
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2420	<!-- _______________________________________________________________________ -->
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2421
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2422	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2423	Instruction</a> </div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2424
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2425	<div class="doc_text">
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2426
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2427	<h5>Syntax:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2428	<pre>
				2429	unwind
				2430	</pre>
				2431
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2432	<h5>Overview:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2433
				2434	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2435	at the first callee in the dynamic call stack which used an <a
				2436	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2437	primarily used to implement exception handling.</p>
				2438
Chris Lattner	5ed6061	2003-09-03 00:41:47 +0000	[diff] [blame]	2439	<h5>Semantics:</h5>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2440
Chris Lattner	fe8519c	2008-04-19 21:01:16 +0000	[diff] [blame]	2441	<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]	2442	immediately halt. The dynamic call stack is then searched for the first <a
				2443	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2444	execution continues at the "exceptional" destination block specified by the
				2445	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2446	dynamic call chain, undefined behavior results.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2447	</div>
Chris Lattner	08b7d5b	2004-10-16 18:04:13 +0000	[diff] [blame]	2448
				2449	<!-- _______________________________________________________________________ -->
				2450
				2451	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2452	Instruction</a> </div>
				2453
				2454	<div class="doc_text">
				2455
				2456	<h5>Syntax:</h5>
				2457	<pre>
				2458	unreachable
				2459	</pre>
				2460
				2461	<h5>Overview:</h5>
				2462
				2463	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2464	instruction is used to inform the optimizer that a particular portion of the
				2465	code is not reachable. This can be used to indicate that the code after a
				2466	no-return function cannot be reached, and other facts.</p>
				2467
				2468	<h5>Semantics:</h5>
				2469
				2470	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2471	</div>
				2472
				2473
				2474
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2475	<!-- ======================================================================= -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2476	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2477	<div class="doc_text">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2478	<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]	2479	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]	2480	produce a single value. The operands might represent
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	2481	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]	2482	The result value has the same type as its operands.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2483	<p>There are several different binary operators:</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2484	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2485	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2486	<div class="doc_subsubsection">
				2487	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2488	</div>
				2489
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2490	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2491
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2492	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2493
				2494	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2495	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2496	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2497
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2498	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2499
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2500	<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]	2501
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2502	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2503
				2504	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
				2505	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>, or
				2506	<a href="#t_vector">vector</a> values. Both arguments must have identical
				2507	types.</p>
				2508
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2509	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2510
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2511	<p>The value produced is the integer or floating point sum of the two
				2512	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2513
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2514	<p>If an integer sum has unsigned overflow, the result returned is the
				2515	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2516	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2517
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2518	<p>Because LLVM integers use a two's complement representation, this
				2519	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2520
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2521	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2522
				2523	<pre>
				2524	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2525	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2526	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2527	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2528	<div class="doc_subsubsection">
				2529	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2530	</div>
				2531
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2532	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2533
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2534	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2535
				2536	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2537	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2538	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2539
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2540	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2541
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2542	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2543	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2544
				2545	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2546	'<tt>neg</tt>' instruction present in most other intermediate
				2547	representations.</p>
				2548
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2549	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2550
				2551	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
				2552	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2553	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2554	types.</p>
				2555
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2556	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2557
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2558	<p>The value produced is the integer or floating point difference of
				2559	the two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2560
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2561	<p>If an integer difference has unsigned overflow, the result returned is the
				2562	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2563	the result.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2564
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2565	<p>Because LLVM integers use a two's complement representation, this
				2566	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2567
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2568	<h5>Example:</h5>
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	2569	<pre>
				2570	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2571	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2572	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2573	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2574
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2575	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2576	<div class="doc_subsubsection">
				2577	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2578	</div>
				2579
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2580	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2581
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2582	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2583	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2584	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2585	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2586	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2587	operands.</p>
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>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2590
				2591	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
				2592	href="#t_integer">integer</a>, <a href="#t_floating">floating point</a>,
				2593	or <a href="#t_vector">vector</a> values. Both arguments must have identical
				2594	types.</p>
				2595
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2596	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2597
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2598	<p>The value produced is the integer or floating point product of the
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2599	two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2600
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2601	<p>If the result of an integer multiplication has unsigned overflow,
				2602	the result returned is the mathematical result modulo
				2603	2<sup>n</sup>, where n is the bit width of the result.</p>
				2604	<p>Because LLVM integers use a two's complement representation, and the
				2605	result is the same width as the operands, this instruction returns the
				2606	correct result for both signed and unsigned integers. If a full product
				2607	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2608	should be sign-extended or zero-extended as appropriate to the
				2609	width of the full product.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2610	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2611	<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]	2612	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2613	</div>
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	<!-- _______________________________________________________________________ -->
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2616	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2617	</a></div>
				2618	<div class="doc_text">
				2619	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2620	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2621	</pre>
				2622	<h5>Overview:</h5>
				2623	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2624	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2625
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2626	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2627
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2628	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2629	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2630	values. Both arguments must have identical types.</p>
				2631
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2632	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2633
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2634	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2635	<p>Note that unsigned integer division and signed integer division are distinct
				2636	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2637	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2638	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2639	<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]	2640	</pre>
				2641	</div>
				2642	<!-- _______________________________________________________________________ -->
				2643	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2644	</a> </div>
				2645	<div class="doc_text">
				2646	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2647	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2648	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2649	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2650
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2651	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2652
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2653	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2654	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2655
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2656	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2657
				2658	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2659	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2660	values. Both arguments must have identical types.</p>
				2661
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2662	<h5>Semantics:</h5>
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2663	<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]	2664	<p>Note that signed integer division and unsigned integer division are distinct
				2665	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2666	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2667	undefined behavior; this is a rare case, but can occur, for example,
				2668	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2669	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2670	<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]	2671	</pre>
				2672	</div>
				2673	<!-- _______________________________________________________________________ -->
				2674	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2675	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2676	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2677	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2678	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2679	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2680	</pre>
				2681	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2682
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2683	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2684	operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2685
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2686	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2687
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2688	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2689	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2690	of floating point values. Both arguments must have identical types.</p>
				2691
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2692	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2693
Reid Spencer	7e80b0b	2006-10-26 06:15:43 +0000	[diff] [blame]	2694	<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]	2695
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2696	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2697
				2698	<pre>
				2699	<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]	2700	</pre>
				2701	</div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2702
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2703	<!-- _______________________________________________________________________ -->
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2704	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2705	</div>
				2706	<div class="doc_text">
				2707	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2708	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2709	</pre>
				2710	<h5>Overview:</h5>
				2711	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2712	unsigned division of its two arguments.</p>
				2713	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2714	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2715	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2716	values. Both arguments must have identical types.</p>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2717	<h5>Semantics:</h5>
				2718	<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]	2719	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2720	<p>Note that unsigned integer remainder and signed integer remainder are
				2721	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2722	<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]	2723	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2724	<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]	2725	</pre>
				2726
				2727	</div>
				2728	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2729	<div class="doc_subsubsection">
				2730	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2731	</div>
				2732
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2733	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2734
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2735	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2736
				2737	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2738	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2739	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2740
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2741	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2742
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2743	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	08143e3	2007-11-05 23:35:22 +0000	[diff] [blame]	2744	signed division of its two operands. This instruction can also take
				2745	<a href="#t_vector">vector</a> versions of the values in which case
				2746	the elements must be integers.</p>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	2747
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2748	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2749
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2750	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2751	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2752	values. Both arguments must have identical types.</p>
				2753
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2754	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2755
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2756	<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]	2757	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2758	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]	2759	a value. For more information about the difference, see <a
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2760	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]	2761	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]	2762	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	806ad6a	2007-03-24 22:23:39 +0000	[diff] [blame]	2763	Wikipedia: modulo operation</a>.</p>
Chris Lattner	2f2427e	2008-01-28 00:36:27 +0000	[diff] [blame]	2764	<p>Note that signed integer remainder and unsigned integer remainder are
				2765	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2766	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2767	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2768	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2769	(The remainder doesn't actually overflow, but this rule lets srem be
				2770	implemented using instructions that return both the result of the division
				2771	and the remainder.)</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2772	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2773	<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]	2774	</pre>
				2775
				2776	</div>
				2777	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2778	<div class="doc_subsubsection">
				2779	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2780
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2781	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2782
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2783	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2784	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2785	</pre>
				2786	<h5>Overview:</h5>
				2787	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2788	division of its two operands.</p>
				2789	<h5>Arguments:</h5>
				2790	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2791	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2792	of floating point values. Both arguments must have identical types.</p>
				2793
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2794	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2795
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2796	<p>This instruction returns the <i>remainder</i> of a division.
				2797	The remainder has the same sign as the dividend.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2798
Reid Spencer	7eb55b3	2006-11-02 01:53:59 +0000	[diff] [blame]	2799	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2800
				2801	<pre>
				2802	<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]	2803	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2804	</div>
Robert Bocchino	820bc75b	2006-02-17 21:18:08 +0000	[diff] [blame]	2805
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2806	<!-- ======================================================================= -->
				2807	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2808	Operations</a> </div>
				2809	<div class="doc_text">
				2810	<p>Bitwise binary operators are used to do various forms of
				2811	bit-twiddling in a program. They are generally very efficient
				2812	instructions and can commonly be strength reduced from other
Chris Lattner	1429e6f	2008-04-01 18:45:27 +0000	[diff] [blame]	2813	instructions. They require two operands of the same type, execute an operation on them,
				2814	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]	2815	</div>
				2816
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2817	<!-- _______________________________________________________________________ -->
				2818	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2819	Instruction</a> </div>
				2820	<div class="doc_text">
				2821	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2822	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2823	</pre>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2824
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2825	<h5>Overview:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2826
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2827	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2828	the left a specified number of bits.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2829
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2830	<h5>Arguments:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2831
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2832	<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]	2833	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]	2834	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2835
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2836	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2837
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2838	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2839	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]	2840	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2841	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2842	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2843
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2844	<h5>Example:</h5><pre>
				2845	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2846	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2847	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2848	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2849	<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]	2850	</pre>
				2851	</div>
				2852	<!-- _______________________________________________________________________ -->
				2853	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2854	Instruction</a> </div>
				2855	<div class="doc_text">
				2856	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2857	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2858	</pre>
				2859
				2860	<h5>Overview:</h5>
				2861	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2862	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]	2863
				2864	<h5>Arguments:</h5>
				2865	<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]	2866	<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]	2867	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2868
				2869	<h5>Semantics:</h5>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2870
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2871	<p>This instruction always performs a logical shift right operation. The most
				2872	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]	2873	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]	2874	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				2875	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				2876	amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2877
				2878	<h5>Example:</h5>
				2879	<pre>
				2880	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2881	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2882	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2883	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2884	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2885	<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]	2886	</pre>
				2887	</div>
				2888
Reid Spencer	2ab0193	2007-02-02 13:57:07 +0000	[diff] [blame]	2889	<!-- _______________________________________________________________________ -->
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2890	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				2891	Instruction</a> </div>
				2892	<div class="doc_text">
				2893
				2894	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2895	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2896	</pre>
				2897
				2898	<h5>Overview:</h5>
				2899	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	2900	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]	2901
				2902	<h5>Arguments:</h5>
				2903	<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]	2904	<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]	2905	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2906
				2907	<h5>Semantics:</h5>
				2908	<p>This instruction always performs an arithmetic shift right operation,
				2909	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]	2910	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]	2911	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				2912	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2913	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	04e259b	2007-01-31 21:39:12 +0000	[diff] [blame]	2914
				2915	<h5>Example:</h5>
				2916	<pre>
				2917	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				2918	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				2919	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				2920	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	f0e5011	2007-10-03 21:01:14 +0000	[diff] [blame]	2921	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	4dd832d	2008-12-09 05:46:39 +0000	[diff] [blame]	2922	<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]	2923	</pre>
				2924	</div>
				2925
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2926	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2927	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				2928	Instruction</a> </div>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2929
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2930	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2931
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2932	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2933
				2934	<pre>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2935	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2936	</pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2937
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2938	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2939
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2940	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				2941	its two operands.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2942
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2943	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2944
				2945	<p>The two arguments to the '<tt>and</tt>' instruction must be
				2946	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2947	values. Both arguments must have identical types.</p>
				2948
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2949	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2950	<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]	2951	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	2952	<div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2953	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2954	<tbody>
				2955	<tr>
				2956	<td>In0</td>
				2957	<td>In1</td>
				2958	<td>Out</td>
				2959	</tr>
				2960	<tr>
				2961	<td>0</td>
				2962	<td>0</td>
				2963	<td>0</td>
				2964	</tr>
				2965	<tr>
				2966	<td>0</td>
				2967	<td>1</td>
				2968	<td>0</td>
				2969	</tr>
				2970	<tr>
				2971	<td>1</td>
				2972	<td>0</td>
				2973	<td>0</td>
				2974	</tr>
				2975	<tr>
				2976	<td>1</td>
				2977	<td>1</td>
				2978	<td>1</td>
				2979	</tr>
				2980	</tbody>
				2981	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	2982	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2983	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	2984	<pre>
				2985	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	2986	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				2987	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2988	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	2989	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2990	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2991	<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]	2992	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2993	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	2994	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2995	</pre>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	2996	<h5>Overview:</h5>
				2997	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				2998	or of its two operands.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	2999	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3000
				3001	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3002	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3003	values. Both arguments must have identical types.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3004	<h5>Semantics:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3005	<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]	3006	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3007	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3008	<table border="1" cellspacing="0" cellpadding="4">
				3009	<tbody>
				3010	<tr>
				3011	<td>In0</td>
				3012	<td>In1</td>
				3013	<td>Out</td>
				3014	</tr>
				3015	<tr>
				3016	<td>0</td>
				3017	<td>0</td>
				3018	<td>0</td>
				3019	</tr>
				3020	<tr>
				3021	<td>0</td>
				3022	<td>1</td>
				3023	<td>1</td>
				3024	</tr>
				3025	<tr>
				3026	<td>1</td>
				3027	<td>0</td>
				3028	<td>1</td>
				3029	</tr>
				3030	<tr>
				3031	<td>1</td>
				3032	<td>1</td>
				3033	<td>1</td>
				3034	</tr>
				3035	</tbody>
				3036	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3037	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3038	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3039	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3040	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3041	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3042	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3043	</div>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3044	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3045	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3046	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3047	<div class="doc_text">
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3048	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	3049	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3050	</pre>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3051	<h5>Overview:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3052	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3053	or of its two operands. The <tt>xor</tt> is used to implement the
				3054	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3055	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3056	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3057	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3058	values. Both arguments must have identical types.</p>
				3059
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3060	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	3061
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3062	<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]	3063	<p> </p>
Bill Wendling	5703c6e	2008-09-07 10:29:20 +0000	[diff] [blame]	3064	<div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3065	<table border="1" cellspacing="0" cellpadding="4">
				3066	<tbody>
				3067	<tr>
				3068	<td>In0</td>
				3069	<td>In1</td>
				3070	<td>Out</td>
				3071	</tr>
				3072	<tr>
				3073	<td>0</td>
				3074	<td>0</td>
				3075	<td>0</td>
				3076	</tr>
				3077	<tr>
				3078	<td>0</td>
				3079	<td>1</td>
				3080	<td>1</td>
				3081	</tr>
				3082	<tr>
				3083	<td>1</td>
				3084	<td>0</td>
				3085	<td>1</td>
				3086	</tr>
				3087	<tr>
				3088	<td>1</td>
				3089	<td>1</td>
				3090	<td>0</td>
				3091	</tr>
				3092	</tbody>
				3093	</table>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	3094	</div>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3095	<p> </p>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3096	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3097	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3098	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3099	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3100	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</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	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3103
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3104	<!-- ======================================================================= -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3105	<div class="doc_subsection">
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3106	<a name="vectorops">Vector Operations</a>
				3107	</div>
				3108
				3109	<div class="doc_text">
				3110
				3111	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3112	target-independent manner. These instructions cover the element-access and
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3113	vector-specific operations needed to process vectors effectively. While LLVM
				3114	does directly support these vector operations, many sophisticated algorithms
				3115	will want to use target-specific intrinsics to take full advantage of a specific
				3116	target.</p>
				3117
				3118	</div>
				3119
				3120	<!-- _______________________________________________________________________ -->
				3121	<div class="doc_subsubsection">
				3122	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3123	</div>
				3124
				3125	<div class="doc_text">
				3126
				3127	<h5>Syntax:</h5>
				3128
				3129	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3130	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3131	</pre>
				3132
				3133	<h5>Overview:</h5>
				3134
				3135	<p>
				3136	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3137	element from a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3138	</p>
				3139
				3140
				3141	<h5>Arguments:</h5>
				3142
				3143	<p>
				3144	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3145	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]	3146	an index indicating the position from which to extract the element.
				3147	The index may be a variable.</p>
				3148
				3149	<h5>Semantics:</h5>
				3150
				3151	<p>
				3152	The result is a scalar of the same type as the element type of
				3153	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3154	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3155	results are undefined.
				3156	</p>
				3157
				3158	<h5>Example:</h5>
				3159
				3160	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3161	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3162	</pre>
				3163	</div>
				3164
				3165
				3166	<!-- _______________________________________________________________________ -->
				3167	<div class="doc_subsubsection">
				3168	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3169	</div>
				3170
				3171	<div class="doc_text">
				3172
				3173	<h5>Syntax:</h5>
				3174
				3175	<pre>
Dan Gohman	43ba067	2008-05-12 23:38:42 +0000	[diff] [blame]	3176	<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]	3177	</pre>
				3178
				3179	<h5>Overview:</h5>
				3180
				3181	<p>
				3182	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3183	element into a vector at a specified index.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3184	</p>
				3185
				3186
				3187	<h5>Arguments:</h5>
				3188
				3189	<p>
				3190	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3191	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]	3192	scalar value whose type must equal the element type of the first
				3193	operand. The third operand is an index indicating the position at
				3194	which to insert the value. The index may be a variable.</p>
				3195
				3196	<h5>Semantics:</h5>
				3197
				3198	<p>
Reid Spencer	404a325	2007-02-15 03:07:05 +0000	[diff] [blame]	3199	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]	3200	element values are those of <tt>val</tt> except at position
				3201	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3202	exceeds the length of <tt>val</tt>, the results are undefined.
				3203	</p>
				3204
				3205	<h5>Example:</h5>
				3206
				3207	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3208	%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]	3209	</pre>
				3210	</div>
				3211
				3212	<!-- _______________________________________________________________________ -->
				3213	<div class="doc_subsubsection">
				3214	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3215	</div>
				3216
				3217	<div class="doc_text">
				3218
				3219	<h5>Syntax:</h5>
				3220
				3221	<pre>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3222	<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]	3223	</pre>
				3224
				3225	<h5>Overview:</h5>
				3226
				3227	<p>
				3228	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3229	from two input vectors, returning a vector with the same element type as
				3230	the input and length that is the same as the shuffle mask.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3231	</p>
				3232
				3233	<h5>Arguments:</h5>
				3234
				3235	<p>
Mon P Wang	25f0106	2008-11-10 04:46:22 +0000	[diff] [blame]	3236	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3237	with types that match each other. The third argument is a shuffle mask whose
				3238	element type is always 'i32'. The result of the instruction is a vector whose
				3239	length is the same as the shuffle mask and whose element type is the same as
				3240	the element type of the first two operands.
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3241	</p>
				3242
				3243	<p>
				3244	The shuffle mask operand is required to be a constant vector with either
				3245	constant integer or undef values.
				3246	</p>
				3247
				3248	<h5>Semantics:</h5>
				3249
				3250	<p>
				3251	The elements of the two input vectors are numbered from left to right across
				3252	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]	3253	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]	3254	gets. The element selector may be undef (meaning "don't care") and the second
				3255	operand may be undef if performing a shuffle from only one vector.
				3256	</p>
				3257
				3258	<h5>Example:</h5>
				3259
				3260	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3261	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3262	<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]	3263	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3264	<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]	3265	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3266	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3267	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3268	<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]	3269	</pre>
				3270	</div>
				3271
Tanya Lattner	b138bbe	2006-04-14 19:24:33 +0000	[diff] [blame]	3272
Chris Lattner	ce83bff	2006-04-08 23:07:04 +0000	[diff] [blame]	3273	<!-- ======================================================================= -->
				3274	<div class="doc_subsection">
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3275	<a name="aggregateops">Aggregate Operations</a>
				3276	</div>
				3277
				3278	<div class="doc_text">
				3279
				3280	<p>LLVM supports several instructions for working with aggregate values.
				3281	</p>
				3282
				3283	</div>
				3284
				3285	<!-- _______________________________________________________________________ -->
				3286	<div class="doc_subsubsection">
				3287	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3288	</div>
				3289
				3290	<div class="doc_text">
				3291
				3292	<h5>Syntax:</h5>
				3293
				3294	<pre>
				3295	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3296	</pre>
				3297
				3298	<h5>Overview:</h5>
				3299
				3300	<p>
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3301	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3302	or array element from an aggregate value.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3303	</p>
				3304
				3305
				3306	<h5>Arguments:</h5>
				3307
				3308	<p>
				3309	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3310	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]	3311	type. The operands are constant indices to specify which value to extract
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3312	in a similar manner as indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3313	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3314	</p>
				3315
				3316	<h5>Semantics:</h5>
				3317
				3318	<p>
				3319	The result is the value at the position in the aggregate specified by
				3320	the index operands.
				3321	</p>
				3322
				3323	<h5>Example:</h5>
				3324
				3325	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3326	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3327	</pre>
				3328	</div>
				3329
				3330
				3331	<!-- _______________________________________________________________________ -->
				3332	<div class="doc_subsubsection">
				3333	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3334	</div>
				3335
				3336	<div class="doc_text">
				3337
				3338	<h5>Syntax:</h5>
				3339
				3340	<pre>
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3341	<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]	3342	</pre>
				3343
				3344	<h5>Overview:</h5>
				3345
				3346	<p>
				3347	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	35a835c	2008-05-13 18:16:06 +0000	[diff] [blame]	3348	into a struct field or array element in an aggregate.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3349	</p>
				3350
				3351
				3352	<h5>Arguments:</h5>
				3353
				3354	<p>
				3355	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3356	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3357	The second operand is a first-class value to insert.
Dan Gohman	34d1c0d	2008-05-23 21:53:15 +0000	[diff] [blame]	3358	The following operands are constant indices
Dan Gohman	1ecaf45	2008-05-31 00:58:22 +0000	[diff] [blame]	3359	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]	3360	indices in a
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3361	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3362	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]	3363	by the indices.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3364	</p>
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3365
				3366	<h5>Semantics:</h5>
				3367
				3368	<p>
				3369	The result is an aggregate of the same type as <tt>val</tt>. Its
				3370	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]	3371	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	b9d6660	2008-05-12 23:51:09 +0000	[diff] [blame]	3372	</p>
				3373
				3374	<h5>Example:</h5>
				3375
				3376	<pre>
Dan Gohman	88ce1a5	2008-06-23 15:26:37 +0000	[diff] [blame]	3377	%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]	3378	</pre>
				3379	</div>
				3380
				3381
				3382	<!-- ======================================================================= -->
				3383	<div class="doc_subsection">
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3384	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3385	</div>
				3386
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3387	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3388
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3389	<p>A key design point of an SSA-based representation is how it
				3390	represents memory. In LLVM, no memory locations are in SSA form, which
				3391	makes things very simple. This section describes how to read, write,
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3392	allocate, and free memory in LLVM.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3393
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3394	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3395
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3396	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3397	<div class="doc_subsubsection">
				3398	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3399	</div>
				3400
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3401	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3402
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3403	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3404
				3405	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3406	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3407	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3408
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3409	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3410
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3411	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3412	heap and returns a pointer to it. The object is always allocated in the generic
				3413	address space (address space zero).</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3414
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3415	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3416
				3417	<p>The '<tt>malloc</tt>' instruction allocates
				3418	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	a92e586	2004-02-24 16:13:56 +0000	[diff] [blame]	3419	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]	3420	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3421	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3422	If a constant alignment is specified, the value result of the allocation is guaranteed to
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3423	be aligned to at least that boundary. If not specified, or if zero, the target can
				3424	choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3425
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3426	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3427
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3428	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3429
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3430	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	f5ffcbc	2008-11-24 03:41:24 +0000	[diff] [blame]	3431	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]	3432	result is null if there is insufficient memory available.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3433
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3434	<h5>Example:</h5>
				3435
				3436	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3437	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3438
Bill Wendling	2d8b9a8	2007-05-29 09:42:13 +0000	[diff] [blame]	3439	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3440	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3441	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3442	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3443	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3444	</pre>
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	3445
				3446	<p>Note that the code generator does not yet respect the
				3447	alignment value.</p>
				3448
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3449	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3450
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3451	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3452	<div class="doc_subsubsection">
				3453	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3454	</div>
				3455
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3456	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3457
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3458	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3459
				3460	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3461	free <type> <value> <i>; yields {void}</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3462	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3463
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3464	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3465
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3466	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3467	memory heap to be reallocated in the future.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3468
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3469	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3470
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3471	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3472	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3473	instruction.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3474
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3475	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3476
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3477	<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]	3478	after this instruction executes. If the pointer is null, the operation
				3479	is a noop.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3480
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3481	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3482
				3483	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3484	%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]	3485	free [4 x i8]* %array
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3486	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3487	</div>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3488
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3489	<!-- _______________________________________________________________________ -->
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3490	<div class="doc_subsubsection">
				3491	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3492	</div>
				3493
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3494	<div class="doc_text">
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3495
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3496	<h5>Syntax:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3497
				3498	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3499	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3500	</pre>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3501
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3502	<h5>Overview:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3503
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3504	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3505	currently executing function, to be automatically released when this function
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	3506	returns to its caller. The object is always allocated in the generic address
				3507	space (address space zero).</p>
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	<h5>Arguments:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3510
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	3511	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3512	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3513	appropriate type to the program. If "NumElements" is specified, it is the
				3514	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3515	If a constant alignment is specified, the value result of the allocation is guaranteed
Gabor Greif	dd1fc98	2008-02-09 22:24:34 +0000	[diff] [blame]	3516	to be aligned to at least that boundary. If not specified, or if zero, the target
				3517	can choose to align the allocation on any convenient boundary.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3518
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3519	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3520
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3521	<h5>Semantics:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3522
Bill Wendling	9ee6a31	2009-05-08 20:49:29 +0000	[diff] [blame]	3523	<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]	3524	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3525	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3526	instruction is commonly used to represent automatic variables that must
				3527	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]	3528	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]	3529	instructions), the memory is reclaimed. Allocating zero bytes
				3530	is legal, but the result is undefined.</p>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3531
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3532	<h5>Example:</h5>
Chris Lattner	54611b4	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
				3534	<pre>
Dan Gohman	7a5acb5	2009-01-04 23:49:44 +0000	[diff] [blame]	3535	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3536	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3537	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3538	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3539	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3540	</div>
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	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3543	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3544	Instruction</a> </div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3545	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3546	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3547	<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]	3548	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3549	<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]	3550	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3551	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	4c0cf7f	2005-10-24 16:17:18 +0000	[diff] [blame]	3552	address from which to load. The pointer must point to a <a
Chris Lattner	10ee965	2004-06-03 22:57:15 +0000	[diff] [blame]	3553	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]	3554	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]	3555	the number or order of execution of this <tt>load</tt> with other
				3556	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3557	instructions. </p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3558	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3559	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3560	(that is, the alignment of the memory address). A value of 0 or an
				3561	omitted "align" argument means that the operation has the preferential
				3562	alignment for the target. It is the responsibility of the code emitter
				3563	to ensure that the alignment information is correct. Overestimating
				3564	the alignment results in an undefined behavior. Underestimating the
				3565	alignment may produce less efficient code. An alignment of 1 is always
				3566	safe.
				3567	</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3568	<h5>Semantics:</h5>
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3569	<p>The location of memory pointed to is loaded. If the value being loaded
				3570	is of scalar type then the number of bytes read does not exceed the minimum
				3571	number of bytes needed to hold all bits of the type. For example, loading an
				3572	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3573	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3574	is undefined if the value was not originally written using a store of the
				3575	same type.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3576	<h5>Examples:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3577	<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]	3578	<a
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3579	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3580	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3581	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3582	</div>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3583	<!-- _______________________________________________________________________ -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3584	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3585	Instruction</a> </div>
Reid Spencer	a89fb18	2006-11-09 21:18:01 +0000	[diff] [blame]	3586	<div class="doc_text">
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3587	<h5>Syntax:</h5>
Christopher Lamb	bff5020	2007-04-21 08:16:25 +0000	[diff] [blame]	3588	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3589	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3590	</pre>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3591	<h5>Overview:</h5>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3592	<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]	3593	<h5>Arguments:</h5>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3594	<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]	3595	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]	3596	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3597	of the '<tt><value></tt>'
John Criswell	4a3327e	2005-05-13 22:25:59 +0000	[diff] [blame]	3598	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]	3599	optimizer is not allowed to modify the number or order of execution of
				3600	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3601	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3602	<p>
Chris Lattner	1f17cce	2008-04-02 00:38:26 +0000	[diff] [blame]	3603	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	2a1993f	2008-01-06 21:04:43 +0000	[diff] [blame]	3604	(that is, the alignment of the memory address). A value of 0 or an
				3605	omitted "align" argument means that the operation has the preferential
				3606	alignment for the target. It is the responsibility of the code emitter
				3607	to ensure that the alignment information is correct. Overestimating
				3608	the alignment results in an undefined behavior. Underestimating the
				3609	alignment may produce less efficient code. An alignment of 1 is always
				3610	safe.
				3611	</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3612	<h5>Semantics:</h5>
				3613	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	b1656c1	2009-03-22 11:33:16 +0000	[diff] [blame]	3614	at the location specified by the '<tt><pointer></tt>' operand.
				3615	If '<tt><value></tt>' is of scalar type then the number of bytes
				3616	written does not exceed the minimum number of bytes needed to hold all
				3617	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3618	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3619	size that is not an integral number of bytes, it is unspecified what
				3620	happens to the extra bits that do not belong to the type, but they will
				3621	typically be overwritten.</p>
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3622	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3623	<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]	3624	store i32 3, i32* %ptr <i>; yields {void}</i>
				3625	%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]	3626	</pre>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3627	</div>
				3628
Chris Lattner	095735d	2002-05-06 03:03:22 +0000	[diff] [blame]	3629	<!-- _______________________________________________________________________ -->
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3630	<div class="doc_subsubsection">
				3631	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3632	</div>
				3633
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3634	<div class="doc_text">
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3635	<h5>Syntax:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3636	<pre>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3637	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3638	</pre>
				3639
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3640	<h5>Overview:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3641
				3642	<p>
				3643	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]	3644	subelement of an aggregate data structure. It performs address calculation only
				3645	and does not access memory.</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3646
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3647	<h5>Arguments:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3648
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3649	<p>The first argument is always a pointer, and forms the basis of the
				3650	calculation. The remaining arguments are indices, that indicate which of the
				3651	elements of the aggregate object are indexed. The interpretation of each index
				3652	is dependent on the type being indexed into. The first index always indexes the
				3653	pointer value given as the first argument, the second index indexes a value of
				3654	the type pointed to (not necessarily the value directly pointed to, since the
				3655	first index can be non-zero), etc. The first type indexed into must be a pointer
				3656	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3657	types being indexed into can never be pointers, since that would require loading
				3658	the pointer before continuing calculation.</p>
				3659
				3660	<p>The type of each index argument depends on the type it is indexing into.
				3661	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3662	<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]	3663	integers of any width are allowed (also non-constants).</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3664
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3665	<p>For example, let's consider a C code fragment and how it gets
				3666	compiled to LLVM:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3667
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3668	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3669	<pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3670	struct RT {
				3671	char A;
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3672	int B[10][20];
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3673	char C;
				3674	};
				3675	struct ST {
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3676	int X;
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3677	double Y;
				3678	struct RT Z;
				3679	};
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3680
Chris Lattner	a446f1b	2007-05-29 15:43:56 +0000	[diff] [blame]	3681	int foo(struct ST s) {
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3682	return &s[1].Z.B[5][13];
				3683	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3684	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3685	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3686
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3687	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3688
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3689	<div class="doc_code">
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3690	<pre>
Chris Lattner	bc08821	2009-01-11 20:53:49 +0000	[diff] [blame]	3691	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3692	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3693
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3694	define i32* %foo(%ST* %s) {
				3695	entry:
				3696	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3697	ret i32* %reg
				3698	}
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3699	</pre>
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	3700	</div>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3701
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3702	<h5>Semantics:</h5>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3703
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3704	<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]	3705	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]	3706	}</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]	3707	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3708	i8 }</tt>' type, another structure. The third index indexes into the second
				3709	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]	3710	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3711	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3712	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]	3713
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	3714	<p>Note that it is perfectly legal to index partially through a
				3715	structure, returning a pointer to an inner element. Because of this,
				3716	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3717
				3718	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3719	define i32* %foo(%ST* %s) {
				3720	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	5819f18	2007-04-22 01:17:39 +0000	[diff] [blame]	3721	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3722	%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]	3723	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3724	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3725	ret i32* %t5
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3726	}
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3727	</pre>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3728
Chris Lattner	dd28282	2009-03-09 20:55:18 +0000	[diff] [blame]	3729	<p>Note that it is undefined to access an array out of bounds: array
				3730	and pointer indexes must always be within the defined bounds of the
				3731	array type when accessed with an instruction that dereferences the
				3732	pointer (e.g. a load or store instruction). The one exception for
				3733	this rule is zero length arrays. These arrays are defined to be
				3734	accessible as variable length arrays, which requires access beyond the
				3735	zero'th element.</p>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3736
Chris Lattner	6ab6672	2006-08-15 00:45:58 +0000	[diff] [blame]	3737	<p>The getelementptr instruction is often confusing. For some more insight
				3738	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3739	FAQ</a>.</p>
				3740
Chris Lattner	590645f	2002-04-14 06:13:44 +0000	[diff] [blame]	3741	<h5>Example:</h5>
Chris Lattner	c0ad71e	2005-06-24 17:22:57 +0000	[diff] [blame]	3742
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3743	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3744	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	0e26827	2008-10-13 13:44:15 +0000	[diff] [blame]	3745	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3746	<i>; yields i8*:vptr</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	3747	%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]	3748	<i>; yields i8*:eptr</i>
				3749	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	0c155e6	2009-04-25 07:27:44 +0000	[diff] [blame]	3750	<i>; yields i32*:iptr</i>
Sanjiv Gupta	77abea0	2009-04-24 16:38:13 +0000	[diff] [blame]	3751	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3752	</pre>
Chris Lattner	33fd702	2004-04-05 01:30:49 +0000	[diff] [blame]	3753	</div>
Reid Spencer	443460a	2006-11-09 21:15:49 +0000	[diff] [blame]	3754
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	3755	<!-- ======================================================================= -->
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3756	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3757	</div>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3758	<div class="doc_text">
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	3759	<p>The instructions in this category are the conversion instructions (casting)
				3760	which all take a single operand and a type. They perform various bit conversions
				3761	on the operand.</p>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	3762	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3763
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	3764	<!-- _______________________________________________________________________ -->
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	3765	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3766	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3767	</div>
				3768	<div class="doc_text">
				3769
				3770	<h5>Syntax:</h5>
				3771	<pre>
				3772	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3773	</pre>
				3774
				3775	<h5>Overview:</h5>
				3776	<p>
				3777	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3778	</p>
				3779
				3780	<h5>Arguments:</h5>
				3781	<p>
				3782	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3783	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]	3784	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]	3785	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3786	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3787
				3788	<h5>Semantics:</h5>
				3789	<p>
				3790	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]	3791	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3792	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3793	It will always truncate bits.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3794
				3795	<h5>Example:</h5>
				3796	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3797	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3798	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3799	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3800	</pre>
				3801	</div>
				3802
				3803	<!-- _______________________________________________________________________ -->
				3804	<div class="doc_subsubsection">
				3805	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3806	</div>
				3807	<div class="doc_text">
				3808
				3809	<h5>Syntax:</h5>
				3810	<pre>
				3811	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3812	</pre>
				3813
				3814	<h5>Overview:</h5>
				3815	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3816	<tt>ty2</tt>.</p>
				3817
				3818
				3819	<h5>Arguments:</h5>
				3820	<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]	3821	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3822	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]	3823	<tt>value</tt> must be smaller than the bit size of the destination type,
				3824	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3825
				3826	<h5>Semantics:</h5>
				3827	<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]	3828	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]	3829
Reid Spencer	07c9c68	2007-01-12 15:46:11 +0000	[diff] [blame]	3830	<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]	3831
				3832	<h5>Example:</h5>
				3833	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3834	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3835	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3836	</pre>
				3837	</div>
				3838
				3839	<!-- _______________________________________________________________________ -->
				3840	<div class="doc_subsubsection">
				3841	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3842	</div>
				3843	<div class="doc_text">
				3844
				3845	<h5>Syntax:</h5>
				3846	<pre>
				3847	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3848	</pre>
				3849
				3850	<h5>Overview:</h5>
				3851	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3852
				3853	<h5>Arguments:</h5>
				3854	<p>
				3855	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]	3856	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3857	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]	3858	<tt>value</tt> must be smaller than the bit size of the destination type,
				3859	<tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3860
				3861	<h5>Semantics:</h5>
				3862	<p>
				3863	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3864	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]	3865	the type <tt>ty2</tt>.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3866
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3867	<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]	3868
				3869	<h5>Example:</h5>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3870	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	3871	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	3872	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3873	</pre>
				3874	</div>
				3875
				3876	<!-- _______________________________________________________________________ -->
				3877	<div class="doc_subsubsection">
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3878	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				3879	</div>
				3880
				3881	<div class="doc_text">
				3882
				3883	<h5>Syntax:</h5>
				3884
				3885	<pre>
				3886	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3887	</pre>
				3888
				3889	<h5>Overview:</h5>
				3890	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				3891	<tt>ty2</tt>.</p>
				3892
				3893
				3894	<h5>Arguments:</h5>
				3895	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				3896	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				3897	cast it to. The size of <tt>value</tt> must be larger than the size of
				3898	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				3899	<i>no-op cast</i>.</p>
				3900
				3901	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3902	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				3903	<a href="#t_floating">floating point</a> type to a smaller
				3904	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				3905	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	2e2740d	2006-11-09 21:48:10 +0000	[diff] [blame]	3906
				3907	<h5>Example:</h5>
				3908	<pre>
				3909	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				3910	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				3911	</pre>
				3912	</div>
				3913
				3914	<!-- _______________________________________________________________________ -->
				3915	<div class="doc_subsubsection">
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3916	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				3917	</div>
				3918	<div class="doc_text">
				3919
				3920	<h5>Syntax:</h5>
				3921	<pre>
				3922	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				3923	</pre>
				3924
				3925	<h5>Overview:</h5>
				3926	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				3927	floating point value.</p>
				3928
				3929	<h5>Arguments:</h5>
				3930	<p>The '<tt>fpext</tt>' instruction takes a
				3931	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3932	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				3933	type must be smaller than the destination type.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3934
				3935	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3936	<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]	3937	<a href="#t_floating">floating point</a> type to a larger
				3938	<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]	3939	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]	3940	<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]	3941
				3942	<h5>Example:</h5>
				3943	<pre>
				3944	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				3945	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				3946	</pre>
				3947	</div>
				3948
				3949	<!-- _______________________________________________________________________ -->
				3950	<div class="doc_subsubsection">
Reid Spencer	2eadb53	2007-01-21 00:29:26 +0000	[diff] [blame]	3951	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3952	</div>
				3953	<div class="doc_text">
				3954
				3955	<h5>Syntax:</h5>
				3956	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3957	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3958	</pre>
				3959
				3960	<h5>Overview:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3961	<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]	3962	unsigned integer equivalent of type <tt>ty2</tt>.
				3963	</p>
				3964
				3965	<h5>Arguments:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3966	<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]	3967	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				3968	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				3969	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				3970	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]	3971
				3972	<h5>Semantics:</h5>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3973	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3974	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				3975	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				3976	the results are undefined.</p>
				3977
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3978	<h5>Example:</h5>
				3979	<pre>
Reid Spencer	753163d	2007-07-31 14:40:14 +0000	[diff] [blame]	3980	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	3981	%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]	3982	%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]	3983	</pre>
				3984	</div>
				3985
				3986	<!-- _______________________________________________________________________ -->
				3987	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3988	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3989	</div>
				3990	<div class="doc_text">
				3991
				3992	<h5>Syntax:</h5>
				3993	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3994	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3995	</pre>
				3996
				3997	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	3998	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	3999	<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]	4000	</p>
				4001
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4002	<h5>Arguments:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4003	<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]	4004	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4005	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4006	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4007	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]	4008
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4009	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4010	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4011	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4012	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4013	the results are undefined.</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4014
Chris Lattner	70de663	2001-07-09 00:26:23 +0000	[diff] [blame]	4015	<h5>Example:</h5>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4016	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4017	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	5b95a17	2007-09-22 03:17:52 +0000	[diff] [blame]	4018	%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]	4019	%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]	4020	</pre>
				4021	</div>
				4022
				4023	<!-- _______________________________________________________________________ -->
				4024	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4025	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4026	</div>
				4027	<div class="doc_text">
				4028
				4029	<h5>Syntax:</h5>
				4030	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4031	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4032	</pre>
				4033
				4034	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4035	<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]	4036	integer and converts that value to the <tt>ty2</tt> type.</p>
				4037
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4038	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4039	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4040	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4041	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4042	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4043	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]	4044
				4045	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4046	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4047	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4048	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]	4049
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4050	<h5>Example:</h5>
				4051	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4052	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4053	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4054	</pre>
				4055	</div>
				4056
				4057	<!-- _______________________________________________________________________ -->
				4058	<div class="doc_subsubsection">
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4059	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4060	</div>
				4061	<div class="doc_text">
				4062
				4063	<h5>Syntax:</h5>
				4064	<pre>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4065	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4066	</pre>
				4067
				4068	<h5>Overview:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4069	<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]	4070	integer and converts that value to the <tt>ty2</tt> type.</p>
				4071
				4072	<h5>Arguments:</h5>
Nate Begeman	d4d45c2	2007-11-17 03:58:34 +0000	[diff] [blame]	4073	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4074	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4075	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4076	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4077	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]	4078
				4079	<h5>Semantics:</h5>
Reid Spencer	51b0725	2006-11-09 23:03:26 +0000	[diff] [blame]	4080	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4081	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	beccb74	2007-04-22 14:56:37 +0000	[diff] [blame]	4082	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]	4083
				4084	<h5>Example:</h5>
				4085	<pre>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4086	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4087	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4088	</pre>
				4089	</div>
				4090
				4091	<!-- _______________________________________________________________________ -->
				4092	<div class="doc_subsubsection">
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4093	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4094	</div>
				4095	<div class="doc_text">
				4096
				4097	<h5>Syntax:</h5>
				4098	<pre>
				4099	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4100	</pre>
				4101
				4102	<h5>Overview:</h5>
				4103	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4104	the integer type <tt>ty2</tt>.</p>
				4105
				4106	<h5>Arguments:</h5>
				4107	<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]	4108	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]	4109	<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]	4110
				4111	<h5>Semantics:</h5>
				4112	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4113	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4114	truncating or zero extending that value to the size of the integer type. If
				4115	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4116	<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]	4117	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4118	change.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4119
				4120	<h5>Example:</h5>
				4121	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4122	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4123	%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]	4124	</pre>
				4125	</div>
				4126
				4127	<!-- _______________________________________________________________________ -->
				4128	<div class="doc_subsubsection">
				4129	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4130	</div>
				4131	<div class="doc_text">
				4132
				4133	<h5>Syntax:</h5>
				4134	<pre>
				4135	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4136	</pre>
				4137
				4138	<h5>Overview:</h5>
				4139	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4140	a pointer type, <tt>ty2</tt>.</p>
				4141
				4142	<h5>Arguments:</h5>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4143	<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]	4144	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]	4145	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4146
				4147	<h5>Semantics:</h5>
				4148	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4149	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4150	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4151	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4152	the size of a pointer then a zero extension is done. If they are the same size,
				4153	nothing is done (<i>no-op cast</i>).</p>
				4154
				4155	<h5>Example:</h5>
				4156	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4157	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4158	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4159	%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]	4160	</pre>
				4161	</div>
				4162
				4163	<!-- _______________________________________________________________________ -->
				4164	<div class="doc_subsubsection">
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4165	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4166	</div>
				4167	<div class="doc_text">
				4168
				4169	<h5>Syntax:</h5>
				4170	<pre>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4171	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4172	</pre>
				4173
				4174	<h5>Overview:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4175
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4176	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4177	<tt>ty2</tt> without changing any bits.</p>
				4178
				4179	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4180
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4181	<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]	4182	a non-aggregate first class value, and a type to cast it to, which must also be
				4183	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4184	<tt>value</tt>
Reid Spencer	e3db84c	2007-01-09 20:08:58 +0000	[diff] [blame]	4185	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]	4186	type is a pointer, the destination type must also be a pointer. This
				4187	instruction supports bitwise conversion of vectors to integers and to vectors
				4188	of other types (as long as they have the same size).</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4189
				4190	<h5>Semantics:</h5>
Reid Spencer	5b95064	2006-11-11 23:08:07 +0000	[diff] [blame]	4191	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	b7344ff	2006-11-11 21:00:47 +0000	[diff] [blame]	4192	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4193	this conversion. The conversion is done as if the <tt>value</tt> had been
				4194	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4195	converted to other pointer types with this instruction. To convert pointers to
				4196	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4197	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	59b6b7d	2006-11-08 01:11:31 +0000	[diff] [blame]	4198
				4199	<h5>Example:</h5>
				4200	<pre>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4201	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4202	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4203	%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]	4204	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4205	</div>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4206
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4207	<!-- ======================================================================= -->
				4208	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4209	<div class="doc_text">
				4210	<p>The instructions in this category are the "miscellaneous"
				4211	instructions, which defy better classification.</p>
				4212	</div>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4213
				4214	<!-- _______________________________________________________________________ -->
				4215	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4216	</div>
				4217	<div class="doc_text">
				4218	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4219	<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]	4220	</pre>
				4221	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4222	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4223	a vector of boolean values based on comparison
				4224	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4225	<h5>Arguments:</h5>
				4226	<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]	4227	the condition code indicating the kind of comparison to perform. It is not
				4228	a value, just a keyword. The possible condition code are:
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4229	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4230	<ol>
				4231	<li><tt>eq</tt>: equal</li>
				4232	<li><tt>ne</tt>: not equal </li>
				4233	<li><tt>ugt</tt>: unsigned greater than</li>
				4234	<li><tt>uge</tt>: unsigned greater or equal</li>
				4235	<li><tt>ult</tt>: unsigned less than</li>
				4236	<li><tt>ule</tt>: unsigned less or equal</li>
				4237	<li><tt>sgt</tt>: signed greater than</li>
				4238	<li><tt>sge</tt>: signed greater or equal</li>
				4239	<li><tt>slt</tt>: signed less than</li>
				4240	<li><tt>sle</tt>: signed less or equal</li>
				4241	</ol>
Chris Lattner	c0f423a	2007-01-15 01:54:13 +0000	[diff] [blame]	4242	<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]	4243	<a href="#t_pointer">pointer</a>
				4244	or integer <a href="#t_vector">vector</a> typed.
				4245	They must also be identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4246	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4247	<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]	4248	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4249	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]	4250	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4251	<ol>
				4252	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4253	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4254	</li>
				4255	<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]	4256	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4257	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4258	<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]	4259	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4260	<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]	4261	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4262	<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]	4263	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4264	<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]	4265	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4266	<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]	4267	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4268	<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]	4269	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4270	<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]	4271	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4272	<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]	4273	</ol>
				4274	<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]	4275	values are compared as if they were integers.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4276	<p>If the operands are integer vectors, then they are compared
				4277	element by element. The result is an <tt>i1</tt> vector with
				4278	the same number of elements as the values being compared.
				4279	Otherwise, the result is an <tt>i1</tt>.
				4280	</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4281
				4282	<h5>Example:</h5>
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4283	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4284	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4285	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4286	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4287	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4288	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4289	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4290
				4291	<p>Note that the code generator does not yet support vector types with
				4292	the <tt>icmp</tt> instruction.</p>
				4293
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4294	</div>
				4295
				4296	<!-- _______________________________________________________________________ -->
				4297	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4298	</div>
				4299	<div class="doc_text">
				4300	<h5>Syntax:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4301	<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]	4302	</pre>
				4303	<h5>Overview:</h5>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4304	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4305	or vector of boolean values based on comparison
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4306	of its operands.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4307	<p>
				4308	If the operands are floating point scalars, then the result
				4309	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4310	</p>
				4311	<p>If the operands are floating point vectors, then the result type
				4312	is a vector of boolean with the same number of elements as the
				4313	operands being compared.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4314	<h5>Arguments:</h5>
				4315	<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]	4316	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]	4317	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4318	<ol>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4319	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4320	<li><tt>oeq</tt>: ordered and equal</li>
				4321	<li><tt>ogt</tt>: ordered and greater than </li>
				4322	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4323	<li><tt>olt</tt>: ordered and less than </li>
				4324	<li><tt>ole</tt>: ordered and less than or equal</li>
				4325	<li><tt>one</tt>: ordered and not equal</li>
				4326	<li><tt>ord</tt>: ordered (no nans)</li>
				4327	<li><tt>ueq</tt>: unordered or equal</li>
				4328	<li><tt>ugt</tt>: unordered or greater than </li>
				4329	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4330	<li><tt>ult</tt>: unordered or less than </li>
				4331	<li><tt>ule</tt>: unordered or less than or equal</li>
				4332	<li><tt>une</tt>: unordered or not equal</li>
				4333	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4334	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4335	</ol>
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4336	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	02e0d1d	2006-12-06 07:08:07 +0000	[diff] [blame]	4337	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4338	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4339	either a <a href="#t_floating">floating point</a> type
				4340	or a <a href="#t_vector">vector</a> of floating point type.
				4341	They must have identical types.</p>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4342	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4343	<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]	4344	according to the condition code given as <tt>cond</tt>.
				4345	If the operands are vectors, then the vectors are compared
				4346	element by element.
				4347	Each comparison performed
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4348	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]	4349	<ol>
				4350	<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]	4351	<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]	4352	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4353	<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]	4354	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4355	<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]	4356	<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]	4357	<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]	4358	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4359	<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]	4360	<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]	4361	<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]	4362	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4363	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4364	<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]	4365	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4366	<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]	4367	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4368	<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]	4369	<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]	4370	<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]	4371	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4372	<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]	4373	<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]	4374	<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]	4375	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	f69acf3	2006-11-19 03:00:14 +0000	[diff] [blame]	4376	<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]	4377	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4378	</ol>
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4379
				4380	<h5>Example:</h5>
				4381	<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]	4382	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4383	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4384	<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]	4385	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4386
				4387	<p>Note that the code generator does not yet support vector types with
				4388	the <tt>fcmp</tt> instruction.</p>
				4389
Reid Spencer	c828a0e	2006-11-18 21:50:54 +0000	[diff] [blame]	4390	</div>
				4391
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4392	<!-- _______________________________________________________________________ -->
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4393	<div class="doc_subsubsection">
				4394	<a name="i_vicmp">'<tt>vicmp</tt>' Instruction</a>
				4395	</div>
				4396	<div class="doc_text">
				4397	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4398	<pre> <result> = vicmp <cond> <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4399	</pre>
				4400	<h5>Overview:</h5>
				4401	<p>The '<tt>vicmp</tt>' instruction returns an integer vector value based on
				4402	element-wise comparison of its two integer vector operands.</p>
				4403	<h5>Arguments:</h5>
				4404	<p>The '<tt>vicmp</tt>' instruction takes three operands. The first operand is
				4405	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]	4406	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4407	<ol>
				4408	<li><tt>eq</tt>: equal</li>
				4409	<li><tt>ne</tt>: not equal </li>
				4410	<li><tt>ugt</tt>: unsigned greater than</li>
				4411	<li><tt>uge</tt>: unsigned greater or equal</li>
				4412	<li><tt>ult</tt>: unsigned less than</li>
				4413	<li><tt>ule</tt>: unsigned less or equal</li>
				4414	<li><tt>sgt</tt>: signed greater than</li>
				4415	<li><tt>sge</tt>: signed greater or equal</li>
				4416	<li><tt>slt</tt>: signed less than</li>
				4417	<li><tt>sle</tt>: signed less or equal</li>
				4418	</ol>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4419	<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]	4420	<a href="#t_integer">integer</a> typed. They must also be identical types.</p>
				4421	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4422	<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]	4423	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4424	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, of
				4425	identical type as the values being compared. The most significant bit in each
				4426	element is 1 if the element-wise comparison evaluates to true, and is 0
				4427	otherwise. All other bits of the result are undefined. The condition codes
				4428	are evaluated identically to the <a href="#i_icmp">'<tt>icmp</tt>'
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4429	instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4430
				4431	<h5>Example:</h5>
				4432	<pre>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4433	<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>
				4434	<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]	4435	</pre>
				4436	</div>
				4437
				4438	<!-- _______________________________________________________________________ -->
				4439	<div class="doc_subsubsection">
				4440	<a name="i_vfcmp">'<tt>vfcmp</tt>' Instruction</a>
				4441	</div>
				4442	<div class="doc_text">
				4443	<h5>Syntax:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4444	<pre> <result> = vfcmp <cond> <ty> <op1>, <op2></pre>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4445	<h5>Overview:</h5>
				4446	<p>The '<tt>vfcmp</tt>' instruction returns an integer vector value based on
				4447	element-wise comparison of its two floating point vector operands. The output
				4448	elements have the same width as the input elements.</p>
				4449	<h5>Arguments:</h5>
				4450	<p>The '<tt>vfcmp</tt>' instruction takes three operands. The first operand is
				4451	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]	4452	a value, just a keyword. The possible condition code are:</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4453	<ol>
				4454	<li><tt>false</tt>: no comparison, always returns false</li>
				4455	<li><tt>oeq</tt>: ordered and equal</li>
				4456	<li><tt>ogt</tt>: ordered and greater than </li>
				4457	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4458	<li><tt>olt</tt>: ordered and less than </li>
				4459	<li><tt>ole</tt>: ordered and less than or equal</li>
				4460	<li><tt>one</tt>: ordered and not equal</li>
				4461	<li><tt>ord</tt>: ordered (no nans)</li>
				4462	<li><tt>ueq</tt>: unordered or equal</li>
				4463	<li><tt>ugt</tt>: unordered or greater than </li>
				4464	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4465	<li><tt>ult</tt>: unordered or less than </li>
				4466	<li><tt>ule</tt>: unordered or less than or equal</li>
				4467	<li><tt>une</tt>: unordered or not equal</li>
				4468	<li><tt>uno</tt>: unordered (either nans)</li>
				4469	<li><tt>true</tt>: no comparison, always returns true</li>
				4470	</ol>
				4471	<p>The remaining two arguments must be <a href="#t_vector">vector</a> of
				4472	<a href="#t_floating">floating point</a> typed. They must also be identical
				4473	types.</p>
				4474	<h5>Semantics:</h5>
Gabor Greif	0f75ad0	2008-08-07 21:46:00 +0000	[diff] [blame]	4475	<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]	4476	according to the condition code given as <tt>cond</tt>. The comparison yields a
				4477	<a href="#t_vector">vector</a> of <a href="#t_integer">integer</a> result, with
				4478	an identical number of elements as the values being compared, and each element
				4479	having identical with to the width of the floating point elements. The most
				4480	significant bit in each element is 1 if the element-wise comparison evaluates to
				4481	true, and is 0 otherwise. All other bits of the result are undefined. The
				4482	condition codes are evaluated identically to the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4483	<a href="#i_fcmp">'<tt>fcmp</tt>' instruction</a>.</p>
Nate Begeman	d219570	2008-05-12 19:01:56 +0000	[diff] [blame]	4484
				4485	<h5>Example:</h5>
				4486	<pre>
Chris Lattner	0ae0209	2008-10-13 16:55:18 +0000	[diff] [blame]	4487	<i>; yields: result=<2 x i32> < i32 0, i32 -1 ></i>
				4488	<result> = vfcmp oeq <2 x float> < float 4, float 0 >, < float 5, float 0 >
				4489
				4490	<i>; yields: result=<2 x i64> < i64 -1, i64 0 ></i>
				4491	<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]	4492	</pre>
				4493	</div>
				4494
				4495	<!-- _______________________________________________________________________ -->
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4496	<div class="doc_subsubsection">
				4497	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4498	</div>
				4499
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4500	<div class="doc_text">
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4501
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4502	<h5>Syntax:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4503
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4504	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4505	<h5>Overview:</h5>
				4506	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4507	the SSA graph representing the function.</p>
				4508	<h5>Arguments:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4509
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4510	<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]	4511	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4512	as arguments, with one pair for each predecessor basic block of the
				4513	current block. Only values of <a href="#t_firstclass">first class</a>
				4514	type may be used as the value arguments to the PHI node. Only labels
				4515	may be used as the label arguments.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4516
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4517	<p>There must be no non-phi instructions between the start of a basic
				4518	block and the PHI instructions: i.e. PHI instructions must be first in
				4519	a basic block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4520
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4521	<h5>Semantics:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4522
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4523	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4524	specified by the pair corresponding to the predecessor basic block that executed
				4525	just prior to the current block.</p>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4526
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4527	<h5>Example:</h5>
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4528	<pre>
				4529	Loop: ; Infinite loop that counts from 0 on up...
				4530	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4531	%nextindvar = add i32 %indvar, 1
				4532	br label %Loop
				4533	</pre>
Reid Spencer	97c5fa4	2006-11-08 01:18:52 +0000	[diff] [blame]	4534	</div>
				4535
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4536	<!-- _______________________________________________________________________ -->
				4537	<div class="doc_subsubsection">
				4538	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4539	</div>
				4540
				4541	<div class="doc_text">
				4542
				4543	<h5>Syntax:</h5>
				4544
				4545	<pre>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4546	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4547
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4548	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4549	</pre>
				4550
				4551	<h5>Overview:</h5>
				4552
				4553	<p>
				4554	The '<tt>select</tt>' instruction is used to choose one value based on a
				4555	condition, without branching.
				4556	</p>
				4557
				4558
				4559	<h5>Arguments:</h5>
				4560
				4561	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4562	The '<tt>select</tt>' instruction requires an 'i1' value or
				4563	a vector of 'i1' values indicating the
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4564	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]	4565	type. If the val1/val2 are vectors and
				4566	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	b54c30f	2008-05-20 20:48:21 +0000	[diff] [blame]	4567	individual elements.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4568	</p>
				4569
				4570	<h5>Semantics:</h5>
				4571
				4572	<p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4573	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]	4574	value argument; otherwise, it returns the second value argument.
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4575	</p>
Dan Gohman	c579d97	2008-09-09 01:02:47 +0000	[diff] [blame]	4576	<p>
				4577	If the condition is a vector of i1, then the value arguments must
				4578	be vectors of the same size, and the selection is done element
				4579	by element.
				4580	</p>
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4581
				4582	<h5>Example:</h5>
				4583
				4584	<pre>
Reid Spencer	36a1542	2007-01-12 03:35:51 +0000	[diff] [blame]	4585	%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]	4586	</pre>
Dan Gohman	a5127ab	2009-01-22 01:39:38 +0000	[diff] [blame]	4587
				4588	<p>Note that the code generator does not yet support conditions
				4589	with vector type.</p>
				4590
Chris Lattner	b53c28d	2004-03-12 05:50:16 +0000	[diff] [blame]	4591	</div>
				4592
Robert Bocchino	f72fdfe	2006-01-15 20:48:27 +0000	[diff] [blame]	4593
				4594	<!-- _______________________________________________________________________ -->
				4595	<div class="doc_subsubsection">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4596	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4597	</div>
				4598
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4599	<div class="doc_text">
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4600
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4601	<h5>Syntax:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4602	<pre>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4603	<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]	4604	</pre>
				4605
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4606	<h5>Overview:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4607
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4608	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4609
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4610	<h5>Arguments:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4611
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4612	<p>This instruction requires several arguments:</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4613
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4614	<ol>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4615	<li>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4616	<p>The optional "tail" marker indicates whether the callee function accesses
				4617	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]	4618	function call is eligible for tail call optimization. Note that calls may
				4619	be marked "tail" even if they do not occur before a <a
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4620	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4621	</li>
				4622	<li>
Duncan Sands	16f122e	2007-03-30 12:22:09 +0000	[diff] [blame]	4623	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4624	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]	4625	to using C calling conventions.</p>
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4626	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4627
				4628	<li>
				4629	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4630	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4631	and '<tt>inreg</tt>' attributes are valid here.</p>
				4632	</li>
				4633
Chris Lattner	0132aff	2005-05-06 22:57:40 +0000	[diff] [blame]	4634	<li>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4635	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4636	the type of the return value. Functions that return no value are marked
				4637	<tt><a href="#t_void">void</a></tt>.</p>
				4638	</li>
				4639	<li>
				4640	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4641	value being invoked. The argument types must match the types implied by
				4642	this signature. This type can be omitted if the function is not varargs
				4643	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]	4644	</li>
				4645	<li>
				4646	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4647	be invoked. In most cases, this is a direct function invocation, but
				4648	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]	4649	to function value.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4650	</li>
				4651	<li>
				4652	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	d845d16	2005-05-01 22:22:57 +0000	[diff] [blame]	4653	function signature argument types. All arguments must be of
				4654	<a href="#t_firstclass">first class</a> type. If the function signature
				4655	indicates the function accepts a variable number of arguments, the extra
				4656	arguments can be specified.</p>
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4657	</li>
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4658	<li>
Devang Patel	0225623	2008-10-07 17:48:33 +0000	[diff] [blame]	4659	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4660	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4661	'<tt>readnone</tt>' attributes are valid here.</p>
				4662	</li>
Chris Lattner	a8292f3	2002-05-06 22:08:29 +0000	[diff] [blame]	4663	</ol>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4664
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4665	<h5>Semantics:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4666
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4667	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4668	transfer to a specified function, with its incoming arguments bound to
				4669	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4670	instruction in the called function, control flow continues with the
				4671	instruction after the function call, and the return value of the
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4672	function is bound to the result argument.</p>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4673
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	4674	<h5>Example:</h5>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4675
				4676	<pre>
Nick Lewycky	a9b13d5	2007-09-08 13:57:50 +0000	[diff] [blame]	4677	%retval = call i32 @test(i32 %argc)
Chris Lattner	fb7c88d	2008-03-21 17:24:17 +0000	[diff] [blame]	4678	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4679	%X = tail call i32 @foo() <i>; yields i32</i>
				4680	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4681	call void %foo(i8 97 signext)
Devang Patel	d6cff51	2008-03-10 20:49:15 +0000	[diff] [blame]	4682
				4683	%struct.A = type { i32, i8 }
Devang Patel	7e9b05e	2008-10-06 18:50:38 +0000	[diff] [blame]	4684	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	cc3132e	2008-10-04 19:00:07 +0000	[diff] [blame]	4685	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4686	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	6cbe8e9	2008-10-08 06:26:11 +0000	[diff] [blame]	4687	%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]	4688	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	e23c139	2005-05-06 05:47:36 +0000	[diff] [blame]	4689	</pre>
				4690
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4691	</div>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4692
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4693	<!-- _______________________________________________________________________ -->
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4694	<div class="doc_subsubsection">
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4695	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4696	</div>
				4697
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4698	<div class="doc_text">
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4699
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4700	<h5>Syntax:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4701
				4702	<pre>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4703	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4704	</pre>
				4705
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4706	<h5>Overview:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4707
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4708	<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]	4709	the "variable argument" area of a function call. It is used to implement the
				4710	<tt>va_arg</tt> macro in C.</p>
				4711
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4712	<h5>Arguments:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4713
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4714	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4715	the argument. It returns a value of the specified argument type and
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4716	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]	4717	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4718
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4719	<h5>Semantics:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4720
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4721	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4722	type from the specified <tt>va_list</tt> and causes the
				4723	<tt>va_list</tt> to point to the next argument. For more information,
				4724	see the variable argument handling <a href="#int_varargs">Intrinsic
				4725	Functions</a>.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4726
				4727	<p>It is legal for this instruction to be called in a function which does not
				4728	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4729	function.</p>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4730
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4731	<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]	4732	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4733	argument.</p>
				4734
Chris Lattner	26ca62e	2003-10-18 05:51:36 +0000	[diff] [blame]	4735	<h5>Example:</h5>
Chris Lattner	6a4a049	2004-09-27 21:51:25 +0000	[diff] [blame]	4736
				4737	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4738
Dan Gohman	3065b61	2009-01-12 23:12:39 +0000	[diff] [blame]	4739	<p>Note that the code generator does not yet fully support va_arg
				4740	on many targets. Also, it does not currently support va_arg with
				4741	aggregate types on any target.</p>
				4742
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4743	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4744
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4745	<!-- *********************************************************************** -->
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4746	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4747	<!-- *********************************************************************** -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4748
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4749	<div class="doc_text">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4750
				4751	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4752	well known names and semantics and are required to follow certain restrictions.
				4753	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4754	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]	4755	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]	4756
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	4757	<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]	4758	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4759	begin with this prefix. Intrinsic functions must always be external functions:
				4760	you cannot define the body of intrinsic functions. Intrinsic functions may
				4761	only be used in call or invoke instructions: it is illegal to take the address
				4762	of an intrinsic function. Additionally, because intrinsic functions are part
				4763	of the LLVM language, it is required if any are added that they be documented
				4764	here.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4765
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4766	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4767	a family of functions that perform the same operation but on different data
				4768	types. Because LLVM can represent over 8 million different integer types,
				4769	overloading is used commonly to allow an intrinsic function to operate on any
				4770	integer type. One or more of the argument types or the result type can be
				4771	overloaded to accept any integer type. Argument types may also be defined as
				4772	exactly matching a previous argument's type or the result type. This allows an
				4773	intrinsic function which accepts multiple arguments, but needs all of them to
				4774	be of the same type, to only be overloaded with respect to a single argument or
				4775	the result.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4776
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	4777	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4778	encoded into its function name, each preceded by a period. Only those types
				4779	which are overloaded result in a name suffix. Arguments whose type is matched
				4780	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4781	take an integer of any width and returns an integer of exactly the same integer
				4782	width. This leads to a family of functions such as
				4783	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4784	Only one type, the return type, is overloaded, and only one type suffix is
				4785	required. Because the argument's type is matched against the return type, it
				4786	does not require its own name suffix.</p>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	4787
				4788	<p>To learn how to add an intrinsic function, please see the
				4789	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4790	</p>
				4791
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4792	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4793
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4794	<!-- ======================================================================= -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4795	<div class="doc_subsection">
				4796	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4797	</div>
				4798
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4799	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4800
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4801	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	3333747	2006-01-13 23:26:01 +0000	[diff] [blame]	4802	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]	4803	intrinsic functions. These functions are related to the similarly
				4804	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4805
Chris Lattner	48b383b0	2003-11-25 01:02:51 +0000	[diff] [blame]	4806	<p>All of these functions operate on arguments that use a
				4807	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4808	language reference manual does not define what this type is, so all
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4809	transformations should be prepared to handle these functions regardless of
				4810	the type used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4811
Chris Lattner	30b868d	2006-05-15 17:26:46 +0000	[diff] [blame]	4812	<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]	4813	instruction and the variable argument handling intrinsic functions are
				4814	used.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4815
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4816	<div class="doc_code">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4817	<pre>
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4818	define i32 @test(i32 %X, ...) {
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4819	; Initialize variable argument processing
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4820	%ap = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4821	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4822	call void @llvm.va_start(i8* %ap2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4823
				4824	; Read a single integer argument
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4825	%tmp = va_arg i8** %ap, i32
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4826
				4827	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4828	%aq = alloca i8*
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4829	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4830	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4831	call void @llvm.va_end(i8* %aq2)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4832
				4833	; Stop processing of arguments.
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4834	call void @llvm.va_end(i8* %ap2)
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	4835	ret i32 %tmp
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4836	}
Anton Korobeynikov	640bbe0	2007-03-21 23:58:04 +0000	[diff] [blame]	4837
				4838	declare void @llvm.va_start(i8*)
				4839	declare void @llvm.va_copy(i8, i8)
				4840	declare void @llvm.va_end(i8*)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4841	</pre>
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4842	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4843
Bill Wendling	3716c5d	2007-05-29 09:04:49 +0000	[diff] [blame]	4844	</div>
				4845
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4846	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4847	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4848	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4849	</div>
				4850
				4851
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4852	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4853	<h5>Syntax:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4854	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4855	<h5>Overview:</h5>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4856	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4857	<tt>*<arglist></tt> for subsequent use by <tt><a
				4858	href="#i_va_arg">va_arg</a></tt>.</p>
				4859
				4860	<h5>Arguments:</h5>
				4861
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4862	<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]	4863
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4864	<h5>Semantics:</h5>
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4865
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	4866	<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]	4867	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4868	<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]	4869	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4870	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]	4871	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]	4872
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4873	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4874
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4875	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4876	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4877	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4878	</div>
				4879
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4880	<div class="doc_text">
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4881	<h5>Syntax:</h5>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4882	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4883	<h5>Overview:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4884
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4885	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4886	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]	4887	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]	4888
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4889	<h5>Arguments:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4890
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4891	<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]	4892
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4893	<h5>Semantics:</h5>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4894
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4895	<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]	4896	macro available in C. In a target-dependent way, it destroys the
				4897	<tt>va_list</tt> element to which the argument points. Calls to <a
				4898	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4899	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4900	<tt>llvm.va_end</tt>.</p>
Chris Lattner	db0790c	2007-01-08 07:55:15 +0000	[diff] [blame]	4901
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4902	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4903
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4904	<!-- _______________________________________________________________________ -->
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4905	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4906	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4907	</div>
				4908
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4909	<div class="doc_text">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4910
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4911	<h5>Syntax:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4912
				4913	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	4914	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4915	</pre>
				4916
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4917	<h5>Overview:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4918
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4919	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4920	from the source argument list to the destination argument list.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4921
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4922	<h5>Arguments:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4923
Andrew Lenharth	5fb787c	2005-06-18 18:28:17 +0000	[diff] [blame]	4924	<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]	4925	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]	4926
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4927
Chris Lattner	bd64b4e	2003-05-08 04:57:36 +0000	[diff] [blame]	4928	<h5>Semantics:</h5>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4929
Jeff Cohen	222a8a4	2007-04-29 01:07:00 +0000	[diff] [blame]	4930	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4931	macro available in C. In a target-dependent way, it copies the source
				4932	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4933	intrinsic is necessary because the <tt><a href="#int_va_start">
				4934	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4935	example, memory allocation.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4936
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	4937	</div>
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	4938
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	4939	<!-- ======================================================================= -->
				4940	<div class="doc_subsection">
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4941	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4942	</div>
				4943
				4944	<div class="doc_text">
				4945
				4946	<p>
				4947	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	67c37d1	2008-08-05 18:29:16 +0000	[diff] [blame]	4948	Collection</a> (GC) requires the implementation and generation of these
				4949	intrinsics.
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4950	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]	4951	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4952	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]	4953	Front-ends for type-safe garbage collected languages should generate these
				4954	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4955	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4956	</p>
Christopher Lamb	55c6d4f	2007-12-17 01:00:21 +0000	[diff] [blame]	4957
				4958	<p>The garbage collection intrinsics only operate on objects in the generic
				4959	address space (address space zero).</p>
				4960
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4961	</div>
				4962
				4963	<!-- _______________________________________________________________________ -->
				4964	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	4965	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4966	</div>
				4967
				4968	<div class="doc_text">
				4969
				4970	<h5>Syntax:</h5>
				4971
				4972	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	4973	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4974	</pre>
				4975
				4976	<h5>Overview:</h5>
				4977
John Criswell	dfe6a86	2004-12-10 15:51:16 +0000	[diff] [blame]	4978	<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]	4979	the code generator, and allows some metadata to be associated with it.</p>
				4980
				4981	<h5>Arguments:</h5>
				4982
				4983	<p>The first argument specifies the address of a stack object that contains the
				4984	root pointer. The second pointer (which must be either a constant or a global
				4985	value address) contains the meta-data to be associated with the root.</p>
				4986
				4987	<h5>Semantics:</h5>
				4988
Chris Lattner	851b771	2008-04-24 05:59:56 +0000	[diff] [blame]	4989	<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]	4990	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	4991	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				4992	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				4993	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	4994
				4995	</div>
				4996
				4997
				4998	<!-- _______________________________________________________________________ -->
				4999	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5000	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5001	</div>
				5002
				5003	<div class="doc_text">
				5004
				5005	<h5>Syntax:</h5>
				5006
				5007	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5008	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5009	</pre>
				5010
				5011	<h5>Overview:</h5>
				5012
				5013	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5014	locations, allowing garbage collector implementations that require read
				5015	barriers.</p>
				5016
				5017	<h5>Arguments:</h5>
				5018
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5019	<p>The second argument is the address to read from, which should be an address
				5020	allocated from the garbage collector. The first object is a pointer to the
				5021	start of the referenced object, if needed by the language runtime (otherwise
				5022	null).</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5023
				5024	<h5>Semantics:</h5>
				5025
				5026	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5027	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5028	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5029	may only be used in a function which <a href="#gc">specifies a GC
				5030	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5031
				5032	</div>
				5033
				5034
				5035	<!-- _______________________________________________________________________ -->
				5036	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5037	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5038	</div>
				5039
				5040	<div class="doc_text">
				5041
				5042	<h5>Syntax:</h5>
				5043
				5044	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5045	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5046	</pre>
				5047
				5048	<h5>Overview:</h5>
				5049
				5050	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5051	locations, allowing garbage collector implementations that require write
				5052	barriers (such as generational or reference counting collectors).</p>
				5053
				5054	<h5>Arguments:</h5>
				5055
Chris Lattner	f922807	2006-03-14 20:02:51 +0000	[diff] [blame]	5056	<p>The first argument is the reference to store, the second is the start of the
				5057	object to store it to, and the third is the address of the field of Obj to
				5058	store to. If the runtime does not require a pointer to the object, Obj may be
				5059	null.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5060
				5061	<h5>Semantics:</h5>
				5062
				5063	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5064	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	fb56bde	2007-12-25 02:31:26 +0000	[diff] [blame]	5065	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5066	may only be used in a function which <a href="#gc">specifies a GC
				5067	algorithm</a>.</p>
Chris Lattner	757528b0b	2004-05-23 21:06:01 +0000	[diff] [blame]	5068
				5069	</div>
				5070
				5071
				5072
				5073	<!-- ======================================================================= -->
				5074	<div class="doc_subsection">
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5075	<a name="int_codegen">Code Generator Intrinsics</a>
				5076	</div>
				5077
				5078	<div class="doc_text">
				5079	<p>
				5080	These intrinsics are provided by LLVM to expose special features that may only
				5081	be implemented with code generator support.
				5082	</p>
				5083
				5084	</div>
				5085
				5086	<!-- _______________________________________________________________________ -->
				5087	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5088	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5089	</div>
				5090
				5091	<div class="doc_text">
				5092
				5093	<h5>Syntax:</h5>
				5094	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5095	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5096	</pre>
				5097
				5098	<h5>Overview:</h5>
				5099
				5100	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5101	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5102	target-specific value indicating the return address of the current function
				5103	or one of its callers.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5104	</p>
				5105
				5106	<h5>Arguments:</h5>
				5107
				5108	<p>
				5109	The argument to this intrinsic indicates which function to return the address
				5110	for. Zero indicates the calling function, one indicates its caller, etc. The
				5111	argument is <b>required</b> to be a constant integer value.
				5112	</p>
				5113
				5114	<h5>Semantics:</h5>
				5115
				5116	<p>
				5117	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5118	the return address of the specified call frame, or zero if it cannot be
				5119	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5120	for arguments other than zero, so it should only be used for debugging purposes.
				5121	</p>
				5122
				5123	<p>
				5124	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5125	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]	5126	source-language caller.
				5127	</p>
				5128	</div>
				5129
				5130
				5131	<!-- _______________________________________________________________________ -->
				5132	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5133	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5134	</div>
				5135
				5136	<div class="doc_text">
				5137
				5138	<h5>Syntax:</h5>
				5139	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5140	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5141	</pre>
				5142
				5143	<h5>Overview:</h5>
				5144
				5145	<p>
Chris Lattner	c1fb426	2006-10-15 20:05:59 +0000	[diff] [blame]	5146	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5147	target-specific frame pointer value for the specified stack frame.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5148	</p>
				5149
				5150	<h5>Arguments:</h5>
				5151
				5152	<p>
				5153	The argument to this intrinsic indicates which function to return the frame
				5154	pointer for. Zero indicates the calling function, one indicates its caller,
				5155	etc. The argument is <b>required</b> to be a constant integer value.
				5156	</p>
				5157
				5158	<h5>Semantics:</h5>
				5159
				5160	<p>
				5161	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5162	the frame address of the specified call frame, or zero if it cannot be
				5163	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5164	for arguments other than zero, so it should only be used for debugging purposes.
				5165	</p>
				5166
				5167	<p>
				5168	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	2e6eb5f	2005-03-07 20:30:51 +0000	[diff] [blame]	5169	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]	5170	source-language caller.
				5171	</p>
				5172	</div>
				5173
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5174	<!-- _______________________________________________________________________ -->
				5175	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5176	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5177	</div>
				5178
				5179	<div class="doc_text">
				5180
				5181	<h5>Syntax:</h5>
				5182	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5183	declare i8 *@llvm.stacksave()
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5184	</pre>
				5185
				5186	<h5>Overview:</h5>
				5187
				5188	<p>
				5189	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]	5190	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5191	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5192	features like scoped automatic variable sized arrays in C99.
				5193	</p>
				5194
				5195	<h5>Semantics:</h5>
				5196
				5197	<p>
				5198	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]	5199	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5200	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5201	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5202	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5203	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5204	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5205	</p>
				5206
				5207	</div>
				5208
				5209	<!-- _______________________________________________________________________ -->
				5210	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5211	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5212	</div>
				5213
				5214	<div class="doc_text">
				5215
				5216	<h5>Syntax:</h5>
				5217	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5218	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5219	</pre>
				5220
				5221	<h5>Overview:</h5>
				5222
				5223	<p>
				5224	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5225	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]	5226	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	2f0f001	2006-01-13 02:03:13 +0000	[diff] [blame]	5227	useful for implementing language features like scoped automatic variable sized
				5228	arrays in C99.
				5229	</p>
				5230
				5231	<h5>Semantics:</h5>
				5232
				5233	<p>
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5234	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]	5235	</p>
				5236
				5237	</div>
				5238
				5239
				5240	<!-- _______________________________________________________________________ -->
				5241	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5242	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5243	</div>
				5244
				5245	<div class="doc_text">
				5246
				5247	<h5>Syntax:</h5>
				5248	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5249	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5250	</pre>
				5251
				5252	<h5>Overview:</h5>
				5253
				5254
				5255	<p>
				5256	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]	5257	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5258	no
				5259	effect on the behavior of the program but can change its performance
Chris Lattner	ff85107	2005-02-28 19:47:14 +0000	[diff] [blame]	5260	characteristics.
Chris Lattner	c8a2c22	2005-02-28 19:24:19 +0000	[diff] [blame]	5261	</p>
				5262
				5263	<h5>Arguments:</h5>
				5264
				5265	<p>
				5266	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5267	determining if the fetch should be for a read (0) or write (1), and
				5268	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	d3e641c	2005-03-07 20:31:38 +0000	[diff] [blame]	5269	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]	5270	<tt>locality</tt> arguments must be constant integers.
				5271	</p>
				5272
				5273	<h5>Semantics:</h5>
				5274
				5275	<p>
				5276	This intrinsic does not modify the behavior of the program. In particular,
				5277	prefetches cannot trap and do not produce a value. On targets that support this
				5278	intrinsic, the prefetch can provide hints to the processor cache for better
				5279	performance.
				5280	</p>
				5281
				5282	</div>
				5283
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5284	<!-- _______________________________________________________________________ -->
				5285	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5286	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5287	</div>
				5288
				5289	<div class="doc_text">
				5290
				5291	<h5>Syntax:</h5>
				5292	<pre>
Chris Lattner	1247773	2007-09-21 17:30:40 +0000	[diff] [blame]	5293	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5294	</pre>
				5295
				5296	<h5>Overview:</h5>
				5297
				5298
				5299	<p>
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5300	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]	5301	(PC) in a region of
				5302	code to simulators and other tools. The method is target specific, but it is
				5303	expected that the marker will use exported symbols to transmit the PC of the
				5304	marker.
				5305	The marker makes no guarantees that it will remain with any specific instruction
				5306	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]	5307	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	8819056	2005-05-16 16:17:45 +0000	[diff] [blame]	5308	correlations of simulation runs.
Andrew Lenharth	b442791	2005-03-28 20:05:49 +0000	[diff] [blame]	5309	</p>
				5310
				5311	<h5>Arguments:</h5>
				5312
				5313	<p>
				5314	<tt>id</tt> is a numerical id identifying the marker.
				5315	</p>
				5316
				5317	<h5>Semantics:</h5>
				5318
				5319	<p>
				5320	This intrinsic does not modify the behavior of the program. Backends that do not
				5321	support this intrinisic may ignore it.
				5322	</p>
				5323
				5324	</div>
				5325
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5326	<!-- _______________________________________________________________________ -->
				5327	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5328	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5329	</div>
				5330
				5331	<div class="doc_text">
				5332
				5333	<h5>Syntax:</h5>
				5334	<pre>
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5335	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	01aa563	2005-11-11 16:47:30 +0000	[diff] [blame]	5336	</pre>
				5337
				5338	<h5>Overview:</h5>
				5339
				5340
				5341	<p>
				5342	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5343	counter register (or similar low latency, high accuracy clocks) on those targets
				5344	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5345	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5346	should only be used for small timings.
				5347	</p>
				5348
				5349	<h5>Semantics:</h5>
				5350
				5351	<p>
				5352	When directly supported, reading the cycle counter should not modify any memory.
				5353	Implementations are allowed to either return a application specific value or a
				5354	system wide value. On backends without support, this is lowered to a constant 0.
				5355	</p>
				5356
				5357	</div>
				5358
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5359	<!-- ======================================================================= -->
				5360	<div class="doc_subsection">
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5361	<a name="int_libc">Standard C Library Intrinsics</a>
				5362	</div>
				5363
				5364	<div class="doc_text">
				5365	<p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5366	LLVM provides intrinsics for a few important standard C library functions.
				5367	These intrinsics allow source-language front-ends to pass information about the
				5368	alignment of the pointer arguments to the code generator, providing opportunity
				5369	for more efficient code generation.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5370	</p>
				5371
				5372	</div>
				5373
				5374	<!-- _______________________________________________________________________ -->
				5375	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5376	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5377	</div>
				5378
				5379	<div class="doc_text">
				5380
				5381	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5382	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5383	width. Not all targets support all bit widths however.</p>
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5384	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5385	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5386	i8 <len>, i32 <align>)
				5387	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5388	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5389	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5390	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5391	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5392	i64 <len>, i32 <align>)
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5393	</pre>
				5394
				5395	<h5>Overview:</h5>
				5396
				5397	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5398	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]	5399	location to the destination location.
				5400	</p>
				5401
				5402	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5403	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5404	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5405	</p>
				5406
				5407	<h5>Arguments:</h5>
				5408
				5409	<p>
				5410	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]	5411	the source. The third argument is an integer argument
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5412	specifying the number of bytes to copy, and the fourth argument is the alignment
				5413	of the source and destination locations.
				5414	</p>
				5415
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5416	<p>
				5417	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]	5418	the caller guarantees that both the source and destination pointers are aligned
				5419	to that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5420	</p>
				5421
Chris Lattner	fee1146	2004-02-12 17:01:32 +0000	[diff] [blame]	5422	<h5>Semantics:</h5>
				5423
				5424	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5425	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]	5426	location to the destination location, which are not allowed to overlap. It
				5427	copies "len" bytes of memory over. If the argument is known to be aligned to
				5428	some boundary, this can be specified as the fourth argument, otherwise it should
				5429	be set to 0 or 1.
				5430	</p>
				5431	</div>
				5432
				5433
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5434	<!-- _______________________________________________________________________ -->
				5435	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5436	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5437	</div>
				5438
				5439	<div class="doc_text">
				5440
				5441	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5442	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5443	width. Not all targets support all bit widths however.</p>
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5444	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5445	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5446	i8 <len>, i32 <align>)
				5447	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5448	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5449	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5450	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5451	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5452	i64 <len>, i32 <align>)
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5453	</pre>
				5454
				5455	<h5>Overview:</h5>
				5456
				5457	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5458	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5459	location to the destination location. It is similar to the
Chris Lattner	ec56402	2008-01-06 19:51:52 +0000	[diff] [blame]	5460	'<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]	5461	</p>
				5462
				5463	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5464	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5465	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5466	</p>
				5467
				5468	<h5>Arguments:</h5>
				5469
				5470	<p>
				5471	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]	5472	the source. The third argument is an integer argument
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5473	specifying the number of bytes to copy, and the fourth argument is the alignment
				5474	of the source and destination locations.
				5475	</p>
				5476
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5477	<p>
				5478	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]	5479	the caller guarantees that the source and destination pointers are aligned to
				5480	that boundary.
Chris Lattner	4c67c48	2004-02-12 21:18:15 +0000	[diff] [blame]	5481	</p>
				5482
Chris Lattner	f30152e	2004-02-12 18:10:10 +0000	[diff] [blame]	5483	<h5>Semantics:</h5>
				5484
				5485	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5486	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]	5487	location to the destination location, which may overlap. It
				5488	copies "len" bytes of memory over. If the argument is known to be aligned to
				5489	some boundary, this can be specified as the fourth argument, otherwise it should
				5490	be set to 0 or 1.
				5491	</p>
				5492	</div>
				5493
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	5494
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5495	<!-- _______________________________________________________________________ -->
				5496	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5497	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5498	</div>
				5499
				5500	<div class="doc_text">
				5501
				5502	<h5>Syntax:</h5>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5503	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5504	width. Not all targets support all bit widths however.</p>
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5505	<pre>
Chris Lattner	dd70834	2008-11-21 16:42:48 +0000	[diff] [blame]	5506	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5507	i8 <len>, i32 <align>)
				5508	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5509	i16 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5510	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5511	i32 <len>, i32 <align>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5512	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	b5ebf3d	2006-12-31 07:07:53 +0000	[diff] [blame]	5513	i64 <len>, i32 <align>)
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5514	</pre>
				5515
				5516	<h5>Overview:</h5>
				5517
				5518	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5519	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]	5520	byte value.
				5521	</p>
				5522
				5523	<p>
				5524	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5525	does not return a value, and takes an extra alignment argument.
				5526	</p>
				5527
				5528	<h5>Arguments:</h5>
				5529
				5530	<p>
				5531	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]	5532	byte value to fill it with, the third argument is an integer
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5533	argument specifying the number of bytes to fill, and the fourth argument is the
				5534	known alignment of destination location.
				5535	</p>
				5536
				5537	<p>
				5538	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]	5539	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5540	</p>
				5541
				5542	<h5>Semantics:</h5>
				5543
				5544	<p>
Chris Lattner	0c8b259	2006-03-03 00:07:20 +0000	[diff] [blame]	5545	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5546	the
Chris Lattner	3649c3a	2004-02-14 04:08:35 +0000	[diff] [blame]	5547	destination location. If the argument is known to be aligned to some boundary,
				5548	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5549	1.
				5550	</p>
				5551	</div>
				5552
				5553
Chris Lattner	3b4f437	2004-06-11 02:28:03 +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_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5557	</div>
				5558
				5559	<div class="doc_text">
				5560
				5561	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5562	<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]	5563	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]	5564	types however.</p>
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5565	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5566	declare float @llvm.sqrt.f32(float %Val)
				5567	declare double @llvm.sqrt.f64(double %Val)
				5568	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5569	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5570	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5571	</pre>
				5572
				5573	<h5>Overview:</h5>
				5574
				5575	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5576	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]	5577	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]	5578	<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]	5579	negative numbers other than -0.0 (which allows for better optimization, because
				5580	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5581	defined to return -0.0 like IEEE sqrt.
Chris Lattner	8a8f2e5	2005-07-21 01:29:16 +0000	[diff] [blame]	5582	</p>
				5583
				5584	<h5>Arguments:</h5>
				5585
				5586	<p>
				5587	The argument and return value are floating point numbers of the same type.
				5588	</p>
				5589
				5590	<h5>Semantics:</h5>
				5591
				5592	<p>
Dan Gohman	33988db	2007-07-16 14:37:41 +0000	[diff] [blame]	5593	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]	5594	floating point number.
				5595	</p>
				5596	</div>
				5597
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5598	<!-- _______________________________________________________________________ -->
				5599	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5600	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5601	</div>
				5602
				5603	<div class="doc_text">
				5604
				5605	<h5>Syntax:</h5>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5606	<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]	5607	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]	5608	types however.</p>
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5609	<pre>
Dale Johannesen	dd89d27	2007-10-02 17:47:38 +0000	[diff] [blame]	5610	declare float @llvm.powi.f32(float %Val, i32 %power)
				5611	declare double @llvm.powi.f64(double %Val, i32 %power)
				5612	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5613	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5614	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5615	</pre>
				5616
				5617	<h5>Overview:</h5>
				5618
				5619	<p>
				5620	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5621	specified (positive or negative) power. The order of evaluation of
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5622	multiplications is not defined. When a vector of floating point type is
				5623	used, the second argument remains a scalar integer value.
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5624	</p>
				5625
				5626	<h5>Arguments:</h5>
				5627
				5628	<p>
				5629	The second argument is an integer power, and the first is a value to raise to
				5630	that power.
				5631	</p>
				5632
				5633	<h5>Semantics:</h5>
				5634
				5635	<p>
				5636	This function returns the first value raised to the second power with an
				5637	unspecified sequence of rounding operations.</p>
				5638	</div>
				5639
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5640	<!-- _______________________________________________________________________ -->
				5641	<div class="doc_subsubsection">
				5642	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5643	</div>
				5644
				5645	<div class="doc_text">
				5646
				5647	<h5>Syntax:</h5>
				5648	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5649	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]	5650	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5651	<pre>
				5652	declare float @llvm.sin.f32(float %Val)
				5653	declare double @llvm.sin.f64(double %Val)
				5654	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5655	declare fp128 @llvm.sin.f128(fp128 %Val)
				5656	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5657	</pre>
				5658
				5659	<h5>Overview:</h5>
				5660
				5661	<p>
				5662	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5663	</p>
				5664
				5665	<h5>Arguments:</h5>
				5666
				5667	<p>
				5668	The argument and return value are floating point numbers of the same type.
				5669	</p>
				5670
				5671	<h5>Semantics:</h5>
				5672
				5673	<p>
				5674	This function returns the sine of the specified operand, returning the
				5675	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]	5676	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5677	</div>
				5678
				5679	<!-- _______________________________________________________________________ -->
				5680	<div class="doc_subsubsection">
				5681	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5682	</div>
				5683
				5684	<div class="doc_text">
				5685
				5686	<h5>Syntax:</h5>
				5687	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5688	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]	5689	types however.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5690	<pre>
				5691	declare float @llvm.cos.f32(float %Val)
				5692	declare double @llvm.cos.f64(double %Val)
				5693	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5694	declare fp128 @llvm.cos.f128(fp128 %Val)
				5695	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5696	</pre>
				5697
				5698	<h5>Overview:</h5>
				5699
				5700	<p>
				5701	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				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>
				5713	This function returns the cosine of the specified operand, returning the
				5714	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]	5715	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5716	</div>
				5717
				5718	<!-- _______________________________________________________________________ -->
				5719	<div class="doc_subsubsection">
				5720	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5721	</div>
				5722
				5723	<div class="doc_text">
				5724
				5725	<h5>Syntax:</h5>
				5726	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				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>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5729	<pre>
				5730	declare float @llvm.pow.f32(float %Val, float %Power)
				5731	declare double @llvm.pow.f64(double %Val, double %Power)
				5732	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5733	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5734	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5735	</pre>
				5736
				5737	<h5>Overview:</h5>
				5738
				5739	<p>
				5740	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5741	specified (positive or negative) power.
				5742	</p>
				5743
				5744	<h5>Arguments:</h5>
				5745
				5746	<p>
				5747	The second argument is a floating point power, and the first is a value to
				5748	raise to that power.
				5749	</p>
				5750
				5751	<h5>Semantics:</h5>
				5752
				5753	<p>
				5754	This function returns the first value raised to the second power,
				5755	returning the
				5756	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]	5757	conditions in the same way.</p>
Dan Gohman	b6324c1	2007-10-15 20:30:11 +0000	[diff] [blame]	5758	</div>
				5759
Chris Lattner	33b73f9	2006-09-08 06:34:02 +0000	[diff] [blame]	5760
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5761	<!-- ======================================================================= -->
				5762	<div class="doc_subsection">
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5763	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5764	</div>
				5765
				5766	<div class="doc_text">
				5767	<p>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5768	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5769	These allow efficient code generation for some algorithms.
				5770	</p>
				5771
				5772	</div>
				5773
				5774	<!-- _______________________________________________________________________ -->
				5775	<div class="doc_subsubsection">
Reid Spencer	96a5f02	2007-04-04 02:42:35 +0000	[diff] [blame]	5776	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5777	</div>
				5778
				5779	<div class="doc_text">
				5780
				5781	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5782	<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]	5783	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]	5784	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5785	declare i16 @llvm.bswap.i16(i16 <id>)
				5786	declare i32 @llvm.bswap.i32(i32 <id>)
				5787	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5788	</pre>
				5789
				5790	<h5>Overview:</h5>
				5791
				5792	<p>
Reid Spencer	f361c4f	2007-04-02 02:25:19 +0000	[diff] [blame]	5793	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]	5794	values with an even number of bytes (positive multiple of 16 bits). These are
				5795	useful for performing operations on data that is not in the target's native
				5796	byte order.
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5797	</p>
				5798
				5799	<h5>Semantics:</h5>
				5800
				5801	<p>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5802	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]	5803	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5804	intrinsic returns an i32 value that has the four bytes of the input i32
				5805	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]	5806	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5807	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5808	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	0f223bb	2006-01-13 23:26:38 +0000	[diff] [blame]	5809	</p>
				5810
				5811	</div>
				5812
				5813	<!-- _______________________________________________________________________ -->
				5814	<div class="doc_subsubsection">
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5815	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5816	</div>
				5817
				5818	<div class="doc_text">
				5819
				5820	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5821	<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]	5822	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5823	<pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	5824	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5825	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5826	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5827	declare i64 @llvm.ctpop.i64(i64 <src>)
				5828	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5829	</pre>
				5830
				5831	<h5>Overview:</h5>
				5832
				5833	<p>
Chris Lattner	069b5bd	2006-01-16 22:38:59 +0000	[diff] [blame]	5834	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5835	value.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5836	</p>
				5837
				5838	<h5>Arguments:</h5>
				5839
				5840	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5841	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]	5842	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5843	</p>
				5844
				5845	<h5>Semantics:</h5>
				5846
				5847	<p>
				5848	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5849	</p>
				5850	</div>
				5851
				5852	<!-- _______________________________________________________________________ -->
				5853	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5854	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5855	</div>
				5856
				5857	<div class="doc_text">
				5858
				5859	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5860	<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]	5861	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5862	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5863	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5864	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5865	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5866	declare i64 @llvm.ctlz.i64(i64 <src>)
				5867	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5868	</pre>
				5869
				5870	<h5>Overview:</h5>
				5871
				5872	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5873	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5874	leading zeros in a variable.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5875	</p>
				5876
				5877	<h5>Arguments:</h5>
				5878
				5879	<p>
Chris Lattner	573f64e	2005-05-07 01:46:40 +0000	[diff] [blame]	5880	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]	5881	integer type. The return type must match the argument type.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5882	</p>
				5883
				5884	<h5>Semantics:</h5>
				5885
				5886	<p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5887	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5888	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]	5889	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	1d46352	2005-05-03 18:01:48 +0000	[diff] [blame]	5890	</p>
				5891	</div>
Chris Lattner	3b4f437	2004-06-11 02:28:03 +0000	[diff] [blame]	5892
				5893
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5894
				5895	<!-- _______________________________________________________________________ -->
				5896	<div class="doc_subsubsection">
Chris Lattner	b748c67	2006-01-16 22:34:14 +0000	[diff] [blame]	5897	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5898	</div>
				5899
				5900	<div class="doc_text">
				5901
				5902	<h5>Syntax:</h5>
Reid Spencer	4eefaab	2007-04-01 08:04:23 +0000	[diff] [blame]	5903	<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]	5904	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5905	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5906	declare i8 @llvm.cttz.i8 (i8 <src>)
				5907	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	be9c93c	2007-03-22 00:02:17 +0000	[diff] [blame]	5908	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5909	declare i64 @llvm.cttz.i64(i64 <src>)
				5910	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5911	</pre>
				5912
				5913	<h5>Overview:</h5>
				5914
				5915	<p>
Reid Spencer	b4f9a6f	2006-01-16 21:12:35 +0000	[diff] [blame]	5916	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5917	trailing zeros.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5918	</p>
				5919
				5920	<h5>Arguments:</h5>
				5921
				5922	<p>
				5923	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]	5924	integer type. The return type must match the argument type.
Chris Lattner	efa20fa	2005-05-15 19:39:26 +0000	[diff] [blame]	5925	</p>
				5926
				5927	<h5>Semantics:</h5>
				5928
				5929	<p>
				5930	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5931	in a variable. If the src == 0 then the result is the size in bits of the type
				5932	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5933	</p>
				5934	</div>
				5935
Reid Spencer	8a5799f	2007-04-01 08:27:01 +0000	[diff] [blame]	5936	<!-- _______________________________________________________________________ -->
				5937	<div class="doc_subsubsection">
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5938	<a name="int_part_select">'<tt>llvm.part.select.*</tt>' Intrinsic</a>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5939	</div>
				5940
				5941	<div class="doc_text">
				5942
				5943	<h5>Syntax:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5944	<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]	5945	on any integer bit width.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5946	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5947	declare i17 @llvm.part.select.i17 (i17 %val, i32 %loBit, i32 %hiBit)
				5948	declare i29 @llvm.part.select.i29 (i29 %val, i32 %loBit, i32 %hiBit)
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5949	</pre>
				5950
				5951	<h5>Overview:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5952	<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]	5953	range of bits from an integer value and returns them in the same bit width as
				5954	the original value.</p>
				5955
				5956	<h5>Arguments:</h5>
				5957	<p>The first argument, <tt>%val</tt> and the result may be integer types of
				5958	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]	5959	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]	5960
				5961	<h5>Semantics:</h5>
Reid Spencer	ea2945e	2007-04-10 02:51:31 +0000	[diff] [blame]	5962	<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]	5963	of operation: forwards and reverse. If <tt>%loBit</tt> is greater than
				5964	<tt>%hiBits</tt> then the intrinsic operates in reverse mode. Otherwise it
				5965	operates in forward mode.</p>
				5966	<p>In forward mode, this intrinsic is the equivalent of shifting <tt>%val</tt>
				5967	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]	5968	only the <tt>%hiBit - %loBit</tt> bits set, as follows:</p>
				5969	<ol>
				5970	<li>The <tt>%val</tt> is shifted right (LSHR) by the number of bits specified
				5971	by <tt>%loBits</tt>. This normalizes the value to the low order bits.</li>
				5972	<li>The <tt>%loBits</tt> value is subtracted from the <tt>%hiBits</tt> value
				5973	to determine the number of bits to retain.</li>
				5974	<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]	5975	<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]	5976	</ol>
Reid Spencer	70845c0	2007-05-14 16:14:57 +0000	[diff] [blame]	5977	<p>In reverse mode, a similar computation is made except that the bits are
				5978	returned in the reverse order. So, for example, if <tt>X</tt> has the value
				5979	<tt>i16 0x0ACF (101011001111)</tt> and we apply
				5980	<tt>part.select(i16 X, 8, 3)</tt> to it, we get back the value
				5981	<tt>i16 0x0026 (000000100110)</tt>.</p>
Reid Spencer	8bc7d95	2007-04-01 19:00:37 +0000	[diff] [blame]	5982	</div>
				5983
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5984	<div class="doc_subsubsection">
				5985	<a name="int_part_set">'<tt>llvm.part.set.*</tt>' Intrinsic</a>
				5986	</div>
				5987
				5988	<div class="doc_text">
				5989
				5990	<h5>Syntax:</h5>
				5991	<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]	5992	on any integer bit width.</p>
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	5993	<pre>
Chandler Carruth	7132e00	2007-08-04 01:51:18 +0000	[diff] [blame]	5994	declare i17 @llvm.part.set.i17.i9 (i17 %val, i9 %repl, i32 %lo, i32 %hi)
				5995	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]	5996	</pre>
				5997
				5998	<h5>Overview:</h5>
				5999	<p>The '<tt>llvm.part.set</tt>' family of intrinsic functions replaces a range
				6000	of bits in an integer value with another integer value. It returns the integer
				6001	with the replaced bits.</p>
				6002
				6003	<h5>Arguments:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6004	<p>The first argument, <tt>%val</tt>, and the result may be integer types of
				6005	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]	6006	whose bits will be replaced. The second argument, <tt>%repl</tt> may be an
				6007	integer of any bit width. The third and fourth arguments must be <tt>i32</tt>
				6008	type since they specify only a bit index.</p>
				6009
				6010	<h5>Semantics:</h5>
				6011	<p>The operation of the '<tt>llvm.part.set</tt>' intrinsic has two modes
				6012	of operation: forwards and reverse. If <tt>%lo</tt> is greater than
				6013	<tt>%hi</tt> then the intrinsic operates in reverse mode. Otherwise it
				6014	operates in forward mode.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6015
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6016	<p>For both modes, the <tt>%repl</tt> value is prepared for use by either
				6017	truncating it down to the size of the replacement area or zero extending it
				6018	up to that size.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6019
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6020	<p>In forward mode, the bits between <tt>%lo</tt> and <tt>%hi</tt> (inclusive)
				6021	are replaced with corresponding bits from <tt>%repl</tt>. That is the 0th bit
				6022	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]	6023	to the <tt>%hi</tt>th bit.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6024
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6025	<p>In reverse mode, a similar computation is made except that the bits are
				6026	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]	6027	<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]	6028
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6029	<h5>Examples:</h5>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6030
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6031	<pre>
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6032	llvm.part.set(0xFFFF, 0, 4, 7) -> 0xFF0F
Reid Spencer	146281c	2007-05-14 16:50:20 +0000	[diff] [blame]	6033	llvm.part.set(0xFFFF, 0, 7, 4) -> 0xFF0F
				6034	llvm.part.set(0xFFFF, 1, 7, 4) -> 0xFF8F
				6035	llvm.part.set(0xFFFF, F, 8, 3) -> 0xFFE7
Reid Spencer	c70afc3	2007-04-12 01:03:03 +0000	[diff] [blame]	6036	llvm.part.set(0xFFFF, 0, 3, 8) -> 0xFE07
Reid Spencer	7972c47	2007-04-11 23:49:50 +0000	[diff] [blame]	6037	</pre>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6038
				6039	</div>
				6040
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6041	<!-- ======================================================================= -->
				6042	<div class="doc_subsection">
				6043	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				6044	</div>
				6045
				6046	<div class="doc_text">
				6047	<p>
				6048	LLVM provides intrinsics for some arithmetic with overflow operations.
				6049	</p>
				6050
				6051	</div>
				6052
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6053	<!-- _______________________________________________________________________ -->
				6054	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6055	<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]	6056	</div>
				6057
				6058	<div class="doc_text">
				6059
				6060	<h5>Syntax:</h5>
				6061
				6062	<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]	6063	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6064
				6065	<pre>
				6066	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				6067	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6068	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				6069	</pre>
				6070
				6071	<h5>Overview:</h5>
				6072
				6073	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6074	a signed addition of the two arguments, and indicate whether an overflow
				6075	occurred during the signed summation.</p>
				6076
				6077	<h5>Arguments:</h5>
				6078
				6079	<p>The arguments (%a and %b) and the first element of the result structure may
				6080	be of integer types of any bit width, but they must have the same bit width. The
				6081	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6082	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6083
				6084	<h5>Semantics:</h5>
				6085
				6086	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6087	a signed addition of the two variables. They return a structure — the
				6088	first element of which is the signed summation, and the second element of which
				6089	is a bit specifying if the signed summation resulted in an overflow.</p>
				6090
				6091	<h5>Examples:</h5>
				6092	<pre>
				6093	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6094	%sum = extractvalue {i32, i1} %res, 0
				6095	%obit = extractvalue {i32, i1} %res, 1
				6096	br i1 %obit, label %overflow, label %normal
				6097	</pre>
				6098
				6099	</div>
				6100
				6101	<!-- _______________________________________________________________________ -->
				6102	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6103	<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]	6104	</div>
				6105
				6106	<div class="doc_text">
				6107
				6108	<h5>Syntax:</h5>
				6109
				6110	<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]	6111	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6112
				6113	<pre>
				6114	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6115	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6116	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6117	</pre>
				6118
				6119	<h5>Overview:</h5>
				6120
				6121	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6122	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6123	during the unsigned summation.</p>
				6124
				6125	<h5>Arguments:</h5>
				6126
				6127	<p>The arguments (%a and %b) and the first element of the result structure may
				6128	be of integer types of any bit width, but they must have the same bit width. The
				6129	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6130	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6131
				6132	<h5>Semantics:</h5>
				6133
				6134	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6135	an unsigned addition of the two arguments. They return a structure — the
				6136	first element of which is the sum, and the second element of which is a bit
				6137	specifying if the unsigned summation resulted in a carry.</p>
				6138
				6139	<h5>Examples:</h5>
				6140	<pre>
				6141	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6142	%sum = extractvalue {i32, i1} %res, 0
				6143	%obit = extractvalue {i32, i1} %res, 1
				6144	br i1 %obit, label %carry, label %normal
				6145	</pre>
				6146
				6147	</div>
				6148
				6149	<!-- _______________________________________________________________________ -->
				6150	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6151	<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]	6152	</div>
				6153
				6154	<div class="doc_text">
				6155
				6156	<h5>Syntax:</h5>
				6157
				6158	<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]	6159	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6160
				6161	<pre>
				6162	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6163	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6164	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6165	</pre>
				6166
				6167	<h5>Overview:</h5>
				6168
				6169	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6170	a signed subtraction of the two arguments, and indicate whether an overflow
				6171	occurred during the signed subtraction.</p>
				6172
				6173	<h5>Arguments:</h5>
				6174
				6175	<p>The arguments (%a and %b) and the first element of the result structure may
				6176	be of integer types of any bit width, but they must have the same bit width. The
				6177	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6178	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6179
				6180	<h5>Semantics:</h5>
				6181
				6182	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6183	a signed subtraction of the two arguments. They return a structure — the
				6184	first element of which is the subtraction, and the second element of which is a bit
				6185	specifying if the signed subtraction resulted in an overflow.</p>
				6186
				6187	<h5>Examples:</h5>
				6188	<pre>
				6189	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6190	%sum = extractvalue {i32, i1} %res, 0
				6191	%obit = extractvalue {i32, i1} %res, 1
				6192	br i1 %obit, label %overflow, label %normal
				6193	</pre>
				6194
				6195	</div>
				6196
				6197	<!-- _______________________________________________________________________ -->
				6198	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6199	<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]	6200	</div>
				6201
				6202	<div class="doc_text">
				6203
				6204	<h5>Syntax:</h5>
				6205
				6206	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6207	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6208
				6209	<pre>
				6210	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6211	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6212	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6213	</pre>
				6214
				6215	<h5>Overview:</h5>
				6216
				6217	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6218	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6219	occurred during the unsigned subtraction.</p>
				6220
				6221	<h5>Arguments:</h5>
				6222
				6223	<p>The arguments (%a and %b) and the first element of the result structure may
				6224	be of integer types of any bit width, but they must have the same bit width. The
				6225	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6226	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6227
				6228	<h5>Semantics:</h5>
				6229
				6230	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6231	an unsigned subtraction of the two arguments. They return a structure — the
				6232	first element of which is the subtraction, and the second element of which is a bit
				6233	specifying if the unsigned subtraction resulted in an overflow.</p>
				6234
				6235	<h5>Examples:</h5>
				6236	<pre>
				6237	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6238	%sum = extractvalue {i32, i1} %res, 0
				6239	%obit = extractvalue {i32, i1} %res, 1
				6240	br i1 %obit, label %overflow, label %normal
				6241	</pre>
				6242
				6243	</div>
				6244
				6245	<!-- _______________________________________________________________________ -->
				6246	<div class="doc_subsubsection">
Bill Wendling	fd2bd72	2009-02-08 04:04:40 +0000	[diff] [blame]	6247	<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]	6248	</div>
				6249
				6250	<div class="doc_text">
				6251
				6252	<h5>Syntax:</h5>
				6253
				6254	<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]	6255	on any integer bit width.</p>
Bill Wendling	f4d7062	2009-02-08 01:40:31 +0000	[diff] [blame]	6256
				6257	<pre>
				6258	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6259	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6260	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6261	</pre>
				6262
				6263	<h5>Overview:</h5>
				6264
				6265	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6266	a signed multiplication of the two arguments, and indicate whether an overflow
				6267	occurred during the signed multiplication.</p>
				6268
				6269	<h5>Arguments:</h5>
				6270
				6271	<p>The arguments (%a and %b) and the first element of the result structure may
				6272	be of integer types of any bit width, but they must have the same bit width. The
				6273	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6274	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6275
				6276	<h5>Semantics:</h5>
				6277
				6278	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6279	a signed multiplication of the two arguments. They return a structure —
				6280	the first element of which is the multiplication, and the second element of
				6281	which is a bit specifying if the signed multiplication resulted in an
				6282	overflow.</p>
				6283
				6284	<h5>Examples:</h5>
				6285	<pre>
				6286	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6287	%sum = extractvalue {i32, i1} %res, 0
				6288	%obit = extractvalue {i32, i1} %res, 1
				6289	br i1 %obit, label %overflow, label %normal
				6290	</pre>
				6291
Reid Spencer	5bf54c8	2007-04-11 23:23:49 +0000	[diff] [blame]	6292	</div>
				6293
Bill Wendling	b9a7327	2009-02-08 23:00:09 +0000	[diff] [blame]	6294	<!-- _______________________________________________________________________ -->
				6295	<div class="doc_subsubsection">
				6296	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6297	</div>
				6298
				6299	<div class="doc_text">
				6300
				6301	<h5>Syntax:</h5>
				6302
				6303	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6304	on any integer bit width.</p>
				6305
				6306	<pre>
				6307	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6308	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6309	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6310	</pre>
				6311
				6312	<h5>Overview:</h5>
				6313
				6314	<p><i><b>Warning:</b> '<tt>llvm.umul.with.overflow</tt>' is badly broken. It is
				6315	actively being fixed, but it should not currently be used!</i></p>
				6316
				6317	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6318	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6319	occurred during the unsigned multiplication.</p>
				6320
				6321	<h5>Arguments:</h5>
				6322
				6323	<p>The arguments (%a and %b) and the first element of the result structure may
				6324	be of integer types of any bit width, but they must have the same bit width. The
				6325	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6326	and <tt>%b</tt> are the two values that will undergo unsigned
				6327	multiplication.</p>
				6328
				6329	<h5>Semantics:</h5>
				6330
				6331	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6332	an unsigned multiplication of the two arguments. They return a structure —
				6333	the first element of which is the multiplication, and the second element of
				6334	which is a bit specifying if the unsigned multiplication resulted in an
				6335	overflow.</p>
				6336
				6337	<h5>Examples:</h5>
				6338	<pre>
				6339	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6340	%sum = extractvalue {i32, i1} %res, 0
				6341	%obit = extractvalue {i32, i1} %res, 1
				6342	br i1 %obit, label %overflow, label %normal
				6343	</pre>
				6344
				6345	</div>
				6346
Chris Lattner	941515c	2004-01-06 05:31:32 +0000	[diff] [blame]	6347	<!-- ======================================================================= -->
				6348	<div class="doc_subsection">
				6349	<a name="int_debugger">Debugger Intrinsics</a>
				6350	</div>
				6351
				6352	<div class="doc_text">
				6353	<p>
				6354	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6355	are described in the <a
				6356	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6357	Debugging</a> document.
				6358	</p>
				6359	</div>
				6360
				6361
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	6362	<!-- ======================================================================= -->
				6363	<div class="doc_subsection">
				6364	<a name="int_eh">Exception Handling Intrinsics</a>
				6365	</div>
				6366
				6367	<div class="doc_text">
				6368	<p> The LLVM exception handling intrinsics (which all start with
				6369	<tt>llvm.eh.</tt> prefix), are described in the <a
				6370	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6371	Handling</a> document. </p>
				6372	</div>
				6373
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6374	<!-- ======================================================================= -->
				6375	<div class="doc_subsection">
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6376	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6377	</div>
				6378
				6379	<div class="doc_text">
				6380	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6381	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6382	the <tt>nest</tt> attribute, from a function. The result is a callable
				6383	function pointer lacking the nest parameter - the caller does not need
				6384	to provide a value for it. Instead, the value to use is stored in
				6385	advance in a "trampoline", a block of memory usually allocated
				6386	on the stack, which also contains code to splice the nest value into the
				6387	argument list. This is used to implement the GCC nested function address
				6388	extension.
				6389	</p>
				6390	<p>
				6391	For example, if the function is
				6392	<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]	6393	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]	6394	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6395	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6396	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6397	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6398	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6399	</pre>
Bill Wendling	252570f	2007-09-22 09:23:55 +0000	[diff] [blame]	6400	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6401	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]	6402	</div>
				6403
				6404	<!-- _______________________________________________________________________ -->
				6405	<div class="doc_subsubsection">
				6406	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6407	</div>
				6408	<div class="doc_text">
				6409	<h5>Syntax:</h5>
				6410	<pre>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6411	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6412	</pre>
				6413	<h5>Overview:</h5>
				6414	<p>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6415	This fills the memory pointed to by <tt>tramp</tt> with code
				6416	and returns a function pointer suitable for executing it.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6417	</p>
				6418	<h5>Arguments:</h5>
				6419	<p>
				6420	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6421	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6422	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]	6423	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6424	currently provides no portable way of determining them, so a front-end that
				6425	generates this intrinsic needs to have some target-specific knowledge.
				6426	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]	6427	</p>
				6428	<h5>Semantics:</h5>
				6429	<p>
				6430	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]	6431	dependent code, turning it into a function. A pointer to this function is
				6432	returned, but needs to be bitcast to an
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6433	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	86e0119	2007-09-11 14:10:23 +0000	[diff] [blame]	6434	before being called. The new function's signature is the same as that of
				6435	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6436	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6437	of pointer type. Calling the new function is equivalent to calling
				6438	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6439	missing <tt>nest</tt> argument. If, after calling
				6440	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6441	modified, then the effect of any later call to the returned function pointer is
				6442	undefined.
Duncan Sands	644f917	2007-07-27 12:58:54 +0000	[diff] [blame]	6443	</p>
				6444	</div>
				6445
				6446	<!-- ======================================================================= -->
				6447	<div class="doc_subsection">
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6448	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6449	</div>
				6450
				6451	<div class="doc_text">
				6452	<p>
				6453	These intrinsic functions expand the "universal IR" of LLVM to represent
				6454	hardware constructs for atomic operations and memory synchronization. This
				6455	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]	6456	is aimed at a low enough level to allow any programming models or APIs
				6457	(Application Programming Interfaces) which
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6458	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6459	hardware behavior. Just as hardware provides a "universal IR" for source
				6460	languages, it also provides a starting point for developing a "universal"
				6461	atomic operation and synchronization IR.
				6462	</p>
				6463	<p>
				6464	These do <em>not</em> form an API such as high-level threading libraries,
				6465	software transaction memory systems, atomic primitives, and intrinsic
				6466	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6467	application libraries. The hardware interface provided by LLVM should allow
				6468	a clean implementation of all of these APIs and parallel programming models.
				6469	No one model or paradigm should be selected above others unless the hardware
				6470	itself ubiquitously does so.
				6471
				6472	</p>
				6473	</div>
				6474
				6475	<!-- _______________________________________________________________________ -->
				6476	<div class="doc_subsubsection">
				6477	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6478	</div>
				6479	<div class="doc_text">
				6480	<h5>Syntax:</h5>
				6481	<pre>
				6482	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6483	i1 <device> )
				6484
				6485	</pre>
				6486	<h5>Overview:</h5>
				6487	<p>
				6488	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6489	specific pairs of memory access types.
				6490	</p>
				6491	<h5>Arguments:</h5>
				6492	<p>
				6493	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6494	The first four arguments enables a specific barrier as listed below. The fith
				6495	argument specifies that the barrier applies to io or device or uncached memory.
				6496
				6497	</p>
				6498	<ul>
				6499	<li><tt>ll</tt>: load-load barrier</li>
				6500	<li><tt>ls</tt>: load-store barrier</li>
				6501	<li><tt>sl</tt>: store-load barrier</li>
				6502	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	6503	<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]	6504	</ul>
				6505	<h5>Semantics:</h5>
				6506	<p>
				6507	This intrinsic causes the system to enforce some ordering constraints upon
				6508	the loads and stores of the program. This barrier does not indicate
				6509	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6510	which they occur. For any of the specified pairs of load and store operations
				6511	(f.ex. load-load, or store-load), all of the first operations preceding the
				6512	barrier will complete before any of the second operations succeeding the
				6513	barrier begin. Specifically the semantics for each pairing is as follows:
				6514	</p>
				6515	<ul>
				6516	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6517	after the barrier begins.</li>
				6518
				6519	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6520	store after the barrier begins.</li>
				6521	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6522	store after the barrier begins.</li>
				6523	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6524	load after the barrier begins.</li>
				6525	</ul>
				6526	<p>
				6527	These semantics are applied with a logical "and" behavior when more than one
				6528	is enabled in a single memory barrier intrinsic.
				6529	</p>
				6530	<p>
				6531	Backends may implement stronger barriers than those requested when they do not
				6532	support as fine grained a barrier as requested. Some architectures do not
				6533	need all types of barriers and on such architectures, these become noops.
				6534	</p>
				6535	<h5>Example:</h5>
				6536	<pre>
				6537	%ptr = malloc i32
				6538	store i32 4, %ptr
				6539
				6540	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6541	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6542	<i>; guarantee the above finishes</i>
				6543	store i32 8, %ptr <i>; before this begins</i>
				6544	</pre>
				6545	</div>
				6546
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6547	<!-- _______________________________________________________________________ -->
				6548	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6549	<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]	6550	</div>
				6551	<div class="doc_text">
				6552	<h5>Syntax:</h5>
				6553	<p>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6554	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6555	any integer bit width and for different address spaces. Not all targets
				6556	support all bit widths however.</p>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6557
				6558	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6559	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6560	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6561	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6562	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]	6563
				6564	</pre>
				6565	<h5>Overview:</h5>
				6566	<p>
				6567	This loads a value in memory and compares it to a given value. If they are
				6568	equal, it stores a new value into the memory.
				6569	</p>
				6570	<h5>Arguments:</h5>
				6571	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6572	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]	6573	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6574	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6575	this integer type. While any bit width integer may be used, targets may only
				6576	lower representations they support in hardware.
				6577
				6578	</p>
				6579	<h5>Semantics:</h5>
				6580	<p>
				6581	This entire intrinsic must be executed atomically. It first loads the value
				6582	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6583	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6584	loaded value is yielded in all cases. This provides the equivalent of an
				6585	atomic compare-and-swap operation within the SSA framework.
				6586	</p>
				6587	<h5>Examples:</h5>
				6588
				6589	<pre>
				6590	%ptr = malloc i32
				6591	store i32 4, %ptr
				6592
				6593	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6594	%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]	6595	<i>; yields {i32}:result1 = 4</i>
				6596	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6597	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6598
				6599	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6600	%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]	6601	<i>; yields {i32}:result2 = 8</i>
				6602	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6603
				6604	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6605	</pre>
				6606	</div>
				6607
				6608	<!-- _______________________________________________________________________ -->
				6609	<div class="doc_subsubsection">
				6610	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6611	</div>
				6612	<div class="doc_text">
				6613	<h5>Syntax:</h5>
				6614
				6615	<p>
				6616	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6617	integer bit width. Not all targets support all bit widths however.</p>
				6618	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6619	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6620	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6621	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6622	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6623
				6624	</pre>
				6625	<h5>Overview:</h5>
				6626	<p>
				6627	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6628	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6629	at <tt>ptr</tt>.
				6630	</p>
				6631	<h5>Arguments:</h5>
				6632
				6633	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6634	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6635	<tt>val</tt> argument and the result must be integers of the same bit width.
				6636	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6637	integer type. The targets may only lower integer representations they
				6638	support.
				6639	</p>
				6640	<h5>Semantics:</h5>
				6641	<p>
				6642	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6643	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6644	equivalent of an atomic swap operation within the SSA framework.
				6645
				6646	</p>
				6647	<h5>Examples:</h5>
				6648	<pre>
				6649	%ptr = malloc i32
				6650	store i32 4, %ptr
				6651
				6652	%val1 = add i32 4, 4
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6653	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6654	<i>; yields {i32}:result1 = 4</i>
				6655	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6656	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6657
				6658	%val2 = add i32 1, 1
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6659	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6660	<i>; yields {i32}:result2 = 8</i>
				6661
				6662	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6663	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6664	</pre>
				6665	</div>
				6666
				6667	<!-- _______________________________________________________________________ -->
				6668	<div class="doc_subsubsection">
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6669	<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]	6670
				6671	</div>
				6672	<div class="doc_text">
				6673	<h5>Syntax:</h5>
				6674	<p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6675	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]	6676	integer bit width. Not all targets support all bit widths however.</p>
				6677	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6678	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6679	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6680	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6681	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6682
				6683	</pre>
				6684	<h5>Overview:</h5>
				6685	<p>
				6686	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6687	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6688	</p>
				6689	<h5>Arguments:</h5>
				6690	<p>
				6691
				6692	The intrinsic takes two arguments, the first a pointer to an integer value
				6693	and the second an integer value. The result is also an integer value. These
				6694	integer types can have any bit width, but they must all have the same bit
				6695	width. The targets may only lower integer representations they support.
				6696	</p>
				6697	<h5>Semantics:</h5>
				6698	<p>
				6699	This intrinsic does a series of operations atomically. It first loads the
				6700	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6701	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6702	</p>
				6703
				6704	<h5>Examples:</h5>
				6705	<pre>
				6706	%ptr = malloc i32
				6707	store i32 4, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6708	%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]	6709	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6710	%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]	6711	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6712	%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]	6713	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6714	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	9552894	2008-02-21 06:45:13 +0000	[diff] [blame]	6715	</pre>
				6716	</div>
				6717
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6718	<!-- _______________________________________________________________________ -->
				6719	<div class="doc_subsubsection">
				6720	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6721
				6722	</div>
				6723	<div class="doc_text">
				6724	<h5>Syntax:</h5>
				6725	<p>
				6726	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]	6727	any integer bit width and for different address spaces. Not all targets
				6728	support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6729	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6730	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6731	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6732	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6733	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]	6734
				6735	</pre>
				6736	<h5>Overview:</h5>
				6737	<p>
				6738	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6739	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6740	</p>
				6741	<h5>Arguments:</h5>
				6742	<p>
				6743
				6744	The intrinsic takes two arguments, the first a pointer to an integer value
				6745	and the second an integer value. The result is also an integer value. These
				6746	integer types can have any bit width, but they must all have the same bit
				6747	width. The targets may only lower integer representations they support.
				6748	</p>
				6749	<h5>Semantics:</h5>
				6750	<p>
				6751	This intrinsic does a series of operations atomically. It first loads the
				6752	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6753	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6754	</p>
				6755
				6756	<h5>Examples:</h5>
				6757	<pre>
				6758	%ptr = malloc i32
				6759	store i32 8, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6760	%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]	6761	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6762	%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]	6763	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6764	%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]	6765	<i>; yields {i32}:result3 = 2</i>
				6766	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6767	</pre>
				6768	</div>
				6769
				6770	<!-- _______________________________________________________________________ -->
				6771	<div class="doc_subsubsection">
				6772	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6773	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6774	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6775	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6776
				6777	</div>
				6778	<div class="doc_text">
				6779	<h5>Syntax:</h5>
				6780	<p>
				6781	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6782	<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]	6783	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6784	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6785	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6786	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6787	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6788	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6789	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]	6790
				6791	</pre>
				6792
				6793	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6794	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6795	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6796	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6797	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]	6798
				6799	</pre>
				6800
				6801	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6802	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6803	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6804	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6805	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]	6806
				6807	</pre>
				6808
				6809	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6810	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6811	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6812	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6813	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]	6814
				6815	</pre>
				6816	<h5>Overview:</h5>
				6817	<p>
				6818	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6819	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6820	at <tt>ptr</tt>.
				6821	</p>
				6822	<h5>Arguments:</h5>
				6823	<p>
				6824
				6825	These intrinsics take two arguments, the first a pointer to an integer value
				6826	and the second an integer value. The result is also an integer value. These
				6827	integer types can have any bit width, but they must all have the same bit
				6828	width. The targets may only lower integer representations they support.
				6829	</p>
				6830	<h5>Semantics:</h5>
				6831	<p>
				6832	These intrinsics does a series of operations atomically. They first load the
				6833	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6834	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6835	value stored at <tt>ptr</tt>.
				6836	</p>
				6837
				6838	<h5>Examples:</h5>
				6839	<pre>
				6840	%ptr = malloc i32
				6841	store i32 0x0F0F, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6842	%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]	6843	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6844	%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]	6845	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6846	%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]	6847	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6848	%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]	6849	<i>; yields {i32}:result3 = FF</i>
				6850	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6851	</pre>
				6852	</div>
				6853
				6854
				6855	<!-- _______________________________________________________________________ -->
				6856	<div class="doc_subsubsection">
				6857	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6858	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6859	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6860	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6861
				6862	</div>
				6863	<div class="doc_text">
				6864	<h5>Syntax:</h5>
				6865	<p>
				6866	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6867	<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]	6868	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6869	address spaces. Not all targets
Mon P Wang	6a49037	2008-06-25 08:15:39 +0000	[diff] [blame]	6870	support all bit widths however.</p>
				6871	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6872	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6873	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6874	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6875	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]	6876
				6877	</pre>
				6878
				6879	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6880	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6881	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6882	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6883	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]	6884
				6885	</pre>
				6886
				6887	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6888	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6889	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6890	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6891	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]	6892
				6893	</pre>
				6894
				6895	<pre>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6896	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6897	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6898	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6899	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]	6900
				6901	</pre>
				6902	<h5>Overview:</h5>
				6903	<p>
				6904	These intrinsics takes the signed or unsigned minimum or maximum of
				6905	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6906	original value at <tt>ptr</tt>.
				6907	</p>
				6908	<h5>Arguments:</h5>
				6909	<p>
				6910
				6911	These intrinsics take two arguments, the first a pointer to an integer value
				6912	and the second an integer value. The result is also an integer value. These
				6913	integer types can have any bit width, but they must all have the same bit
				6914	width. The targets may only lower integer representations they support.
				6915	</p>
				6916	<h5>Semantics:</h5>
				6917	<p>
				6918	These intrinsics does a series of operations atomically. They first load the
				6919	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6920	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6921	the original value stored at <tt>ptr</tt>.
				6922	</p>
				6923
				6924	<h5>Examples:</h5>
				6925	<pre>
				6926	%ptr = malloc i32
				6927	store i32 7, %ptr
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6928	%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]	6929	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6930	%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]	6931	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6932	%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]	6933	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	2c839d4	2008-07-30 04:36:53 +0000	[diff] [blame]	6934	%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]	6935	<i>; yields {i32}:result3 = 8</i>
				6936	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6937	</pre>
				6938	</div>
Andrew Lenharth	9b254ee	2008-02-16 01:24:58 +0000	[diff] [blame]	6939
				6940	<!-- ======================================================================= -->
				6941	<div class="doc_subsection">
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6942	<a name="int_general">General Intrinsics</a>
				6943	</div>
				6944
				6945	<div class="doc_text">
				6946	<p> This class of intrinsics is designed to be generic and has
				6947	no specific purpose. </p>
				6948	</div>
				6949
				6950	<!-- _______________________________________________________________________ -->
				6951	<div class="doc_subsubsection">
				6952	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6953	</div>
				6954
				6955	<div class="doc_text">
				6956
				6957	<h5>Syntax:</h5>
				6958	<pre>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6959	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]	6960	</pre>
				6961
				6962	<h5>Overview:</h5>
				6963
				6964	<p>
				6965	The '<tt>llvm.var.annotation</tt>' intrinsic
				6966	</p>
				6967
				6968	<h5>Arguments:</h5>
				6969
				6970	<p>
Tanya Lattner	bed1d4d	2007-06-18 23:42:37 +0000	[diff] [blame]	6971	The first argument is a pointer to a value, the second is a pointer to a
				6972	global string, the third is a pointer to a global string which is the source
				6973	file name, and the last argument is the line number.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6974	</p>
				6975
				6976	<h5>Semantics:</h5>
				6977
				6978	<p>
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	6979	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6980	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]	6981	annotations. These have no other defined use, they are ignored by code
				6982	generation and optimization.
				6983	</p>
Tanya Lattner	cb1b960	2007-06-15 20:50:54 +0000	[diff] [blame]	6984	</div>
				6985
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6986	<!-- _______________________________________________________________________ -->
				6987	<div class="doc_subsubsection">
Tanya Lattner	0186a65	2007-09-21 23:57:59 +0000	[diff] [blame]	6988	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6989	</div>
				6990
				6991	<div class="doc_text">
				6992
				6993	<h5>Syntax:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	6994	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6995	any integer bit width.
				6996	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	6997	<pre>
Tanya Lattner	cf3e26f	2007-09-22 00:03:01 +0000	[diff] [blame]	6998	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6999	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				7000	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				7001	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				7002	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]	7003	</pre>
				7004
				7005	<h5>Overview:</h5>
Tanya Lattner	23dbd57	2007-09-21 23:56:27 +0000	[diff] [blame]	7006
				7007	<p>
				7008	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7009	</p>
				7010
				7011	<h5>Arguments:</h5>
				7012
				7013	<p>
				7014	The first argument is an integer value (result of some expression),
				7015	the second is a pointer to a global string, the third is a pointer to a global
				7016	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]	7017	It returns the value of the first argument.
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7018	</p>
				7019
				7020	<h5>Semantics:</h5>
				7021
				7022	<p>
				7023	This intrinsic allows annotations to be put on arbitrary expressions
				7024	with arbitrary strings. This can be useful for special purpose optimizations
				7025	that want to look for these annotations. These have no other defined use, they
				7026	are ignored by code generation and optimization.
Dan Gohman	ef9462f	2008-10-14 16:51:45 +0000	[diff] [blame]	7027	</p>
Tanya Lattner	293c037	2007-09-21 22:59:12 +0000	[diff] [blame]	7028	</div>
Jim Laskey	2211f49	2007-03-14 19:31:19 +0000	[diff] [blame]	7029
Anton Korobeynikov	06cbb65	2008-01-15 22:31:34 +0000	[diff] [blame]	7030	<!-- _______________________________________________________________________ -->
				7031	<div class="doc_subsubsection">
				7032	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				7033	</div>
				7034
				7035	<div class="doc_text">
				7036
				7037	<h5>Syntax:</h5>
				7038	<pre>
				7039	declare void @llvm.trap()
				7040	</pre>
				7041
				7042	<h5>Overview:</h5>
				7043
				7044	<p>
				7045	The '<tt>llvm.trap</tt>' intrinsic
				7046	</p>
				7047
				7048	<h5>Arguments:</h5>
				7049
				7050	<p>
				7051	None
				7052	</p>
				7053
				7054	<h5>Semantics:</h5>
				7055
				7056	<p>
				7057	This intrinsics is lowered to the target dependent trap instruction. If the
				7058	target does not have a trap instruction, this intrinsic will be lowered to the
				7059	call of the abort() function.
				7060	</p>
				7061	</div>
				7062
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7063	<!-- _______________________________________________________________________ -->
				7064	<div class="doc_subsubsection">
Misha Brukman	50de2b2	2008-11-22 23:55:29 +0000	[diff] [blame]	7065	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	1431331	2008-11-19 05:56:17 +0000	[diff] [blame]	7066	</div>
				7067	<div class="doc_text">
				7068	<h5>Syntax:</h5>
				7069	<pre>
				7070	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				7071
				7072	</pre>
				7073	<h5>Overview:</h5>
				7074	<p>
				7075	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7076	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7077	it is placed on the stack before local variables.
				7078	</p>
				7079	<h5>Arguments:</h5>
				7080	<p>
				7081	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7082	first argument is the value loaded from the stack guard
				7083	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7084	has enough space to hold the value of the guard.
				7085	</p>
				7086	<h5>Semantics:</h5>
				7087	<p>
				7088	This intrinsic causes the prologue/epilogue inserter to force the position of
				7089	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7090	stack. This is to ensure that if a local variable on the stack is overwritten,
				7091	it will destroy the value of the guard. When the function exits, the guard on
				7092	the stack is checked against the original guard. If they're different, then
				7093	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7094	</p>
				7095	</div>
				7096
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7097	<!-- *********************************************************************** -->
Chris Lattner	2f7c963	2001-06-06 20:29:01 +0000	[diff] [blame]	7098	<hr>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7099	<address>
				7100	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7101	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]	7102	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	86242e1	2008-12-11 17:34:48 +0000	[diff] [blame]	7103	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]	7104
				7105	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	ca05854	2006-03-14 05:39:39 +0000	[diff] [blame]	7106	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	c501f55	2004-03-01 17:47:27 +0000	[diff] [blame]	7107	Last modified: $Date$
				7108	</address>
Chris Lattner	b8f816e	2008-01-04 04:33:49 +0000	[diff] [blame]	7109
Misha Brukman	7630785	2003-11-08 01:05:38 +0000	[diff] [blame]	7110	</body>
				7111	</html>