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Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3	<html>
				4	<head>
				5	<title>LLVM Assembly Language Reference Manual</title>
Reid Spencer	3921c74	2004-08-26 20:44:00 +0000	[diff] [blame]	6	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				7	<meta name="author" content="Chris Lattner">
				8	<meta name="description"
				9	content="LLVM Assembly Language Reference Manual.">
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	10	<link rel="stylesheet" href="llvm.css" type="text/css">
				11	</head>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	12
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	13	<body>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	14
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	15	<div class="doc_title"> LLVM Language Reference Manual </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	16	<ol>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	17	<li><a href="#abstract">Abstract</a></li>
				18	<li><a href="#introduction">Introduction</a></li>
				19	<li><a href="#identifiers">Identifiers</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	20	<li><a href="#highlevel">High Level Structure</a>
				21	<ol>
				22	<li><a href="#modulestructure">Module Structure</a></li>
Bill Wendling	3d10a5a	2009-07-20 01:03:30 +0000	[diff] [blame^]	23	<li><a href="#linkage">Linkage Types</a>
				24	<ol>
				25	<li><a href="#linkage_private">private</a></li>
				26	<li><a href="#linkage_linker_private">linker_private</a></li>
				27	<li><a href="#linkage_internal">internal</a></li>
				28	<li><a href="#linkage_available_externally">available_externally</a></li>
				29	<li><a href="#linkage_linkonce">linkonce</a></li>
				30	<li><a href="#linkage_common">common</a></li>
				31	<li><a href="#linkage_weak">weak</a></li>
				32	<li><a href="#linkage_appending">appending</a></li>
				33	<li><a href="#linkage_externweak">extern_weak</a></li>
				34	<li><a href="#linkage_linkonce">linkonce_odr</a></li>
				35	<li><a href="#linkage_weak">weak_odr</a></li>
				36	<li><a href="#linkage_external">externally visible</a></li>
				37	<li><a href="#linkage_dllimport">dllimport</a></li>
				38	<li><a href="#linkage_dllexport">dllexport</a></li>
				39	</ol>
				40	</li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	41	<li><a href="#callingconv">Calling Conventions</a></li>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	42	<li><a href="#namedtypes">Named Types</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	43	<li><a href="#globalvars">Global Variables</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	44	<li><a href="#functionstructure">Functions</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	45	<li><a href="#aliasstructure">Aliases</a></li>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	46	<li><a href="#paramattrs">Parameter Attributes</a></li>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	47	<li><a href="#fnattrs">Function Attributes</a></li>
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	48	<li><a href="#gc">Garbage Collector Names</a></li>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	49	<li><a href="#moduleasm">Module-Level Inline Assembly</a></li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	50	<li><a href="#datalayout">Data Layout</a></li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	51	</ol>
				52	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	53	<li><a href="#typesystem">Type System</a>
				54	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	55	<li><a href="#t_classifications">Type Classifications</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	56	<li><a href="#t_primitive">Primitive Types</a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	57	<ol>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	58	<li><a href="#t_floating">Floating Point Types</a></li>
				59	<li><a href="#t_void">Void Type</a></li>
				60	<li><a href="#t_label">Label Type</a></li>
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	61	<li><a href="#t_metadata">Metadata Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	62	</ol>
				63	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	64	<li><a href="#t_derived">Derived Types</a>
				65	<ol>
Chris Lattner	b9488a6	2007-12-18 06:18:21 +0000	[diff] [blame]	66	<li><a href="#t_integer">Integer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	67	<li><a href="#t_array">Array Type</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	68	<li><a href="#t_function">Function Type</a></li>
				69	<li><a href="#t_pointer">Pointer Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	70	<li><a href="#t_struct">Structure Type</a></li>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	71	<li><a href="#t_pstruct">Packed Structure Type</a></li>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	72	<li><a href="#t_vector">Vector Type</a></li>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	73	<li><a href="#t_opaque">Opaque Type</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	74	</ol>
				75	</li>
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	76	<li><a href="#t_uprefs">Type Up-references</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	77	</ol>
				78	</li>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	79	<li><a href="#constants">Constants</a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	80	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	81	<li><a href="#simpleconstants">Simple Constants</a></li>
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	82	<li><a href="#complexconstants">Complex Constants</a></li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	83	<li><a href="#globalconstants">Global Variable and Function Addresses</a></li>
				84	<li><a href="#undefvalues">Undefined Values</a></li>
				85	<li><a href="#constantexprs">Constant Expressions</a></li>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	86	<li><a href="#metadata">Embedded Metadata</a></li>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	87	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	88	</li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	89	<li><a href="#othervalues">Other Values</a>
				90	<ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	91	<li><a href="#inlineasm">Inline Assembler Expressions</a></li>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	92	</ol>
				93	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	94	<li><a href="#instref">Instruction Reference</a>
				95	<ol>
				96	<li><a href="#terminators">Terminator Instructions</a>
				97	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	98	<li><a href="#i_ret">'<tt>ret</tt>' Instruction</a></li>
				99	<li><a href="#i_br">'<tt>br</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	100	<li><a href="#i_switch">'<tt>switch</tt>' Instruction</a></li>
				101	<li><a href="#i_invoke">'<tt>invoke</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	102	<li><a href="#i_unwind">'<tt>unwind</tt>' Instruction</a></li>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	103	<li><a href="#i_unreachable">'<tt>unreachable</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	104	</ol>
				105	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	106	<li><a href="#binaryops">Binary Operations</a>
				107	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	108	<li><a href="#i_add">'<tt>add</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	109	<li><a href="#i_fadd">'<tt>fadd</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	110	<li><a href="#i_sub">'<tt>sub</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	111	<li><a href="#i_fsub">'<tt>fsub</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	112	<li><a href="#i_mul">'<tt>mul</tt>' Instruction</a></li>
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	113	<li><a href="#i_fmul">'<tt>fmul</tt>' Instruction</a></li>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	114	<li><a href="#i_udiv">'<tt>udiv</tt>' Instruction</a></li>
				115	<li><a href="#i_sdiv">'<tt>sdiv</tt>' Instruction</a></li>
				116	<li><a href="#i_fdiv">'<tt>fdiv</tt>' Instruction</a></li>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	117	<li><a href="#i_urem">'<tt>urem</tt>' Instruction</a></li>
				118	<li><a href="#i_srem">'<tt>srem</tt>' Instruction</a></li>
				119	<li><a href="#i_frem">'<tt>frem</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	120	</ol>
				121	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	122	<li><a href="#bitwiseops">Bitwise Binary Operations</a>
				123	<ol>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	124	<li><a href="#i_shl">'<tt>shl</tt>' Instruction</a></li>
				125	<li><a href="#i_lshr">'<tt>lshr</tt>' Instruction</a></li>
				126	<li><a href="#i_ashr">'<tt>ashr</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	127	<li><a href="#i_and">'<tt>and</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	128	<li><a href="#i_or">'<tt>or</tt>' Instruction</a></li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	129	<li><a href="#i_xor">'<tt>xor</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	130	</ol>
				131	</li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	132	<li><a href="#vectorops">Vector Operations</a>
				133	<ol>
				134	<li><a href="#i_extractelement">'<tt>extractelement</tt>' Instruction</a></li>
				135	<li><a href="#i_insertelement">'<tt>insertelement</tt>' Instruction</a></li>
				136	<li><a href="#i_shufflevector">'<tt>shufflevector</tt>' Instruction</a></li>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	137	</ol>
				138	</li>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	139	<li><a href="#aggregateops">Aggregate Operations</a>
				140	<ol>
				141	<li><a href="#i_extractvalue">'<tt>extractvalue</tt>' Instruction</a></li>
				142	<li><a href="#i_insertvalue">'<tt>insertvalue</tt>' Instruction</a></li>
				143	</ol>
				144	</li>
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	145	<li><a href="#memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	146	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	147	<li><a href="#i_malloc">'<tt>malloc</tt>' Instruction</a></li>
				148	<li><a href="#i_free">'<tt>free</tt>' Instruction</a></li>
				149	<li><a href="#i_alloca">'<tt>alloca</tt>' Instruction</a></li>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	150	<li><a href="#i_load">'<tt>load</tt>' Instruction</a></li>
				151	<li><a href="#i_store">'<tt>store</tt>' Instruction</a></li>
				152	<li><a href="#i_getelementptr">'<tt>getelementptr</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	153	</ol>
				154	</li>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	155	<li><a href="#convertops">Conversion Operations</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	156	<ol>
				157	<li><a href="#i_trunc">'<tt>trunc .. to</tt>' Instruction</a></li>
				158	<li><a href="#i_zext">'<tt>zext .. to</tt>' Instruction</a></li>
				159	<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
				160	<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
				161	<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	162	<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
				163	<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
				164	<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
				165	<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	166	<li><a href="#i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a></li>
				167	<li><a href="#i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a></li>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	168	<li><a href="#i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a></li>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	169	</ol>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	170	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	171	<li><a href="#otherops">Other Operations</a>
				172	<ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	173	<li><a href="#i_icmp">'<tt>icmp</tt>' Instruction</a></li>
				174	<li><a href="#i_fcmp">'<tt>fcmp</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	175	<li><a href="#i_phi">'<tt>phi</tt>' Instruction</a></li>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	176	<li><a href="#i_select">'<tt>select</tt>' Instruction</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	177	<li><a href="#i_call">'<tt>call</tt>' Instruction</a></li>
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	178	<li><a href="#i_va_arg">'<tt>va_arg</tt>' Instruction</a></li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	179	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	180	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	181	</ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	182	</li>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	183	<li><a href="#intrinsics">Intrinsic Functions</a>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	184	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	185	<li><a href="#int_varargs">Variable Argument Handling Intrinsics</a>
				186	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	187	<li><a href="#int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a></li>
				188	<li><a href="#int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a></li>
				189	<li><a href="#int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a></li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	190	</ol>
				191	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	192	<li><a href="#int_gc">Accurate Garbage Collection Intrinsics</a>
				193	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	194	<li><a href="#int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a></li>
				195	<li><a href="#int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a></li>
				196	<li><a href="#int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a></li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	197	</ol>
				198	</li>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	199	<li><a href="#int_codegen">Code Generator Intrinsics</a>
				200	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	201	<li><a href="#int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a></li>
				202	<li><a href="#int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a></li>
				203	<li><a href="#int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a></li>
				204	<li><a href="#int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a></li>
				205	<li><a href="#int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a></li>
				206	<li><a href="#int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a></li>
				207	<li><a href="#int_readcyclecounter"><tt>llvm.readcyclecounter</tt>' Intrinsic</a></li>
John Criswell	7123e27	2004-04-09 16:43:20 +0000	[diff] [blame]	208	</ol>
				209	</li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	210	<li><a href="#int_libc">Standard C Library Intrinsics</a>
				211	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	212	<li><a href="#int_memcpy">'<tt>llvm.memcpy.*</tt>' Intrinsic</a></li>
				213	<li><a href="#int_memmove">'<tt>llvm.memmove.*</tt>' Intrinsic</a></li>
				214	<li><a href="#int_memset">'<tt>llvm.memset.*</tt>' Intrinsic</a></li>
				215	<li><a href="#int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a></li>
				216	<li><a href="#int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a></li>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	217	<li><a href="#int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a></li>
				218	<li><a href="#int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a></li>
				219	<li><a href="#int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a></li>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	220	</ol>
				221	</li>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	222	<li><a href="#int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	223	<ol>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	224	<li><a href="#int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a></li>
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	225	<li><a href="#int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic </a></li>
				226	<li><a href="#int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic </a></li>
				227	<li><a href="#int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic </a></li>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	228	</ol>
				229	</li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	230	<li><a href="#int_overflow">Arithmetic with Overflow Intrinsics</a>
				231	<ol>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	232	<li><a href="#int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt> Intrinsics</a></li>
				233	<li><a href="#int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt> Intrinsics</a></li>
				234	<li><a href="#int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt> Intrinsics</a></li>
				235	<li><a href="#int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt> Intrinsics</a></li>
				236	<li><a href="#int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	237	<li><a href="#int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt> Intrinsics</a></li>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	238	</ol>
				239	</li>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	240	<li><a href="#int_debugger">Debugger intrinsics</a></li>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	241	<li><a href="#int_eh">Exception Handling intrinsics</a></li>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	242	<li><a href="#int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	243	<ol>
				244	<li><a href="#int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a></li>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	245	</ol>
				246	</li>
Bill Wendling	3c44f5b	2008-11-18 22:10:53 +0000	[diff] [blame]	247	<li><a href="#int_atomics">Atomic intrinsics</a>
				248	<ol>
				249	<li><a href="#int_memory_barrier"><tt>llvm.memory_barrier</tt></a></li>
				250	<li><a href="#int_atomic_cmp_swap"><tt>llvm.atomic.cmp.swap</tt></a></li>
				251	<li><a href="#int_atomic_swap"><tt>llvm.atomic.swap</tt></a></li>
				252	<li><a href="#int_atomic_load_add"><tt>llvm.atomic.load.add</tt></a></li>
				253	<li><a href="#int_atomic_load_sub"><tt>llvm.atomic.load.sub</tt></a></li>
				254	<li><a href="#int_atomic_load_and"><tt>llvm.atomic.load.and</tt></a></li>
				255	<li><a href="#int_atomic_load_nand"><tt>llvm.atomic.load.nand</tt></a></li>
				256	<li><a href="#int_atomic_load_or"><tt>llvm.atomic.load.or</tt></a></li>
				257	<li><a href="#int_atomic_load_xor"><tt>llvm.atomic.load.xor</tt></a></li>
				258	<li><a href="#int_atomic_load_max"><tt>llvm.atomic.load.max</tt></a></li>
				259	<li><a href="#int_atomic_load_min"><tt>llvm.atomic.load.min</tt></a></li>
				260	<li><a href="#int_atomic_load_umax"><tt>llvm.atomic.load.umax</tt></a></li>
				261	<li><a href="#int_atomic_load_umin"><tt>llvm.atomic.load.umin</tt></a></li>
				262	</ol>
				263	</li>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	264	<li><a href="#int_general">General intrinsics</a>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	265	<ol>
Reid Spencer	2067764	2007-07-20 19:59:11 +0000	[diff] [blame]	266	<li><a href="#int_var_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	267	'<tt>llvm.var.annotation</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	268	<li><a href="#int_annotation">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	269	'<tt>llvm.annotation.*</tt>' Intrinsic</a></li>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	270	<li><a href="#int_trap">
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	271	'<tt>llvm.trap</tt>' Intrinsic</a></li>
				272	<li><a href="#int_stackprotector">
				273	'<tt>llvm.stackprotector</tt>' Intrinsic</a></li>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	274	</ol>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	275	</li>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	276	</ol>
				277	</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	278	</ol>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	279
				280	<div class="doc_author">
				281	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>
				282	and <a href="mailto:vadve@cs.uiuc.edu">Vikram Adve</a></p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	283	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	284
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	285	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	286	<div class="doc_section"> <a name="abstract">Abstract </a></div>
				287	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	288
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	289	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	290	<p>This document is a reference manual for the LLVM assembly language.
Bill Wendling	837f39b	2008-08-05 22:29:16 +0000	[diff] [blame]	291	LLVM is a Static Single Assignment (SSA) based representation that provides
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	292	type safety, low-level operations, flexibility, and the capability of
				293	representing 'all' high-level languages cleanly. It is the common code
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	294	representation used throughout all phases of the LLVM compilation
				295	strategy.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	296	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	297
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	298	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	299	<div class="doc_section"> <a name="introduction">Introduction</a> </div>
				300	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	301
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	302	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	303
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	304	<p>The LLVM code representation is designed to be used in three
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	305	different forms: as an in-memory compiler IR, as an on-disk bitcode
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	306	representation (suitable for fast loading by a Just-In-Time compiler),
				307	and as a human readable assembly language representation. This allows
				308	LLVM to provide a powerful intermediate representation for efficient
				309	compiler transformations and analysis, while providing a natural means
				310	to debug and visualize the transformations. The three different forms
				311	of LLVM are all equivalent. This document describes the human readable
				312	representation and notation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	313
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	314	<p>The LLVM representation aims to be light-weight and low-level
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	315	while being expressive, typed, and extensible at the same time. It
				316	aims to be a "universal IR" of sorts, by being at a low enough level
				317	that high-level ideas may be cleanly mapped to it (similar to how
				318	microprocessors are "universal IR's", allowing many source languages to
				319	be mapped to them). By providing type information, LLVM can be used as
				320	the target of optimizations: for example, through pointer analysis, it
				321	can be proven that a C automatic variable is never accessed outside of
				322	the current function... allowing it to be promoted to a simple SSA
				323	value instead of a memory location.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	324
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	325	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	326
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	327	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	328	<div class="doc_subsubsection"> <a name="wellformed">Well-Formedness</a> </div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	329
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	330	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	331
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	332	<p>It is important to note that this document describes 'well formed'
				333	LLVM assembly language. There is a difference between what the parser
				334	accepts and what is considered 'well formed'. For example, the
				335	following instruction is syntactically okay, but not well formed:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	336
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	337	<div class="doc_code">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	338	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	339	%x = <a href="#i_add">add</a> i32 1, %x
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	340	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	341	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	342
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	343	<p>...because the definition of <tt>%x</tt> does not dominate all of
				344	its uses. The LLVM infrastructure provides a verification pass that may
				345	be used to verify that an LLVM module is well formed. This pass is
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	346	automatically run by the parser after parsing input assembly and by
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	347	the optimizer before it outputs bitcode. The violations pointed out
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	348	by the verifier pass indicate bugs in transformation passes or input to
				349	the parser.</p>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	350	</div>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	351
Chris Lattner	cc68939	2007-10-03 17:34:29 +0000	[diff] [blame]	352	<!-- Describe the typesetting conventions here. -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	353
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	354	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	355	<div class="doc_section"> <a name="identifiers">Identifiers</a> </div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	356	<!-- *********************************************************************** -->
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	357
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	358	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	359
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	360	<p>LLVM identifiers come in two basic types: global and local. Global
				361	identifiers (functions, global variables) begin with the @ character. Local
				362	identifiers (register names, types) begin with the % character. Additionally,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	363	there are three different formats for identifiers, for different purposes:</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	364
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	365	<ol>
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	366	<li>Named values are represented as a string of characters with their prefix.
				367	For example, %foo, @DivisionByZero, %a.really.long.identifier. The actual
				368	regular expression used is '<tt>[%@][a-zA-Z$._][a-zA-Z$._0-9]*</tt>'.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	369	Identifiers which require other characters in their names can be surrounded
Daniel Dunbar	76dea95	2008-10-14 23:51:43 +0000	[diff] [blame]	370	with quotes. Special characters may be escaped using "\xx" where xx is the
				371	ASCII code for the character in hexadecimal. In this way, any character can
				372	be used in a name value, even quotes themselves.
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	373
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	374	<li>Unnamed values are represented as an unsigned numeric value with their
				375	prefix. For example, %12, @2, %44.</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	376
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	377	<li>Constants, which are described in a <a href="#constants">section about
				378	constants</a>, below.</li>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	379	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	380
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	381	<p>LLVM requires that values start with a prefix for two reasons: Compilers
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	382	don't need to worry about name clashes with reserved words, and the set of
				383	reserved words may be expanded in the future without penalty. Additionally,
				384	unnamed identifiers allow a compiler to quickly come up with a temporary
				385	variable without having to avoid symbol table conflicts.</p>
				386
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	387	<p>Reserved words in LLVM are very similar to reserved words in other
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	388	languages. There are keywords for different opcodes
				389	('<tt><a href="#i_add">add</a></tt>',
				390	'<tt><a href="#i_bitcast">bitcast</a></tt>',
				391	'<tt><a href="#i_ret">ret</a></tt>', etc...), for primitive type names ('<tt><a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	392	href="#t_void">void</a></tt>', '<tt><a href="#t_primitive">i32</a></tt>', etc...),
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	393	and others. These reserved words cannot conflict with variable names, because
Reid Spencer	2c45228	2007-08-07 14:34:28 +0000	[diff] [blame]	394	none of them start with a prefix character ('%' or '@').</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	395
				396	<p>Here is an example of LLVM code to multiply the integer variable
				397	'<tt>%X</tt>' by 8:</p>
				398
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	399	<p>The easy way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	400
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	401	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	402	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	403	%result = <a href="#i_mul">mul</a> i32 %X, 8
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	404	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	405	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	406
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	407	<p>After strength reduction:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	408
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	409	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	410	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	411	%result = <a href="#i_shl">shl</a> i32 %X, i8 3
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	412	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	413	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	414
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	415	<p>And the hard way:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	416
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	417	<div class="doc_code">
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	418	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	419	<a href="#i_add">add</a> i32 %X, %X <i>; yields {i32}:%0</i>
				420	<a href="#i_add">add</a> i32 %0, %0 <i>; yields {i32}:%1</i>
				421	%result = <a href="#i_add">add</a> i32 %1, %1
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	422	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	423	</div>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	424
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	425	<p>This last way of multiplying <tt>%X</tt> by 8 illustrates several
				426	important lexical features of LLVM:</p>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	427
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	428	<ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	429
				430	<li>Comments are delimited with a '<tt>;</tt>' and go until the end of
				431	line.</li>
				432
				433	<li>Unnamed temporaries are created when the result of a computation is not
				434	assigned to a named value.</li>
				435
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	436	<li>Unnamed temporaries are numbered sequentially</li>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	437
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	438	</ol>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	439
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	440	<p>...and it also shows a convention that we follow in this document. When
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	441	demonstrating instructions, we will follow an instruction with a comment that
				442	defines the type and name of value produced. Comments are shown in italic
				443	text.</p>
				444
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	445	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	446
				447	<!-- *********************************************************************** -->
				448	<div class="doc_section"> <a name="highlevel">High Level Structure</a> </div>
				449	<!-- *********************************************************************** -->
				450
				451	<!-- ======================================================================= -->
				452	<div class="doc_subsection"> <a name="modulestructure">Module Structure</a>
				453	</div>
				454
				455	<div class="doc_text">
				456
				457	<p>LLVM programs are composed of "Module"s, each of which is a
				458	translation unit of the input programs. Each module consists of
				459	functions, global variables, and symbol table entries. Modules may be
				460	combined together with the LLVM linker, which merges function (and
				461	global variable) definitions, resolves forward declarations, and merges
				462	symbol table entries. Here is an example of the "hello world" module:</p>
				463
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	464	<div class="doc_code">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	465	<pre><i>; Declare the string constant as a global constant...</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	466	<a href="#identifiers">@.LC0</a> = <a href="#linkage_internal">internal</a> <a
				467	href="#globalvars">constant</a> <a href="#t_array">[13 x i8]</a> c"hello world\0A\00" <i>; [13 x i8]*</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	468
				469	<i>; External declaration of the puts function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	470	<a href="#functionstructure">declare</a> i32 @puts(i8 ) <i>; i32(i8 )* </i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	471
				472	<i>; Definition of main function</i>
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	473	define i32 @main() { <i>; i32()* </i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	474	<i>; Convert [13 x i8]* to i8 *...</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	475	%cast210 = <a
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	476	href="#i_getelementptr">getelementptr</a> [13 x i8]* @.LC0, i64 0, i64 0 <i>; i8 *</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	477
				478	<i>; Call puts function to write out the string to stdout...</i>
				479	<a
Chris Lattner	a89e5f1	2007-06-12 17:00:26 +0000	[diff] [blame]	480	href="#i_call">call</a> i32 @puts(i8 * %cast210) <i>; i32</i>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	481	<a
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	482	href="#i_ret">ret</a> i32 0<br>}<br>
				483	</pre>
				484	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	485
				486	<p>This example is made up of a <a href="#globalvars">global variable</a>
				487	named "<tt>.LC0</tt>", an external declaration of the "<tt>puts</tt>"
				488	function, and a <a href="#functionstructure">function definition</a>
				489	for "<tt>main</tt>".</p>
				490
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	491	<p>In general, a module is made up of a list of global values,
				492	where both functions and global variables are global values. Global values are
				493	represented by a pointer to a memory location (in this case, a pointer to an
				494	array of char, and a pointer to a function), and have one of the following <a
				495	href="#linkage">linkage types</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	496
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	497	</div>
				498
				499	<!-- ======================================================================= -->
				500	<div class="doc_subsection">
				501	<a name="linkage">Linkage Types</a>
				502	</div>
				503
				504	<div class="doc_text">
				505
				506	<p>
				507	All Global Variables and Functions have one of the following types of linkage:
				508	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	509
				510	<dl>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	511
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	512	<dt><tt><b><a name="linkage_private">private</a></b></tt>: </dt>
				513
				514	<dd>Global values with private linkage are only directly accessible by
				515	objects in the current module. In particular, linking code into a module with
				516	an private global value may cause the private to be renamed as necessary to
				517	avoid collisions. Because the symbol is private to the module, all
				518	references can be updated. This doesn't show up in any symbol table in the
				519	object file.
				520	</dd>
				521
Bill Wendling	3d10a5a	2009-07-20 01:03:30 +0000	[diff] [blame^]	522	<dt><tt><b><a name="linkage_linker_private">linker_private</a></b></tt>: </dt>
				523
				524	<dd>Similar to private, but the symbol is passed through the assembler and
				525	removed by the linker after evaluation.</dd>
				526
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	527	<dt><tt><b><a name="linkage_internal">internal</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	528
Duncan Sands	81d05c2	2009-01-16 09:29:46 +0000	[diff] [blame]	529	<dd> Similar to private, but the value shows as a local symbol (STB_LOCAL in
Rafael Espindola	bb46f52	2009-01-15 20:18:42 +0000	[diff] [blame]	530	the case of ELF) in the object file. This corresponds to the notion of the
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	531	'<tt>static</tt>' keyword in C.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	532	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	533
Bill Wendling	3d10a5a	2009-07-20 01:03:30 +0000	[diff] [blame^]	534	<dt><tt><b><a name="linkage_available_externally">available_externally</a></b></tt>:
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	535	</dt>
				536
				537	<dd>Globals with "<tt>available_externally</tt>" linkage are never emitted
				538	into the object file corresponding to the LLVM module. They exist to
				539	allow inlining and other optimizations to take place given knowledge of the
				540	definition of the global, which is known to be somewhere outside the module.
				541	Globals with <tt>available_externally</tt> linkage are allowed to be discarded
				542	at will, and are otherwise the same as <tt>linkonce_odr</tt>. This linkage
				543	type is only allowed on definitions, not declarations.</dd>
				544
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	545	<dt><tt><b><a name="linkage_linkonce">linkonce</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	546
Chris Lattner	4887bd8	2007-01-14 06:51:48 +0000	[diff] [blame]	547	<dd>Globals with "<tt>linkonce</tt>" linkage are merged with other globals of
				548	the same name when linkage occurs. This is typically used to implement
				549	inline functions, templates, or other code which must be generated in each
				550	translation unit that uses it. Unreferenced <tt>linkonce</tt> globals are
				551	allowed to be discarded.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	552	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	553
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	554	<dt><tt><b><a name="linkage_common">common</a></b></tt>: </dt>
				555
				556	<dd>"<tt>common</tt>" linkage is exactly the same as <tt>linkonce</tt>
				557	linkage, except that unreferenced <tt>common</tt> globals may not be
				558	discarded. This is used for globals that may be emitted in multiple
				559	translation units, but that are not guaranteed to be emitted into every
				560	translation unit that uses them. One example of this is tentative
				561	definitions in C, such as "<tt>int X;</tt>" at global scope.
				562	</dd>
				563
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	564	<dt><tt><b><a name="linkage_weak">weak</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	565
Dale Johannesen	2307a7f	2008-05-23 23:13:41 +0000	[diff] [blame]	566	<dd>"<tt>weak</tt>" linkage is the same as <tt>common</tt> linkage, except
				567	that some targets may choose to emit different assembly sequences for them
				568	for target-dependent reasons. This is used for globals that are declared
				569	"weak" in C source code.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	570	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	571
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	572	<dt><tt><b><a name="linkage_appending">appending</a></b></tt>: </dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	573
				574	<dd>"<tt>appending</tt>" linkage may only be applied to global variables of
				575	pointer to array type. When two global variables with appending linkage are
				576	linked together, the two global arrays are appended together. This is the
				577	LLVM, typesafe, equivalent of having the system linker append together
				578	"sections" with identical names when .o files are linked.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	579	</dd>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	580
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	581	<dt><tt><b><a name="linkage_externweak">extern_weak</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	582
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	583	<dd>The semantics of this linkage follow the ELF object file model: the
				584	symbol is weak until linked, if not linked, the symbol becomes null instead
				585	of being an undefined reference.
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	586	</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	587
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	588	<dt><tt><b><a name="linkage_linkonce">linkonce_odr</a></b></tt>: </dt>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	589	<dt><tt><b><a name="linkage_weak">weak_odr</a></b></tt>: </dt>
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	590	<dd>Some languages allow differing globals to be merged, such as two
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	591	functions with different semantics. Other languages, such as <tt>C++</tt>,
				592	ensure that only equivalent globals are ever merged (the "one definition
Chris Lattner	266c7bb	2009-04-13 05:44:34 +0000	[diff] [blame]	593	rule" - "ODR"). Such languages can use the <tt>linkonce_odr</tt>
Duncan Sands	4dc2b39	2009-03-11 20:14:15 +0000	[diff] [blame]	594	and <tt>weak_odr</tt> linkage types to indicate that the global will only
				595	be merged with equivalent globals. These linkage types are otherwise the
				596	same as their non-<tt>odr</tt> versions.
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	597	</dd>
				598
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	599	<dt><tt><b><a name="linkage_external">externally visible</a></b></tt>:</dt>
Chris Lattner	e5d947b	2004-12-09 16:36:40 +0000	[diff] [blame]	600
				601	<dd>If none of the above identifiers are used, the global is externally
				602	visible, meaning that it participates in linkage and can be used to resolve
				603	external symbol references.
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	604	</dd>
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	605	</dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	606
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	607	<p>
				608	The next two types of linkage are targeted for Microsoft Windows platform
				609	only. They are designed to support importing (exporting) symbols from (to)
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	610	DLLs (Dynamic Link Libraries).
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	611	</p>
				612
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	613	<dl>
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	614	<dt><tt><b><a name="linkage_dllimport">dllimport</a></b></tt>: </dt>
				615
				616	<dd>"<tt>dllimport</tt>" linkage causes the compiler to reference a function
				617	or variable via a global pointer to a pointer that is set up by the DLL
				618	exporting the symbol. On Microsoft Windows targets, the pointer name is
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	619	formed by combining <code>__imp_</code> and the function or variable name.
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	620	</dd>
				621
				622	<dt><tt><b><a name="linkage_dllexport">dllexport</a></b></tt>: </dt>
				623
				624	<dd>"<tt>dllexport</tt>" linkage causes the compiler to provide a global
				625	pointer to a pointer in a DLL, so that it can be referenced with the
				626	<tt>dllimport</tt> attribute. On Microsoft Windows targets, the pointer
Dan Gohman	7956412	2009-01-12 21:35:55 +0000	[diff] [blame]	627	name is formed by combining <code>__imp_</code> and the function or variable
Anton Korobeynikov	b74ed07	2006-09-14 18:23:27 +0000	[diff] [blame]	628	name.
				629	</dd>
				630
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	631	</dl>
				632
Dan Gohman	f003276	2008-11-24 17:18:39 +0000	[diff] [blame]	633	<p>For example, since the "<tt>.LC0</tt>"
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	634	variable is defined to be internal, if another module defined a "<tt>.LC0</tt>"
				635	variable and was linked with this one, one of the two would be renamed,
				636	preventing a collision. Since "<tt>main</tt>" and "<tt>puts</tt>" are
				637	external (i.e., lacking any linkage declarations), they are accessible
Reid Spencer	ac8d276	2007-01-05 00:59:10 +0000	[diff] [blame]	638	outside of the current module.</p>
				639	<p>It is illegal for a function <i>declaration</i>
Duncan Sands	5f4ee1f	2009-03-11 08:08:06 +0000	[diff] [blame]	640	to have any linkage type other than "externally visible", <tt>dllimport</tt>
				641	or <tt>extern_weak</tt>.</p>
Duncan Sands	667d4b8	2009-03-07 15:45:40 +0000	[diff] [blame]	642	<p>Aliases can have only <tt>external</tt>, <tt>internal</tt>, <tt>weak</tt>
				643	or <tt>weak_odr</tt> linkages.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	644	</div>
				645
				646	<!-- ======================================================================= -->
				647	<div class="doc_subsection">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	648	<a name="callingconv">Calling Conventions</a>
				649	</div>
				650
				651	<div class="doc_text">
				652
				653	<p>LLVM <a href="#functionstructure">functions</a>, <a href="#i_call">calls</a>
				654	and <a href="#i_invoke">invokes</a> can all have an optional calling convention
				655	specified for the call. The calling convention of any pair of dynamic
				656	caller/callee must match, or the behavior of the program is undefined. The
				657	following calling conventions are supported by LLVM, and more may be added in
				658	the future:</p>
				659
				660	<dl>
				661	<dt><b>"<tt>ccc</tt>" - The C calling convention</b>:</dt>
				662
				663	<dd>This calling convention (the default if no other calling convention is
				664	specified) matches the target C calling conventions. This calling convention
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	665	supports varargs function calls and tolerates some mismatch in the declared
Reid Spencer	c28d2bc	2006-12-31 21:30:18 +0000	[diff] [blame]	666	prototype and implemented declaration of the function (as does normal C).
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	667	</dd>
				668
				669	<dt><b>"<tt>fastcc</tt>" - The fast calling convention</b>:</dt>
				670
				671	<dd>This calling convention attempts to make calls as fast as possible
				672	(e.g. by passing things in registers). This calling convention allows the
				673	target to use whatever tricks it wants to produce fast code for the target,
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	674	without having to conform to an externally specified ABI (Application Binary
				675	Interface). Implementations of this convention should allow arbitrary
Arnold Schwaighofer	9097d14	2008-05-14 09:17:12 +0000	[diff] [blame]	676	<a href="CodeGenerator.html#tailcallopt">tail call optimization</a> to be
				677	supported. This calling convention does not support varargs and requires the
				678	prototype of all callees to exactly match the prototype of the function
				679	definition.
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	680	</dd>
				681
				682	<dt><b>"<tt>coldcc</tt>" - The cold calling convention</b>:</dt>
				683
				684	<dd>This calling convention attempts to make code in the caller as efficient
				685	as possible under the assumption that the call is not commonly executed. As
				686	such, these calls often preserve all registers so that the call does not break
				687	any live ranges in the caller side. This calling convention does not support
				688	varargs and requires the prototype of all callees to exactly match the
				689	prototype of the function definition.
				690	</dd>
				691
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	692	<dt><b>"<tt>cc <<em>n</em>></tt>" - Numbered convention</b>:</dt>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	693
				694	<dd>Any calling convention may be specified by number, allowing
				695	target-specific calling conventions to be used. Target specific calling
				696	conventions start at 64.
				697	</dd>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	698	</dl>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	699
				700	<p>More calling conventions can be added/defined on an as-needed basis, to
				701	support pascal conventions or any other well-known target-independent
				702	convention.</p>
				703
				704	</div>
				705
				706	<!-- ======================================================================= -->
				707	<div class="doc_subsection">
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	708	<a name="visibility">Visibility Styles</a>
				709	</div>
				710
				711	<div class="doc_text">
				712
				713	<p>
				714	All Global Variables and Functions have one of the following visibility styles:
				715	</p>
				716
				717	<dl>
				718	<dt><b>"<tt>default</tt>" - Default style</b>:</dt>
				719
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	720	<dd>On targets that use the ELF object file format, default visibility means
				721	that the declaration is visible to other
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	722	modules and, in shared libraries, means that the declared entity may be
				723	overridden. On Darwin, default visibility means that the declaration is
				724	visible to other modules. Default visibility corresponds to "external
				725	linkage" in the language.
				726	</dd>
				727
				728	<dt><b>"<tt>hidden</tt>" - Hidden style</b>:</dt>
				729
				730	<dd>Two declarations of an object with hidden visibility refer to the same
				731	object if they are in the same shared object. Usually, hidden visibility
				732	indicates that the symbol will not be placed into the dynamic symbol table,
				733	so no other module (executable or shared library) can reference it
				734	directly.
				735	</dd>
				736
Anton Korobeynikov	6f9896f	2007-04-29 18:35:00 +0000	[diff] [blame]	737	<dt><b>"<tt>protected</tt>" - Protected style</b>:</dt>
				738
				739	<dd>On ELF, protected visibility indicates that the symbol will be placed in
				740	the dynamic symbol table, but that references within the defining module will
				741	bind to the local symbol. That is, the symbol cannot be overridden by another
				742	module.
				743	</dd>
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	744	</dl>
				745
				746	</div>
				747
				748	<!-- ======================================================================= -->
				749	<div class="doc_subsection">
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	750	<a name="namedtypes">Named Types</a>
				751	</div>
				752
				753	<div class="doc_text">
				754
				755	<p>LLVM IR allows you to specify name aliases for certain types. This can make
				756	it easier to read the IR and make the IR more condensed (particularly when
				757	recursive types are involved). An example of a name specification is:
				758	</p>
				759
				760	<div class="doc_code">
				761	<pre>
				762	%mytype = type { %mytype*, i32 }
				763	</pre>
				764	</div>
				765
				766	<p>You may give a name to any <a href="#typesystem">type</a> except "<a
				767	href="t_void">void</a>". Type name aliases may be used anywhere a type is
				768	expected with the syntax "%mytype".</p>
				769
				770	<p>Note that type names are aliases for the structural type that they indicate,
				771	and that you can therefore specify multiple names for the same type. This often
				772	leads to confusing behavior when dumping out a .ll file. Since LLVM IR uses
				773	structural typing, the name is not part of the type. When printing out LLVM IR,
				774	the printer will pick <em>one name</em> to render all types of a particular
				775	shape. This means that if you have code where two different source types end up
				776	having the same LLVM type, that the dumper will sometimes print the "wrong" or
				777	unexpected type. This is an important design point and isn't going to
				778	change.</p>
				779
				780	</div>
				781
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	782	<!-- ======================================================================= -->
				783	<div class="doc_subsection">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	784	<a name="globalvars">Global Variables</a>
				785	</div>
				786
				787	<div class="doc_text">
				788
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	789	<p>Global variables define regions of memory allocated at compilation time
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	790	instead of run-time. Global variables may optionally be initialized, may have
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	791	an explicit section to be placed in, and may have an optional explicit alignment
				792	specified. A variable may be defined as "thread_local", which means that it
				793	will not be shared by threads (each thread will have a separated copy of the
				794	variable). A variable may be defined as a global "constant," which indicates
				795	that the contents of the variable will <b>never</b> be modified (enabling better
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	796	optimization, allowing the global data to be placed in the read-only section of
				797	an executable, etc). Note that variables that need runtime initialization
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	798	cannot be marked "constant" as there is a store to the variable.</p>
Chris Lattner	3689a34	2005-02-12 19:30:21 +0000	[diff] [blame]	799
				800	<p>
				801	LLVM explicitly allows <em>declarations</em> of global variables to be marked
				802	constant, even if the final definition of the global is not. This capability
				803	can be used to enable slightly better optimization of the program, but requires
				804	the language definition to guarantee that optimizations based on the
				805	'constantness' are valid for the translation units that do not include the
				806	definition.
				807	</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	808
				809	<p>As SSA values, global variables define pointer values that are in
				810	scope (i.e. they dominate) all basic blocks in the program. Global
				811	variables always define a pointer to their "content" type because they
				812	describe a region of memory, and all memory objects in LLVM are
				813	accessed through pointers.</p>
				814
Chris Lattner	8ad2f98	2009-07-18 21:47:15 +0000	[diff] [blame]	815	<p>A global variable may be declared to reside in a target-specific numbered
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	816	address space. For targets that support them, address spaces may affect how
				817	optimizations are performed and/or what target instructions are used to access
Christopher Lamb	d49e18d	2007-12-12 08:44:39 +0000	[diff] [blame]	818	the variable. The default address space is zero. The address space qualifier
				819	must precede any other attributes.</p>
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	820
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	821	<p>LLVM allows an explicit section to be specified for globals. If the target
				822	supports it, it will emit globals to the section specified.</p>
				823
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	824	<p>An explicit alignment may be specified for a global. If not present, or if
				825	the alignment is set to zero, the alignment of the global is set by the target
				826	to whatever it feels convenient. If an explicit alignment is specified, the
				827	global is forced to have at least that much alignment. All alignments must be
				828	a power of 2.</p>
				829
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	830	<p>For example, the following defines a global in a numbered address space with
				831	an initializer, section, and alignment:</p>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	832
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	833	<div class="doc_code">
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	834	<pre>
Dan Gohman	398873c	2009-01-11 00:40:00 +0000	[diff] [blame]	835	@G = addrspace(5) constant float 1.0, section "foo", align 4
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	836	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	837	</div>
Chris Lattner	68027ea	2007-01-14 00:27:09 +0000	[diff] [blame]	838
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	839	</div>
				840
				841
				842	<!-- ======================================================================= -->
				843	<div class="doc_subsection">
				844	<a name="functionstructure">Functions</a>
				845	</div>
				846
				847	<div class="doc_text">
				848
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	849	<p>LLVM function definitions consist of the "<tt>define</tt>" keyord,
				850	an optional <a href="#linkage">linkage type</a>, an optional
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	851	<a href="#visibility">visibility style</a>, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	852	<a href="#callingconv">calling convention</a>, a return type, an optional
				853	<a href="#paramattrs">parameter attribute</a> for the return type, a function
				854	name, a (possibly empty) argument list (each with optional
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	855	<a href="#paramattrs">parameter attributes</a>), optional
				856	<a href="#fnattrs">function attributes</a>, an optional section,
				857	an optional alignment, an optional <a href="#gc">garbage collector name</a>,
Chris Lattner	0c46a7d	2008-10-04 18:10:21 +0000	[diff] [blame]	858	an opening curly brace, a list of basic blocks, and a closing curly brace.
Anton Korobeynikov	8cea37b	2007-01-23 12:35:46 +0000	[diff] [blame]	859
				860	LLVM function declarations consist of the "<tt>declare</tt>" keyword, an
				861	optional <a href="#linkage">linkage type</a>, an optional
				862	<a href="#visibility">visibility style</a>, an optional
				863	<a href="#callingconv">calling convention</a>, a return type, an optional
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	864	<a href="#paramattrs">parameter attribute</a> for the return type, a function
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	865	name, a possibly empty list of arguments, an optional alignment, and an optional
Gordon Henriksen	e754abe	2007-12-10 03:30:21 +0000	[diff] [blame]	866	<a href="#gc">garbage collector name</a>.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	867
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	868	<p>A function definition contains a list of basic blocks, forming the CFG
				869	(Control Flow Graph) for
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	870	the function. Each basic block may optionally start with a label (giving the
				871	basic block a symbol table entry), contains a list of instructions, and ends
				872	with a <a href="#terminators">terminator</a> instruction (such as a branch or
				873	function return).</p>
				874
Chris Lattner	4a3c901	2007-06-08 16:52:14 +0000	[diff] [blame]	875	<p>The first basic block in a function is special in two ways: it is immediately
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	876	executed on entrance to the function, and it is not allowed to have predecessor
				877	basic blocks (i.e. there can not be any branches to the entry block of a
				878	function). Because the block can have no predecessors, it also cannot have any
				879	<a href="#i_phi">PHI nodes</a>.</p>
				880
Chris Lattner	88f6c46	2005-11-12 00:45:07 +0000	[diff] [blame]	881	<p>LLVM allows an explicit section to be specified for functions. If the target
				882	supports it, it will emit functions to the section specified.</p>
				883
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	884	<p>An explicit alignment may be specified for a function. If not present, or if
				885	the alignment is set to zero, the alignment of the function is set by the target
				886	to whatever it feels convenient. If an explicit alignment is specified, the
				887	function is forced to have at least that much alignment. All alignments must be
				888	a power of 2.</p>
				889
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	890	<h5>Syntax:</h5>
				891
				892	<div class="doc_code">
Chris Lattner	50ad45c	2008-10-13 16:55:18 +0000	[diff] [blame]	893	<tt>
				894	define [<a href="#linkage">linkage</a>] [<a href="#visibility">visibility</a>]
				895	[<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>]
				896	<ResultType> @<FunctionName> ([argument list])
				897	[<a href="#fnattrs">fn Attrs</a>] [section "name"] [align N]
				898	[<a href="#gc">gc</a>] { ... }
				899	</tt>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	900	</div>
				901
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	902	</div>
				903
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	904
				905	<!-- ======================================================================= -->
				906	<div class="doc_subsection">
				907	<a name="aliasstructure">Aliases</a>
				908	</div>
				909	<div class="doc_text">
				910	<p>Aliases act as "second name" for the aliasee value (which can be either
Anton Korobeynikov	726d45c	2008-03-22 08:36:14 +0000	[diff] [blame]	911	function, global variable, another alias or bitcast of global value). Aliases
				912	may have an optional <a href="#linkage">linkage type</a>, and an
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	913	optional <a href="#visibility">visibility style</a>.</p>
				914
				915	<h5>Syntax:</h5>
				916
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	917	<div class="doc_code">
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	918	<pre>
Duncan Sands	0b23ac1	2008-09-12 20:48:21 +0000	[diff] [blame]	919	@<Name> = alias [Linkage] [Visibility] <AliaseeTy> @<Aliasee>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	920	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	921	</div>
Anton Korobeynikov	8b0a8c8	2007-04-25 14:27:10 +0000	[diff] [blame]	922
				923	</div>
				924
				925
				926
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	927	<!-- ======================================================================= -->
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	928	<div class="doc_subsection"><a name="paramattrs">Parameter Attributes</a></div>
				929	<div class="doc_text">
				930	<p>The return type and each parameter of a function type may have a set of
				931	<i>parameter attributes</i> associated with them. Parameter attributes are
				932	used to communicate additional information about the result or parameters of
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	933	a function. Parameter attributes are considered to be part of the function,
				934	not of the function type, so functions with different parameter attributes
				935	can have the same function type.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	936
Reid Spencer	950e9f8	2007-01-15 18:27:39 +0000	[diff] [blame]	937	<p>Parameter attributes are simple keywords that follow the type specified. If
				938	multiple parameter attributes are needed, they are space separated. For
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	939	example:</p>
				940
				941	<div class="doc_code">
				942	<pre>
Nick Lewycky	b6a7d25	2009-02-15 23:06:14 +0000	[diff] [blame]	943	declare i32 @printf(i8* noalias nocapture, ...)
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	944	declare i32 @atoi(i8 zeroext)
				945	declare signext i8 @returns_signed_char()
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	946	</pre>
				947	</div>
				948
Duncan Sands	dc02467	2007-11-27 13:23:08 +0000	[diff] [blame]	949	<p>Note that any attributes for the function result (<tt>nounwind</tt>,
				950	<tt>readonly</tt>) come immediately after the argument list.</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	951
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	952	<p>Currently, only the following parameter attributes are defined:</p>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	953	<dl>
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	954	<dt><tt>zeroext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	955	<dd>This indicates to the code generator that the parameter or return value
				956	should be zero-extended to a 32-bit value by the caller (for a parameter)
				957	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	958
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	959	<dt><tt>signext</tt></dt>
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	960	<dd>This indicates to the code generator that the parameter or return value
				961	should be sign-extended to a 32-bit value by the caller (for a parameter)
				962	or the callee (for a return value).</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	963
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	964	<dt><tt>inreg</tt></dt>
Dale Johannesen	c9c6da6	2008-09-25 20:47:45 +0000	[diff] [blame]	965	<dd>This indicates that this parameter or return value should be treated
				966	in a special target-dependent fashion during while emitting code for a
				967	function call or return (usually, by putting it in a register as opposed
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	968	to memory, though some targets use it to distinguish between two different
				969	kinds of registers). Use of this attribute is target-specific.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	970
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	971	<dt><tt><a name="byval">byval</a></tt></dt>
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	972	<dd>This indicates that the pointer parameter should really be passed by
				973	value to the function. The attribute implies that a hidden copy of the
				974	pointee is made between the caller and the callee, so the callee is unable
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	975	to modify the value in the callee. This attribute is only valid on LLVM
Chris Lattner	0747baa	2008-01-15 04:34:22 +0000	[diff] [blame]	976	pointer arguments. It is generally used to pass structs and arrays by
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	977	value, but is also valid on pointers to scalars. The copy is considered to
				978	belong to the caller not the callee (for example,
				979	<tt><a href="#readonly">readonly</a></tt> functions should not write to
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	980	<tt>byval</tt> parameters). This is not a valid attribute for return
Chris Lattner	ce459b1	2009-02-05 05:42:28 +0000	[diff] [blame]	981	values. The byval attribute also supports specifying an alignment with the
				982	align attribute. This has a target-specific effect on the code generator
				983	that usually indicates a desired alignment for the synthesized stack
				984	slot.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	985
Anton Korobeynikov	34d6dea	2007-01-28 14:30:45 +0000	[diff] [blame]	986	<dt><tt>sret</tt></dt>
Duncan Sands	e26dec6	2008-02-18 04:19:38 +0000	[diff] [blame]	987	<dd>This indicates that the pointer parameter specifies the address of a
				988	structure that is the return value of the function in the source program.
Chris Lattner	66d922c	2008-10-04 18:33:34 +0000	[diff] [blame]	989	This pointer must be guaranteed by the caller to be valid: loads and stores
				990	to the structure may be assumed by the callee to not to trap. This may only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	991	be applied to the first parameter. This is not a valid attribute for
				992	return values. </dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	993
Zhou Sheng	febca34	2007-06-05 05:28:26 +0000	[diff] [blame]	994	<dt><tt>noalias</tt></dt>
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	995	<dd>This indicates that the pointer does not alias any global or any other
				996	parameter. The caller is responsible for ensuring that this is the
Nick Lewycky	b2b32fd	2008-11-24 05:00:44 +0000	[diff] [blame]	997	case. On a function return value, <tt>noalias</tt> additionally indicates
				998	that the pointer does not alias any other pointers visible to the
Nick Lewycky	f23d0d3	2008-12-19 06:39:12 +0000	[diff] [blame]	999	caller. For further details, please see the discussion of the NoAlias
				1000	response in
				1001	<a href="http://llvm.org/docs/AliasAnalysis.html#MustMayNo">alias
				1002	analysis</a>.</dd>
				1003
				1004	<dt><tt>nocapture</tt></dt>
				1005	<dd>This indicates that the callee does not make any copies of the pointer
				1006	that outlive the callee itself. This is not a valid attribute for return
				1007	values.</dd>
Chris Lattner	47507de	2008-01-11 06:20:47 +0000	[diff] [blame]	1008
Duncan Sands	50f19f5	2007-07-27 19:57:41 +0000	[diff] [blame]	1009	<dt><tt>nest</tt></dt>
Duncan Sands	0789b8b	2008-07-08 09:27:25 +0000	[diff] [blame]	1010	<dd>This indicates that the pointer parameter can be excised using the
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	1011	<a href="#int_trampoline">trampoline intrinsics</a>. This is not a valid
				1012	attribute for return values.</dd>
Anton Korobeynikov	7f70559	2007-01-12 19:20:47 +0000	[diff] [blame]	1013	</dl>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1014
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1015	</div>
				1016
				1017	<!-- ======================================================================= -->
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1018	<div class="doc_subsection">
Gordon Henriksen	80a75bf	2007-12-10 03:18:06 +0000	[diff] [blame]	1019	<a name="gc">Garbage Collector Names</a>
				1020	</div>
				1021
				1022	<div class="doc_text">
				1023	<p>Each function may specify a garbage collector name, which is simply a
				1024	string.</p>
				1025
				1026	<div class="doc_code"><pre
				1027	>define void @f() gc "name" { ...</pre></div>
				1028
				1029	<p>The compiler declares the supported values of <i>name</i>. Specifying a
				1030	collector which will cause the compiler to alter its output in order to support
				1031	the named garbage collection algorithm.</p>
				1032	</div>
				1033
				1034	<!-- ======================================================================= -->
				1035	<div class="doc_subsection">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1036	<a name="fnattrs">Function Attributes</a>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1037	</div>
				1038
				1039	<div class="doc_text">
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1040
				1041	<p>Function attributes are set to communicate additional information about
				1042	a function. Function attributes are considered to be part of the function,
				1043	not of the function type, so functions with different parameter attributes
				1044	can have the same function type.</p>
				1045
				1046	<p>Function attributes are simple keywords that follow the type specified. If
				1047	multiple attributes are needed, they are space separated. For
				1048	example:</p>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1049
				1050	<div class="doc_code">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1051	<pre>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1052	define void @f() noinline { ... }
				1053	define void @f() alwaysinline { ... }
				1054	define void @f() alwaysinline optsize { ... }
				1055	define void @f() optsize
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1056	</pre>
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1057	</div>
				1058
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1059	<dl>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1060	<dt><tt>alwaysinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1061	<dd>This attribute indicates that the inliner should attempt to inline this
				1062	function into callers whenever possible, ignoring any active inlining size
				1063	threshold for this caller.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1064
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1065	<dt><tt>noinline</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1066	<dd>This attribute indicates that the inliner should never inline this function
Chris Lattner	94b5f7d	2008-10-05 17:14:59 +0000	[diff] [blame]	1067	in any situation. This attribute may not be used together with the
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1068	<tt>alwaysinline</tt> attribute.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1069
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1070	<dt><tt>optsize</tt></dt>
Devang Patel	66c6c65	2008-09-29 18:34:44 +0000	[diff] [blame]	1071	<dd>This attribute suggests that optimization passes and code generator passes
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1072	make choices that keep the code size of this function low, and otherwise do
				1073	optimizations specifically to reduce code size.</dd>
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1074
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1075	<dt><tt>noreturn</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1076	<dd>This function attribute indicates that the function never returns normally.
				1077	This produces undefined behavior at runtime if the function ever does
				1078	dynamically return.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1079
				1080	<dt><tt>nounwind</tt></dt>
Chris Lattner	88d4b59	2008-10-04 18:23:17 +0000	[diff] [blame]	1081	<dd>This function attribute indicates that the function never returns with an
				1082	unwind or exceptional control flow. If the function does unwind, its runtime
				1083	behavior is undefined.</dd>
				1084
				1085	<dt><tt>readnone</tt></dt>
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1086	<dd>This attribute indicates that the function computes its result (or decides to
				1087	unwind an exception) based strictly on its arguments, without dereferencing any
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1088	pointer arguments or otherwise accessing any mutable state (e.g. memory, control
				1089	registers, etc) visible to caller functions. It does not write through any
				1090	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments) and
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1091	never changes any state visible to callers. This means that it cannot unwind
				1092	exceptions by calling the <tt>C++</tt> exception throwing methods, but could
				1093	use the <tt>unwind</tt> instruction.</dd>
Devang Patel	2c9c3e7	2008-09-26 23:51:19 +0000	[diff] [blame]	1094
Duncan Sands	edb05df	2008-10-06 08:14:18 +0000	[diff] [blame]	1095	<dt><tt><a name="readonly">readonly</a></tt></dt>
				1096	<dd>This attribute indicates that the function does not write through any
				1097	pointer arguments (including <tt><a href="#byval">byval</a></tt> arguments)
				1098	or otherwise modify any state (e.g. memory, control registers, etc) visible to
				1099	caller functions. It may dereference pointer arguments and read state that may
Duncan Sands	7af1c78	2009-05-06 06:49:50 +0000	[diff] [blame]	1100	be set in the caller. A readonly function always returns the same value (or
				1101	unwinds an exception identically) when called with the same set of arguments
				1102	and global state. It cannot unwind an exception by calling the <tt>C++</tt>
				1103	exception throwing methods, but may use the <tt>unwind</tt> instruction.</dd>
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1104
				1105	<dt><tt><a name="ssp">ssp</a></tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1106	<dd>This attribute indicates that the function should emit a stack smashing
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1107	protector. It is in the form of a "canary"—a random value placed on the
				1108	stack before the local variables that's checked upon return from the function to
				1109	see if it has been overwritten. A heuristic is used to determine if a function
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1110	needs stack protectors or not.
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1111
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1112	<br><br>If a function that has an <tt>ssp</tt> attribute is inlined into a function
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1113	that doesn't have an <tt>ssp</tt> attribute, then the resulting function will
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1114	have an <tt>ssp</tt> attribute.</dd>
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1115
				1116	<dt><tt>sspreq</tt></dt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1117	<dd>This attribute indicates that the function should <em>always</em> emit a
Bill Wendling	31359ba	2008-11-13 01:02:51 +0000	[diff] [blame]	1118	stack smashing protector. This overrides the <tt><a href="#ssp">ssp</a></tt>
Bill Wendling	baa39d8	2008-11-26 19:19:05 +0000	[diff] [blame]	1119	function attribute.
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1120
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1121	If a function that has an <tt>sspreq</tt> attribute is inlined into a
Bill Wendling	fbaa7ed	2008-11-26 19:07:40 +0000	[diff] [blame]	1122	function that doesn't have an <tt>sspreq</tt> attribute or which has
				1123	an <tt>ssp</tt> attribute, then the resulting function will have
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1124	an <tt>sspreq</tt> attribute.</dd>
				1125
				1126	<dt><tt>noredzone</tt></dt>
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1127	<dd>This attribute indicates that the code generator should not use a
Dan Gohman	125473b	2009-06-15 21:18:01 +0000	[diff] [blame]	1128	red zone, even if the target-specific ABI normally permits it.
Dan Gohman	2185f9e	2009-06-15 17:37:09 +0000	[diff] [blame]	1129	</dd>
Devang Patel	5d96fda	2009-06-12 19:45:19 +0000	[diff] [blame]	1130
				1131	<dt><tt>noimplicitfloat</tt></dt>
				1132	<dd>This attributes disables implicit floating point instructions.</dd>
				1133
Anton Korobeynikov	c5ec8a7	2009-07-17 18:07:26 +0000	[diff] [blame]	1134	<dt><tt>naked</tt></dt>
Chris Lattner	0c542ff	2009-07-17 21:14:28 +0000	[diff] [blame]	1135	<dd>This attribute disables prologue / epilogue emission for the function.
				1136	This can have very system-specific consequences.</dd>
Anton Korobeynikov	c5ec8a7	2009-07-17 18:07:26 +0000	[diff] [blame]	1137
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1138	</dl>
				1139
Devang Patel	f8b9481	2008-09-04 23:05:13 +0000	[diff] [blame]	1140	</div>
				1141
				1142	<!-- ======================================================================= -->
				1143	<div class="doc_subsection">
Chris Lattner	1eeeb0c	2006-04-08 04:40:53 +0000	[diff] [blame]	1144	<a name="moduleasm">Module-Level Inline Assembly</a>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1145	</div>
				1146
				1147	<div class="doc_text">
				1148	<p>
				1149	Modules may contain "module-level inline asm" blocks, which corresponds to the
				1150	GCC "file scope inline asm" blocks. These blocks are internally concatenated by
				1151	LLVM and treated as a single unit, but may be separated in the .ll file if
				1152	desired. The syntax is very simple:
				1153	</p>
				1154
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1155	<div class="doc_code">
				1156	<pre>
				1157	module asm "inline asm code goes here"
				1158	module asm "more can go here"
				1159	</pre>
				1160	</div>
Chris Lattner	4e9aba7	2006-01-23 23:23:47 +0000	[diff] [blame]	1161
				1162	<p>The strings can contain any character by escaping non-printable characters.
				1163	The escape sequence used is simply "\xx" where "xx" is the two digit hex code
				1164	for the number.
				1165	</p>
				1166
				1167	<p>
				1168	The inline asm code is simply printed to the machine code .s file when
				1169	assembly code is generated.
				1170	</p>
				1171	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1172
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1173	<!-- ======================================================================= -->
				1174	<div class="doc_subsection">
				1175	<a name="datalayout">Data Layout</a>
				1176	</div>
				1177
				1178	<div class="doc_text">
				1179	<p>A module may specify a target specific data layout string that specifies how
Reid Spencer	c891084	2007-04-11 23:49:50 +0000	[diff] [blame]	1180	data is to be laid out in memory. The syntax for the data layout is simply:</p>
				1181	<pre> target datalayout = "<i>layout specification</i>"</pre>
				1182	<p>The <i>layout specification</i> consists of a list of specifications
				1183	separated by the minus sign character ('-'). Each specification starts with a
				1184	letter and may include other information after the letter to define some
				1185	aspect of the data layout. The specifications accepted are as follows: </p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1186	<dl>
				1187	<dt><tt>E</tt></dt>
				1188	<dd>Specifies that the target lays out data in big-endian form. That is, the
				1189	bits with the most significance have the lowest address location.</dd>
				1190	<dt><tt>e</tt></dt>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1191	<dd>Specifies that the target lays out data in little-endian form. That is,
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1192	the bits with the least significance have the lowest address location.</dd>
				1193	<dt><tt>p:<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1194	<dd>This specifies the <i>size</i> of a pointer and its <i>abi</i> and
				1195	<i>preferred</i> alignments. All sizes are in bits. Specifying the <i>pref</i>
				1196	alignment is optional. If omitted, the preceding <tt>:</tt> should be omitted
				1197	too.</dd>
				1198	<dt><tt>i<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1199	<dd>This specifies the alignment for an integer type of a given bit
				1200	<i>size</i>. The value of <i>size</i> must be in the range [1,2^23).</dd>
				1201	<dt><tt>v<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1202	<dd>This specifies the alignment for a vector type of a given bit
				1203	<i>size</i>.</dd>
				1204	<dt><tt>f<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1205	<dd>This specifies the alignment for a floating point type of a given bit
				1206	<i>size</i>. The value of <i>size</i> must be either 32 (float) or 64
				1207	(double).</dd>
				1208	<dt><tt>a<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1209	<dd>This specifies the alignment for an aggregate type of a given bit
				1210	<i>size</i>.</dd>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1211	<dt><tt>s<i>size</i>:<i>abi</i>:<i>pref</i></tt></dt>
				1212	<dd>This specifies the alignment for a stack object of a given bit
				1213	<i>size</i>.</dd>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1214	</dl>
				1215	<p>When constructing the data layout for a given target, LLVM starts with a
				1216	default set of specifications which are then (possibly) overriden by the
				1217	specifications in the <tt>datalayout</tt> keyword. The default specifications
				1218	are given in this list:</p>
				1219	<ul>
				1220	<li><tt>E</tt> - big endian</li>
				1221	<li><tt>p:32:64:64</tt> - 32-bit pointers with 64-bit alignment</li>
				1222	<li><tt>i1:8:8</tt> - i1 is 8-bit (byte) aligned</li>
				1223	<li><tt>i8:8:8</tt> - i8 is 8-bit (byte) aligned</li>
				1224	<li><tt>i16:16:16</tt> - i16 is 16-bit aligned</li>
				1225	<li><tt>i32:32:32</tt> - i32 is 32-bit aligned</li>
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1226	<li><tt>i64:32:64</tt> - i64 has ABI alignment of 32-bits but preferred
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1227	alignment of 64-bits</li>
				1228	<li><tt>f32:32:32</tt> - float is 32-bit aligned</li>
				1229	<li><tt>f64:64:64</tt> - double is 64-bit aligned</li>
				1230	<li><tt>v64:64:64</tt> - 64-bit vector is 64-bit aligned</li>
				1231	<li><tt>v128:128:128</tt> - 128-bit vector is 128-bit aligned</li>
				1232	<li><tt>a0:0:1</tt> - aggregates are 8-bit aligned</li>
Daniel Dunbar	87bde0b	2009-06-08 22:17:53 +0000	[diff] [blame]	1233	<li><tt>s0:64:64</tt> - stack objects are 64-bit aligned</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1234	</ul>
Chris Lattner	ebec678	2008-08-05 18:21:08 +0000	[diff] [blame]	1235	<p>When LLVM is determining the alignment for a given type, it uses the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1236	following rules:</p>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1237	<ol>
				1238	<li>If the type sought is an exact match for one of the specifications, that
				1239	specification is used.</li>
				1240	<li>If no match is found, and the type sought is an integer type, then the
				1241	smallest integer type that is larger than the bitwidth of the sought type is
				1242	used. If none of the specifications are larger than the bitwidth then the the
				1243	largest integer type is used. For example, given the default specifications
				1244	above, the i7 type will use the alignment of i8 (next largest) while both
				1245	i65 and i256 will use the alignment of i64 (largest specified).</li>
				1246	<li>If no match is found, and the type sought is a vector type, then the
				1247	largest vector type that is smaller than the sought vector type will be used
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	1248	as a fall back. This happens because <128 x double> can be implemented
				1249	in terms of 64 <2 x double>, for example.</li>
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	1250	</ol>
				1251	</div>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1252
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1253	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1254	<div class="doc_section"> <a name="typesystem">Type System</a> </div>
				1255	<!-- *********************************************************************** -->
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1256
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1257	<div class="doc_text">
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1258
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1259	<p>The LLVM type system is one of the most important features of the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1260	intermediate representation. Being typed enables a number of
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	1261	optimizations to be performed on the intermediate representation directly,
				1262	without having to do
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1263	extra analyses on the side before the transformation. A strong type
				1264	system makes it easier to read the generated code and enables novel
				1265	analyses and transformations that are not feasible to perform on normal
				1266	three address code representations.</p>
Chris Lattner	fa73021	2004-12-09 16:11:40 +0000	[diff] [blame]	1267
				1268	</div>
				1269
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1270	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1271	<div class="doc_subsection"> <a name="t_classifications">Type
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1272	Classifications</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1273	<div class="doc_text">
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1274	<p>The types fall into a few useful
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1275	classifications:</p>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1276
				1277	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1278	<tbody>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1279	<tr><th>Classification</th><th>Types</th></tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1280	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1281	<td><a href="#t_integer">integer</a></td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1282	<td><tt>i1, i2, i3, ... i8, ... i16, ... i32, ... i64, ... </tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1283	</tr>
				1284	<tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1285	<td><a href="#t_floating">floating point</a></td>
				1286	<td><tt>float, double, x86_fp80, fp128, ppc_fp128</tt></td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1287	</tr>
				1288	<tr>
				1289	<td><a name="t_firstclass">first class</a></td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1290	<td><a href="#t_integer">integer</a>,
				1291	<a href="#t_floating">floating point</a>,
				1292	<a href="#t_pointer">pointer</a>,
Dan Gohman	0066db6	2008-06-18 18:42:13 +0000	[diff] [blame]	1293	<a href="#t_vector">vector</a>,
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	1294	<a href="#t_struct">structure</a>,
				1295	<a href="#t_array">array</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1296	<a href="#t_label">label</a>,
				1297	<a href="#t_metadata">metadata</a>.
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1298	</td>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1299	</tr>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1300	<tr>
				1301	<td><a href="#t_primitive">primitive</a></td>
				1302	<td><a href="#t_label">label</a>,
				1303	<a href="#t_void">void</a>,
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1304	<a href="#t_floating">floating point</a>,
				1305	<a href="#t_metadata">metadata</a>.</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1306	</tr>
				1307	<tr>
				1308	<td><a href="#t_derived">derived</a></td>
				1309	<td><a href="#t_integer">integer</a>,
				1310	<a href="#t_array">array</a>,
				1311	<a href="#t_function">function</a>,
				1312	<a href="#t_pointer">pointer</a>,
				1313	<a href="#t_struct">structure</a>,
				1314	<a href="#t_pstruct">packed structure</a>,
				1315	<a href="#t_vector">vector</a>,
				1316	<a href="#t_opaque">opaque</a>.
Dan Gohman	01ac101	2008-10-14 16:32:04 +0000	[diff] [blame]	1317	</td>
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1318	</tr>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1319	</tbody>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1320	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1321
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1322	<p>The <a href="#t_firstclass">first class</a> types are perhaps the
				1323	most important. Values of these types are the only ones which can be
				1324	produced by instructions, passed as arguments, or used as operands to
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	1325	instructions.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1326	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1327
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1328	<!-- ======================================================================= -->
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1329	<div class="doc_subsection"> <a name="t_primitive">Primitive Types</a> </div>
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1330
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1331	<div class="doc_text">
				1332	<p>The primitive types are the fundamental building blocks of the LLVM
				1333	system.</p>
				1334
Chris Lattner	8f8c7b7	2008-01-04 04:34:14 +0000	[diff] [blame]	1335	</div>
				1336
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1337	<!-- _______________________________________________________________________ -->
				1338	<div class="doc_subsubsection"> <a name="t_floating">Floating Point Types</a> </div>
				1339
				1340	<div class="doc_text">
				1341	<table>
				1342	<tbody>
				1343	<tr><th>Type</th><th>Description</th></tr>
				1344	<tr><td><tt>float</tt></td><td>32-bit floating point value</td></tr>
				1345	<tr><td><tt>double</tt></td><td>64-bit floating point value</td></tr>
				1346	<tr><td><tt>fp128</tt></td><td>128-bit floating point value (112-bit mantissa)</td></tr>
				1347	<tr><td><tt>x86_fp80</tt></td><td>80-bit floating point value (X87)</td></tr>
				1348	<tr><td><tt>ppc_fp128</tt></td><td>128-bit floating point value (two 64-bits)</td></tr>
				1349	</tbody>
				1350	</table>
				1351	</div>
				1352
				1353	<!-- _______________________________________________________________________ -->
				1354	<div class="doc_subsubsection"> <a name="t_void">Void Type</a> </div>
				1355
				1356	<div class="doc_text">
				1357	<h5>Overview:</h5>
				1358	<p>The void type does not represent any value and has no size.</p>
				1359
				1360	<h5>Syntax:</h5>
				1361
				1362	<pre>
				1363	void
				1364	</pre>
				1365	</div>
				1366
				1367	<!-- _______________________________________________________________________ -->
				1368	<div class="doc_subsubsection"> <a name="t_label">Label Type</a> </div>
				1369
				1370	<div class="doc_text">
				1371	<h5>Overview:</h5>
				1372	<p>The label type represents code labels.</p>
				1373
				1374	<h5>Syntax:</h5>
				1375
				1376	<pre>
				1377	label
				1378	</pre>
				1379	</div>
				1380
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	1381	<!-- _______________________________________________________________________ -->
				1382	<div class="doc_subsubsection"> <a name="t_metadata">Metadata Type</a> </div>
				1383
				1384	<div class="doc_text">
				1385	<h5>Overview:</h5>
				1386	<p>The metadata type represents embedded metadata. The only derived type that
				1387	may contain metadata is <tt>metadata*</tt> or a function type that returns or
				1388	takes metadata typed parameters, but not pointer to metadata types.</p>
				1389
				1390	<h5>Syntax:</h5>
				1391
				1392	<pre>
				1393	metadata
				1394	</pre>
				1395	</div>
				1396
Chris Lattner	4f69f46	2008-01-04 04:32:38 +0000	[diff] [blame]	1397
				1398	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1399	<div class="doc_subsection"> <a name="t_derived">Derived Types</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1400
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1401	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1402
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1403	<p>The real power in LLVM comes from the derived types in the system.
				1404	This is what allows a programmer to represent arrays, functions,
				1405	pointers, and other useful types. Note that these derived types may be
				1406	recursive: For example, it is possible to have a two dimensional array.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1407
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1408	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1409
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1410	<!-- _______________________________________________________________________ -->
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1411	<div class="doc_subsubsection"> <a name="t_integer">Integer Type</a> </div>
				1412
				1413	<div class="doc_text">
				1414
				1415	<h5>Overview:</h5>
				1416	<p>The integer type is a very simple derived type that simply specifies an
				1417	arbitrary bit width for the integer type desired. Any bit width from 1 bit to
				1418	2^23-1 (about 8 million) can be specified.</p>
				1419
				1420	<h5>Syntax:</h5>
				1421
				1422	<pre>
				1423	iN
				1424	</pre>
				1425
				1426	<p>The number of bits the integer will occupy is specified by the <tt>N</tt>
				1427	value.</p>
				1428
				1429	<h5>Examples:</h5>
				1430	<table class="layout">
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1431	<tr class="layout">
				1432	<td class="left"><tt>i1</tt></td>
				1433	<td class="left">a single-bit integer.</td>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1434	</tr>
Nick Lewycky	86c4864	2009-05-24 02:46:06 +0000	[diff] [blame]	1435	<tr class="layout">
				1436	<td class="left"><tt>i32</tt></td>
				1437	<td class="left">a 32-bit integer.</td>
				1438	</tr>
				1439	<tr class="layout">
				1440	<td class="left"><tt>i1942652</tt></td>
				1441	<td class="left">a really big integer of over 1 million bits.</td>
				1442	</tr>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1443	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1444
				1445	<p>Note that the code generator does not yet support large integer types
				1446	to be used as function return types. The specific limit on how large a
				1447	return type the code generator can currently handle is target-dependent;
				1448	currently it's often 64 bits for 32-bit targets and 128 bits for 64-bit
				1449	targets.</p>
				1450
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1451	</div>
Reid Spencer	2b91631	2007-05-16 18:44:01 +0000	[diff] [blame]	1452
				1453	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1454	<div class="doc_subsubsection"> <a name="t_array">Array Type</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1455
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1456	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1457
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1458	<h5>Overview:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1459
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1460	<p>The array type is a very simple derived type that arranges elements
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1461	sequentially in memory. The array type requires a size (number of
				1462	elements) and an underlying data type.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1463
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1464	<h5>Syntax:</h5>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1465
				1466	<pre>
				1467	[<# elements> x <elementtype>]
				1468	</pre>
				1469
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	1470	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1471	be any type with a size.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1472
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1473	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1474	<table class="layout">
				1475	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1476	<td class="left"><tt>[40 x i32]</tt></td>
				1477	<td class="left">Array of 40 32-bit integer values.</td>
				1478	</tr>
				1479	<tr class="layout">
				1480	<td class="left"><tt>[41 x i32]</tt></td>
				1481	<td class="left">Array of 41 32-bit integer values.</td>
				1482	</tr>
				1483	<tr class="layout">
				1484	<td class="left"><tt>[4 x i8]</tt></td>
				1485	<td class="left">Array of 4 8-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1486	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1487	</table>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1488	<p>Here are some examples of multidimensional arrays:</p>
				1489	<table class="layout">
				1490	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1491	<td class="left"><tt>[3 x [4 x i32]]</tt></td>
				1492	<td class="left">3x4 array of 32-bit integer values.</td>
				1493	</tr>
				1494	<tr class="layout">
				1495	<td class="left"><tt>[12 x [10 x float]]</tt></td>
				1496	<td class="left">12x10 array of single precision floating point values.</td>
				1497	</tr>
				1498	<tr class="layout">
				1499	<td class="left"><tt>[2 x [3 x [4 x i16]]]</tt></td>
				1500	<td class="left">2x3x4 array of 16-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1501	</tr>
				1502	</table>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1503
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1504	<p>Note that 'variable sized arrays' can be implemented in LLVM with a zero
				1505	length array. Normally, accesses past the end of an array are undefined in
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1506	LLVM (e.g. it is illegal to access the 5th element of a 3 element array).
				1507	As a special case, however, zero length arrays are recognized to be variable
				1508	length. This allows implementation of 'pascal style arrays' with the LLVM
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1509	type "{ i32, [0 x float]}", for example.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	1510
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1511	<p>Note that the code generator does not yet support large aggregate types
				1512	to be used as function return types. The specific limit on how large an
				1513	aggregate return type the code generator can currently handle is
				1514	target-dependent, and also dependent on the aggregate element types.</p>
				1515
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1516	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1517
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1518	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1519	<div class="doc_subsubsection"> <a name="t_function">Function Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1520	<div class="doc_text">
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1521
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1522	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1523
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1524	<p>The function type can be thought of as a function signature. It
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1525	consists of a return type and a list of formal parameter types. The
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1526	return type of a function type is a scalar type, a void type, or a struct type.
Devang Patel	7a3ad1a	2008-03-24 20:52:42 +0000	[diff] [blame]	1527	If the return type is a struct type then all struct elements must be of first
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1528	class types, and the struct must have at least one element.</p>
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1529
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1530	<h5>Syntax:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1531
				1532	<pre>
				1533	<returntype list> (<parameter list>)
				1534	</pre>
				1535
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1536	<p>...where '<tt><parameter list></tt>' is a comma-separated list of type
Misha Brukman	c24b758	2004-08-12 20:16:08 +0000	[diff] [blame]	1537	specifiers. Optionally, the parameter list may include a type <tt>...</tt>,
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	1538	which indicates that the function takes a variable number of arguments.
				1539	Variable argument functions can access their arguments with the <a
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	1540	href="#int_varargs">variable argument handling intrinsic</a> functions.
				1541	'<tt><returntype list></tt>' is a comma-separated list of
				1542	<a href="#t_firstclass">first class</a> type specifiers.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	1543
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1544	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1545	<table class="layout">
				1546	<tr class="layout">
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1547	<td class="left"><tt>i32 (i32)</tt></td>
				1548	<td class="left">function taking an <tt>i32</tt>, returning an <tt>i32</tt>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1549	</td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1550	</tr><tr class="layout">
Reid Spencer	9445e9a	2007-07-19 23:13:04 +0000	[diff] [blame]	1551	<td class="left"><tt>float (i16 signext, i32 )
Reid Spencer	f17a0b7	2006-12-31 07:20:23 +0000	[diff] [blame]	1552	</tt></td>
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1553	<td class="left"><a href="#t_pointer">Pointer</a> to a function that takes
				1554	an <tt>i16</tt> that should be sign extended and a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1555	<a href="#t_pointer">pointer</a> to <tt>i32</tt>, returning
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1556	<tt>float</tt>.
				1557	</td>
				1558	</tr><tr class="layout">
				1559	<td class="left"><tt>i32 (i8*, ...)</tt></td>
				1560	<td class="left">A vararg function that takes at least one
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1561	<a href="#t_pointer">pointer</a> to <tt>i8 </tt> (char in C),
Reid Spencer	92f8230	2006-12-31 07:18:34 +0000	[diff] [blame]	1562	which returns an integer. This is the signature for <tt>printf</tt> in
				1563	LLVM.
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1564	</td>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1565	</tr><tr class="layout">
				1566	<td class="left"><tt>{i32, i32} (i32)</tt></td>
Misha Brukman	b0a57aa	2008-11-27 06:41:20 +0000	[diff] [blame]	1567	<td class="left">A function taking an <tt>i32</tt>, returning two
				1568	<tt>i32</tt> values as an aggregate of type <tt>{ i32, i32 }</tt>
Devang Patel	a582f40	2008-03-24 05:35:41 +0000	[diff] [blame]	1569	</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1570	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1571	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	1572
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1573	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1574	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1575	<div class="doc_subsubsection"> <a name="t_struct">Structure Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1576	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1577	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1578	<p>The structure type is used to represent a collection of data members
				1579	together in memory. The packing of the field types is defined to match
				1580	the ABI of the underlying processor. The elements of a structure may
				1581	be any type that has a size.</p>
				1582	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1583	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1584	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1585	instruction.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1586	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1587	<pre> { <type list> }<br></pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1588	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1589	<table class="layout">
				1590	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1591	<td class="left"><tt>{ i32, i32, i32 }</tt></td>
				1592	<td class="left">A triple of three <tt>i32</tt> values</td>
				1593	</tr><tr class="layout">
				1594	<td class="left"><tt>{ float, i32 (i32) * }</tt></td>
				1595	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1596	second element is a <a href="#t_pointer">pointer</a> to a
				1597	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1598	an <tt>i32</tt>.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1599	</tr>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1600	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1601
				1602	<p>Note that the code generator does not yet support large aggregate types
				1603	to be used as function return types. The specific limit on how large an
				1604	aggregate return type the code generator can currently handle is
				1605	target-dependent, and also dependent on the aggregate element types.</p>
				1606
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1607	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1608
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	1609	<!-- _______________________________________________________________________ -->
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1610	<div class="doc_subsubsection"> <a name="t_pstruct">Packed Structure Type</a>
				1611	</div>
				1612	<div class="doc_text">
				1613	<h5>Overview:</h5>
				1614	<p>The packed structure type is used to represent a collection of data members
				1615	together in memory. There is no padding between fields. Further, the alignment
				1616	of a packed structure is 1 byte. The elements of a packed structure may
				1617	be any type that has a size.</p>
				1618	<p>Structures are accessed using '<tt><a href="#i_load">load</a></tt>
				1619	and '<tt><a href="#i_store">store</a></tt>' by getting a pointer to a
				1620	field with the '<tt><a href="#i_getelementptr">getelementptr</a></tt>'
				1621	instruction.</p>
				1622	<h5>Syntax:</h5>
				1623	<pre> < { <type list> } > <br></pre>
				1624	<h5>Examples:</h5>
				1625	<table class="layout">
				1626	<tr class="layout">
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1627	<td class="left"><tt>< { i32, i32, i32 } ></tt></td>
				1628	<td class="left">A triple of three <tt>i32</tt> values</td>
				1629	</tr><tr class="layout">
Bill Wendling	e36dccc	2008-09-07 10:26:33 +0000	[diff] [blame]	1630	<td class="left">
				1631	<tt>< { float, i32 (i32)* } ></tt></td>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1632	<td class="left">A pair, where the first element is a <tt>float</tt> and the
				1633	second element is a <a href="#t_pointer">pointer</a> to a
				1634	<a href="#t_function">function</a> that takes an <tt>i32</tt>, returning
				1635	an <tt>i32</tt>.</td>
Andrew Lenharth	75e1068	2006-12-08 17:13:00 +0000	[diff] [blame]	1636	</tr>
				1637	</table>
				1638	</div>
				1639
				1640	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1641	<div class="doc_subsubsection"> <a name="t_pointer">Pointer Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1642	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1643	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1644	<p>As in many languages, the pointer type represents a pointer or
Christopher Lamb	284d992	2007-12-11 09:31:00 +0000	[diff] [blame]	1645	reference to another object, which must live in memory. Pointer types may have
				1646	an optional address space attribute defining the target-specific numbered
				1647	address space where the pointed-to object resides. The default address space is
				1648	zero.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1649
				1650	<p>Note that LLVM does not permit pointers to void (<tt>void*</tt>) nor does
Chris Lattner	e220e8c	2009-02-08 22:21:28 +0000	[diff] [blame]	1651	it permit pointers to labels (<tt>label</tt>). Use <tt>i8</tt> instead.</p>
Chris Lattner	0fd4a27	2009-02-08 19:53:29 +0000	[diff] [blame]	1652
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1653	<h5>Syntax:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	1654	<pre> <type> *<br></pre>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	1655	<h5>Examples:</h5>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1656	<table class="layout">
				1657	<tr class="layout">
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	1658	<td class="left"><tt>[4 x i32]*</tt></td>
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1659	<td class="left">A <a href="#t_pointer">pointer</a> to <a
				1660	href="#t_array">array</a> of four <tt>i32</tt> values.</td>
				1661	</tr>
				1662	<tr class="layout">
				1663	<td class="left"><tt>i32 (i32 ) </tt></td>
				1664	<td class="left"> A <a href="#t_pointer">pointer</a> to a <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1665	href="#t_function">function</a> that takes an <tt>i32*</tt>, returning an
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1666	<tt>i32</tt>.</td>
				1667	</tr>
				1668	<tr class="layout">
				1669	<td class="left"><tt>i32 addrspace(5)*</tt></td>
				1670	<td class="left">A <a href="#t_pointer">pointer</a> to an <tt>i32</tt> value
				1671	that resides in address space #5.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1672	</tr>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1673	</table>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1674	</div>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1675
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1676	<!-- _______________________________________________________________________ -->
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1677	<div class="doc_subsubsection"> <a name="t_vector">Vector Type</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1678	<div class="doc_text">
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1679
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1680	<h5>Overview:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1681
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1682	<p>A vector type is a simple derived type that represents a vector
				1683	of elements. Vector types are used when multiple primitive data
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1684	are operated in parallel using a single instruction (SIMD).
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1685	A vector type requires a size (number of
Chris Lattner	b8d172f	2005-11-10 01:44:22 +0000	[diff] [blame]	1686	elements) and an underlying primitive data type. Vectors must have a power
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1687	of two length (1, 2, 4, 8, 16 ...). Vector types are
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1688	considered <a href="#t_firstclass">first class</a>.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1689
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1690	<h5>Syntax:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1691
				1692	<pre>
				1693	< <# elements> x <elementtype> >
				1694	</pre>
				1695
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1696	<p>The number of elements is a constant integer value; elementtype may
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1697	be any integer or floating point type.</p>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1698
Chris Lattner	a58561b	2004-08-12 19:12:28 +0000	[diff] [blame]	1699	<h5>Examples:</h5>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1700
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1701	<table class="layout">
				1702	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1703	<td class="left"><tt><4 x i32></tt></td>
				1704	<td class="left">Vector of 4 32-bit integer values.</td>
				1705	</tr>
				1706	<tr class="layout">
				1707	<td class="left"><tt><8 x float></tt></td>
				1708	<td class="left">Vector of 8 32-bit floating-point values.</td>
				1709	</tr>
				1710	<tr class="layout">
				1711	<td class="left"><tt><2 x i64></tt></td>
				1712	<td class="left">Vector of 2 64-bit integer values.</td>
Reid Spencer	d3f876c	2004-11-01 08:19:36 +0000	[diff] [blame]	1713	</tr>
				1714	</table>
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	1715
				1716	<p>Note that the code generator does not yet support large vector types
				1717	to be used as function return types. The specific limit on how large a
				1718	vector return type codegen can currently handle is target-dependent;
				1719	currently it's often a few times longer than a hardware vector register.</p>
				1720
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	1721	</div>
				1722
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1723	<!-- _______________________________________________________________________ -->
				1724	<div class="doc_subsubsection"> <a name="t_opaque">Opaque Type</a> </div>
				1725	<div class="doc_text">
				1726
				1727	<h5>Overview:</h5>
				1728
				1729	<p>Opaque types are used to represent unknown types in the system. This
Gordon Henriksen	8ac04ff	2007-10-14 00:34:53 +0000	[diff] [blame]	1730	corresponds (for example) to the C notion of a forward declared structure type.
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1731	In LLVM, opaque types can eventually be resolved to any type (not just a
				1732	structure type).</p>
				1733
				1734	<h5>Syntax:</h5>
				1735
				1736	<pre>
				1737	opaque
				1738	</pre>
				1739
				1740	<h5>Examples:</h5>
				1741
				1742	<table class="layout">
				1743	<tr class="layout">
Chris Lattner	23ff1f9	2007-12-19 05:04:11 +0000	[diff] [blame]	1744	<td class="left"><tt>opaque</tt></td>
				1745	<td class="left">An opaque type.</td>
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1746	</tr>
				1747	</table>
				1748	</div>
				1749
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1750	<!-- ======================================================================= -->
				1751	<div class="doc_subsection">
				1752	<a name="t_uprefs">Type Up-references</a>
				1753	</div>
				1754
				1755	<div class="doc_text">
				1756	<h5>Overview:</h5>
				1757	<p>
				1758	An "up reference" allows you to refer to a lexically enclosing type without
				1759	requiring it to have a name. For instance, a structure declaration may contain a
				1760	pointer to any of the types it is lexically a member of. Example of up
				1761	references (with their equivalent as named type declarations) include:</p>
				1762
				1763	<pre>
Chris Lattner	3060f5b	2009-02-09 10:00:56 +0000	[diff] [blame]	1764	{ \2 * } %x = type { %x* }
Chris Lattner	242d61d	2009-02-02 07:32:36 +0000	[diff] [blame]	1765	{ \2 }* %y = type { %y }*
				1766	\1* %z = type %z*
				1767	</pre>
				1768
				1769	<p>
				1770	An up reference is needed by the asmprinter for printing out cyclic types when
				1771	there is no declared name for a type in the cycle. Because the asmprinter does
				1772	not want to print out an infinite type string, it needs a syntax to handle
				1773	recursive types that have no names (all names are optional in llvm IR).
				1774	</p>
				1775
				1776	<h5>Syntax:</h5>
				1777	<pre>
				1778	\<level>
				1779	</pre>
				1780
				1781	<p>
				1782	The level is the count of the lexical type that is being referred to.
				1783	</p>
				1784
				1785	<h5>Examples:</h5>
				1786
				1787	<table class="layout">
				1788	<tr class="layout">
				1789	<td class="left"><tt>\1*</tt></td>
				1790	<td class="left">Self-referential pointer.</td>
				1791	</tr>
				1792	<tr class="layout">
				1793	<td class="left"><tt>{ { \3*, i8 }, i32 }</tt></td>
				1794	<td class="left">Recursive structure where the upref refers to the out-most
				1795	structure.</td>
				1796	</tr>
				1797	</table>
				1798	</div>
				1799
Chris Lattner	69c11bb	2005-04-25 17:34:15 +0000	[diff] [blame]	1800
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1801	<!-- *********************************************************************** -->
				1802	<div class="doc_section"> <a name="constants">Constants</a> </div>
				1803	<!-- *********************************************************************** -->
				1804
				1805	<div class="doc_text">
				1806
				1807	<p>LLVM has several different basic types of constants. This section describes
				1808	them all and their syntax.</p>
				1809
				1810	</div>
				1811
				1812	<!-- ======================================================================= -->
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1813	<div class="doc_subsection"><a name="simpleconstants">Simple Constants</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1814
				1815	<div class="doc_text">
				1816
				1817	<dl>
				1818	<dt><b>Boolean constants</b></dt>
				1819
				1820	<dd>The two strings '<tt>true</tt>' and '<tt>false</tt>' are both valid
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	1821	constants of the <tt><a href="#t_primitive">i1</a></tt> type.
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1822	</dd>
				1823
				1824	<dt><b>Integer constants</b></dt>
				1825
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1826	<dd>Standard integers (such as '4') are constants of the <a
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	1827	href="#t_integer">integer</a> type. Negative numbers may be used with
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1828	integer types.
				1829	</dd>
				1830
				1831	<dt><b>Floating point constants</b></dt>
				1832
				1833	<dd>Floating point constants use standard decimal notation (e.g. 123.421),
				1834	exponential notation (e.g. 1.23421e+2), or a more precise hexadecimal
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	1835	notation (see below). The assembler requires the exact decimal value of
				1836	a floating-point constant. For example, the assembler accepts 1.25 but
				1837	rejects 1.3 because 1.3 is a repeating decimal in binary. Floating point
				1838	constants must have a <a href="#t_floating">floating point</a> type. </dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1839
				1840	<dt><b>Null pointer constants</b></dt>
				1841
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1842	<dd>The identifier '<tt>null</tt>' is recognized as a null pointer constant
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1843	and must be of <a href="#t_pointer">pointer type</a>.</dd>
				1844
				1845	</dl>
				1846
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1847	<p>The one non-intuitive notation for constants is the hexadecimal form
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1848	of floating point constants. For example, the form '<tt>double
				1849	0x432ff973cafa8000</tt>' is equivalent to (but harder to read than) '<tt>double
				1850	4.5e+15</tt>'. The only time hexadecimal floating point constants are required
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1851	(and the only time that they are generated by the disassembler) is when a
				1852	floating point constant must be emitted but it cannot be represented as a
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1853	decimal floating point number in a reasonable number of digits. For example,
				1854	NaN's, infinities, and other
Reid Spencer	cc16dc3	2004-12-09 18:02:53 +0000	[diff] [blame]	1855	special values are represented in their IEEE hexadecimal format so that
				1856	assembly and disassembly do not cause any bits to change in the constants.</p>
Dale Johannesen	bd5e5a8	2009-02-11 22:14:51 +0000	[diff] [blame]	1857	<p>When using the hexadecimal form, constants of types float and double are
				1858	represented using the 16-digit form shown above (which matches the IEEE754
				1859	representation for double); float values must, however, be exactly representable
				1860	as IEE754 single precision.
				1861	Hexadecimal format is always used for long
				1862	double, and there are three forms of long double. The 80-bit
				1863	format used by x86 is represented as <tt>0xK</tt>
				1864	followed by 20 hexadecimal digits.
				1865	The 128-bit format used by PowerPC (two adjacent doubles) is represented
				1866	by <tt>0xM</tt> followed by 32 hexadecimal digits. The IEEE 128-bit
				1867	format is represented
				1868	by <tt>0xL</tt> followed by 32 hexadecimal digits; no currently supported
				1869	target uses this format. Long doubles will only work if they match
				1870	the long double format on your target. All hexadecimal formats are big-endian
				1871	(sign bit at the left).</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1872	</div>
				1873
				1874	<!-- ======================================================================= -->
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1875	<div class="doc_subsection">
				1876	<a name="aggregateconstants"> <!-- old anchor -->
				1877	<a name="complexconstants">Complex Constants</a></a>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1878	</div>
				1879
				1880	<div class="doc_text">
Chris Lattner	7088279	2009-02-28 18:32:25 +0000	[diff] [blame]	1881	<p>Complex constants are a (potentially recursive) combination of simple
				1882	constants and smaller complex constants.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1883
				1884	<dl>
				1885	<dt><b>Structure constants</b></dt>
				1886
				1887	<dd>Structure constants are represented with notation similar to structure
				1888	type definitions (a comma separated list of elements, surrounded by braces
Chris Lattner	64910ee	2007-12-25 20:34:52 +0000	[diff] [blame]	1889	(<tt>{}</tt>)). For example: "<tt>{ i32 4, float 17.0, i32* @G }</tt>",
				1890	where "<tt>@G</tt>" is declared as "<tt>@G = external global i32</tt>". Structure constants
Chris Lattner	d4f6b17	2005-03-07 22:13:59 +0000	[diff] [blame]	1891	must have <a href="#t_struct">structure type</a>, and the number and
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1892	types of elements must match those specified by the type.
				1893	</dd>
				1894
				1895	<dt><b>Array constants</b></dt>
				1896
				1897	<dd>Array constants are represented with notation similar to array type
				1898	definitions (a comma separated list of elements, surrounded by square brackets
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1899	(<tt>[]</tt>)). For example: "<tt>[ i32 42, i32 11, i32 74 ]</tt>". Array
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1900	constants must have <a href="#t_array">array type</a>, and the number and
				1901	types of elements must match those specified by the type.
				1902	</dd>
				1903
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1904	<dt><b>Vector constants</b></dt>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1905
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1906	<dd>Vector constants are represented with notation similar to vector type
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1907	definitions (a comma separated list of elements, surrounded by
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	1908	less-than/greater-than's (<tt><></tt>)). For example: "<tt>< i32 42,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	1909	i32 11, i32 74, i32 100 ></tt>". Vector constants must have <a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	1910	href="#t_vector">vector type</a>, and the number and types of elements must
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1911	match those specified by the type.
				1912	</dd>
				1913
				1914	<dt><b>Zero initialization</b></dt>
				1915
				1916	<dd>The string '<tt>zeroinitializer</tt>' can be used to zero initialize a
				1917	value to zero of <em>any</em> type, including scalar and aggregate types.
				1918	This is often used to avoid having to print large zero initializers (e.g. for
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	1919	large arrays) and is always exactly equivalent to using explicit zero
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1920	initializers.
				1921	</dd>
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1922
				1923	<dt><b>Metadata node</b></dt>
				1924
Nick Lewycky	1e8c7a6	2009-05-30 16:08:30 +0000	[diff] [blame]	1925	<dd>A metadata node is a structure-like constant with
				1926	<a href="#t_metadata">metadata type</a>. For example:
				1927	"<tt>metadata !{ i32 0, metadata !"test" }</tt>". Unlike other constants
				1928	that are meant to be interpreted as part of the instruction stream, metadata
				1929	is a place to attach additional information such as debug info.
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	1930	</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1931	</dl>
				1932
				1933	</div>
				1934
				1935	<!-- ======================================================================= -->
				1936	<div class="doc_subsection">
				1937	<a name="globalconstants">Global Variable and Function Addresses</a>
				1938	</div>
				1939
				1940	<div class="doc_text">
				1941
				1942	<p>The addresses of <a href="#globalvars">global variables</a> and <a
				1943	href="#functionstructure">functions</a> are always implicitly valid (link-time)
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	1944	constants. These constants are explicitly referenced when the <a
				1945	href="#identifiers">identifier for the global</a> is used and always have <a
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1946	href="#t_pointer">pointer</a> type. For example, the following is a legal LLVM
				1947	file:</p>
				1948
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1949	<div class="doc_code">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1950	<pre>
Chris Lattner	a18a424	2007-06-06 18:28:13 +0000	[diff] [blame]	1951	@X = global i32 17
				1952	@Y = global i32 42
				1953	@Z = global [2 x i32] [ i32 @X, i32* @Y ]
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1954	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	1955	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1956
				1957	</div>
				1958
				1959	<!-- ======================================================================= -->
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1960	<div class="doc_subsection"><a name="undefvalues">Undefined Values</a></div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1961	<div class="doc_text">
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1962	<p>The string '<tt>undef</tt>' is recognized as a type-less constant that has
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1963	no specific value. Undefined values may be of any type and be used anywhere
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1964	a constant is permitted.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1965
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	1966	<p>Undefined values indicate to the compiler that the program is well defined
				1967	no matter what value is used, giving the compiler more freedom to optimize.
				1968	</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1969	</div>
				1970
				1971	<!-- ======================================================================= -->
				1972	<div class="doc_subsection"><a name="constantexprs">Constant Expressions</a>
				1973	</div>
				1974
				1975	<div class="doc_text">
				1976
				1977	<p>Constant expressions are used to allow expressions involving other constants
				1978	to be used as constants. Constant expressions may be of any <a
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	1979	href="#t_firstclass">first class</a> type and may involve any LLVM operation
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1980	that does not have side effects (e.g. load and call are not supported). The
				1981	following is the syntax for constant expressions:</p>
				1982
				1983	<dl>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1984	<dt><b><tt>trunc ( CST to TYPE )</tt></b></dt>
				1985	<dd>Truncate a constant to another type. The bit size of CST must be larger
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1986	than the bit size of TYPE. Both types must be integers.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	1987
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1988	<dt><b><tt>zext ( CST to TYPE )</tt></b></dt>
				1989	<dd>Zero extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1990	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1991
				1992	<dt><b><tt>sext ( CST to TYPE )</tt></b></dt>
				1993	<dd>Sign extend a constant to another type. The bit size of CST must be
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	1994	smaller or equal to the bit size of TYPE. Both types must be integers.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	1995
				1996	<dt><b><tt>fptrunc ( CST to TYPE )</tt></b></dt>
				1997	<dd>Truncate a floating point constant to another floating point type. The
				1998	size of CST must be larger than the size of TYPE. Both types must be
				1999	floating point.</dd>
				2000
				2001	<dt><b><tt>fpext ( CST to TYPE )</tt></b></dt>
				2002	<dd>Floating point extend a constant to another type. The size of CST must be
				2003	smaller or equal to the size of TYPE. Both types must be floating point.</dd>
				2004
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	2005	<dt><b><tt>fptoui ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2006	<dd>Convert a floating point constant to the corresponding unsigned integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2007	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				2008	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				2009	of the same number of elements. If the value won't fit in the integer type,
				2010	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2011
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2012	<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2013	<dd>Convert a floating point constant to the corresponding signed integer
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2014	constant. TYPE must be a scalar or vector integer type. CST must be of scalar
				2015	or vector floating point type. Both CST and TYPE must be scalars, or vectors
				2016	of the same number of elements. If the value won't fit in the integer type,
				2017	the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2018
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2019	<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2020	<dd>Convert an unsigned integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2021	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2022	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2023	of the same number of elements. If the value won't fit in the floating point
				2024	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2025
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	2026	<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2027	<dd>Convert a signed integer constant to the corresponding floating point
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	2028	constant. TYPE must be a scalar or vector floating point type. CST must be of
				2029	scalar or vector integer type. Both CST and TYPE must be scalars, or vectors
				2030	of the same number of elements. If the value won't fit in the floating point
				2031	type, the results are undefined.</dd>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	2032
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	2033	<dt><b><tt>ptrtoint ( CST to TYPE )</tt></b></dt>
				2034	<dd>Convert a pointer typed constant to the corresponding integer constant
				2035	TYPE must be an integer type. CST must be of pointer type. The CST value is
				2036	zero extended, truncated, or unchanged to make it fit in TYPE.</dd>
				2037
				2038	<dt><b><tt>inttoptr ( CST to TYPE )</tt></b></dt>
				2039	<dd>Convert a integer constant to a pointer constant. TYPE must be a
				2040	pointer type. CST must be of integer type. The CST value is zero extended,
				2041	truncated, or unchanged to make it fit in a pointer size. This one is
				2042	<i>really</i> dangerous!</dd>
				2043
				2044	<dt><b><tt>bitcast ( CST to TYPE )</tt></b></dt>
Chris Lattner	03bbad6	2009-02-28 18:27:03 +0000	[diff] [blame]	2045	<dd>Convert a constant, CST, to another TYPE. The constraints of the operands
				2046	are the same as those for the <a href="#i_bitcast">bitcast
				2047	instruction</a>.</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2048
				2049	<dt><b><tt>getelementptr ( CSTPTR, IDX0, IDX1, ... )</tt></b></dt>
				2050
				2051	<dd>Perform the <a href="#i_getelementptr">getelementptr operation</a> on
				2052	constants. As with the <a href="#i_getelementptr">getelementptr</a>
				2053	instruction, the index list may have zero or more indexes, which are required
				2054	to make sense for the type of "CSTPTR".</dd>
				2055
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2056	<dt><b><tt>select ( COND, VAL1, VAL2 )</tt></b></dt>
				2057
				2058	<dd>Perform the <a href="#i_select">select operation</a> on
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2059	constants.</dd>
				2060
				2061	<dt><b><tt>icmp COND ( VAL1, VAL2 )</tt></b></dt>
				2062	<dd>Performs the <a href="#i_icmp">icmp operation</a> on constants.</dd>
				2063
				2064	<dt><b><tt>fcmp COND ( VAL1, VAL2 )</tt></b></dt>
				2065	<dd>Performs the <a href="#i_fcmp">fcmp operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2066
				2067	<dt><b><tt>extractelement ( VAL, IDX )</tt></b></dt>
				2068
				2069	<dd>Perform the <a href="#i_extractelement">extractelement
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2070	operation</a> on constants.</dd>
Robert Bocchino	9fbe145	2006-01-10 19:31:34 +0000	[diff] [blame]	2071
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2072	<dt><b><tt>insertelement ( VAL, ELT, IDX )</tt></b></dt>
				2073
				2074	<dd>Perform the <a href="#i_insertelement">insertelement
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2075	operation</a> on constants.</dd>
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	2076
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2077
				2078	<dt><b><tt>shufflevector ( VEC1, VEC2, IDXMASK )</tt></b></dt>
				2079
				2080	<dd>Perform the <a href="#i_shufflevector">shufflevector
Reid Spencer	01c4259	2006-12-04 19:23:19 +0000	[diff] [blame]	2081	operation</a> on constants.</dd>
Chris Lattner	c198954	2006-04-08 00:13:41 +0000	[diff] [blame]	2082
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2083	<dt><b><tt>OPCODE ( LHS, RHS )</tt></b></dt>
				2084
Reid Spencer	2dc45b8	2004-12-09 18:13:12 +0000	[diff] [blame]	2085	<dd>Perform the specified operation of the LHS and RHS constants. OPCODE may
				2086	be any of the <a href="#binaryops">binary</a> or <a href="#bitwiseops">bitwise
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2087	binary</a> operations. The constraints on operands are the same as those for
				2088	the corresponding instruction (e.g. no bitwise operations on floating point
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2089	values are allowed).</dd>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2090	</dl>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2091	</div>
Chris Lattner	9ee5d22	2004-03-08 16:49:10 +0000	[diff] [blame]	2092
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2093	<!-- ======================================================================= -->
				2094	<div class="doc_subsection"><a name="metadata">Embedded Metadata</a>
				2095	</div>
				2096
				2097	<div class="doc_text">
				2098
				2099	<p>Embedded metadata provides a way to attach arbitrary data to the
				2100	instruction stream without affecting the behaviour of the program. There are
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2101	two metadata primitives, strings and nodes. All metadata has the
				2102	<tt>metadata</tt> type and is identified in syntax by a preceding exclamation
				2103	point ('<tt>!</tt>').
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2104	</p>
				2105
				2106	<p>A metadata string is a string surrounded by double quotes. It can contain
				2107	any character by escaping non-printable characters with "\xx" where "xx" is
				2108	the two digit hex code. For example: "<tt>!"test\00"</tt>".
				2109	</p>
				2110
				2111	<p>Metadata nodes are represented with notation similar to structure constants
				2112	(a comma separated list of elements, surrounded by braces and preceeded by an
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2113	exclamation point). For example: "<tt>!{ metadata !"test\00", i32 10}</tt>".
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2114	</p>
				2115
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2116	<p>A metadata node will attempt to track changes to the values it holds. In
				2117	the event that a value is deleted, it will be replaced with a typeless
Nick Lewycky	7a0370f	2009-05-30 05:06:04 +0000	[diff] [blame]	2118	"<tt>null</tt>", such as "<tt>metadata !{null, i32 10}</tt>".</p>
Nick Lewycky	cb33799	2009-05-10 20:57:05 +0000	[diff] [blame]	2119
Nick Lewycky	21cc446	2009-04-04 07:22:01 +0000	[diff] [blame]	2120	<p>Optimizations may rely on metadata to provide additional information about
				2121	the program that isn't available in the instructions, or that isn't easily
				2122	computable. Similarly, the code generator may expect a certain metadata format
				2123	to be used to express debugging information.</p>
				2124	</div>
				2125
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2126	<!-- *********************************************************************** -->
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2127	<div class="doc_section"> <a name="othervalues">Other Values</a> </div>
				2128	<!-- *********************************************************************** -->
				2129
				2130	<!-- ======================================================================= -->
				2131	<div class="doc_subsection">
				2132	<a name="inlineasm">Inline Assembler Expressions</a>
				2133	</div>
				2134
				2135	<div class="doc_text">
				2136
				2137	<p>
				2138	LLVM supports inline assembler expressions (as opposed to <a href="#moduleasm">
				2139	Module-Level Inline Assembly</a>) through the use of a special value. This
				2140	value represents the inline assembler as a string (containing the instructions
				2141	to emit), a list of operand constraints (stored as a string), and a flag that
				2142	indicates whether or not the inline asm expression has side effects. An example
				2143	inline assembler expression is:
				2144	</p>
				2145
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2146	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2147	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2148	i32 (i32) asm "bswap $0", "=r,r"
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2149	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2150	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2151
				2152	<p>
				2153	Inline assembler expressions may <b>only</b> be used as the callee operand of
				2154	a <a href="#i_call"><tt>call</tt> instruction</a>. Thus, typically we have:
				2155	</p>
				2156
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2157	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2158	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2159	%X = call i32 asm "<a href="#int_bswap">bswap</a> $0", "=r,r"(i32 %Y)
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2160	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2161	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2162
				2163	<p>
				2164	Inline asms with side effects not visible in the constraint list must be marked
				2165	as having side effects. This is done through the use of the
				2166	'<tt>sideeffect</tt>' keyword, like so:
				2167	</p>
				2168
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2169	<div class="doc_code">
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2170	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2171	call void asm sideeffect "eieio", ""()
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2172	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	2173	</div>
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2174
				2175	<p>TODO: The format of the asm and constraints string still need to be
				2176	documented here. Constraints on what can be done (e.g. duplication, moving, etc
Chris Lattner	4f99335	2008-10-04 18:36:02 +0000	[diff] [blame]	2177	need to be documented). This is probably best done by reference to another
				2178	document that covers inline asm from a holistic perspective.
Chris Lattner	e87d653	2006-01-25 23:47:57 +0000	[diff] [blame]	2179	</p>
				2180
				2181	</div>
				2182
				2183	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2184	<div class="doc_section"> <a name="instref">Instruction Reference</a> </div>
				2185	<!-- *********************************************************************** -->
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2186
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2187	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2188
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2189	<p>The LLVM instruction set consists of several different
				2190	classifications of instructions: <a href="#terminators">terminator
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	2191	instructions</a>, <a href="#binaryops">binary instructions</a>,
				2192	<a href="#bitwiseops">bitwise binary instructions</a>, <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2193	href="#memoryops">memory instructions</a>, and <a href="#otherops">other
				2194	instructions</a>.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2195
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2196	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2197
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2198	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2199	<div class="doc_subsection"> <a name="terminators">Terminator
				2200	Instructions</a> </div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2201
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2202	<div class="doc_text">
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2203
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2204	<p>As mentioned <a href="#functionstructure">previously</a>, every
				2205	basic block in a program ends with a "Terminator" instruction, which
				2206	indicates which block should be executed after the current block is
				2207	finished. These terminator instructions typically yield a '<tt>void</tt>'
				2208	value: they produce control flow, not values (the one exception being
				2209	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction).</p>
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2210	<p>There are six different terminator instructions: the '<a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2211	href="#i_ret"><tt>ret</tt></a>' instruction, the '<a href="#i_br"><tt>br</tt></a>'
				2212	instruction, the '<a href="#i_switch"><tt>switch</tt></a>' instruction,
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2213	the '<a href="#i_invoke"><tt>invoke</tt></a>' instruction, the '<a
				2214	href="#i_unwind"><tt>unwind</tt></a>' instruction, and the '<a
				2215	href="#i_unreachable"><tt>unreachable</tt></a>' instruction.</p>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2216
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2217	</div>
Chris Lattner	c3f5976	2004-12-09 17:30:23 +0000	[diff] [blame]	2218
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2219	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2220	<div class="doc_subsubsection"> <a name="i_ret">'<tt>ret</tt>'
				2221	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2222	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2223	<h5>Syntax:</h5>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2224	<pre>
				2225	ret <type> <value> <i>; Return a value from a non-void function</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2226	ret void <i>; Return from void function</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2227	</pre>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2228
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2229	<h5>Overview:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2230
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2231	<p>The '<tt>ret</tt>' instruction is used to return control flow (and
				2232	optionally a value) from a function back to the caller.</p>
John Criswell	4457dc9	2004-04-09 16:48:45 +0000	[diff] [blame]	2233	<p>There are two forms of the '<tt>ret</tt>' instruction: one that
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2234	returns a value and then causes control flow, and one that just causes
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2235	control flow to occur.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2236
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2237	<h5>Arguments:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2238
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	2239	<p>The '<tt>ret</tt>' instruction optionally accepts a single argument,
				2240	the return value. The type of the return value must be a
				2241	'<a href="#t_firstclass">first class</a>' type.</p>
				2242
				2243	<p>A function is not <a href="#wellformed">well formed</a> if
				2244	it it has a non-void return type and contains a '<tt>ret</tt>'
				2245	instruction with no return value or a return value with a type that
				2246	does not match its type, or if it has a void return type and contains
				2247	a '<tt>ret</tt>' instruction with a return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2248
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2249	<h5>Semantics:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2250
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2251	<p>When the '<tt>ret</tt>' instruction is executed, control flow
				2252	returns back to the calling function's context. If the caller is a "<a
John Criswell	fa08187	2004-06-25 15:16:57 +0000	[diff] [blame]	2253	href="#i_call"><tt>call</tt></a>" instruction, execution continues at
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2254	the instruction after the call. If the caller was an "<a
				2255	href="#i_invoke"><tt>invoke</tt></a>" instruction, execution continues
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2256	at the beginning of the "normal" destination block. If the instruction
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2257	returns a value, that value shall set the call or invoke instruction's
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2258	return value.</p>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2259
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2260	<h5>Example:</h5>
Chris Lattner	f4cde4e	2008-04-23 04:59:35 +0000	[diff] [blame]	2261
				2262	<pre>
				2263	ret i32 5 <i>; Return an integer value of 5</i>
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	2264	ret void <i>; Return from a void function</i>
Bill Wendling	0a4bbbf	2009-02-28 22:12:54 +0000	[diff] [blame]	2265	ret { i32, i8 } { i32 4, i8 2 } <i>; Return a struct of values 4 and 2</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2266	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2267
Dan Gohman	d8791e5	2009-01-24 15:58:40 +0000	[diff] [blame]	2268	<p>Note that the code generator does not yet fully support large
				2269	return values. The specific sizes that are currently supported are
				2270	dependent on the target. For integers, on 32-bit targets the limit
				2271	is often 64 bits, and on 64-bit targets the limit is often 128 bits.
				2272	For aggregate types, the current limits are dependent on the element
				2273	types; for example targets are often limited to 2 total integer
				2274	elements and 2 total floating-point elements.</p>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	2275
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2276	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2277	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2278	<div class="doc_subsubsection"> <a name="i_br">'<tt>br</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2279	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2280	<h5>Syntax:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2281	<pre> br i1 <cond>, label <iftrue>, label <iffalse><br> br label <dest> <i>; Unconditional branch</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2282	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2283	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2284	<p>The '<tt>br</tt>' instruction is used to cause control flow to
				2285	transfer to a different basic block in the current function. There are
				2286	two forms of this instruction, corresponding to a conditional branch
				2287	and an unconditional branch.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2288	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2289	<p>The conditional branch form of the '<tt>br</tt>' instruction takes a
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2290	single '<tt>i1</tt>' value and two '<tt>label</tt>' values. The
Reid Spencer	de15194	2007-02-19 23:54:10 +0000	[diff] [blame]	2291	unconditional form of the '<tt>br</tt>' instruction takes a single
				2292	'<tt>label</tt>' value as a target.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2293	<h5>Semantics:</h5>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2294	<p>Upon execution of a conditional '<tt>br</tt>' instruction, the '<tt>i1</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2295	argument is evaluated. If the value is <tt>true</tt>, control flows
				2296	to the '<tt>iftrue</tt>' <tt>label</tt> argument. If "cond" is <tt>false</tt>,
				2297	control flows to the '<tt>iffalse</tt>' <tt>label</tt> argument.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2298	<h5>Example:</h5>
Chris Lattner	60150a3	2009-05-09 18:11:50 +0000	[diff] [blame]	2299	<pre>Test:<br> %cond = <a href="#i_icmp">icmp</a> eq i32 %a, %b<br> br i1 %cond, label %IfEqual, label %IfUnequal<br>IfEqual:<br> <a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2300	href="#i_ret">ret</a> i32 1<br>IfUnequal:<br> <a href="#i_ret">ret</a> i32 0<br></pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2301	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2302	<!-- _______________________________________________________________________ -->
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2303	<div class="doc_subsubsection">
				2304	<a name="i_switch">'<tt>switch</tt>' Instruction</a>
				2305	</div>
				2306
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2307	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2308	<h5>Syntax:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2309
				2310	<pre>
				2311	switch <intty> <value>, label <defaultdest> [ <intty> <val>, label <dest> ... ]
				2312	</pre>
				2313
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2314	<h5>Overview:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2315
				2316	<p>The '<tt>switch</tt>' instruction is used to transfer control flow to one of
				2317	several different places. It is a generalization of the '<tt>br</tt>'
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2318	instruction, allowing a branch to occur to one of many possible
				2319	destinations.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2320
				2321
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2322	<h5>Arguments:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2323
				2324	<p>The '<tt>switch</tt>' instruction uses three parameters: an integer
				2325	comparison value '<tt>value</tt>', a default '<tt>label</tt>' destination, and
				2326	an array of pairs of comparison value constants and '<tt>label</tt>'s. The
				2327	table is not allowed to contain duplicate constant entries.</p>
				2328
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2329	<h5>Semantics:</h5>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2330
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2331	<p>The <tt>switch</tt> instruction specifies a table of values and
				2332	destinations. When the '<tt>switch</tt>' instruction is executed, this
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2333	table is searched for the given value. If the value is found, control flow is
				2334	transfered to the corresponding destination; otherwise, control flow is
				2335	transfered to the default destination.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2336
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2337	<h5>Implementation:</h5>
				2338
				2339	<p>Depending on properties of the target machine and the particular
				2340	<tt>switch</tt> instruction, this instruction may be code generated in different
John Criswell	8411475	2004-06-25 16:05:06 +0000	[diff] [blame]	2341	ways. For example, it could be generated as a series of chained conditional
				2342	branches or with a lookup table.</p>
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2343
				2344	<h5>Example:</h5>
				2345
				2346	<pre>
				2347	<i>; Emulate a conditional br instruction</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	2348	%Val = <a href="#i_zext">zext</a> i1 %value to i32
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2349	switch i32 %Val, label %truedest [ i32 0, label %falsedest ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2350
				2351	<i>; Emulate an unconditional br instruction</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2352	switch i32 0, label %dest [ ]
Chris Lattner	c88c17b	2004-02-24 04:54:45 +0000	[diff] [blame]	2353
				2354	<i>; Implement a jump table:</i>
Dan Gohman	2a08c53	2009-01-04 23:44:43 +0000	[diff] [blame]	2355	switch i32 %val, label %otherwise [ i32 0, label %onzero
				2356	i32 1, label %onone
				2357	i32 2, label %ontwo ]
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2358	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2359	</div>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2360
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2361	<!-- _______________________________________________________________________ -->
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2362	<div class="doc_subsubsection">
				2363	<a name="i_invoke">'<tt>invoke</tt>' Instruction</a>
				2364	</div>
				2365
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2366	<div class="doc_text">
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2367
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2368	<h5>Syntax:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2369
				2370	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2371	<result> = invoke [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ptr to function ty> <function ptr val>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	76b8a33	2006-05-14 18:23:06 +0000	[diff] [blame]	2372	to label <normal label> unwind label <exception label>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2373	</pre>
				2374
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	2375	<h5>Overview:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2376
				2377	<p>The '<tt>invoke</tt>' instruction causes control to transfer to a specified
				2378	function, with the possibility of control flow transfer to either the
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2379	'<tt>normal</tt>' label or the
				2380	'<tt>exception</tt>' label. If the callee function returns with the
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2381	"<tt><a href="#i_ret">ret</a></tt>" instruction, control flow will return to the
				2382	"normal" label. If the callee (or any indirect callees) returns with the "<a
John Criswell	e4c57cc	2005-05-12 16:52:32 +0000	[diff] [blame]	2383	href="#i_unwind"><tt>unwind</tt></a>" instruction, control is interrupted and
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	2384	continued at the dynamically nearest "exception" label.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2385
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2386	<h5>Arguments:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2387
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2388	<p>This instruction requires several arguments:</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2389
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2390	<ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2391	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	2392	The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2393	convention</a> the call should use. If none is specified, the call defaults
				2394	to using C calling conventions.
				2395	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2396
				2397	<li>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				2398	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				2399	and '<tt>inreg</tt>' attributes are valid here.</li>
				2400
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2401	<li>'<tt>ptr to function ty</tt>': shall be the signature of the pointer to
				2402	function value being invoked. In most cases, this is a direct function
				2403	invocation, but indirect <tt>invoke</tt>s are just as possible, branching off
				2404	an arbitrary pointer to function value.
				2405	</li>
				2406
				2407	<li>'<tt>function ptr val</tt>': An LLVM value containing a pointer to a
				2408	function to be invoked. </li>
				2409
				2410	<li>'<tt>function args</tt>': argument list whose types match the function
				2411	signature argument types. If the function signature indicates the function
				2412	accepts a variable number of arguments, the extra arguments can be
				2413	specified. </li>
				2414
				2415	<li>'<tt>normal label</tt>': the label reached when the called function
				2416	executes a '<tt><a href="#i_ret">ret</a></tt>' instruction. </li>
				2417
				2418	<li>'<tt>exception label</tt>': the label reached when a callee returns with
				2419	the <a href="#i_unwind"><tt>unwind</tt></a> instruction. </li>
				2420
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	2421	<li>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	2422	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				2423	'<tt>readnone</tt>' attributes are valid here.</li>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2424	</ol>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2425
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2426	<h5>Semantics:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2427
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2428	<p>This instruction is designed to operate as a standard '<tt><a
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2429	href="#i_call">call</a></tt>' instruction in most regards. The primary
				2430	difference is that it establishes an association with a label, which is used by
				2431	the runtime library to unwind the stack.</p>
				2432
				2433	<p>This instruction is used in languages with destructors to ensure that proper
				2434	cleanup is performed in the case of either a <tt>longjmp</tt> or a thrown
				2435	exception. Additionally, this is important for implementation of
				2436	'<tt>catch</tt>' clauses in high-level languages that support them.</p>
				2437
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	2438	<p>For the purposes of the SSA form, the definition of the value
				2439	returned by the '<tt>invoke</tt>' instruction is deemed to occur on
				2440	the edge from the current block to the "normal" label. If the callee
				2441	unwinds then no return value is available.</p>
Dan Gohman	f96a499	2009-05-22 21:47:08 +0000	[diff] [blame]	2442
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2443	<h5>Example:</h5>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	2444	<pre>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2445	%retval = invoke i32 @Test(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2446	unwind label %TestCleanup <i>; {i32}:retval set</i>
Nick Lewycky	d703f65	2008-03-16 07:18:12 +0000	[diff] [blame]	2447	%retval = invoke <a href="#callingconv">coldcc</a> i32 %Testfnptr(i32 15) to label %Continue
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2448	unwind label %TestCleanup <i>; {i32}:retval set</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2449	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2450	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2451
				2452
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2453	<!-- _______________________________________________________________________ -->
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2454
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2455	<div class="doc_subsubsection"> <a name="i_unwind">'<tt>unwind</tt>'
				2456	Instruction</a> </div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2457
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2458	<div class="doc_text">
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2459
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2460	<h5>Syntax:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2461	<pre>
				2462	unwind
				2463	</pre>
				2464
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2465	<h5>Overview:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2466
				2467	<p>The '<tt>unwind</tt>' instruction unwinds the stack, continuing control flow
				2468	at the first callee in the dynamic call stack which used an <a
				2469	href="#i_invoke"><tt>invoke</tt></a> instruction to perform the call. This is
				2470	primarily used to implement exception handling.</p>
				2471
Chris Lattner	27f71f2	2003-09-03 00:41:47 +0000	[diff] [blame]	2472	<h5>Semantics:</h5>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2473
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	2474	<p>The '<tt>unwind</tt>' instruction causes execution of the current function to
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2475	immediately halt. The dynamic call stack is then searched for the first <a
				2476	href="#i_invoke"><tt>invoke</tt></a> instruction on the call stack. Once found,
				2477	execution continues at the "exceptional" destination block specified by the
				2478	<tt>invoke</tt> instruction. If there is no <tt>invoke</tt> instruction in the
				2479	dynamic call chain, undefined behavior results.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2480	</div>
Chris Lattner	35eca58	2004-10-16 18:04:13 +0000	[diff] [blame]	2481
				2482	<!-- _______________________________________________________________________ -->
				2483
				2484	<div class="doc_subsubsection"> <a name="i_unreachable">'<tt>unreachable</tt>'
				2485	Instruction</a> </div>
				2486
				2487	<div class="doc_text">
				2488
				2489	<h5>Syntax:</h5>
				2490	<pre>
				2491	unreachable
				2492	</pre>
				2493
				2494	<h5>Overview:</h5>
				2495
				2496	<p>The '<tt>unreachable</tt>' instruction has no defined semantics. This
				2497	instruction is used to inform the optimizer that a particular portion of the
				2498	code is not reachable. This can be used to indicate that the code after a
				2499	no-return function cannot be reached, and other facts.</p>
				2500
				2501	<h5>Semantics:</h5>
				2502
				2503	<p>The '<tt>unreachable</tt>' instruction has no defined semantics.</p>
				2504	</div>
				2505
				2506
				2507
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2508	<!-- ======================================================================= -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2509	<div class="doc_subsection"> <a name="binaryops">Binary Operations</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2510	<div class="doc_text">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2511	<p>Binary operators are used to do most of the computation in a
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2512	program. They require two operands of the same type, execute an operation on them, and
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	2513	produce a single value. The operands might represent
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	2514	multiple data, as is the case with the <a href="#t_vector">vector</a> data type.
Chris Lattner	5a15814	2008-04-01 18:47:32 +0000	[diff] [blame]	2515	The result value has the same type as its operands.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2516	<p>There are several different binary operators:</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2517	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2518	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2519	<div class="doc_subsubsection">
				2520	<a name="i_add">'<tt>add</tt>' Instruction</a>
				2521	</div>
				2522
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2523	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2524
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2525	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2526
				2527	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2528	<result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2529	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2530
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2531	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2532
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2533	<p>The '<tt>add</tt>' instruction returns the sum of its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2534
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2535	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2536
				2537	<p>The two arguments to the '<tt>add</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2538	href="#t_integer">integer</a> or
				2539	<a href="#t_vector">vector</a> of integer values. Both arguments must
				2540	have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2541
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2542	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2543
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2544	<p>The value produced is the integer sum of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2545
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2546	<p>If the sum has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2547	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2548	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2549
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2550	<p>Because LLVM integers use a two's complement representation, this
				2551	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2552
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2553	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2554
				2555	<pre>
				2556	<result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2557	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2558	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2559	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2560	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2561	<a name="i_fadd">'<tt>fadd</tt>' Instruction</a>
				2562	</div>
				2563
				2564	<div class="doc_text">
				2565
				2566	<h5>Syntax:</h5>
				2567
				2568	<pre>
				2569	<result> = fadd <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2570	</pre>
				2571
				2572	<h5>Overview:</h5>
				2573
				2574	<p>The '<tt>fadd</tt>' instruction returns the sum of its two operands.</p>
				2575
				2576	<h5>Arguments:</h5>
				2577
				2578	<p>The two arguments to the '<tt>fadd</tt>' instruction must be
				2579	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a> of
				2580	floating point values. Both arguments must have identical types.</p>
				2581
				2582	<h5>Semantics:</h5>
				2583
				2584	<p>The value produced is the floating point sum of the two operands.</p>
				2585
				2586	<h5>Example:</h5>
				2587
				2588	<pre>
				2589	<result> = fadd float 4.0, %var <i>; yields {float}:result = 4.0 + %var</i>
				2590	</pre>
				2591	</div>
				2592	<!-- _______________________________________________________________________ -->
				2593	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2594	<a name="i_sub">'<tt>sub</tt>' Instruction</a>
				2595	</div>
				2596
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2597	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2598
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2599	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2600
				2601	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2602	<result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2603	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2604
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2605	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2606
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2607	<p>The '<tt>sub</tt>' instruction returns the difference of its two
				2608	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2609
				2610	<p>Note that the '<tt>sub</tt>' instruction is used to represent the
				2611	'<tt>neg</tt>' instruction present in most other intermediate
				2612	representations.</p>
				2613
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2614	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2615
				2616	<p>The two arguments to the '<tt>sub</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2617	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of
				2618	integer values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2619
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2620	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2621
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2622	<p>The value produced is the integer difference of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2623
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2624	<p>If the difference has unsigned overflow, the result returned is the
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2625	mathematical result modulo 2<sup>n</sup>, where n is the bit width of
				2626	the result.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2627
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2628	<p>Because LLVM integers use a two's complement representation, this
				2629	instruction is appropriate for both signed and unsigned integers.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2630
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2631	<h5>Example:</h5>
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	2632	<pre>
				2633	<result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2634	<result> = sub i32 0, %val <i>; yields {i32}:result = -%var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2635	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2636	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2637
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2638	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2639	<div class="doc_subsubsection">
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2640	<a name="i_fsub">'<tt>fsub</tt>' Instruction</a>
				2641	</div>
				2642
				2643	<div class="doc_text">
				2644
				2645	<h5>Syntax:</h5>
				2646
				2647	<pre>
				2648	<result> = fsub <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2649	</pre>
				2650
				2651	<h5>Overview:</h5>
				2652
				2653	<p>The '<tt>fsub</tt>' instruction returns the difference of its two
				2654	operands.</p>
				2655
				2656	<p>Note that the '<tt>fsub</tt>' instruction is used to represent the
				2657	'<tt>fneg</tt>' instruction present in most other intermediate
				2658	representations.</p>
				2659
				2660	<h5>Arguments:</h5>
				2661
				2662	<p>The two arguments to the '<tt>fsub</tt>' instruction must be <a
				2663	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2664	of floating point values. Both arguments must have identical types.</p>
				2665
				2666	<h5>Semantics:</h5>
				2667
				2668	<p>The value produced is the floating point difference of the two operands.</p>
				2669
				2670	<h5>Example:</h5>
				2671	<pre>
				2672	<result> = fsub float 4.0, %var <i>; yields {float}:result = 4.0 - %var</i>
				2673	<result> = fsub float -0.0, %val <i>; yields {float}:result = -%var</i>
				2674	</pre>
				2675	</div>
				2676
				2677	<!-- _______________________________________________________________________ -->
				2678	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2679	<a name="i_mul">'<tt>mul</tt>' Instruction</a>
				2680	</div>
				2681
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2682	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2683
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2684	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2685	<pre> <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2686	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2687	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2688	<p>The '<tt>mul</tt>' instruction returns the product of its two
				2689	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2690
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2691	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2692
				2693	<p>The two arguments to the '<tt>mul</tt>' instruction must be <a
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2694	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2695	values. Both arguments must have identical types.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2696
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2697	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2698
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2699	<p>The value produced is the integer product of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2700
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2701	<p>If the result of the multiplication has unsigned overflow,
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2702	the result returned is the mathematical result modulo
				2703	2<sup>n</sup>, where n is the bit width of the result.</p>
				2704	<p>Because LLVM integers use a two's complement representation, and the
				2705	result is the same width as the operands, this instruction returns the
				2706	correct result for both signed and unsigned integers. If a full product
				2707	(e.g. <tt>i32</tt>x<tt>i32</tt>-><tt>i64</tt>) is needed, the operands
				2708	should be sign-extended or zero-extended as appropriate to the
				2709	width of the full product.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2710	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2711	<pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2712	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2713	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2714
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2715	<!-- _______________________________________________________________________ -->
Dan Gohman	ae3a0be	2009-06-04 22:49:04 +0000	[diff] [blame]	2716	<div class="doc_subsubsection">
				2717	<a name="i_fmul">'<tt>fmul</tt>' Instruction</a>
				2718	</div>
				2719
				2720	<div class="doc_text">
				2721
				2722	<h5>Syntax:</h5>
				2723	<pre> <result> = fmul <ty> <op1>, <op2> <i>; yields {ty}:result</i>
				2724	</pre>
				2725	<h5>Overview:</h5>
				2726	<p>The '<tt>fmul</tt>' instruction returns the product of its two
				2727	operands.</p>
				2728
				2729	<h5>Arguments:</h5>
				2730
				2731	<p>The two arguments to the '<tt>fmul</tt>' instruction must be
				2732	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2733	of floating point values. Both arguments must have identical types.</p>
				2734
				2735	<h5>Semantics:</h5>
				2736
				2737	<p>The value produced is the floating point product of the two operands.</p>
				2738
				2739	<h5>Example:</h5>
				2740	<pre> <result> = fmul float 4.0, %var <i>; yields {float}:result = 4.0 * %var</i>
				2741	</pre>
				2742	</div>
				2743
				2744	<!-- _______________________________________________________________________ -->
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2745	<div class="doc_subsubsection"> <a name="i_udiv">'<tt>udiv</tt>' Instruction
				2746	</a></div>
				2747	<div class="doc_text">
				2748	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2749	<pre> <result> = udiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2750	</pre>
				2751	<h5>Overview:</h5>
				2752	<p>The '<tt>udiv</tt>' instruction returns the quotient of its two
				2753	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2754
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2755	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2756
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2757	<p>The two arguments to the '<tt>udiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2758	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2759	values. Both arguments must have identical types.</p>
				2760
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2761	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2762
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2763	<p>The value produced is the unsigned integer quotient of the two operands.</p>
				2764	<p>Note that unsigned integer division and signed integer division are distinct
				2765	operations; for signed integer division, use '<tt>sdiv</tt>'.</p>
				2766	<p>Division by zero leads to undefined behavior.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2767	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2768	<pre> <result> = udiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2769	</pre>
				2770	</div>
				2771	<!-- _______________________________________________________________________ -->
				2772	<div class="doc_subsubsection"> <a name="i_sdiv">'<tt>sdiv</tt>' Instruction
				2773	</a> </div>
				2774	<div class="doc_text">
				2775	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2776	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2777	<result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2778	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2779
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2780	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2781
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2782	<p>The '<tt>sdiv</tt>' instruction returns the quotient of its two
				2783	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2784
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2785	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2786
				2787	<p>The two arguments to the '<tt>sdiv</tt>' instruction must be
				2788	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2789	values. Both arguments must have identical types.</p>
				2790
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2791	<h5>Semantics:</h5>
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2792	<p>The value produced is the signed integer quotient of the two operands rounded towards zero.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2793	<p>Note that signed integer division and unsigned integer division are distinct
				2794	operations; for unsigned integer division, use '<tt>udiv</tt>'.</p>
				2795	<p>Division by zero leads to undefined behavior. Overflow also leads to
				2796	undefined behavior; this is a rare case, but can occur, for example,
				2797	by doing a 32-bit division of -2147483648 by -1.</p>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2798	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2799	<pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i>
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2800	</pre>
				2801	</div>
				2802	<!-- _______________________________________________________________________ -->
				2803	<div class="doc_subsubsection"> <a name="i_fdiv">'<tt>fdiv</tt>'
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2804	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2805	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	2806	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2807	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2808	<result> = fdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2809	</pre>
				2810	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2811
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2812	<p>The '<tt>fdiv</tt>' instruction returns the quotient of its two
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2813	operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2814
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2815	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2816
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2817	<p>The two arguments to the '<tt>fdiv</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2818	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2819	of floating point values. Both arguments must have identical types.</p>
				2820
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2821	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2822
Reid Spencer	1628cec	2006-10-26 06:15:43 +0000	[diff] [blame]	2823	<p>The value produced is the floating point quotient of the two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2824
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2825	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2826
				2827	<pre>
				2828	<result> = fdiv float 4.0, %var <i>; yields {float}:result = 4.0 / %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2829	</pre>
				2830	</div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2831
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2832	<!-- _______________________________________________________________________ -->
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2833	<div class="doc_subsubsection"> <a name="i_urem">'<tt>urem</tt>' Instruction</a>
				2834	</div>
				2835	<div class="doc_text">
				2836	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2837	<pre> <result> = urem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2838	</pre>
				2839	<h5>Overview:</h5>
				2840	<p>The '<tt>urem</tt>' instruction returns the remainder from the
				2841	unsigned division of its two arguments.</p>
				2842	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2843	<p>The two arguments to the '<tt>urem</tt>' instruction must be
				2844	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2845	values. Both arguments must have identical types.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2846	<h5>Semantics:</h5>
				2847	<p>This instruction returns the unsigned integer <i>remainder</i> of a division.
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2848	This instruction always performs an unsigned division to get the remainder.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2849	<p>Note that unsigned integer remainder and signed integer remainder are
				2850	distinct operations; for signed integer remainder, use '<tt>srem</tt>'.</p>
				2851	<p>Taking the remainder of a division by zero leads to undefined behavior.</p>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2852	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2853	<pre> <result> = urem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2854	</pre>
				2855
				2856	</div>
				2857	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2858	<div class="doc_subsubsection">
				2859	<a name="i_srem">'<tt>srem</tt>' Instruction</a>
				2860	</div>
				2861
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2862	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2863
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2864	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2865
				2866	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2867	<result> = srem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2868	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2869
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2870	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2871
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2872	<p>The '<tt>srem</tt>' instruction returns the remainder from the
Dan Gohman	8017631	2007-11-05 23:35:22 +0000	[diff] [blame]	2873	signed division of its two operands. This instruction can also take
				2874	<a href="#t_vector">vector</a> versions of the values in which case
				2875	the elements must be integers.</p>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	2876
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2877	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2878
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2879	<p>The two arguments to the '<tt>srem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2880	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				2881	values. Both arguments must have identical types.</p>
				2882
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2883	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2884
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2885	<p>This instruction returns the <i>remainder</i> of a division (where the result
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2886	has the same sign as the dividend, <tt>op1</tt>), not the <i>modulo</i>
				2887	operator (where the result has the same sign as the divisor, <tt>op2</tt>) of
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2888	a value. For more information about the difference, see <a
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2889	href="http://mathforum.org/dr.math/problems/anne.4.28.99.html">The
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2890	Math Forum</a>. For a table of how this is implemented in various languages,
Reid Spencer	64f5c6c	2007-03-24 22:40:44 +0000	[diff] [blame]	2891	please see <a href="http://en.wikipedia.org/wiki/Modulo_operation">
Reid Spencer	c9fdfc8	2007-03-24 22:23:39 +0000	[diff] [blame]	2892	Wikipedia: modulo operation</a>.</p>
Chris Lattner	5ec8983	2008-01-28 00:36:27 +0000	[diff] [blame]	2893	<p>Note that signed integer remainder and unsigned integer remainder are
				2894	distinct operations; for unsigned integer remainder, use '<tt>urem</tt>'.</p>
				2895	<p>Taking the remainder of a division by zero leads to undefined behavior.
				2896	Overflow also leads to undefined behavior; this is a rare case, but can occur,
				2897	for example, by taking the remainder of a 32-bit division of -2147483648 by -1.
				2898	(The remainder doesn't actually overflow, but this rule lets srem be
				2899	implemented using instructions that return both the result of the division
				2900	and the remainder.)</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2901	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	2902	<pre> <result> = srem i32 4, %var <i>; yields {i32}:result = 4 % %var</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2903	</pre>
				2904
				2905	</div>
				2906	<!-- _______________________________________________________________________ -->
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2907	<div class="doc_subsubsection">
				2908	<a name="i_frem">'<tt>frem</tt>' Instruction</a> </div>
				2909
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2910	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2911
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2912	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2913	<pre> <result> = frem <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2914	</pre>
				2915	<h5>Overview:</h5>
				2916	<p>The '<tt>frem</tt>' instruction returns the remainder from the
				2917	division of its two operands.</p>
				2918	<h5>Arguments:</h5>
				2919	<p>The two arguments to the '<tt>frem</tt>' instruction must be
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2920	<a href="#t_floating">floating point</a> or <a href="#t_vector">vector</a>
				2921	of floating point values. Both arguments must have identical types.</p>
				2922
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2923	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2924
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2925	<p>This instruction returns the <i>remainder</i> of a division.
				2926	The remainder has the same sign as the dividend.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2927
Reid Spencer	0a783f7	2006-11-02 01:53:59 +0000	[diff] [blame]	2928	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	2929
				2930	<pre>
				2931	<result> = frem float 4.0, %var <i>; yields {float}:result = 4.0 % %var</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	2932	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	2933	</div>
Robert Bocchino	7b81c75	2006-02-17 21:18:08 +0000	[diff] [blame]	2934
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2935	<!-- ======================================================================= -->
				2936	<div class="doc_subsection"> <a name="bitwiseops">Bitwise Binary
				2937	Operations</a> </div>
				2938	<div class="doc_text">
				2939	<p>Bitwise binary operators are used to do various forms of
				2940	bit-twiddling in a program. They are generally very efficient
				2941	instructions and can commonly be strength reduced from other
Chris Lattner	a73afe0	2008-04-01 18:45:27 +0000	[diff] [blame]	2942	instructions. They require two operands of the same type, execute an operation on them,
				2943	and produce a single value. The resulting value is the same type as its operands.</p>
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	2944	</div>
				2945
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2946	<!-- _______________________________________________________________________ -->
				2947	<div class="doc_subsubsection"> <a name="i_shl">'<tt>shl</tt>'
				2948	Instruction</a> </div>
				2949	<div class="doc_text">
				2950	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2951	<pre> <result> = shl <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2952	</pre>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2953
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2954	<h5>Overview:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2955
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2956	<p>The '<tt>shl</tt>' instruction returns the first operand shifted to
				2957	the left a specified number of bits.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2958
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2959	<h5>Arguments:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2960
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2961	<p>Both arguments to the '<tt>shl</tt>' instruction must be the same <a
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2962	href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2963	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2964
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2965	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2966
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2967	<p>The value produced is <tt>op1</tt> * 2<sup><tt>op2</tt></sup> mod 2<sup>n</sup>,
				2968	where n is the width of the result. If <tt>op2</tt> is (statically or dynamically) negative or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	2969	equal to or larger than the number of bits in <tt>op1</tt>, the result is undefined.
				2970	If the arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				2971	corresponding shift amount in <tt>op2</tt>.</p>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2972
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2973	<h5>Example:</h5><pre>
				2974	<result> = shl i32 4, %var <i>; yields {i32}: 4 << %var</i>
				2975	<result> = shl i32 4, 2 <i>; yields {i32}: 16</i>
				2976	<result> = shl i32 1, 10 <i>; yields {i32}: 1024</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2977	<result> = shl i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	2978	<result> = shl <2 x i32> < i32 1, i32 1>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 2, i32 4></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2979	</pre>
				2980	</div>
				2981	<!-- _______________________________________________________________________ -->
				2982	<div class="doc_subsubsection"> <a name="i_lshr">'<tt>lshr</tt>'
				2983	Instruction</a> </div>
				2984	<div class="doc_text">
				2985	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2986	<pre> <result> = lshr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2987	</pre>
				2988
				2989	<h5>Overview:</h5>
				2990	<p>The '<tt>lshr</tt>' instruction (logical shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	2991	operand shifted to the right a specified number of bits with zero fill.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2992
				2993	<h5>Arguments:</h5>
				2994	<p>Both arguments to the '<tt>lshr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	2995	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	2996	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	2997
				2998	<h5>Semantics:</h5>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	2999
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3000	<p>This instruction always performs a logical shift right operation. The most
				3001	significant bits of the result will be filled with zero bits after the
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3002	shift. If <tt>op2</tt> is (statically or dynamically) equal to or larger than
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	3003	the number of bits in <tt>op1</tt>, the result is undefined. If the arguments are
				3004	vectors, each vector element of <tt>op1</tt> is shifted by the corresponding shift
				3005	amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3006
				3007	<h5>Example:</h5>
				3008	<pre>
				3009	<result> = lshr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3010	<result> = lshr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3011	<result> = lshr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3012	<result> = lshr i8 -2, 1 <i>; yields {i8}:result = 0x7FFFFFFF </i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3013	<result> = lshr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3014	<result> = lshr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 2> <i>; yields: result=<2 x i32> < i32 0x7FFFFFFF, i32 1></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3015	</pre>
				3016	</div>
				3017
Reid Spencer	8e11bf8	2007-02-02 13:57:07 +0000	[diff] [blame]	3018	<!-- _______________________________________________________________________ -->
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3019	<div class="doc_subsubsection"> <a name="i_ashr">'<tt>ashr</tt>'
				3020	Instruction</a> </div>
				3021	<div class="doc_text">
				3022
				3023	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3024	<pre> <result> = ashr <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3025	</pre>
				3026
				3027	<h5>Overview:</h5>
				3028	<p>The '<tt>ashr</tt>' instruction (arithmetic shift right) returns the first
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3029	operand shifted to the right a specified number of bits with sign extension.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3030
				3031	<h5>Arguments:</h5>
				3032	<p>Both arguments to the '<tt>ashr</tt>' instruction must be the same
Nate Begeman	5bc1ea0	2008-07-29 15:49:41 +0000	[diff] [blame]	3033	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3034	type. '<tt>op2</tt>' is treated as an unsigned value.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3035
				3036	<h5>Semantics:</h5>
				3037	<p>This instruction always performs an arithmetic shift right operation,
				3038	The most significant bits of the result will be filled with the sign bit
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3039	of <tt>op1</tt>. If <tt>op2</tt> is (statically or dynamically) equal to or
Mon P Wang	01f8d09	2008-12-10 08:55:09 +0000	[diff] [blame]	3040	larger than the number of bits in <tt>op1</tt>, the result is undefined. If the
				3041	arguments are vectors, each vector element of <tt>op1</tt> is shifted by the
				3042	corresponding shift amount in <tt>op2</tt>.</p>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3043
				3044	<h5>Example:</h5>
				3045	<pre>
				3046	<result> = ashr i32 4, 1 <i>; yields {i32}:result = 2</i>
				3047	<result> = ashr i32 4, 2 <i>; yields {i32}:result = 1</i>
				3048	<result> = ashr i8 4, 3 <i>; yields {i8}:result = 0</i>
				3049	<result> = ashr i8 -2, 1 <i>; yields {i8}:result = -1</i>
Chris Lattner	6ccc2d5	2007-10-03 21:01:14 +0000	[diff] [blame]	3050	<result> = ashr i32 1, 32 <i>; undefined</i>
Mon P Wang	e9f1015	2008-12-09 05:46:39 +0000	[diff] [blame]	3051	<result> = ashr <2 x i32> < i32 -2, i32 4>, < i32 1, i32 3> <i>; yields: result=<2 x i32> < i32 -1, i32 0></i>
Reid Spencer	569f2fa	2007-01-31 21:39:12 +0000	[diff] [blame]	3052	</pre>
				3053	</div>
				3054
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3055	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3056	<div class="doc_subsubsection"> <a name="i_and">'<tt>and</tt>'
				3057	Instruction</a> </div>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3058
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3059	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3060
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3061	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3062
				3063	<pre>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3064	<result> = and <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3065	</pre>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3066
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3067	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3068
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3069	<p>The '<tt>and</tt>' instruction returns the bitwise logical and of
				3070	its two operands.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3071
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3072	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3073
				3074	<p>The two arguments to the '<tt>and</tt>' instruction must be
				3075	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3076	values. Both arguments must have identical types.</p>
				3077
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3078	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3079	<p>The truth table used for the '<tt>and</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3080	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3081	<div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3082	<table border="1" cellspacing="0" cellpadding="4">
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3083	<tbody>
				3084	<tr>
				3085	<td>In0</td>
				3086	<td>In1</td>
				3087	<td>Out</td>
				3088	</tr>
				3089	<tr>
				3090	<td>0</td>
				3091	<td>0</td>
				3092	<td>0</td>
				3093	</tr>
				3094	<tr>
				3095	<td>0</td>
				3096	<td>1</td>
				3097	<td>0</td>
				3098	</tr>
				3099	<tr>
				3100	<td>1</td>
				3101	<td>0</td>
				3102	<td>0</td>
				3103	</tr>
				3104	<tr>
				3105	<td>1</td>
				3106	<td>1</td>
				3107	<td>1</td>
				3108	</tr>
				3109	</tbody>
				3110	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3111	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3112	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3113	<pre>
				3114	<result> = and i32 4, %var <i>; yields {i32}:result = 4 & %var</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3115	<result> = and i32 15, 40 <i>; yields {i32}:result = 8</i>
				3116	<result> = and i32 4, 8 <i>; yields {i32}:result = 0</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3117	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3118	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3119	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3120	<div class="doc_subsubsection"> <a name="i_or">'<tt>or</tt>' Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3121	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3122	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3123	<pre> <result> = or <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3124	</pre>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3125	<h5>Overview:</h5>
				3126	<p>The '<tt>or</tt>' instruction returns the bitwise logical inclusive
				3127	or of its two operands.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3128	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3129
				3130	<p>The two arguments to the '<tt>or</tt>' instruction must be
				3131	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3132	values. Both arguments must have identical types.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3133	<h5>Semantics:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3134	<p>The truth table used for the '<tt>or</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3135	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3136	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3137	<table border="1" cellspacing="0" cellpadding="4">
				3138	<tbody>
				3139	<tr>
				3140	<td>In0</td>
				3141	<td>In1</td>
				3142	<td>Out</td>
				3143	</tr>
				3144	<tr>
				3145	<td>0</td>
				3146	<td>0</td>
				3147	<td>0</td>
				3148	</tr>
				3149	<tr>
				3150	<td>0</td>
				3151	<td>1</td>
				3152	<td>1</td>
				3153	</tr>
				3154	<tr>
				3155	<td>1</td>
				3156	<td>0</td>
				3157	<td>1</td>
				3158	</tr>
				3159	<tr>
				3160	<td>1</td>
				3161	<td>1</td>
				3162	<td>1</td>
				3163	</tr>
				3164	</tbody>
				3165	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3166	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3167	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3168	<pre> <result> = or i32 4, %var <i>; yields {i32}:result = 4 \| %var</i>
				3169	<result> = or i32 15, 40 <i>; yields {i32}:result = 47</i>
				3170	<result> = or i32 4, 8 <i>; yields {i32}:result = 12</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3171	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3172	</div>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3173	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3174	<div class="doc_subsubsection"> <a name="i_xor">'<tt>xor</tt>'
				3175	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3176	<div class="doc_text">
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3177	<h5>Syntax:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	3178	<pre> <result> = xor <ty> <op1>, <op2> <i>; yields {ty}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3179	</pre>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3180	<h5>Overview:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3181	<p>The '<tt>xor</tt>' instruction returns the bitwise logical exclusive
				3182	or of its two operands. The <tt>xor</tt> is used to implement the
				3183	"one's complement" operation, which is the "~" operator in C.</p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3184	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3185	<p>The two arguments to the '<tt>xor</tt>' instruction must be
				3186	<a href="#t_integer">integer</a> or <a href="#t_vector">vector</a> of integer
				3187	values. Both arguments must have identical types.</p>
				3188
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3189	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	3190
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3191	<p>The truth table used for the '<tt>xor</tt>' instruction is:</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3192	<p> </p>
Bill Wendling	c7e4c4d	2008-09-07 10:29:20 +0000	[diff] [blame]	3193	<div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3194	<table border="1" cellspacing="0" cellpadding="4">
				3195	<tbody>
				3196	<tr>
				3197	<td>In0</td>
				3198	<td>In1</td>
				3199	<td>Out</td>
				3200	</tr>
				3201	<tr>
				3202	<td>0</td>
				3203	<td>0</td>
				3204	<td>0</td>
				3205	</tr>
				3206	<tr>
				3207	<td>0</td>
				3208	<td>1</td>
				3209	<td>1</td>
				3210	</tr>
				3211	<tr>
				3212	<td>1</td>
				3213	<td>0</td>
				3214	<td>1</td>
				3215	</tr>
				3216	<tr>
				3217	<td>1</td>
				3218	<td>1</td>
				3219	<td>0</td>
				3220	</tr>
				3221	</tbody>
				3222	</table>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	3223	</div>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3224	<p> </p>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3225	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3226	<pre> <result> = xor i32 4, %var <i>; yields {i32}:result = 4 ^ %var</i>
				3227	<result> = xor i32 15, 40 <i>; yields {i32}:result = 39</i>
				3228	<result> = xor i32 4, 8 <i>; yields {i32}:result = 12</i>
				3229	<result> = xor i32 %V, -1 <i>; yields {i32}:result = ~%V</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3230	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3231	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3232
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3233	<!-- ======================================================================= -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3234	<div class="doc_subsection">
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3235	<a name="vectorops">Vector Operations</a>
				3236	</div>
				3237
				3238	<div class="doc_text">
				3239
				3240	<p>LLVM supports several instructions to represent vector operations in a
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3241	target-independent manner. These instructions cover the element-access and
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3242	vector-specific operations needed to process vectors effectively. While LLVM
				3243	does directly support these vector operations, many sophisticated algorithms
				3244	will want to use target-specific intrinsics to take full advantage of a specific
				3245	target.</p>
				3246
				3247	</div>
				3248
				3249	<!-- _______________________________________________________________________ -->
				3250	<div class="doc_subsubsection">
				3251	<a name="i_extractelement">'<tt>extractelement</tt>' Instruction</a>
				3252	</div>
				3253
				3254	<div class="doc_text">
				3255
				3256	<h5>Syntax:</h5>
				3257
				3258	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3259	<result> = extractelement <n x <ty>> <val>, i32 <idx> <i>; yields <ty></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3260	</pre>
				3261
				3262	<h5>Overview:</h5>
				3263
				3264	<p>
				3265	The '<tt>extractelement</tt>' instruction extracts a single scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3266	element from a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3267	</p>
				3268
				3269
				3270	<h5>Arguments:</h5>
				3271
				3272	<p>
				3273	The first operand of an '<tt>extractelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3274	value of <a href="#t_vector">vector</a> type. The second operand is
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3275	an index indicating the position from which to extract the element.
				3276	The index may be a variable.</p>
				3277
				3278	<h5>Semantics:</h5>
				3279
				3280	<p>
				3281	The result is a scalar of the same type as the element type of
				3282	<tt>val</tt>. Its value is the value at position <tt>idx</tt> of
				3283	<tt>val</tt>. If <tt>idx</tt> exceeds the length of <tt>val</tt>, the
				3284	results are undefined.
				3285	</p>
				3286
				3287	<h5>Example:</h5>
				3288
				3289	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3290	%result = extractelement <4 x i32> %vec, i32 0 <i>; yields i32</i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3291	</pre>
				3292	</div>
				3293
				3294
				3295	<!-- _______________________________________________________________________ -->
				3296	<div class="doc_subsubsection">
				3297	<a name="i_insertelement">'<tt>insertelement</tt>' Instruction</a>
				3298	</div>
				3299
				3300	<div class="doc_text">
				3301
				3302	<h5>Syntax:</h5>
				3303
				3304	<pre>
Dan Gohman	f3480b9	2008-05-12 23:38:42 +0000	[diff] [blame]	3305	<result> = insertelement <n x <ty>> <val>, <ty> <elt>, i32 <idx> <i>; yields <n x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3306	</pre>
				3307
				3308	<h5>Overview:</h5>
				3309
				3310	<p>
				3311	The '<tt>insertelement</tt>' instruction inserts a scalar
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3312	element into a vector at a specified index.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3313	</p>
				3314
				3315
				3316	<h5>Arguments:</h5>
				3317
				3318	<p>
				3319	The first operand of an '<tt>insertelement</tt>' instruction is a
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3320	value of <a href="#t_vector">vector</a> type. The second operand is a
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3321	scalar value whose type must equal the element type of the first
				3322	operand. The third operand is an index indicating the position at
				3323	which to insert the value. The index may be a variable.</p>
				3324
				3325	<h5>Semantics:</h5>
				3326
				3327	<p>
Reid Spencer	485bad1	2007-02-15 03:07:05 +0000	[diff] [blame]	3328	The result is a vector of the same type as <tt>val</tt>. Its
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3329	element values are those of <tt>val</tt> except at position
				3330	<tt>idx</tt>, where it gets the value <tt>elt</tt>. If <tt>idx</tt>
				3331	exceeds the length of <tt>val</tt>, the results are undefined.
				3332	</p>
				3333
				3334	<h5>Example:</h5>
				3335
				3336	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3337	%result = insertelement <4 x i32> %vec, i32 1, i32 0 <i>; yields <4 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3338	</pre>
				3339	</div>
				3340
				3341	<!-- _______________________________________________________________________ -->
				3342	<div class="doc_subsubsection">
				3343	<a name="i_shufflevector">'<tt>shufflevector</tt>' Instruction</a>
				3344	</div>
				3345
				3346	<div class="doc_text">
				3347
				3348	<h5>Syntax:</h5>
				3349
				3350	<pre>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3351	<result> = shufflevector <n x <ty>> <v1>, <n x <ty>> <v2>, <m x i32> <mask> <i>; yields <m x <ty>></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3352	</pre>
				3353
				3354	<h5>Overview:</h5>
				3355
				3356	<p>
				3357	The '<tt>shufflevector</tt>' instruction constructs a permutation of elements
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3358	from two input vectors, returning a vector with the same element type as
				3359	the input and length that is the same as the shuffle mask.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3360	</p>
				3361
				3362	<h5>Arguments:</h5>
				3363
				3364	<p>
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3365	The first two operands of a '<tt>shufflevector</tt>' instruction are vectors
				3366	with types that match each other. The third argument is a shuffle mask whose
				3367	element type is always 'i32'. The result of the instruction is a vector whose
				3368	length is the same as the shuffle mask and whose element type is the same as
				3369	the element type of the first two operands.
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3370	</p>
				3371
				3372	<p>
				3373	The shuffle mask operand is required to be a constant vector with either
				3374	constant integer or undef values.
				3375	</p>
				3376
				3377	<h5>Semantics:</h5>
				3378
				3379	<p>
				3380	The elements of the two input vectors are numbered from left to right across
				3381	both of the vectors. The shuffle mask operand specifies, for each element of
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3382	the result vector, which element of the two input vectors the result element
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3383	gets. The element selector may be undef (meaning "don't care") and the second
				3384	operand may be undef if performing a shuffle from only one vector.
				3385	</p>
				3386
				3387	<h5>Example:</h5>
				3388
				3389	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3390	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3391	<4 x i32> <i32 0, i32 4, i32 1, i32 5> <i>; yields <4 x i32></i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3392	%result = shufflevector <4 x i32> %v1, <4 x i32> undef,
				3393	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i> - Identity shuffle.
Mon P Wang	aeb06d2	2008-11-10 04:46:22 +0000	[diff] [blame]	3394	%result = shufflevector <8 x i32> %v1, <8 x i32> undef,
				3395	<4 x i32> <i32 0, i32 1, i32 2, i32 3> <i>; yields <4 x i32></i>
				3396	%result = shufflevector <4 x i32> %v1, <4 x i32> %v2,
				3397	<8 x i32> <i32 0, i32 1, i32 2, i32 3, i32 4, i32 5, i32 6, i32 7 > <i>; yields <8 x i32></i>
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3398	</pre>
				3399	</div>
				3400
Tanya Lattner	0947429	2006-04-14 19:24:33 +0000	[diff] [blame]	3401
Chris Lattner	3df241e	2006-04-08 23:07:04 +0000	[diff] [blame]	3402	<!-- ======================================================================= -->
				3403	<div class="doc_subsection">
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3404	<a name="aggregateops">Aggregate Operations</a>
				3405	</div>
				3406
				3407	<div class="doc_text">
				3408
				3409	<p>LLVM supports several instructions for working with aggregate values.
				3410	</p>
				3411
				3412	</div>
				3413
				3414	<!-- _______________________________________________________________________ -->
				3415	<div class="doc_subsubsection">
				3416	<a name="i_extractvalue">'<tt>extractvalue</tt>' Instruction</a>
				3417	</div>
				3418
				3419	<div class="doc_text">
				3420
				3421	<h5>Syntax:</h5>
				3422
				3423	<pre>
				3424	<result> = extractvalue <aggregate type> <val>, <idx>{, <idx>}*
				3425	</pre>
				3426
				3427	<h5>Overview:</h5>
				3428
				3429	<p>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3430	The '<tt>extractvalue</tt>' instruction extracts the value of a struct field
				3431	or array element from an aggregate value.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3432	</p>
				3433
				3434
				3435	<h5>Arguments:</h5>
				3436
				3437	<p>
				3438	The first operand of an '<tt>extractvalue</tt>' instruction is a
				3439	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a>
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3440	type. The operands are constant indices to specify which value to extract
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3441	in a similar manner as indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3442	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3443	</p>
				3444
				3445	<h5>Semantics:</h5>
				3446
				3447	<p>
				3448	The result is the value at the position in the aggregate specified by
				3449	the index operands.
				3450	</p>
				3451
				3452	<h5>Example:</h5>
				3453
				3454	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3455	%result = extractvalue {i32, float} %agg, 0 <i>; yields i32</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3456	</pre>
				3457	</div>
				3458
				3459
				3460	<!-- _______________________________________________________________________ -->
				3461	<div class="doc_subsubsection">
				3462	<a name="i_insertvalue">'<tt>insertvalue</tt>' Instruction</a>
				3463	</div>
				3464
				3465	<div class="doc_text">
				3466
				3467	<h5>Syntax:</h5>
				3468
				3469	<pre>
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3470	<result> = insertvalue <aggregate type> <val>, <ty> <val>, <idx> <i>; yields <n x <ty>></i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3471	</pre>
				3472
				3473	<h5>Overview:</h5>
				3474
				3475	<p>
				3476	The '<tt>insertvalue</tt>' instruction inserts a value
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3477	into a struct field or array element in an aggregate.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3478	</p>
				3479
				3480
				3481	<h5>Arguments:</h5>
				3482
				3483	<p>
				3484	The first operand of an '<tt>insertvalue</tt>' instruction is a
				3485	value of <a href="#t_struct">struct</a> or <a href="#t_array">array</a> type.
				3486	The second operand is a first-class value to insert.
Dan Gohman	c4b49eb	2008-05-23 21:53:15 +0000	[diff] [blame]	3487	The following operands are constant indices
Dan Gohman	81a0c0b	2008-05-31 00:58:22 +0000	[diff] [blame]	3488	indicating the position at which to insert the value in a similar manner as
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3489	indices in a
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3490	'<tt><a href="#i_getelementptr">getelementptr</a></tt>' instruction.
				3491	The value to insert must have the same type as the value identified
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3492	by the indices.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3493	</p>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3494
				3495	<h5>Semantics:</h5>
				3496
				3497	<p>
				3498	The result is an aggregate of the same type as <tt>val</tt>. Its
				3499	value is that of <tt>val</tt> except that the value at the position
Dan Gohman	c3dac5c	2008-05-13 18:16:06 +0000	[diff] [blame]	3500	specified by the indices is that of <tt>elt</tt>.
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3501	</p>
				3502
				3503	<h5>Example:</h5>
				3504
				3505	<pre>
Dan Gohman	52bb2db	2008-06-23 15:26:37 +0000	[diff] [blame]	3506	%result = insertvalue {i32, float} %agg, i32 1, 0 <i>; yields {i32, float}</i>
Dan Gohman	a334d5f	2008-05-12 23:51:09 +0000	[diff] [blame]	3507	</pre>
				3508	</div>
				3509
				3510
				3511	<!-- ======================================================================= -->
				3512	<div class="doc_subsection">
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3513	<a name="memoryops">Memory Access and Addressing Operations</a>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3514	</div>
				3515
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3516	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3517
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3518	<p>A key design point of an SSA-based representation is how it
				3519	represents memory. In LLVM, no memory locations are in SSA form, which
				3520	makes things very simple. This section describes how to read, write,
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3521	allocate, and free memory in LLVM.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3522
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3523	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3524
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3525	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3526	<div class="doc_subsubsection">
				3527	<a name="i_malloc">'<tt>malloc</tt>' Instruction</a>
				3528	</div>
				3529
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3530	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3531
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3532	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3533
				3534	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3535	<result> = malloc <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3536	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3537
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3538	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3539
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3540	<p>The '<tt>malloc</tt>' instruction allocates memory from the system
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3541	heap and returns a pointer to it. The object is always allocated in the generic
				3542	address space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3543
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3544	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3545
				3546	<p>The '<tt>malloc</tt>' instruction allocates
				3547	<tt>sizeof(<type>)*NumElements</tt>
John Criswell	6e4ca61	2004-02-24 16:13:56 +0000	[diff] [blame]	3548	bytes of memory from the operating system and returns a pointer of the
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3549	appropriate type to the program. If "NumElements" is specified, it is the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3550	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3551	If a constant alignment is specified, the value result of the allocation is
				3552	guaranteed to be aligned to at least that boundary. If not specified, or if
				3553	zero, the target can choose to align the allocation on any convenient boundary
				3554	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3555
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3556	<p>'<tt>type</tt>' must be a sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3557
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3558	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3559
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3560	<p>Memory is allocated using the system "<tt>malloc</tt>" function, and
Nick Lewycky	02ff308	2008-11-24 03:41:24 +0000	[diff] [blame]	3561	a pointer is returned. The result of a zero byte allocation is undefined. The
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3562	result is null if there is insufficient memory available.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3563
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3564	<h5>Example:</h5>
				3565
				3566	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3567	%array = malloc [4 x i8] <i>; yields {[%4 x i8]*}:array</i>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3568
Bill Wendling	aac388b	2007-05-29 09:42:13 +0000	[diff] [blame]	3569	%size = <a href="#i_add">add</a> i32 2, 2 <i>; yields {i32}:size = i32 4</i>
				3570	%array1 = malloc i8, i32 4 <i>; yields {i8*}:array1</i>
				3571	%array2 = malloc [12 x i8], i32 %size <i>; yields {[12 x i8]*}:array2</i>
				3572	%array3 = malloc i32, i32 4, align 1024 <i>; yields {i32*}:array3</i>
				3573	%array4 = malloc i32, align 1024 <i>; yields {i32*}:array4</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3574	</pre>
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	3575
				3576	<p>Note that the code generator does not yet respect the
				3577	alignment value.</p>
				3578
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3579	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3580
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3581	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3582	<div class="doc_subsubsection">
				3583	<a name="i_free">'<tt>free</tt>' Instruction</a>
				3584	</div>
				3585
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3586	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3587
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3588	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3589
				3590	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3591	free <type> <value> <i>; yields {void}</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3592	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3593
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3594	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3595
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3596	<p>The '<tt>free</tt>' instruction returns memory back to the unused
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3597	memory heap to be reallocated in the future.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3598
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3599	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3600
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3601	<p>'<tt>value</tt>' shall be a pointer value that points to a value
				3602	that was allocated with the '<tt><a href="#i_malloc">malloc</a></tt>'
				3603	instruction.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3604
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3605	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3606
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3607	<p>Access to the memory pointed to by the pointer is no longer defined
Chris Lattner	e0db56d	2008-04-19 22:41:32 +0000	[diff] [blame]	3608	after this instruction executes. If the pointer is null, the operation
				3609	is a noop.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3610
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3611	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3612
				3613	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3614	%array = <a href="#i_malloc">malloc</a> [4 x i8] <i>; yields {[4 x i8]*}:array</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3615	free [4 x i8]* %array
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3616	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3617	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3618
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3619	<!-- _______________________________________________________________________ -->
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3620	<div class="doc_subsubsection">
				3621	<a name="i_alloca">'<tt>alloca</tt>' Instruction</a>
				3622	</div>
				3623
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3624	<div class="doc_text">
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3625
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3626	<h5>Syntax:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3627
				3628	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3629	<result> = alloca <type>[, i32 <NumElements>][, align <alignment>] <i>; yields {type*}:result</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3630	</pre>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3631
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3632	<h5>Overview:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3633
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3634	<p>The '<tt>alloca</tt>' instruction allocates memory on the stack frame of the
				3635	currently executing function, to be automatically released when this function
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	3636	returns to its caller. The object is always allocated in the generic address
				3637	space (address space zero).</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3638
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3639	<h5>Arguments:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3640
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	3641	<p>The '<tt>alloca</tt>' instruction allocates <tt>sizeof(<type>)*NumElements</tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3642	bytes of memory on the runtime stack, returning a pointer of the
Gabor Greif	1acd2ee	2008-02-09 22:24:34 +0000	[diff] [blame]	3643	appropriate type to the program. If "NumElements" is specified, it is the
				3644	number of elements allocated, otherwise "NumElements" is defaulted to be one.
Duncan Sands	434ca80	2009-06-20 13:26:06 +0000	[diff] [blame]	3645	If a constant alignment is specified, the value result of the allocation is
				3646	guaranteed to be aligned to at least that boundary. If not specified, or if
				3647	zero, the target can choose to align the allocation on any convenient boundary
				3648	compatible with the type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3649
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3650	<p>'<tt>type</tt>' may be any sized type.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3651
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3652	<h5>Semantics:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3653
Bill Wendling	871eb0a	2009-05-08 20:49:29 +0000	[diff] [blame]	3654	<p>Memory is allocated; a pointer is returned. The operation is undefined if
Chris Lattner	72ed200	2008-04-19 21:01:16 +0000	[diff] [blame]	3655	there is insufficient stack space for the allocation. '<tt>alloca</tt>'d
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3656	memory is automatically released when the function returns. The '<tt>alloca</tt>'
				3657	instruction is commonly used to represent automatic variables that must
				3658	have an address available. When the function returns (either with the <tt><a
John Criswell	dae2e93	2005-05-12 16:55:34 +0000	[diff] [blame]	3659	href="#i_ret">ret</a></tt> or <tt><a href="#i_unwind">unwind</a></tt>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3660	instructions), the memory is reclaimed. Allocating zero bytes
				3661	is legal, but the result is undefined.</p>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3662
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3663	<h5>Example:</h5>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3664
				3665	<pre>
Dan Gohman	81e2167	2009-01-04 23:49:44 +0000	[diff] [blame]	3666	%ptr = alloca i32 <i>; yields {i32*}:ptr</i>
				3667	%ptr = alloca i32, i32 4 <i>; yields {i32*}:ptr</i>
				3668	%ptr = alloca i32, i32 4, align 1024 <i>; yields {i32*}:ptr</i>
				3669	%ptr = alloca i32, align 1024 <i>; yields {i32*}:ptr</i>
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3670	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3671	</div>
Chris Lattner	2cbdc45	2005-11-06 08:02:57 +0000	[diff] [blame]	3672
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3673	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3674	<div class="doc_subsubsection"> <a name="i_load">'<tt>load</tt>'
				3675	Instruction</a> </div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3676	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3677	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3678	<pre> <result> = load <ty>* <pointer>[, align <alignment>]<br> <result> = volatile load <ty>* <pointer>[, align <alignment>]<br></pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3679	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3680	<p>The '<tt>load</tt>' instruction is used to read from memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3681	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3682	<p>The argument to the '<tt>load</tt>' instruction specifies the memory
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3683	address from which to load. The pointer must point to a <a
Chris Lattner	e53e508	2004-06-03 22:57:15 +0000	[diff] [blame]	3684	href="#t_firstclass">first class</a> type. If the <tt>load</tt> is
John Criswell	0ec250c	2005-10-24 16:17:18 +0000	[diff] [blame]	3685	marked as <tt>volatile</tt>, then the optimizer is not allowed to modify
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3686	the number or order of execution of this <tt>load</tt> with other
				3687	volatile <tt>load</tt> and <tt><a href="#i_store">store</a></tt>
				3688	instructions. </p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3689	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3690	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3691	(that is, the alignment of the memory address). A value of 0 or an
				3692	omitted "align" argument means that the operation has the preferential
				3693	alignment for the target. It is the responsibility of the code emitter
				3694	to ensure that the alignment information is correct. Overestimating
				3695	the alignment results in an undefined behavior. Underestimating the
				3696	alignment may produce less efficient code. An alignment of 1 is always
				3697	safe.
				3698	</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3699	<h5>Semantics:</h5>
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3700	<p>The location of memory pointed to is loaded. If the value being loaded
				3701	is of scalar type then the number of bytes read does not exceed the minimum
				3702	number of bytes needed to hold all bits of the type. For example, loading an
				3703	<tt>i24</tt> reads at most three bytes. When loading a value of a type like
				3704	<tt>i20</tt> with a size that is not an integral number of bytes, the result
				3705	is undefined if the value was not originally written using a store of the
				3706	same type.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3707	<h5>Examples:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3708	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3709	<a
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3710	href="#i_store">store</a> i32 3, i32* %ptr <i>; yields {void}</i>
				3711	%val = load i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3712	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3713	</div>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3714	<!-- _______________________________________________________________________ -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3715	<div class="doc_subsubsection"> <a name="i_store">'<tt>store</tt>'
				3716	Instruction</a> </div>
Reid Spencer	035ab57	2006-11-09 21:18:01 +0000	[diff] [blame]	3717	<div class="doc_text">
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3718	<h5>Syntax:</h5>
Christopher Lamb	2330e4d	2007-04-21 08:16:25 +0000	[diff] [blame]	3719	<pre> store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
				3720	volatile store <ty> <value>, <ty>* <pointer>[, align <alignment>] <i>; yields {void}</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3721	</pre>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3722	<h5>Overview:</h5>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3723	<p>The '<tt>store</tt>' instruction is used to write to memory.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3724	<h5>Arguments:</h5>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3725	<p>There are two arguments to the '<tt>store</tt>' instruction: a value
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3726	to store and an address at which to store it. The type of the '<tt><pointer></tt>'
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3727	operand must be a pointer to the <a href="#t_firstclass">first class</a> type
				3728	of the '<tt><value></tt>'
John Criswell	c1f786c	2005-05-13 22:25:59 +0000	[diff] [blame]	3729	operand. If the <tt>store</tt> is marked as <tt>volatile</tt>, then the
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3730	optimizer is not allowed to modify the number or order of execution of
				3731	this <tt>store</tt> with other volatile <tt>load</tt> and <tt><a
				3732	href="#i_store">store</a></tt> instructions.</p>
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3733	<p>
Chris Lattner	4316dec	2008-04-02 00:38:26 +0000	[diff] [blame]	3734	The optional constant "align" argument specifies the alignment of the operation
Chris Lattner	a31d1d7	2008-01-06 21:04:43 +0000	[diff] [blame]	3735	(that is, the alignment of the memory address). A value of 0 or an
				3736	omitted "align" argument means that the operation has the preferential
				3737	alignment for the target. It is the responsibility of the code emitter
				3738	to ensure that the alignment information is correct. Overestimating
				3739	the alignment results in an undefined behavior. Underestimating the
				3740	alignment may produce less efficient code. An alignment of 1 is always
				3741	safe.
				3742	</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3743	<h5>Semantics:</h5>
				3744	<p>The contents of memory are updated to contain '<tt><value></tt>'
Duncan Sands	19527c6	2009-03-22 11:33:16 +0000	[diff] [blame]	3745	at the location specified by the '<tt><pointer></tt>' operand.
				3746	If '<tt><value></tt>' is of scalar type then the number of bytes
				3747	written does not exceed the minimum number of bytes needed to hold all
				3748	bits of the type. For example, storing an <tt>i24</tt> writes at most
				3749	three bytes. When writing a value of a type like <tt>i20</tt> with a
				3750	size that is not an integral number of bytes, it is unspecified what
				3751	happens to the extra bits that do not belong to the type, but they will
				3752	typically be overwritten.</p>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3753	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3754	<pre> %ptr = <a href="#i_alloca">alloca</a> i32 <i>; yields {i32*}:ptr</i>
Bill Wendling	8c6c72d	2007-10-22 05:10:05 +0000	[diff] [blame]	3755	store i32 3, i32* %ptr <i>; yields {void}</i>
				3756	%val = <a href="#i_load">load</a> i32* %ptr <i>; yields {i32}:val = i32 3</i>
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3757	</pre>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3758	</div>
				3759
Chris Lattner	2b7d320	2002-05-06 03:03:22 +0000	[diff] [blame]	3760	<!-- _______________________________________________________________________ -->
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3761	<div class="doc_subsubsection">
				3762	<a name="i_getelementptr">'<tt>getelementptr</tt>' Instruction</a>
				3763	</div>
				3764
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3765	<div class="doc_text">
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3766	<h5>Syntax:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3767	<pre>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3768	<result> = getelementptr <pty>* <ptrval>{, <ty> <idx>}*
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3769	</pre>
				3770
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3771	<h5>Overview:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3772
				3773	<p>
				3774	The '<tt>getelementptr</tt>' instruction is used to get the address of a
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3775	subelement of an aggregate data structure. It performs address calculation only
				3776	and does not access memory.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3777
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3778	<h5>Arguments:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3779
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3780	<p>The first argument is always a pointer, and forms the basis of the
				3781	calculation. The remaining arguments are indices, that indicate which of the
				3782	elements of the aggregate object are indexed. The interpretation of each index
				3783	is dependent on the type being indexed into. The first index always indexes the
				3784	pointer value given as the first argument, the second index indexes a value of
				3785	the type pointed to (not necessarily the value directly pointed to, since the
				3786	first index can be non-zero), etc. The first type indexed into must be a pointer
				3787	value, subsequent types can be arrays, vectors and structs. Note that subsequent
				3788	types being indexed into can never be pointers, since that would require loading
				3789	the pointer before continuing calculation.</p>
				3790
				3791	<p>The type of each index argument depends on the type it is indexing into.
				3792	When indexing into a (packed) structure, only <tt>i32</tt> integer
				3793	<b>constants</b> are allowed. When indexing into an array, pointer or vector,
Sanjiv Gupta	23c70f4	2009-04-27 03:21:00 +0000	[diff] [blame]	3794	integers of any width are allowed (also non-constants).</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3795
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3796	<p>For example, let's consider a C code fragment and how it gets
				3797	compiled to LLVM:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3798
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3799	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3800	<pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3801	struct RT {
				3802	char A;
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3803	int B[10][20];
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3804	char C;
				3805	};
				3806	struct ST {
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3807	int X;
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3808	double Y;
				3809	struct RT Z;
				3810	};
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3811
Chris Lattner	cabc846	2007-05-29 15:43:56 +0000	[diff] [blame]	3812	int foo(struct ST s) {
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3813	return &s[1].Z.B[5][13];
				3814	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3815	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3816	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3817
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3818	<p>The LLVM code generated by the GCC frontend is:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3819
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3820	<div class="doc_code">
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3821	<pre>
Chris Lattner	e7886e4	2009-01-11 20:53:49 +0000	[diff] [blame]	3822	%RT = <a href="#namedtypes">type</a> { i8 , [10 x [20 x i32]], i8 }
				3823	%ST = <a href="#namedtypes">type</a> { i32, double, %RT }
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3824
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3825	define i32* %foo(%ST* %s) {
				3826	entry:
				3827	%reg = getelementptr %ST* %s, i32 1, i32 2, i32 1, i32 5, i32 13
				3828	ret i32* %reg
				3829	}
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3830	</pre>
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	3831	</div>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3832
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3833	<h5>Semantics:</h5>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3834
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3835	<p>In the example above, the first index is indexing into the '<tt>%ST*</tt>'
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3836	type, which is a pointer, yielding a '<tt>%ST</tt>' = '<tt>{ i32, double, %RT
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3837	}</tt>' type, a structure. The second index indexes into the third element of
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3838	the structure, yielding a '<tt>%RT</tt>' = '<tt>{ i8 , [10 x [20 x i32]],
				3839	i8 }</tt>' type, another structure. The third index indexes into the second
				3840	element of the structure, yielding a '<tt>[10 x [20 x i32]]</tt>' type, an
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3841	array. The two dimensions of the array are subscripted into, yielding an
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3842	'<tt>i32</tt>' type. The '<tt>getelementptr</tt>' instruction returns a pointer
				3843	to this element, thus computing a value of '<tt>i32*</tt>' type.</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3844
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	3845	<p>Note that it is perfectly legal to index partially through a
				3846	structure, returning a pointer to an inner element. Because of this,
				3847	the LLVM code for the given testcase is equivalent to:</p>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3848
				3849	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3850	define i32* %foo(%ST* %s) {
				3851	%t1 = getelementptr %ST* %s, i32 1 <i>; yields %ST*:%t1</i>
Jeff Cohen	6f1cc77	2007-04-22 01:17:39 +0000	[diff] [blame]	3852	%t2 = getelementptr %ST* %t1, i32 0, i32 2 <i>; yields %RT*:%t2</i>
				3853	%t3 = getelementptr %RT* %t2, i32 0, i32 1 <i>; yields [10 x [20 x i32]]*:%t3</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3854	%t4 = getelementptr [10 x [20 x i32]]* %t3, i32 0, i32 5 <i>; yields [20 x i32]*:%t4</i>
				3855	%t5 = getelementptr [20 x i32]* %t4, i32 0, i32 13 <i>; yields i32*:%t5</i>
				3856	ret i32* %t5
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3857	}
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3858	</pre>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3859
Chris Lattner	8c0e62c	2009-03-09 20:55:18 +0000	[diff] [blame]	3860	<p>Note that it is undefined to access an array out of bounds: array
				3861	and pointer indexes must always be within the defined bounds of the
				3862	array type when accessed with an instruction that dereferences the
				3863	pointer (e.g. a load or store instruction). The one exception for
				3864	this rule is zero length arrays. These arrays are defined to be
				3865	accessible as variable length arrays, which requires access beyond the
				3866	zero'th element.</p>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3867
Chris Lattner	884a970	2006-08-15 00:45:58 +0000	[diff] [blame]	3868	<p>The getelementptr instruction is often confusing. For some more insight
				3869	into how it works, see <a href="GetElementPtr.html">the getelementptr
				3870	FAQ</a>.</p>
				3871
Chris Lattner	7faa883	2002-04-14 06:13:44 +0000	[diff] [blame]	3872	<h5>Example:</h5>
Chris Lattner	e67a951	2005-06-24 17:22:57 +0000	[diff] [blame]	3873
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3874	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3875	<i>; yields [12 x i8]*:aptr</i>
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3876	%aptr = getelementptr {i32, [12 x i8]}* %saptr, i64 0, i32 1
				3877	<i>; yields i8*:vptr</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	3878	%vptr = getelementptr {i32, <2 x i8>}* %svptr, i64 0, i32 1, i32 1
Matthijs Kooijman	e49d0bc	2008-10-13 13:44:15 +0000	[diff] [blame]	3879	<i>; yields i8*:eptr</i>
				3880	%eptr = getelementptr [12 x i8]* %aptr, i64 0, i32 1
Sanjiv Gupta	9f805c2	2009-04-25 07:27:44 +0000	[diff] [blame]	3881	<i>; yields i32*:iptr</i>
Sanjiv Gupta	16ffa80	2009-04-24 16:38:13 +0000	[diff] [blame]	3882	%iptr = getelementptr [10 x i32]* @arr, i16 0, i16 0
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3883	</pre>
Chris Lattner	f74d5c7	2004-04-05 01:30:49 +0000	[diff] [blame]	3884	</div>
Reid Spencer	47ce179	2006-11-09 21:15:49 +0000	[diff] [blame]	3885
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	3886	<!-- ======================================================================= -->
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3887	<div class="doc_subsection"> <a name="convertops">Conversion Operations</a>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3888	</div>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3889	<div class="doc_text">
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	3890	<p>The instructions in this category are the conversion instructions (casting)
				3891	which all take a single operand and a type. They perform various bit conversions
				3892	on the operand.</p>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	3893	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3894
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	3895	<!-- _______________________________________________________________________ -->
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	3896	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3897	<a name="i_trunc">'<tt>trunc .. to</tt>' Instruction</a>
				3898	</div>
				3899	<div class="doc_text">
				3900
				3901	<h5>Syntax:</h5>
				3902	<pre>
				3903	<result> = trunc <ty> <value> to <ty2> <i>; yields ty2</i>
				3904	</pre>
				3905
				3906	<h5>Overview:</h5>
				3907	<p>
				3908	The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
				3909	</p>
				3910
				3911	<h5>Arguments:</h5>
				3912	<p>
				3913	The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
				3914	be an <a href="#t_integer">integer</a> type, and a type that specifies the size
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3915	and type of the result, which must be an <a href="#t_integer">integer</a>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3916	type. The bit size of <tt>value</tt> must be larger than the bit size of
				3917	<tt>ty2</tt>. Equal sized types are not allowed.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3918
				3919	<h5>Semantics:</h5>
				3920	<p>
				3921	The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3922	and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
				3923	larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
				3924	It will always truncate bits.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3925
				3926	<h5>Example:</h5>
				3927	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3928	%X = trunc i32 257 to i8 <i>; yields i8:1</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3929	%Y = trunc i32 123 to i1 <i>; yields i1:true</i>
				3930	%Y = trunc i32 122 to i1 <i>; yields i1:false</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3931	</pre>
				3932	</div>
				3933
				3934	<!-- _______________________________________________________________________ -->
				3935	<div class="doc_subsubsection">
				3936	<a name="i_zext">'<tt>zext .. to</tt>' Instruction</a>
				3937	</div>
				3938	<div class="doc_text">
				3939
				3940	<h5>Syntax:</h5>
				3941	<pre>
				3942	<result> = zext <ty> <value> to <ty2> <i>; yields ty2</i>
				3943	</pre>
				3944
				3945	<h5>Overview:</h5>
				3946	<p>The '<tt>zext</tt>' instruction zero extends its operand to type
				3947	<tt>ty2</tt>.</p>
				3948
				3949
				3950	<h5>Arguments:</h5>
				3951	<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3952	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3953	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3954	<tt>value</tt> must be smaller than the bit size of the destination type,
				3955	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3956
				3957	<h5>Semantics:</h5>
				3958	<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3959	bits until it reaches the size of the destination type, <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3960
Reid Spencer	b592952	2007-01-12 15:46:11 +0000	[diff] [blame]	3961	<p>When zero extending from i1, the result will always be either 0 or 1.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3962
				3963	<h5>Example:</h5>
				3964	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	3965	%X = zext i32 257 to i64 <i>; yields i64:257</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3966	%Y = zext i1 true to i32 <i>; yields i32:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3967	</pre>
				3968	</div>
				3969
				3970	<!-- _______________________________________________________________________ -->
				3971	<div class="doc_subsubsection">
				3972	<a name="i_sext">'<tt>sext .. to</tt>' Instruction</a>
				3973	</div>
				3974	<div class="doc_text">
				3975
				3976	<h5>Syntax:</h5>
				3977	<pre>
				3978	<result> = sext <ty> <value> to <ty2> <i>; yields ty2</i>
				3979	</pre>
				3980
				3981	<h5>Overview:</h5>
				3982	<p>The '<tt>sext</tt>' sign extends <tt>value</tt> to the type <tt>ty2</tt>.</p>
				3983
				3984	<h5>Arguments:</h5>
				3985	<p>
				3986	The '<tt>sext</tt>' instruction takes a value to cast, which must be of
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	3987	<a href="#t_integer">integer</a> type, and a type to cast it to, which must
				3988	also be of <a href="#t_integer">integer</a> type. The bit size of the
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	3989	<tt>value</tt> must be smaller than the bit size of the destination type,
				3990	<tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3991
				3992	<h5>Semantics:</h5>
				3993	<p>
				3994	The '<tt>sext</tt>' instruction performs a sign extension by copying the sign
				3995	bit (highest order bit) of the <tt>value</tt> until it reaches the bit size of
Chris Lattner	d1d2517	2007-05-24 19:13:27 +0000	[diff] [blame]	3996	the type <tt>ty2</tt>.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3997
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	3998	<p>When sign extending from i1, the extension always results in -1 or 0.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	3999
				4000	<h5>Example:</h5>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4001	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4002	%X = sext i8 -1 to i16 <i>; yields i16 :65535</i>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4003	%Y = sext i1 true to i32 <i>; yields i32:-1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4004	</pre>
				4005	</div>
				4006
				4007	<!-- _______________________________________________________________________ -->
				4008	<div class="doc_subsubsection">
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4009	<a name="i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a>
				4010	</div>
				4011
				4012	<div class="doc_text">
				4013
				4014	<h5>Syntax:</h5>
				4015
				4016	<pre>
				4017	<result> = fptrunc <ty> <value> to <ty2> <i>; yields ty2</i>
				4018	</pre>
				4019
				4020	<h5>Overview:</h5>
				4021	<p>The '<tt>fptrunc</tt>' instruction truncates <tt>value</tt> to type
				4022	<tt>ty2</tt>.</p>
				4023
				4024
				4025	<h5>Arguments:</h5>
				4026	<p>The '<tt>fptrunc</tt>' instruction takes a <a href="#t_floating">floating
				4027	point</a> value to cast and a <a href="#t_floating">floating point</a> type to
				4028	cast it to. The size of <tt>value</tt> must be larger than the size of
				4029	<tt>ty2</tt>. This implies that <tt>fptrunc</tt> cannot be used to make a
				4030	<i>no-op cast</i>.</p>
				4031
				4032	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4033	<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
				4034	<a href="#t_floating">floating point</a> type to a smaller
				4035	<a href="#t_floating">floating point</a> type. If the value cannot fit within
				4036	the destination type, <tt>ty2</tt>, then the results are undefined.</p>
Reid Spencer	3fa91b0	2006-11-09 21:48:10 +0000	[diff] [blame]	4037
				4038	<h5>Example:</h5>
				4039	<pre>
				4040	%X = fptrunc double 123.0 to float <i>; yields float:123.0</i>
				4041	%Y = fptrunc double 1.0E+300 to float <i>; yields undefined</i>
				4042	</pre>
				4043	</div>
				4044
				4045	<!-- _______________________________________________________________________ -->
				4046	<div class="doc_subsubsection">
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4047	<a name="i_fpext">'<tt>fpext .. to</tt>' Instruction</a>
				4048	</div>
				4049	<div class="doc_text">
				4050
				4051	<h5>Syntax:</h5>
				4052	<pre>
				4053	<result> = fpext <ty> <value> to <ty2> <i>; yields ty2</i>
				4054	</pre>
				4055
				4056	<h5>Overview:</h5>
				4057	<p>The '<tt>fpext</tt>' extends a floating point <tt>value</tt> to a larger
				4058	floating point value.</p>
				4059
				4060	<h5>Arguments:</h5>
				4061	<p>The '<tt>fpext</tt>' instruction takes a
				4062	<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4063	and a <a href="#t_floating">floating point</a> type to cast it to. The source
				4064	type must be smaller than the destination type.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4065
				4066	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4067	<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4068	<a href="#t_floating">floating point</a> type to a larger
				4069	<a href="#t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4070	used to make a <i>no-op cast</i> because it always changes bits. Use
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4071	<tt>bitcast</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4072
				4073	<h5>Example:</h5>
				4074	<pre>
				4075	%X = fpext float 3.1415 to double <i>; yields double:3.1415</i>
				4076	%Y = fpext float 1.0 to float <i>; yields float:1.0 (no-op)</i>
				4077	</pre>
				4078	</div>
				4079
				4080	<!-- _______________________________________________________________________ -->
				4081	<div class="doc_subsubsection">
Reid Spencer	24d6da5	2007-01-21 00:29:26 +0000	[diff] [blame]	4082	<a name="i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4083	</div>
				4084	<div class="doc_text">
				4085
				4086	<h5>Syntax:</h5>
				4087	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4088	<result> = fptoui <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4089	</pre>
				4090
				4091	<h5>Overview:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4092	<p>The '<tt>fptoui</tt>' converts a floating point <tt>value</tt> to its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4093	unsigned integer equivalent of type <tt>ty2</tt>.
				4094	</p>
				4095
				4096	<h5>Arguments:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4097	<p>The '<tt>fptoui</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4098	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4099	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4100	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4101	vector integer type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4102
				4103	<h5>Semantics:</h5>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4104	<p> The '<tt>fptoui</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4105	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4106	towards zero) unsigned integer value. If the value cannot fit in <tt>ty2</tt>,
				4107	the results are undefined.</p>
				4108
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4109	<h5>Example:</h5>
				4110	<pre>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4111	%X = fptoui double 123.0 to i32 <i>; yields i32:123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4112	%Y = fptoui float 1.0E+300 to i1 <i>; yields undefined:1</i>
Reid Spencer	1539a1c	2007-07-31 14:40:14 +0000	[diff] [blame]	4113	%X = fptoui float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4114	</pre>
				4115	</div>
				4116
				4117	<!-- _______________________________________________________________________ -->
				4118	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4119	<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4120	</div>
				4121	<div class="doc_text">
				4122
				4123	<h5>Syntax:</h5>
				4124	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4125	<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4126	</pre>
				4127
				4128	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4129	<p>The '<tt>fptosi</tt>' instruction converts
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4130	<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4131	</p>
				4132
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4133	<h5>Arguments:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4134	<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4135	scalar or vector <a href="#t_floating">floating point</a> value, and a type
				4136	to cast it to <tt>ty2</tt>, which must be an <a href="#t_integer">integer</a>
				4137	type. If <tt>ty</tt> is a vector floating point type, <tt>ty2</tt> must be a
				4138	vector integer type with the same number of elements as <tt>ty</tt></p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4139
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4140	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4141	<p>The '<tt>fptosi</tt>' instruction converts its
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4142	<a href="#t_floating">floating point</a> operand into the nearest (rounding
				4143	towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
				4144	the results are undefined.</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4145
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4146	<h5>Example:</h5>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4147	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4148	%X = fptosi double -123.0 to i32 <i>; yields i32:-123</i>
Chris Lattner	8851904	2007-09-22 03:17:52 +0000	[diff] [blame]	4149	%Y = fptosi float 1.0E-247 to i1 <i>; yields undefined:1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4150	%X = fptosi float 1.04E+17 to i8 <i>; yields undefined:1</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4151	</pre>
				4152	</div>
				4153
				4154	<!-- _______________________________________________________________________ -->
				4155	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4156	<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4157	</div>
				4158	<div class="doc_text">
				4159
				4160	<h5>Syntax:</h5>
				4161	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4162	<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4163	</pre>
				4164
				4165	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4166	<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4167	integer and converts that value to the <tt>ty2</tt> type.</p>
				4168
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4169	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4170	<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be a
				4171	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4172	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4173	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4174	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4175
				4176	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4177	<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4178	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4179	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4180
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4181	<h5>Example:</h5>
				4182	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4183	%X = uitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4184	%Y = uitofp i8 -1 to double <i>; yields double:255.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4185	</pre>
				4186	</div>
				4187
				4188	<!-- _______________________________________________________________________ -->
				4189	<div class="doc_subsubsection">
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4190	<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4191	</div>
				4192	<div class="doc_text">
				4193
				4194	<h5>Syntax:</h5>
				4195	<pre>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4196	<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4197	</pre>
				4198
				4199	<h5>Overview:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4200	<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4201	integer and converts that value to the <tt>ty2</tt> type.</p>
				4202
				4203	<h5>Arguments:</h5>
Nate Begeman	b348d18	2007-11-17 03:58:34 +0000	[diff] [blame]	4204	<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be a
				4205	scalar or vector <a href="#t_integer">integer</a> value, and a type to cast it
				4206	to <tt>ty2</tt>, which must be an <a href="#t_floating">floating point</a>
				4207	type. If <tt>ty</tt> is a vector integer type, <tt>ty2</tt> must be a vector
				4208	floating point type with the same number of elements as <tt>ty</tt></p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4209
				4210	<h5>Semantics:</h5>
Reid Spencer	d444879	2006-11-09 23:03:26 +0000	[diff] [blame]	4211	<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4212	integer quantity and converts it to the corresponding floating point value. If
Jeff Cohen	cb75731	2007-04-22 14:56:37 +0000	[diff] [blame]	4213	the value cannot fit in the floating point value, the results are undefined.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4214
				4215	<h5>Example:</h5>
				4216	<pre>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4217	%X = sitofp i32 257 to float <i>; yields float:257.0</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4218	%Y = sitofp i8 -1 to double <i>; yields double:-1.0</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4219	</pre>
				4220	</div>
				4221
				4222	<!-- _______________________________________________________________________ -->
				4223	<div class="doc_subsubsection">
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4224	<a name="i_ptrtoint">'<tt>ptrtoint .. to</tt>' Instruction</a>
				4225	</div>
				4226	<div class="doc_text">
				4227
				4228	<h5>Syntax:</h5>
				4229	<pre>
				4230	<result> = ptrtoint <ty> <value> to <ty2> <i>; yields ty2</i>
				4231	</pre>
				4232
				4233	<h5>Overview:</h5>
				4234	<p>The '<tt>ptrtoint</tt>' instruction converts the pointer <tt>value</tt> to
				4235	the integer type <tt>ty2</tt>.</p>
				4236
				4237	<h5>Arguments:</h5>
				4238	<p>The '<tt>ptrtoint</tt>' instruction takes a <tt>value</tt> to cast, which
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4239	must be a <a href="#t_pointer">pointer</a> value, and a type to cast it to
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4240	<tt>ty2</tt>, which must be an <a href="#t_integer">integer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4241
				4242	<h5>Semantics:</h5>
				4243	<p>The '<tt>ptrtoint</tt>' instruction converts <tt>value</tt> to integer type
				4244	<tt>ty2</tt> by interpreting the pointer value as an integer and either
				4245	truncating or zero extending that value to the size of the integer type. If
				4246	<tt>value</tt> is smaller than <tt>ty2</tt> then a zero extension is done. If
				4247	<tt>value</tt> is larger than <tt>ty2</tt> then a truncation is done. If they
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4248	are the same size, then nothing is done (<i>no-op cast</i>) other than a type
				4249	change.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4250
				4251	<h5>Example:</h5>
				4252	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4253	%X = ptrtoint i32* %X to i8 <i>; yields truncation on 32-bit architecture</i>
				4254	%Y = ptrtoint i32* %x to i64 <i>; yields zero extension on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4255	</pre>
				4256	</div>
				4257
				4258	<!-- _______________________________________________________________________ -->
				4259	<div class="doc_subsubsection">
				4260	<a name="i_inttoptr">'<tt>inttoptr .. to</tt>' Instruction</a>
				4261	</div>
				4262	<div class="doc_text">
				4263
				4264	<h5>Syntax:</h5>
				4265	<pre>
				4266	<result> = inttoptr <ty> <value> to <ty2> <i>; yields ty2</i>
				4267	</pre>
				4268
				4269	<h5>Overview:</h5>
				4270	<p>The '<tt>inttoptr</tt>' instruction converts an integer <tt>value</tt> to
				4271	a pointer type, <tt>ty2</tt>.</p>
				4272
				4273	<h5>Arguments:</h5>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4274	<p>The '<tt>inttoptr</tt>' instruction takes an <a href="#t_integer">integer</a>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4275	value to cast, and a type to cast it to, which must be a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4276	<a href="#t_pointer">pointer</a> type.</p>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4277
				4278	<h5>Semantics:</h5>
				4279	<p>The '<tt>inttoptr</tt>' instruction converts <tt>value</tt> to type
				4280	<tt>ty2</tt> by applying either a zero extension or a truncation depending on
				4281	the size of the integer <tt>value</tt>. If <tt>value</tt> is larger than the
				4282	size of a pointer then a truncation is done. If <tt>value</tt> is smaller than
				4283	the size of a pointer then a zero extension is done. If they are the same size,
				4284	nothing is done (<i>no-op cast</i>).</p>
				4285
				4286	<h5>Example:</h5>
				4287	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4288	%X = inttoptr i32 255 to i32* <i>; yields zero extension on 64-bit architecture</i>
				4289	%X = inttoptr i32 255 to i32* <i>; yields no-op on 32-bit architecture</i>
				4290	%Y = inttoptr i64 0 to i32* <i>; yields truncation on 32-bit architecture</i>
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4291	</pre>
				4292	</div>
				4293
				4294	<!-- _______________________________________________________________________ -->
				4295	<div class="doc_subsubsection">
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4296	<a name="i_bitcast">'<tt>bitcast .. to</tt>' Instruction</a>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4297	</div>
				4298	<div class="doc_text">
				4299
				4300	<h5>Syntax:</h5>
				4301	<pre>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4302	<result> = bitcast <ty> <value> to <ty2> <i>; yields ty2</i>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4303	</pre>
				4304
				4305	<h5>Overview:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4306
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4307	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4308	<tt>ty2</tt> without changing any bits.</p>
				4309
				4310	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4311
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4312	<p>The '<tt>bitcast</tt>' instruction takes a value to cast, which must be
Dan Gohman	500233a	2008-09-08 16:45:59 +0000	[diff] [blame]	4313	a non-aggregate first class value, and a type to cast it to, which must also be
				4314	a non-aggregate <a href="#t_firstclass">first class</a> type. The bit sizes of
				4315	<tt>value</tt>
Reid Spencer	19b569f	2007-01-09 20:08:58 +0000	[diff] [blame]	4316	and the destination type, <tt>ty2</tt>, must be identical. If the source
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4317	type is a pointer, the destination type must also be a pointer. This
				4318	instruction supports bitwise conversion of vectors to integers and to vectors
				4319	of other types (as long as they have the same size).</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4320
				4321	<h5>Semantics:</h5>
Reid Spencer	5c0ef47	2006-11-11 23:08:07 +0000	[diff] [blame]	4322	<p>The '<tt>bitcast</tt>' instruction converts <tt>value</tt> to type
Reid Spencer	7267925	2006-11-11 21:00:47 +0000	[diff] [blame]	4323	<tt>ty2</tt>. It is always a <i>no-op cast</i> because no bits change with
				4324	this conversion. The conversion is done as if the <tt>value</tt> had been
				4325	stored to memory and read back as type <tt>ty2</tt>. Pointer types may only be
				4326	converted to other pointer types with this instruction. To convert pointers to
				4327	other types, use the <a href="#i_inttoptr">inttoptr</a> or
				4328	<a href="#i_ptrtoint">ptrtoint</a> instructions first.</p>
Reid Spencer	9dee3ac	2006-11-08 01:11:31 +0000	[diff] [blame]	4329
				4330	<h5>Example:</h5>
				4331	<pre>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4332	%X = bitcast i8 255 to i8 <i>; yields i8 :-1</i>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4333	%Y = bitcast i32* %x to sint* <i>; yields sint*:%x</i>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4334	%Z = bitcast <2 x int> %V to i64; <i>; yields i64: %V</i>
Chris Lattner	33ba0d9	2001-07-09 00:26:23 +0000	[diff] [blame]	4335	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4336	</div>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4337
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4338	<!-- ======================================================================= -->
				4339	<div class="doc_subsection"> <a name="otherops">Other Operations</a> </div>
				4340	<div class="doc_text">
				4341	<p>The instructions in this category are the "miscellaneous"
				4342	instructions, which defy better classification.</p>
				4343	</div>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4344
				4345	<!-- _______________________________________________________________________ -->
				4346	<div class="doc_subsubsection"><a name="i_icmp">'<tt>icmp</tt>' Instruction</a>
				4347	</div>
				4348	<div class="doc_text">
				4349	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4350	<pre> <result> = icmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4351	</pre>
				4352	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4353	<p>The '<tt>icmp</tt>' instruction returns a boolean value or
				4354	a vector of boolean values based on comparison
				4355	of its two integer, integer vector, or pointer operands.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4356	<h5>Arguments:</h5>
				4357	<p>The '<tt>icmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4358	the condition code indicating the kind of comparison to perform. It is not
				4359	a value, just a keyword. The possible condition code are:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4360	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4361	<ol>
				4362	<li><tt>eq</tt>: equal</li>
				4363	<li><tt>ne</tt>: not equal </li>
				4364	<li><tt>ugt</tt>: unsigned greater than</li>
				4365	<li><tt>uge</tt>: unsigned greater or equal</li>
				4366	<li><tt>ult</tt>: unsigned less than</li>
				4367	<li><tt>ule</tt>: unsigned less or equal</li>
				4368	<li><tt>sgt</tt>: signed greater than</li>
				4369	<li><tt>sge</tt>: signed greater or equal</li>
				4370	<li><tt>slt</tt>: signed less than</li>
				4371	<li><tt>sle</tt>: signed less or equal</li>
				4372	</ol>
Chris Lattner	3b19d65	2007-01-15 01:54:13 +0000	[diff] [blame]	4373	<p>The remaining two arguments must be <a href="#t_integer">integer</a> or
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4374	<a href="#t_pointer">pointer</a>
				4375	or integer <a href="#t_vector">vector</a> typed.
				4376	They must also be identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4377	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4378	<p>The '<tt>icmp</tt>' compares <tt>op1</tt> and <tt>op2</tt> according to
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4379	the condition code given as <tt>cond</tt>. The comparison performed always
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4380	yields either an <a href="#t_primitive"><tt>i1</tt></a> or vector of <tt>i1</tt> result, as follows:
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4381	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4382	<ol>
				4383	<li><tt>eq</tt>: yields <tt>true</tt> if the operands are equal,
				4384	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.
				4385	</li>
				4386	<li><tt>ne</tt>: yields <tt>true</tt> if the operands are unequal,
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4387	<tt>false</tt> otherwise. No sign interpretation is necessary or performed.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4388	<li><tt>ugt</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4389	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4390	<li><tt>uge</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4391	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4392	<li><tt>ult</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4393	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4394	<li><tt>ule</tt>: interprets the operands as unsigned values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4395	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4396	<li><tt>sgt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4397	<tt>true</tt> if <tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4398	<li><tt>sge</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4399	<tt>true</tt> if <tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4400	<li><tt>slt</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4401	<tt>true</tt> if <tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4402	<li><tt>sle</tt>: interprets the operands as signed values and yields
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4403	<tt>true</tt> if <tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4404	</ol>
				4405	<p>If the operands are <a href="#t_pointer">pointer</a> typed, the pointer
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4406	values are compared as if they were integers.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4407	<p>If the operands are integer vectors, then they are compared
				4408	element by element. The result is an <tt>i1</tt> vector with
				4409	the same number of elements as the values being compared.
				4410	Otherwise, the result is an <tt>i1</tt>.
				4411	</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4412
				4413	<h5>Example:</h5>
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4414	<pre> <result> = icmp eq i32 4, 5 <i>; yields: result=false</i>
				4415	<result> = icmp ne float* %X, %X <i>; yields: result=false</i>
				4416	<result> = icmp ult i16 4, 5 <i>; yields: result=true</i>
				4417	<result> = icmp sgt i16 4, 5 <i>; yields: result=false</i>
				4418	<result> = icmp ule i16 -4, 5 <i>; yields: result=false</i>
				4419	<result> = icmp sge i16 4, 5 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4420	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4421
				4422	<p>Note that the code generator does not yet support vector types with
				4423	the <tt>icmp</tt> instruction.</p>
				4424
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4425	</div>
				4426
				4427	<!-- _______________________________________________________________________ -->
				4428	<div class="doc_subsubsection"><a name="i_fcmp">'<tt>fcmp</tt>' Instruction</a>
				4429	</div>
				4430	<div class="doc_text">
				4431	<h5>Syntax:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4432	<pre> <result> = fcmp <cond> <ty> <op1>, <op2> <i>; yields {i1} or {<N x i1>}:result</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4433	</pre>
				4434	<h5>Overview:</h5>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4435	<p>The '<tt>fcmp</tt>' instruction returns a boolean value
				4436	or vector of boolean values based on comparison
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4437	of its operands.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4438	<p>
				4439	If the operands are floating point scalars, then the result
				4440	type is a boolean (<a href="#t_primitive"><tt>i1</tt></a>).
				4441	</p>
				4442	<p>If the operands are floating point vectors, then the result type
				4443	is a vector of boolean with the same number of elements as the
				4444	operands being compared.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4445	<h5>Arguments:</h5>
				4446	<p>The '<tt>fcmp</tt>' instruction takes three operands. The first operand is
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4447	the condition code indicating the kind of comparison to perform. It is not
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4448	a value, just a keyword. The possible condition code are:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4449	<ol>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4450	<li><tt>false</tt>: no comparison, always returns false</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4451	<li><tt>oeq</tt>: ordered and equal</li>
				4452	<li><tt>ogt</tt>: ordered and greater than </li>
				4453	<li><tt>oge</tt>: ordered and greater than or equal</li>
				4454	<li><tt>olt</tt>: ordered and less than </li>
				4455	<li><tt>ole</tt>: ordered and less than or equal</li>
				4456	<li><tt>one</tt>: ordered and not equal</li>
				4457	<li><tt>ord</tt>: ordered (no nans)</li>
				4458	<li><tt>ueq</tt>: unordered or equal</li>
				4459	<li><tt>ugt</tt>: unordered or greater than </li>
				4460	<li><tt>uge</tt>: unordered or greater than or equal</li>
				4461	<li><tt>ult</tt>: unordered or less than </li>
				4462	<li><tt>ule</tt>: unordered or less than or equal</li>
				4463	<li><tt>une</tt>: unordered or not equal</li>
				4464	<li><tt>uno</tt>: unordered (either nans)</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4465	<li><tt>true</tt>: no comparison, always returns true</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4466	</ol>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4467	<p><i>Ordered</i> means that neither operand is a QNAN while
Reid Spencer	93a4985	2006-12-06 07:08:07 +0000	[diff] [blame]	4468	<i>unordered</i> means that either operand may be a QNAN.</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4469	<p>Each of <tt>val1</tt> and <tt>val2</tt> arguments must be
				4470	either a <a href="#t_floating">floating point</a> type
				4471	or a <a href="#t_vector">vector</a> of floating point type.
				4472	They must have identical types.</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4473	<h5>Semantics:</h5>
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4474	<p>The '<tt>fcmp</tt>' instruction compares <tt>op1</tt> and <tt>op2</tt>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4475	according to the condition code given as <tt>cond</tt>.
				4476	If the operands are vectors, then the vectors are compared
				4477	element by element.
				4478	Each comparison performed
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4479	always yields an <a href="#t_primitive">i1</a> result, as follows:</p>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4480	<ol>
				4481	<li><tt>false</tt>: always yields <tt>false</tt>, regardless of operands.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4482	<li><tt>oeq</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4483	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4484	<li><tt>ogt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4485	<tt>op1</tt> is greather than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4486	<li><tt>oge</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4487	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4488	<li><tt>olt</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4489	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4490	<li><tt>ole</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4491	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4492	<li><tt>one</tt>: yields <tt>true</tt> if both operands are not a QNAN and
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4493	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4494	<li><tt>ord</tt>: yields <tt>true</tt> if both operands are not a QNAN.</li>
				4495	<li><tt>ueq</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4496	<tt>op1</tt> is equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4497	<li><tt>ugt</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4498	<tt>op1</tt> is greater than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4499	<li><tt>uge</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4500	<tt>op1</tt> is greater than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4501	<li><tt>ult</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4502	<tt>op1</tt> is less than <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4503	<li><tt>ule</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4504	<tt>op1</tt> is less than or equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4505	<li><tt>une</tt>: yields <tt>true</tt> if either operand is a QNAN or
Gabor Greif	fb224a2	2008-08-07 21:46:00 +0000	[diff] [blame]	4506	<tt>op1</tt> is not equal to <tt>op2</tt>.</li>
Reid Spencer	b7f2628	2006-11-19 03:00:14 +0000	[diff] [blame]	4507	<li><tt>uno</tt>: yields <tt>true</tt> if either operand is a QNAN.</li>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4508	<li><tt>true</tt>: always yields <tt>true</tt>, regardless of operands.</li>
				4509	</ol>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4510
				4511	<h5>Example:</h5>
				4512	<pre> <result> = fcmp oeq float 4.0, 5.0 <i>; yields: result=false</i>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4513	<result> = fcmp one float 4.0, 5.0 <i>; yields: result=true</i>
				4514	<result> = fcmp olt float 4.0, 5.0 <i>; yields: result=true</i>
				4515	<result> = fcmp ueq double 1.0, 2.0 <i>; yields: result=false</i>
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4516	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4517
				4518	<p>Note that the code generator does not yet support vector types with
				4519	the <tt>fcmp</tt> instruction.</p>
				4520
Reid Spencer	f3a70a6	2006-11-18 21:50:54 +0000	[diff] [blame]	4521	</div>
				4522
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4523	<!-- _______________________________________________________________________ -->
Nate Begeman	ac80ade	2008-05-12 19:01:56 +0000	[diff] [blame]	4524	<div class="doc_subsubsection">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4525	<a name="i_phi">'<tt>phi</tt>' Instruction</a>
				4526	</div>
				4527
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4528	<div class="doc_text">
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4529
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4530	<h5>Syntax:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4531
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4532	<pre> <result> = phi <ty> [ <val0>, <label0>], ...<br></pre>
				4533	<h5>Overview:</h5>
				4534	<p>The '<tt>phi</tt>' instruction is used to implement the φ node in
				4535	the SSA graph representing the function.</p>
				4536	<h5>Arguments:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4537
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4538	<p>The type of the incoming values is specified with the first type
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4539	field. After this, the '<tt>phi</tt>' instruction takes a list of pairs
				4540	as arguments, with one pair for each predecessor basic block of the
				4541	current block. Only values of <a href="#t_firstclass">first class</a>
				4542	type may be used as the value arguments to the PHI node. Only labels
				4543	may be used as the label arguments.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4544
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4545	<p>There must be no non-phi instructions between the start of a basic
				4546	block and the PHI instructions: i.e. PHI instructions must be first in
				4547	a basic block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4548
Jay Foad	d244909	2009-06-03 10:20:10 +0000	[diff] [blame]	4549	<p>For the purposes of the SSA form, the use of each incoming value is
				4550	deemed to occur on the edge from the corresponding predecessor block
				4551	to the current block (but after any definition of an '<tt>invoke</tt>'
				4552	instruction's return value on the same edge).</p>
				4553
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4554	<h5>Semantics:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4555
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4556	<p>At runtime, the '<tt>phi</tt>' instruction logically takes on the value
				4557	specified by the pair corresponding to the predecessor basic block that executed
				4558	just prior to the current block.</p>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4559
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4560	<h5>Example:</h5>
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4561	<pre>
				4562	Loop: ; Infinite loop that counts from 0 on up...
				4563	%indvar = phi i32 [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
				4564	%nextindvar = add i32 %indvar, 1
				4565	br label %Loop
				4566	</pre>
Reid Spencer	2fd21e6	2006-11-08 01:18:52 +0000	[diff] [blame]	4567	</div>
				4568
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4569	<!-- _______________________________________________________________________ -->
				4570	<div class="doc_subsubsection">
				4571	<a name="i_select">'<tt>select</tt>' Instruction</a>
				4572	</div>
				4573
				4574	<div class="doc_text">
				4575
				4576	<h5>Syntax:</h5>
				4577
				4578	<pre>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4579	<result> = select <i>selty</i> <cond>, <ty> <val1>, <ty> <val2> <i>; yields ty</i>
				4580
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4581	<i>selty</i> is either i1 or {<N x i1>}
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4582	</pre>
				4583
				4584	<h5>Overview:</h5>
				4585
				4586	<p>
				4587	The '<tt>select</tt>' instruction is used to choose one value based on a
				4588	condition, without branching.
				4589	</p>
				4590
				4591
				4592	<h5>Arguments:</h5>
				4593
				4594	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4595	The '<tt>select</tt>' instruction requires an 'i1' value or
				4596	a vector of 'i1' values indicating the
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4597	condition, and two values of the same <a href="#t_firstclass">first class</a>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4598	type. If the val1/val2 are vectors and
				4599	the condition is a scalar, then entire vectors are selected, not
Chris Lattner	5568e94	2008-05-20 20:48:21 +0000	[diff] [blame]	4600	individual elements.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4601	</p>
				4602
				4603	<h5>Semantics:</h5>
				4604
				4605	<p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4606	If the condition is an i1 and it evaluates to 1, the instruction returns the first
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4607	value argument; otherwise, it returns the second value argument.
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4608	</p>
Dan Gohman	f72fb67	2008-09-09 01:02:47 +0000	[diff] [blame]	4609	<p>
				4610	If the condition is a vector of i1, then the value arguments must
				4611	be vectors of the same size, and the selection is done element
				4612	by element.
				4613	</p>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4614
				4615	<h5>Example:</h5>
				4616
				4617	<pre>
Reid Spencer	c78f337	2007-01-12 03:35:51 +0000	[diff] [blame]	4618	%X = select i1 true, i8 17, i8 42 <i>; yields i8:17</i>
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4619	</pre>
Dan Gohman	c766f72	2009-01-22 01:39:38 +0000	[diff] [blame]	4620
				4621	<p>Note that the code generator does not yet support conditions
				4622	with vector type.</p>
				4623
Chris Lattner	cc37aae	2004-03-12 05:50:16 +0000	[diff] [blame]	4624	</div>
				4625
Robert Bocchino	05ccd70	2006-01-15 20:48:27 +0000	[diff] [blame]	4626
				4627	<!-- _______________________________________________________________________ -->
				4628	<div class="doc_subsubsection">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4629	<a name="i_call">'<tt>call</tt>' Instruction</a>
				4630	</div>
				4631
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4632	<div class="doc_text">
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4633
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4634	<h5>Syntax:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4635	<pre>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4636	<result> = [tail] call [<a href="#callingconv">cconv</a>] [<a href="#paramattrs">ret attrs</a>] <ty> [<fnty>*] <fnptrval>(<function args>) [<a href="#fnattrs">fn attrs</a>]
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4637	</pre>
				4638
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4639	<h5>Overview:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4640
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4641	<p>The '<tt>call</tt>' instruction represents a simple function call.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4642
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4643	<h5>Arguments:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4644
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4645	<p>This instruction requires several arguments:</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4646
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4647	<ol>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4648	<li>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4649	<p>The optional "tail" marker indicates whether the callee function accesses
				4650	any allocas or varargs in the caller. If the "tail" marker is present, the
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4651	function call is eligible for tail call optimization. Note that calls may
				4652	be marked "tail" even if they do not occur before a <a
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4653	href="#i_ret"><tt>ret</tt></a> instruction.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4654	</li>
				4655	<li>
Duncan Sands	8036ca4	2007-03-30 12:22:09 +0000	[diff] [blame]	4656	<p>The optional "cconv" marker indicates which <a href="#callingconv">calling
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4657	convention</a> the call should use. If none is specified, the call defaults
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4658	to using C calling conventions.</p>
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4659	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4660
				4661	<li>
				4662	<p>The optional <a href="#paramattrs">Parameter Attributes</a> list for
				4663	return values. Only '<tt>zeroext</tt>', '<tt>signext</tt>',
				4664	and '<tt>inreg</tt>' attributes are valid here.</p>
				4665	</li>
				4666
Chris Lattner	bad10ee	2005-05-06 22:57:40 +0000	[diff] [blame]	4667	<li>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4668	<p>'<tt>ty</tt>': the type of the call instruction itself which is also
				4669	the type of the return value. Functions that return no value are marked
				4670	<tt><a href="#t_void">void</a></tt>.</p>
				4671	</li>
				4672	<li>
				4673	<p>'<tt>fnty</tt>': shall be the signature of the pointer to function
				4674	value being invoked. The argument types must match the types implied by
				4675	this signature. This type can be omitted if the function is not varargs
				4676	and if the function type does not return a pointer to a function.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4677	</li>
				4678	<li>
				4679	<p>'<tt>fnptrval</tt>': An LLVM value containing a pointer to a function to
				4680	be invoked. In most cases, this is a direct function invocation, but
				4681	indirect <tt>call</tt>s are just as possible, calling an arbitrary pointer
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4682	to function value.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4683	</li>
				4684	<li>
				4685	<p>'<tt>function args</tt>': argument list whose types match the
Reid Spencer	a7e302a	2005-05-01 22:22:57 +0000	[diff] [blame]	4686	function signature argument types. All arguments must be of
				4687	<a href="#t_firstclass">first class</a> type. If the function signature
				4688	indicates the function accepts a variable number of arguments, the extra
				4689	arguments can be specified.</p>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4690	</li>
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4691	<li>
Devang Patel	307e8ab	2008-10-07 17:48:33 +0000	[diff] [blame]	4692	<p>The optional <a href="#fnattrs">function attributes</a> list. Only
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4693	'<tt>noreturn</tt>', '<tt>nounwind</tt>', '<tt>readonly</tt>' and
				4694	'<tt>readnone</tt>' attributes are valid here.</p>
				4695	</li>
Chris Lattner	6536cfe	2002-05-06 22:08:29 +0000	[diff] [blame]	4696	</ol>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4697
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4698	<h5>Semantics:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4699
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4700	<p>The '<tt>call</tt>' instruction is used to cause control flow to
				4701	transfer to a specified function, with its incoming arguments bound to
				4702	the specified values. Upon a '<tt><a href="#i_ret">ret</a></tt>'
				4703	instruction in the called function, control flow continues with the
				4704	instruction after the function call, and the return value of the
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4705	function is bound to the result argument.</p>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4706
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	4707	<h5>Example:</h5>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4708
				4709	<pre>
Nick Lewycky	db7e3c9	2007-09-08 13:57:50 +0000	[diff] [blame]	4710	%retval = call i32 @test(i32 %argc)
Chris Lattner	772fccf	2008-03-21 17:24:17 +0000	[diff] [blame]	4711	call i32 (i8 , ...) @printf(i8 * %msg, i32 12, i8 42) <i>; yields i32</i>
				4712	%X = tail call i32 @foo() <i>; yields i32</i>
				4713	%Y = tail call <a href="#callingconv">fastcc</a> i32 @foo() <i>; yields i32</i>
				4714	call void %foo(i8 97 signext)
Devang Patel	c3fc6df	2008-03-10 20:49:15 +0000	[diff] [blame]	4715
				4716	%struct.A = type { i32, i8 }
Devang Patel	f642f47	2008-10-06 18:50:38 +0000	[diff] [blame]	4717	%r = call %struct.A @foo() <i>; yields { 32, i8 }</i>
Dan Gohman	b1e6b96	2008-10-04 19:00:07 +0000	[diff] [blame]	4718	%gr = extractvalue %struct.A %r, 0 <i>; yields i32</i>
				4719	%gr1 = extractvalue %struct.A %r, 1 <i>; yields i8</i>
Chris Lattner	85a350f	2008-10-08 06:26:11 +0000	[diff] [blame]	4720	%Z = call void @foo() noreturn <i>; indicates that %foo never returns normally</i>
Matthijs Kooijman	cb73d19	2008-10-07 10:03:45 +0000	[diff] [blame]	4721	%ZZ = call zeroext i32 @bar() <i>; Return value is %zero extended</i>
Chris Lattner	2bff524	2005-05-06 05:47:36 +0000	[diff] [blame]	4722	</pre>
				4723
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4724	</div>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4725
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4726	<!-- _______________________________________________________________________ -->
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4727	<div class="doc_subsubsection">
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4728	<a name="i_va_arg">'<tt>va_arg</tt>' Instruction</a>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4729	</div>
				4730
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4731	<div class="doc_text">
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4732
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4733	<h5>Syntax:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4734
				4735	<pre>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4736	<resultval> = va_arg <va_list*> <arglist>, <argty>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4737	</pre>
				4738
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4739	<h5>Overview:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4740
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4741	<p>The '<tt>va_arg</tt>' instruction is used to access arguments passed through
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4742	the "variable argument" area of a function call. It is used to implement the
				4743	<tt>va_arg</tt> macro in C.</p>
				4744
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4745	<h5>Arguments:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4746
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4747	<p>This instruction takes a <tt>va_list*</tt> value and the type of
				4748	the argument. It returns a value of the specified argument type and
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4749	increments the <tt>va_list</tt> to point to the next argument. The
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4750	actual type of <tt>va_list</tt> is target specific.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4751
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4752	<h5>Semantics:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4753
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4754	<p>The '<tt>va_arg</tt>' instruction loads an argument of the specified
				4755	type from the specified <tt>va_list</tt> and causes the
				4756	<tt>va_list</tt> to point to the next argument. For more information,
				4757	see the variable argument handling <a href="#int_varargs">Intrinsic
				4758	Functions</a>.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4759
				4760	<p>It is legal for this instruction to be called in a function which does not
				4761	take a variable number of arguments, for example, the <tt>vfprintf</tt>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4762	function.</p>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4763
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4764	<p><tt>va_arg</tt> is an LLVM instruction instead of an <a
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4765	href="#intrinsics">intrinsic function</a> because it takes a type as an
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4766	argument.</p>
				4767
Chris Lattner	8d1a81d	2003-10-18 05:51:36 +0000	[diff] [blame]	4768	<h5>Example:</h5>
Chris Lattner	e19d7a7	2004-09-27 21:51:25 +0000	[diff] [blame]	4769
				4770	<p>See the <a href="#int_varargs">variable argument processing</a> section.</p>
				4771
Dan Gohman	f3e60bd	2009-01-12 23:12:39 +0000	[diff] [blame]	4772	<p>Note that the code generator does not yet fully support va_arg
				4773	on many targets. Also, it does not currently support va_arg with
				4774	aggregate types on any target.</p>
				4775
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4776	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4777
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4778	<!-- *********************************************************************** -->
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4779	<div class="doc_section"> <a name="intrinsics">Intrinsic Functions</a> </div>
				4780	<!-- *********************************************************************** -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4781
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4782	<div class="doc_text">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4783
				4784	<p>LLVM supports the notion of an "intrinsic function". These functions have
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4785	well known names and semantics and are required to follow certain restrictions.
				4786	Overall, these intrinsics represent an extension mechanism for the LLVM
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4787	language that does not require changing all of the transformations in LLVM when
Gabor Greif	04367bf	2007-07-06 22:07:22 +0000	[diff] [blame]	4788	adding to the language (or the bitcode reader/writer, the parser, etc...).</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4789
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	4790	<p>Intrinsic function names must all start with an "<tt>llvm.</tt>" prefix. This
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4791	prefix is reserved in LLVM for intrinsic names; thus, function names may not
				4792	begin with this prefix. Intrinsic functions must always be external functions:
				4793	you cannot define the body of intrinsic functions. Intrinsic functions may
				4794	only be used in call or invoke instructions: it is illegal to take the address
				4795	of an intrinsic function. Additionally, because intrinsic functions are part
				4796	of the LLVM language, it is required if any are added that they be documented
				4797	here.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4798
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4799	<p>Some intrinsic functions can be overloaded, i.e., the intrinsic represents
				4800	a family of functions that perform the same operation but on different data
				4801	types. Because LLVM can represent over 8 million different integer types,
				4802	overloading is used commonly to allow an intrinsic function to operate on any
				4803	integer type. One or more of the argument types or the result type can be
				4804	overloaded to accept any integer type. Argument types may also be defined as
				4805	exactly matching a previous argument's type or the result type. This allows an
				4806	intrinsic function which accepts multiple arguments, but needs all of them to
				4807	be of the same type, to only be overloaded with respect to a single argument or
				4808	the result.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4809
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	4810	<p>Overloaded intrinsics will have the names of its overloaded argument types
				4811	encoded into its function name, each preceded by a period. Only those types
				4812	which are overloaded result in a name suffix. Arguments whose type is matched
				4813	against another type do not. For example, the <tt>llvm.ctpop</tt> function can
				4814	take an integer of any width and returns an integer of exactly the same integer
				4815	width. This leads to a family of functions such as
				4816	<tt>i8 @llvm.ctpop.i8(i8 %val)</tt> and <tt>i29 @llvm.ctpop.i29(i29 %val)</tt>.
				4817	Only one type, the return type, is overloaded, and only one type suffix is
				4818	required. Because the argument's type is matched against the return type, it
				4819	does not require its own name suffix.</p>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	4820
				4821	<p>To learn how to add an intrinsic function, please see the
				4822	<a href="ExtendingLLVM.html">Extending LLVM Guide</a>.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4823	</p>
				4824
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4825	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4826
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4827	<!-- ======================================================================= -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4828	<div class="doc_subsection">
				4829	<a name="int_varargs">Variable Argument Handling Intrinsics</a>
				4830	</div>
				4831
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4832	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4833
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4834	<p>Variable argument support is defined in LLVM with the <a
Chris Lattner	fb6977d	2006-01-13 23:26:01 +0000	[diff] [blame]	4835	href="#i_va_arg"><tt>va_arg</tt></a> instruction and these three
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4836	intrinsic functions. These functions are related to the similarly
				4837	named macros defined in the <tt><stdarg.h></tt> header file.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4838
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4839	<p>All of these functions operate on arguments that use a
				4840	target-specific value type "<tt>va_list</tt>". The LLVM assembly
				4841	language reference manual does not define what this type is, so all
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4842	transformations should be prepared to handle these functions regardless of
				4843	the type used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4844
Chris Lattner	374ab30	2006-05-15 17:26:46 +0000	[diff] [blame]	4845	<p>This example shows how the <a href="#i_va_arg"><tt>va_arg</tt></a>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4846	instruction and the variable argument handling intrinsic functions are
				4847	used.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4848
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4849	<div class="doc_code">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4850	<pre>
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4851	define i32 @test(i32 %X, ...) {
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4852	; Initialize variable argument processing
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4853	%ap = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4854	%ap2 = bitcast i8** %ap to i8*
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4855	call void @llvm.va_start(i8* %ap2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4856
				4857	; Read a single integer argument
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4858	%tmp = va_arg i8** %ap, i32
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4859
				4860	; Demonstrate usage of llvm.va_copy and llvm.va_end
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4861	%aq = alloca i8*
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4862	%aq2 = bitcast i8** %aq to i8*
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4863	call void @llvm.va_copy(i8* %aq2, i8* %ap2)
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4864	call void @llvm.va_end(i8* %aq2)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4865
				4866	; Stop processing of arguments.
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4867	call void @llvm.va_end(i8* %ap2)
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	4868	ret i32 %tmp
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4869	}
Anton Korobeynikov	5d522f3	2007-03-21 23:58:04 +0000	[diff] [blame]	4870
				4871	declare void @llvm.va_start(i8*)
				4872	declare void @llvm.va_copy(i8, i8)
				4873	declare void @llvm.va_end(i8*)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4874	</pre>
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4875	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4876
Bill Wendling	2f7a8b0	2007-05-29 09:04:49 +0000	[diff] [blame]	4877	</div>
				4878
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4879	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4880	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4881	<a name="int_va_start">'<tt>llvm.va_start</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4882	</div>
				4883
				4884
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4885	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4886	<h5>Syntax:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4887	<pre> declare void %llvm.va_start(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4888	<h5>Overview:</h5>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4889	<p>The '<tt>llvm.va_start</tt>' intrinsic initializes
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4890	<tt>*<arglist></tt> for subsequent use by <tt><a
				4891	href="#i_va_arg">va_arg</a></tt>.</p>
				4892
				4893	<h5>Arguments:</h5>
				4894
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4895	<p>The argument is a pointer to a <tt>va_list</tt> element to initialize.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4896
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4897	<h5>Semantics:</h5>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4898
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	4899	<p>The '<tt>llvm.va_start</tt>' intrinsic works just like the <tt>va_start</tt>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4900	macro available in C. In a target-dependent way, it initializes the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4901	<tt>va_list</tt> element to which the argument points, so that the next call to
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4902	<tt>va_arg</tt> will produce the first variable argument passed to the function.
				4903	Unlike the C <tt>va_start</tt> macro, this intrinsic does not need to know the
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4904	last argument of the function as the compiler can figure that out.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4905
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4906	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4907
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4908	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4909	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4910	<a name="int_va_end">'<tt>llvm.va_end</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4911	</div>
				4912
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4913	<div class="doc_text">
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4914	<h5>Syntax:</h5>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4915	<pre> declare void @llvm.va_end(i8* <arglist>)<br></pre>
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4916	<h5>Overview:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4917
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4918	<p>The '<tt>llvm.va_end</tt>' intrinsic destroys <tt>*<arglist></tt>,
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4919	which has been initialized previously with <tt><a href="#int_va_start">llvm.va_start</a></tt>
Chris Lattner	261efe9	2003-11-25 01:02:51 +0000	[diff] [blame]	4920	or <tt><a href="#i_va_copy">llvm.va_copy</a></tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4921
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4922	<h5>Arguments:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4923
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4924	<p>The argument is a pointer to a <tt>va_list</tt> to destroy.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4925
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4926	<h5>Semantics:</h5>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4927
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4928	<p>The '<tt>llvm.va_end</tt>' intrinsic works just like the <tt>va_end</tt>
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4929	macro available in C. In a target-dependent way, it destroys the
				4930	<tt>va_list</tt> element to which the argument points. Calls to <a
				4931	href="#int_va_start"><tt>llvm.va_start</tt></a> and <a href="#int_va_copy">
				4932	<tt>llvm.va_copy</tt></a> must be matched exactly with calls to
				4933	<tt>llvm.va_end</tt>.</p>
Chris Lattner	b75137d	2007-01-08 07:55:15 +0000	[diff] [blame]	4934
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4935	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4936
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4937	<!-- _______________________________________________________________________ -->
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4938	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4939	<a name="int_va_copy">'<tt>llvm.va_copy</tt>' Intrinsic</a>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4940	</div>
				4941
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4942	<div class="doc_text">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4943
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4944	<h5>Syntax:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4945
				4946	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	4947	declare void @llvm.va_copy(i8* <destarglist>, i8* <srcarglist>)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4948	</pre>
				4949
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4950	<h5>Overview:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4951
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4952	<p>The '<tt>llvm.va_copy</tt>' intrinsic copies the current argument position
				4953	from the source argument list to the destination argument list.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4954
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4955	<h5>Arguments:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4956
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4957	<p>The first argument is a pointer to a <tt>va_list</tt> element to initialize.
Andrew Lenharth	d0a4c62	2005-06-22 20:38:11 +0000	[diff] [blame]	4958	The second argument is a pointer to a <tt>va_list</tt> element to copy from.</p>
Andrew Lenharth	8bf607a	2005-06-18 18:28:17 +0000	[diff] [blame]	4959
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4960
Chris Lattner	d9ad5b3	2003-05-08 04:57:36 +0000	[diff] [blame]	4961	<h5>Semantics:</h5>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4962
Jeff Cohen	b627eab	2007-04-29 01:07:00 +0000	[diff] [blame]	4963	<p>The '<tt>llvm.va_copy</tt>' intrinsic works just like the <tt>va_copy</tt>
				4964	macro available in C. In a target-dependent way, it copies the source
				4965	<tt>va_list</tt> element into the destination <tt>va_list</tt> element. This
				4966	intrinsic is necessary because the <tt><a href="#int_va_start">
				4967	llvm.va_start</a></tt> intrinsic may be arbitrarily complex and require, for
				4968	example, memory allocation.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4969
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	4970	</div>
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	4971
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	4972	<!-- ======================================================================= -->
				4973	<div class="doc_subsection">
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4974	<a name="int_gc">Accurate Garbage Collection Intrinsics</a>
				4975	</div>
				4976
				4977	<div class="doc_text">
				4978
				4979	<p>
				4980	LLVM support for <a href="GarbageCollection.html">Accurate Garbage
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	4981	Collection</a> (GC) requires the implementation and generation of these
				4982	intrinsics.
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4983	These intrinsics allow identification of <a href="#int_gcroot">GC roots on the
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4984	stack</a>, as well as garbage collector implementations that require <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4985	href="#int_gcread">read</a> and <a href="#int_gcwrite">write</a> barriers.
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4986	Front-ends for type-safe garbage collected languages should generate these
				4987	intrinsics to make use of the LLVM garbage collectors. For more details, see <a
				4988	href="GarbageCollection.html">Accurate Garbage Collection with LLVM</a>.
				4989	</p>
Christopher Lamb	303dae9	2007-12-17 01:00:21 +0000	[diff] [blame]	4990
				4991	<p>The garbage collection intrinsics only operate on objects in the generic
				4992	address space (address space zero).</p>
				4993
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4994	</div>
				4995
				4996	<!-- _______________________________________________________________________ -->
				4997	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	4998	<a name="int_gcroot">'<tt>llvm.gcroot</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	4999	</div>
				5000
				5001	<div class="doc_text">
				5002
				5003	<h5>Syntax:</h5>
				5004
				5005	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5006	declare void @llvm.gcroot(i8** %ptrloc, i8* %metadata)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5007	</pre>
				5008
				5009	<h5>Overview:</h5>
				5010
John Criswell	9e2485c	2004-12-10 15:51:16 +0000	[diff] [blame]	5011	<p>The '<tt>llvm.gcroot</tt>' intrinsic declares the existence of a GC root to
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5012	the code generator, and allows some metadata to be associated with it.</p>
				5013
				5014	<h5>Arguments:</h5>
				5015
				5016	<p>The first argument specifies the address of a stack object that contains the
				5017	root pointer. The second pointer (which must be either a constant or a global
				5018	value address) contains the meta-data to be associated with the root.</p>
				5019
				5020	<h5>Semantics:</h5>
				5021
Chris Lattner	05d6709	2008-04-24 05:59:56 +0000	[diff] [blame]	5022	<p>At runtime, a call to this intrinsic stores a null pointer into the "ptrloc"
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5023	location. At compile-time, the code generator generates information to allow
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5024	the runtime to find the pointer at GC safe points. The '<tt>llvm.gcroot</tt>'
				5025	intrinsic may only be used in a function which <a href="#gc">specifies a GC
				5026	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5027
				5028	</div>
				5029
				5030
				5031	<!-- _______________________________________________________________________ -->
				5032	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5033	<a name="int_gcread">'<tt>llvm.gcread</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5034	</div>
				5035
				5036	<div class="doc_text">
				5037
				5038	<h5>Syntax:</h5>
				5039
				5040	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5041	declare i8* @llvm.gcread(i8* %ObjPtr, i8** %Ptr)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5042	</pre>
				5043
				5044	<h5>Overview:</h5>
				5045
				5046	<p>The '<tt>llvm.gcread</tt>' intrinsic identifies reads of references from heap
				5047	locations, allowing garbage collector implementations that require read
				5048	barriers.</p>
				5049
				5050	<h5>Arguments:</h5>
				5051
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5052	<p>The second argument is the address to read from, which should be an address
				5053	allocated from the garbage collector. The first object is a pointer to the
				5054	start of the referenced object, if needed by the language runtime (otherwise
				5055	null).</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5056
				5057	<h5>Semantics:</h5>
				5058
				5059	<p>The '<tt>llvm.gcread</tt>' intrinsic has the same semantics as a load
				5060	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5061	garbage collector runtime, as needed. The '<tt>llvm.gcread</tt>' intrinsic
				5062	may only be used in a function which <a href="#gc">specifies a GC
				5063	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5064
				5065	</div>
				5066
				5067
				5068	<!-- _______________________________________________________________________ -->
				5069	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5070	<a name="int_gcwrite">'<tt>llvm.gcwrite</tt>' Intrinsic</a>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5071	</div>
				5072
				5073	<div class="doc_text">
				5074
				5075	<h5>Syntax:</h5>
				5076
				5077	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5078	declare void @llvm.gcwrite(i8* %P1, i8* %Obj, i8** %P2)
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5079	</pre>
				5080
				5081	<h5>Overview:</h5>
				5082
				5083	<p>The '<tt>llvm.gcwrite</tt>' intrinsic identifies writes of references to heap
				5084	locations, allowing garbage collector implementations that require write
				5085	barriers (such as generational or reference counting collectors).</p>
				5086
				5087	<h5>Arguments:</h5>
				5088
Chris Lattner	80626e9	2006-03-14 20:02:51 +0000	[diff] [blame]	5089	<p>The first argument is the reference to store, the second is the start of the
				5090	object to store it to, and the third is the address of the field of Obj to
				5091	store to. If the runtime does not require a pointer to the object, Obj may be
				5092	null.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5093
				5094	<h5>Semantics:</h5>
				5095
				5096	<p>The '<tt>llvm.gcwrite</tt>' intrinsic has the same semantics as a store
				5097	instruction, but may be replaced with substantially more complex code by the
Gordon Henriksen	e1433f2	2007-12-25 02:31:26 +0000	[diff] [blame]	5098	garbage collector runtime, as needed. The '<tt>llvm.gcwrite</tt>' intrinsic
				5099	may only be used in a function which <a href="#gc">specifies a GC
				5100	algorithm</a>.</p>
Chris Lattner	d792391	2004-05-23 21:06:01 +0000	[diff] [blame]	5101
				5102	</div>
				5103
				5104
				5105
				5106	<!-- ======================================================================= -->
				5107	<div class="doc_subsection">
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5108	<a name="int_codegen">Code Generator Intrinsics</a>
				5109	</div>
				5110
				5111	<div class="doc_text">
				5112	<p>
				5113	These intrinsics are provided by LLVM to expose special features that may only
				5114	be implemented with code generator support.
				5115	</p>
				5116
				5117	</div>
				5118
				5119	<!-- _______________________________________________________________________ -->
				5120	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5121	<a name="int_returnaddress">'<tt>llvm.returnaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5122	</div>
				5123
				5124	<div class="doc_text">
				5125
				5126	<h5>Syntax:</h5>
				5127	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5128	declare i8 *@llvm.returnaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5129	</pre>
				5130
				5131	<h5>Overview:</h5>
				5132
				5133	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5134	The '<tt>llvm.returnaddress</tt>' intrinsic attempts to compute a
				5135	target-specific value indicating the return address of the current function
				5136	or one of its callers.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5137	</p>
				5138
				5139	<h5>Arguments:</h5>
				5140
				5141	<p>
				5142	The argument to this intrinsic indicates which function to return the address
				5143	for. Zero indicates the calling function, one indicates its caller, etc. The
				5144	argument is <b>required</b> to be a constant integer value.
				5145	</p>
				5146
				5147	<h5>Semantics:</h5>
				5148
				5149	<p>
				5150	The '<tt>llvm.returnaddress</tt>' intrinsic either returns a pointer indicating
				5151	the return address of the specified call frame, or zero if it cannot be
				5152	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5153	for arguments other than zero, so it should only be used for debugging purposes.
				5154	</p>
				5155
				5156	<p>
				5157	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5158	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5159	source-language caller.
				5160	</p>
				5161	</div>
				5162
				5163
				5164	<!-- _______________________________________________________________________ -->
				5165	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5166	<a name="int_frameaddress">'<tt>llvm.frameaddress</tt>' Intrinsic</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5167	</div>
				5168
				5169	<div class="doc_text">
				5170
				5171	<h5>Syntax:</h5>
				5172	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5173	declare i8 *@llvm.frameaddress(i32 <level>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5174	</pre>
				5175
				5176	<h5>Overview:</h5>
				5177
				5178	<p>
Chris Lattner	32b5d71	2006-10-15 20:05:59 +0000	[diff] [blame]	5179	The '<tt>llvm.frameaddress</tt>' intrinsic attempts to return the
				5180	target-specific frame pointer value for the specified stack frame.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5181	</p>
				5182
				5183	<h5>Arguments:</h5>
				5184
				5185	<p>
				5186	The argument to this intrinsic indicates which function to return the frame
				5187	pointer for. Zero indicates the calling function, one indicates its caller,
				5188	etc. The argument is <b>required</b> to be a constant integer value.
				5189	</p>
				5190
				5191	<h5>Semantics:</h5>
				5192
				5193	<p>
				5194	The '<tt>llvm.frameaddress</tt>' intrinsic either returns a pointer indicating
				5195	the frame address of the specified call frame, or zero if it cannot be
				5196	identified. The value returned by this intrinsic is likely to be incorrect or 0
				5197	for arguments other than zero, so it should only be used for debugging purposes.
				5198	</p>
				5199
				5200	<p>
				5201	Note that calling this intrinsic does not prevent function inlining or other
Chris Lattner	b40bb38	2005-03-07 20:30:51 +0000	[diff] [blame]	5202	aggressive transformations, so the value returned may not be that of the obvious
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5203	source-language caller.
				5204	</p>
				5205	</div>
				5206
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5207	<!-- _______________________________________________________________________ -->
				5208	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5209	<a name="int_stacksave">'<tt>llvm.stacksave</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5210	</div>
				5211
				5212	<div class="doc_text">
				5213
				5214	<h5>Syntax:</h5>
				5215	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5216	declare i8 *@llvm.stacksave()
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5217	</pre>
				5218
				5219	<h5>Overview:</h5>
				5220
				5221	<p>
				5222	The '<tt>llvm.stacksave</tt>' intrinsic is used to remember the current state of
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5223	the function stack, for use with <a href="#int_stackrestore">
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5224	<tt>llvm.stackrestore</tt></a>. This is useful for implementing language
				5225	features like scoped automatic variable sized arrays in C99.
				5226	</p>
				5227
				5228	<h5>Semantics:</h5>
				5229
				5230	<p>
				5231	This intrinsic returns a opaque pointer value that can be passed to <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5232	href="#int_stackrestore"><tt>llvm.stackrestore</tt></a>. When an
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5233	<tt>llvm.stackrestore</tt> intrinsic is executed with a value saved from
				5234	<tt>llvm.stacksave</tt>, it effectively restores the state of the stack to the
				5235	state it was in when the <tt>llvm.stacksave</tt> intrinsic executed. In
				5236	practice, this pops any <a href="#i_alloca">alloca</a> blocks from the stack
				5237	that were allocated after the <tt>llvm.stacksave</tt> was executed.
				5238	</p>
				5239
				5240	</div>
				5241
				5242	<!-- _______________________________________________________________________ -->
				5243	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5244	<a name="int_stackrestore">'<tt>llvm.stackrestore</tt>' Intrinsic</a>
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5245	</div>
				5246
				5247	<div class="doc_text">
				5248
				5249	<h5>Syntax:</h5>
				5250	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5251	declare void @llvm.stackrestore(i8 * %ptr)
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5252	</pre>
				5253
				5254	<h5>Overview:</h5>
				5255
				5256	<p>
				5257	The '<tt>llvm.stackrestore</tt>' intrinsic is used to restore the state of
				5258	the function stack to the state it was in when the corresponding <a
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5259	href="#int_stacksave"><tt>llvm.stacksave</tt></a> intrinsic executed. This is
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5260	useful for implementing language features like scoped automatic variable sized
				5261	arrays in C99.
				5262	</p>
				5263
				5264	<h5>Semantics:</h5>
				5265
				5266	<p>
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5267	See the description for <a href="#int_stacksave"><tt>llvm.stacksave</tt></a>.
Chris Lattner	57e1f39	2006-01-13 02:03:13 +0000	[diff] [blame]	5268	</p>
				5269
				5270	</div>
				5271
				5272
				5273	<!-- _______________________________________________________________________ -->
				5274	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5275	<a name="int_prefetch">'<tt>llvm.prefetch</tt>' Intrinsic</a>
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5276	</div>
				5277
				5278	<div class="doc_text">
				5279
				5280	<h5>Syntax:</h5>
				5281	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5282	declare void @llvm.prefetch(i8* <address>, i32 <rw>, i32 <locality>)
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5283	</pre>
				5284
				5285	<h5>Overview:</h5>
				5286
				5287
				5288	<p>
				5289	The '<tt>llvm.prefetch</tt>' intrinsic is a hint to the code generator to insert
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5290	a prefetch instruction if supported; otherwise, it is a noop. Prefetches have
				5291	no
				5292	effect on the behavior of the program but can change its performance
Chris Lattner	2a61536	2005-02-28 19:47:14 +0000	[diff] [blame]	5293	characteristics.
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5294	</p>
				5295
				5296	<h5>Arguments:</h5>
				5297
				5298	<p>
				5299	<tt>address</tt> is the address to be prefetched, <tt>rw</tt> is the specifier
				5300	determining if the fetch should be for a read (0) or write (1), and
				5301	<tt>locality</tt> is a temporal locality specifier ranging from (0) - no
Chris Lattner	aeffb4a	2005-03-07 20:31:38 +0000	[diff] [blame]	5302	locality, to (3) - extremely local keep in cache. The <tt>rw</tt> and
Chris Lattner	9a9d7ac	2005-02-28 19:24:19 +0000	[diff] [blame]	5303	<tt>locality</tt> arguments must be constant integers.
				5304	</p>
				5305
				5306	<h5>Semantics:</h5>
				5307
				5308	<p>
				5309	This intrinsic does not modify the behavior of the program. In particular,
				5310	prefetches cannot trap and do not produce a value. On targets that support this
				5311	intrinsic, the prefetch can provide hints to the processor cache for better
				5312	performance.
				5313	</p>
				5314
				5315	</div>
				5316
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5317	<!-- _______________________________________________________________________ -->
				5318	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5319	<a name="int_pcmarker">'<tt>llvm.pcmarker</tt>' Intrinsic</a>
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5320	</div>
				5321
				5322	<div class="doc_text">
				5323
				5324	<h5>Syntax:</h5>
				5325	<pre>
Chris Lattner	1df4f75	2007-09-21 17:30:40 +0000	[diff] [blame]	5326	declare void @llvm.pcmarker(i32 <id>)
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5327	</pre>
				5328
				5329	<h5>Overview:</h5>
				5330
				5331
				5332	<p>
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5333	The '<tt>llvm.pcmarker</tt>' intrinsic is a method to export a Program Counter
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	5334	(PC) in a region of
				5335	code to simulators and other tools. The method is target specific, but it is
				5336	expected that the marker will use exported symbols to transmit the PC of the
				5337	marker.
				5338	The marker makes no guarantees that it will remain with any specific instruction
				5339	after optimizations. It is possible that the presence of a marker will inhibit
Chris Lattner	b3e7afd	2006-03-24 07:16:10 +0000	[diff] [blame]	5340	optimizations. The intended use is to be inserted after optimizations to allow
John Criswell	fc6b895	2005-05-16 16:17:45 +0000	[diff] [blame]	5341	correlations of simulation runs.
Andrew Lenharth	7f4ec3b	2005-03-28 20:05:49 +0000	[diff] [blame]	5342	</p>
				5343
				5344	<h5>Arguments:</h5>
				5345
				5346	<p>
				5347	<tt>id</tt> is a numerical id identifying the marker.
				5348	</p>
				5349
				5350	<h5>Semantics:</h5>
				5351
				5352	<p>
				5353	This intrinsic does not modify the behavior of the program. Backends that do not
				5354	support this intrinisic may ignore it.
				5355	</p>
				5356
				5357	</div>
				5358
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5359	<!-- _______________________________________________________________________ -->
				5360	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5361	<a name="int_readcyclecounter">'<tt>llvm.readcyclecounter</tt>' Intrinsic</a>
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5362	</div>
				5363
				5364	<div class="doc_text">
				5365
				5366	<h5>Syntax:</h5>
				5367	<pre>
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5368	declare i64 @llvm.readcyclecounter( )
Andrew Lenharth	51b8d54	2005-11-11 16:47:30 +0000	[diff] [blame]	5369	</pre>
				5370
				5371	<h5>Overview:</h5>
				5372
				5373
				5374	<p>
				5375	The '<tt>llvm.readcyclecounter</tt>' intrinsic provides access to the cycle
				5376	counter register (or similar low latency, high accuracy clocks) on those targets
				5377	that support it. On X86, it should map to RDTSC. On Alpha, it should map to RPCC.
				5378	As the backing counters overflow quickly (on the order of 9 seconds on alpha), this
				5379	should only be used for small timings.
				5380	</p>
				5381
				5382	<h5>Semantics:</h5>
				5383
				5384	<p>
				5385	When directly supported, reading the cycle counter should not modify any memory.
				5386	Implementations are allowed to either return a application specific value or a
				5387	system wide value. On backends without support, this is lowered to a constant 0.
				5388	</p>
				5389
				5390	</div>
				5391
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5392	<!-- ======================================================================= -->
				5393	<div class="doc_subsection">
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5394	<a name="int_libc">Standard C Library Intrinsics</a>
				5395	</div>
				5396
				5397	<div class="doc_text">
				5398	<p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5399	LLVM provides intrinsics for a few important standard C library functions.
				5400	These intrinsics allow source-language front-ends to pass information about the
				5401	alignment of the pointer arguments to the code generator, providing opportunity
				5402	for more efficient code generation.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5403	</p>
				5404
				5405	</div>
				5406
				5407	<!-- _______________________________________________________________________ -->
				5408	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5409	<a name="int_memcpy">'<tt>llvm.memcpy</tt>' Intrinsic</a>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5410	</div>
				5411
				5412	<div class="doc_text">
				5413
				5414	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5415	<p>This is an overloaded intrinsic. You can use llvm.memcpy on any integer bit
				5416	width. Not all targets support all bit widths however.</p>
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5417	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5418	declare void @llvm.memcpy.i8(i8 * <dest>, i8 * <src>,
				5419	i8 <len>, i32 <align>)
				5420	declare void @llvm.memcpy.i16(i8 * <dest>, i8 * <src>,
				5421	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5422	declare void @llvm.memcpy.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5423	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5424	declare void @llvm.memcpy.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5425	i64 <len>, i32 <align>)
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5426	</pre>
				5427
				5428	<h5>Overview:</h5>
				5429
				5430	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5431	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5432	location to the destination location.
				5433	</p>
				5434
				5435	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5436	Note that, unlike the standard libc function, the <tt>llvm.memcpy.*</tt>
				5437	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5438	</p>
				5439
				5440	<h5>Arguments:</h5>
				5441
				5442	<p>
				5443	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5444	the source. The third argument is an integer argument
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5445	specifying the number of bytes to copy, and the fourth argument is the alignment
				5446	of the source and destination locations.
				5447	</p>
				5448
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5449	<p>
				5450	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5451	the caller guarantees that both the source and destination pointers are aligned
				5452	to that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5453	</p>
				5454
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5455	<h5>Semantics:</h5>
				5456
				5457	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5458	The '<tt>llvm.memcpy.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	33aec9e	2004-02-12 17:01:32 +0000	[diff] [blame]	5459	location to the destination location, which are not allowed to overlap. It
				5460	copies "len" bytes of memory over. If the argument is known to be aligned to
				5461	some boundary, this can be specified as the fourth argument, otherwise it should
				5462	be set to 0 or 1.
				5463	</p>
				5464	</div>
				5465
				5466
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5467	<!-- _______________________________________________________________________ -->
				5468	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5469	<a name="int_memmove">'<tt>llvm.memmove</tt>' Intrinsic</a>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5470	</div>
				5471
				5472	<div class="doc_text">
				5473
				5474	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5475	<p>This is an overloaded intrinsic. You can use llvm.memmove on any integer bit
				5476	width. Not all targets support all bit widths however.</p>
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5477	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5478	declare void @llvm.memmove.i8(i8 * <dest>, i8 * <src>,
				5479	i8 <len>, i32 <align>)
				5480	declare void @llvm.memmove.i16(i8 * <dest>, i8 * <src>,
				5481	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5482	declare void @llvm.memmove.i32(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5483	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5484	declare void @llvm.memmove.i64(i8 * <dest>, i8 * <src>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5485	i64 <len>, i32 <align>)
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5486	</pre>
				5487
				5488	<h5>Overview:</h5>
				5489
				5490	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5491	The '<tt>llvm.memmove.*</tt>' intrinsics move a block of memory from the source
				5492	location to the destination location. It is similar to the
Chris Lattner	4b2cbcf	2008-01-06 19:51:52 +0000	[diff] [blame]	5493	'<tt>llvm.memcpy</tt>' intrinsic but allows the two memory locations to overlap.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5494	</p>
				5495
				5496	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5497	Note that, unlike the standard libc function, the <tt>llvm.memmove.*</tt>
				5498	intrinsics do not return a value, and takes an extra alignment argument.
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5499	</p>
				5500
				5501	<h5>Arguments:</h5>
				5502
				5503	<p>
				5504	The first argument is a pointer to the destination, the second is a pointer to
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5505	the source. The third argument is an integer argument
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5506	specifying the number of bytes to copy, and the fourth argument is the alignment
				5507	of the source and destination locations.
				5508	</p>
				5509
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5510	<p>
				5511	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5512	the caller guarantees that the source and destination pointers are aligned to
				5513	that boundary.
Chris Lattner	3301ced	2004-02-12 21:18:15 +0000	[diff] [blame]	5514	</p>
				5515
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5516	<h5>Semantics:</h5>
				5517
				5518	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5519	The '<tt>llvm.memmove.*</tt>' intrinsics copy a block of memory from the source
Chris Lattner	0eb51b4	2004-02-12 18:10:10 +0000	[diff] [blame]	5520	location to the destination location, which may overlap. It
				5521	copies "len" bytes of memory over. If the argument is known to be aligned to
				5522	some boundary, this can be specified as the fourth argument, otherwise it should
				5523	be set to 0 or 1.
				5524	</p>
				5525	</div>
				5526
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	5527
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5528	<!-- _______________________________________________________________________ -->
				5529	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5530	<a name="int_memset">'<tt>llvm.memset.*</tt>' Intrinsics</a>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5531	</div>
				5532
				5533	<div class="doc_text">
				5534
				5535	<h5>Syntax:</h5>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5536	<p>This is an overloaded intrinsic. You can use llvm.memset on any integer bit
				5537	width. Not all targets support all bit widths however.</p>
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5538	<pre>
Chris Lattner	824b958	2008-11-21 16:42:48 +0000	[diff] [blame]	5539	declare void @llvm.memset.i8(i8 * <dest>, i8 <val>,
				5540	i8 <len>, i32 <align>)
				5541	declare void @llvm.memset.i16(i8 * <dest>, i8 <val>,
				5542	i16 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5543	declare void @llvm.memset.i32(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5544	i32 <len>, i32 <align>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5545	declare void @llvm.memset.i64(i8 * <dest>, i8 <val>,
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5546	i64 <len>, i32 <align>)
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5547	</pre>
				5548
				5549	<h5>Overview:</h5>
				5550
				5551	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5552	The '<tt>llvm.memset.*</tt>' intrinsics fill a block of memory with a particular
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5553	byte value.
				5554	</p>
				5555
				5556	<p>
				5557	Note that, unlike the standard libc function, the <tt>llvm.memset</tt> intrinsic
				5558	does not return a value, and takes an extra alignment argument.
				5559	</p>
				5560
				5561	<h5>Arguments:</h5>
				5562
				5563	<p>
				5564	The first argument is a pointer to the destination to fill, the second is the
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5565	byte value to fill it with, the third argument is an integer
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5566	argument specifying the number of bytes to fill, and the fourth argument is the
				5567	known alignment of destination location.
				5568	</p>
				5569
				5570	<p>
				5571	If the call to this intrinisic has an alignment value that is not 0 or 1, then
Chris Lattner	f0afc2c	2006-03-04 00:02:10 +0000	[diff] [blame]	5572	the caller guarantees that the destination pointer is aligned to that boundary.
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5573	</p>
				5574
				5575	<h5>Semantics:</h5>
				5576
				5577	<p>
Chris Lattner	5b310c3	2006-03-03 00:07:20 +0000	[diff] [blame]	5578	The '<tt>llvm.memset.*</tt>' intrinsics fill "len" bytes of memory starting at
				5579	the
Chris Lattner	1061064	2004-02-14 04:08:35 +0000	[diff] [blame]	5580	destination location. If the argument is known to be aligned to some boundary,
				5581	this can be specified as the fourth argument, otherwise it should be set to 0 or
				5582	1.
				5583	</p>
				5584	</div>
				5585
				5586
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5587	<!-- _______________________________________________________________________ -->
				5588	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5589	<a name="int_sqrt">'<tt>llvm.sqrt.*</tt>' Intrinsic</a>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5590	</div>
				5591
				5592	<div class="doc_text">
				5593
				5594	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5595	<p>This is an overloaded intrinsic. You can use <tt>llvm.sqrt</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5596	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5597	types however.</p>
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5598	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5599	declare float @llvm.sqrt.f32(float %Val)
				5600	declare double @llvm.sqrt.f64(double %Val)
				5601	declare x86_fp80 @llvm.sqrt.f80(x86_fp80 %Val)
				5602	declare fp128 @llvm.sqrt.f128(fp128 %Val)
				5603	declare ppc_fp128 @llvm.sqrt.ppcf128(ppc_fp128 %Val)
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5604	</pre>
				5605
				5606	<h5>Overview:</h5>
				5607
				5608	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5609	The '<tt>llvm.sqrt</tt>' intrinsics return the sqrt of the specified operand,
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5610	returning the same value as the libm '<tt>sqrt</tt>' functions would. Unlike
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5611	<tt>sqrt</tt> in libm, however, <tt>llvm.sqrt</tt> has undefined behavior for
Chris Lattner	103e2d7	2008-01-29 07:00:44 +0000	[diff] [blame]	5612	negative numbers other than -0.0 (which allows for better optimization, because
				5613	there is no need to worry about errno being set). <tt>llvm.sqrt(-0.0)</tt> is
				5614	defined to return -0.0 like IEEE sqrt.
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5615	</p>
				5616
				5617	<h5>Arguments:</h5>
				5618
				5619	<p>
				5620	The argument and return value are floating point numbers of the same type.
				5621	</p>
				5622
				5623	<h5>Semantics:</h5>
				5624
				5625	<p>
Dan Gohman	d6257fe	2007-07-16 14:37:41 +0000	[diff] [blame]	5626	This function returns the sqrt of the specified operand if it is a nonnegative
Chris Lattner	a4d7414	2005-07-21 01:29:16 +0000	[diff] [blame]	5627	floating point number.
				5628	</p>
				5629	</div>
				5630
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5631	<!-- _______________________________________________________________________ -->
				5632	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5633	<a name="int_powi">'<tt>llvm.powi.*</tt>' Intrinsic</a>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5634	</div>
				5635
				5636	<div class="doc_text">
				5637
				5638	<h5>Syntax:</h5>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5639	<p>This is an overloaded intrinsic. You can use <tt>llvm.powi</tt> on any
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5640	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5641	types however.</p>
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5642	<pre>
Dale Johannesen	408f9c1	2007-10-02 17:47:38 +0000	[diff] [blame]	5643	declare float @llvm.powi.f32(float %Val, i32 %power)
				5644	declare double @llvm.powi.f64(double %Val, i32 %power)
				5645	declare x86_fp80 @llvm.powi.f80(x86_fp80 %Val, i32 %power)
				5646	declare fp128 @llvm.powi.f128(fp128 %Val, i32 %power)
				5647	declare ppc_fp128 @llvm.powi.ppcf128(ppc_fp128 %Val, i32 %power)
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5648	</pre>
				5649
				5650	<h5>Overview:</h5>
				5651
				5652	<p>
				5653	The '<tt>llvm.powi.*</tt>' intrinsics return the first operand raised to the
				5654	specified (positive or negative) power. The order of evaluation of
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5655	multiplications is not defined. When a vector of floating point type is
				5656	used, the second argument remains a scalar integer value.
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5657	</p>
				5658
				5659	<h5>Arguments:</h5>
				5660
				5661	<p>
				5662	The second argument is an integer power, and the first is a value to raise to
				5663	that power.
				5664	</p>
				5665
				5666	<h5>Semantics:</h5>
				5667
				5668	<p>
				5669	This function returns the first value raised to the second power with an
				5670	unspecified sequence of rounding operations.</p>
				5671	</div>
				5672
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5673	<!-- _______________________________________________________________________ -->
				5674	<div class="doc_subsubsection">
				5675	<a name="int_sin">'<tt>llvm.sin.*</tt>' Intrinsic</a>
				5676	</div>
				5677
				5678	<div class="doc_text">
				5679
				5680	<h5>Syntax:</h5>
				5681	<p>This is an overloaded intrinsic. You can use <tt>llvm.sin</tt> on any
				5682	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5683	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5684	<pre>
				5685	declare float @llvm.sin.f32(float %Val)
				5686	declare double @llvm.sin.f64(double %Val)
				5687	declare x86_fp80 @llvm.sin.f80(x86_fp80 %Val)
				5688	declare fp128 @llvm.sin.f128(fp128 %Val)
				5689	declare ppc_fp128 @llvm.sin.ppcf128(ppc_fp128 %Val)
				5690	</pre>
				5691
				5692	<h5>Overview:</h5>
				5693
				5694	<p>
				5695	The '<tt>llvm.sin.*</tt>' intrinsics return the sine of the operand.
				5696	</p>
				5697
				5698	<h5>Arguments:</h5>
				5699
				5700	<p>
				5701	The argument and return value are floating point numbers of the same type.
				5702	</p>
				5703
				5704	<h5>Semantics:</h5>
				5705
				5706	<p>
				5707	This function returns the sine of the specified operand, returning the
				5708	same values as the libm <tt>sin</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5709	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5710	</div>
				5711
				5712	<!-- _______________________________________________________________________ -->
				5713	<div class="doc_subsubsection">
				5714	<a name="int_cos">'<tt>llvm.cos.*</tt>' Intrinsic</a>
				5715	</div>
				5716
				5717	<div class="doc_text">
				5718
				5719	<h5>Syntax:</h5>
				5720	<p>This is an overloaded intrinsic. You can use <tt>llvm.cos</tt> on any
				5721	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5722	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5723	<pre>
				5724	declare float @llvm.cos.f32(float %Val)
				5725	declare double @llvm.cos.f64(double %Val)
				5726	declare x86_fp80 @llvm.cos.f80(x86_fp80 %Val)
				5727	declare fp128 @llvm.cos.f128(fp128 %Val)
				5728	declare ppc_fp128 @llvm.cos.ppcf128(ppc_fp128 %Val)
				5729	</pre>
				5730
				5731	<h5>Overview:</h5>
				5732
				5733	<p>
				5734	The '<tt>llvm.cos.*</tt>' intrinsics return the cosine of the operand.
				5735	</p>
				5736
				5737	<h5>Arguments:</h5>
				5738
				5739	<p>
				5740	The argument and return value are floating point numbers of the same type.
				5741	</p>
				5742
				5743	<h5>Semantics:</h5>
				5744
				5745	<p>
				5746	This function returns the cosine of the specified operand, returning the
				5747	same values as the libm <tt>cos</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5748	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5749	</div>
				5750
				5751	<!-- _______________________________________________________________________ -->
				5752	<div class="doc_subsubsection">
				5753	<a name="int_pow">'<tt>llvm.pow.*</tt>' Intrinsic</a>
				5754	</div>
				5755
				5756	<div class="doc_text">
				5757
				5758	<h5>Syntax:</h5>
				5759	<p>This is an overloaded intrinsic. You can use <tt>llvm.pow</tt> on any
				5760	floating point or vector of floating point type. Not all targets support all
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5761	types however.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5762	<pre>
				5763	declare float @llvm.pow.f32(float %Val, float %Power)
				5764	declare double @llvm.pow.f64(double %Val, double %Power)
				5765	declare x86_fp80 @llvm.pow.f80(x86_fp80 %Val, x86_fp80 %Power)
				5766	declare fp128 @llvm.pow.f128(fp128 %Val, fp128 %Power)
				5767	declare ppc_fp128 @llvm.pow.ppcf128(ppc_fp128 %Val, ppc_fp128 Power)
				5768	</pre>
				5769
				5770	<h5>Overview:</h5>
				5771
				5772	<p>
				5773	The '<tt>llvm.pow.*</tt>' intrinsics return the first operand raised to the
				5774	specified (positive or negative) power.
				5775	</p>
				5776
				5777	<h5>Arguments:</h5>
				5778
				5779	<p>
				5780	The second argument is a floating point power, and the first is a value to
				5781	raise to that power.
				5782	</p>
				5783
				5784	<h5>Semantics:</h5>
				5785
				5786	<p>
				5787	This function returns the first value raised to the second power,
				5788	returning the
				5789	same values as the libm <tt>pow</tt> functions would, and handles error
Dan Gohman	ba83b7e	2007-10-17 18:05:13 +0000	[diff] [blame]	5790	conditions in the same way.</p>
Dan Gohman	91c284c	2007-10-15 20:30:11 +0000	[diff] [blame]	5791	</div>
				5792
Chris Lattner	f4d252d	2006-09-08 06:34:02 +0000	[diff] [blame]	5793
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5794	<!-- ======================================================================= -->
				5795	<div class="doc_subsection">
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5796	<a name="int_manip">Bit Manipulation Intrinsics</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5797	</div>
				5798
				5799	<div class="doc_text">
				5800	<p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5801	LLVM provides intrinsics for a few important bit manipulation operations.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5802	These allow efficient code generation for some algorithms.
				5803	</p>
				5804
				5805	</div>
				5806
				5807	<!-- _______________________________________________________________________ -->
				5808	<div class="doc_subsubsection">
Reid Spencer	a3e435f	2007-04-04 02:42:35 +0000	[diff] [blame]	5809	<a name="int_bswap">'<tt>llvm.bswap.*</tt>' Intrinsics</a>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5810	</div>
				5811
				5812	<div class="doc_text">
				5813
				5814	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5815	<p>This is an overloaded intrinsic function. You can use bswap on any integer
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5816	type that is an even number of bytes (i.e. BitWidth % 16 == 0).</p>
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5817	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5818	declare i16 @llvm.bswap.i16(i16 <id>)
				5819	declare i32 @llvm.bswap.i32(i32 <id>)
				5820	declare i64 @llvm.bswap.i64(i64 <id>)
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5821	</pre>
				5822
				5823	<h5>Overview:</h5>
				5824
				5825	<p>
Reid Spencer	338ea09	2007-04-02 02:25:19 +0000	[diff] [blame]	5826	The '<tt>llvm.bswap</tt>' family of intrinsics is used to byte swap integer
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5827	values with an even number of bytes (positive multiple of 16 bits). These are
				5828	useful for performing operations on data that is not in the target's native
				5829	byte order.
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5830	</p>
				5831
				5832	<h5>Semantics:</h5>
				5833
				5834	<p>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5835	The <tt>llvm.bswap.i16</tt> intrinsic returns an i16 value that has the high
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5836	and low byte of the input i16 swapped. Similarly, the <tt>llvm.bswap.i32</tt>
				5837	intrinsic returns an i32 value that has the four bytes of the input i32
				5838	swapped, so that if the input bytes are numbered 0, 1, 2, 3 then the returned
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5839	i32 will have its bytes in 3, 2, 1, 0 order. The <tt>llvm.bswap.i48</tt>,
				5840	<tt>llvm.bswap.i64</tt> and other intrinsics extend this concept to
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5841	additional even-byte lengths (6 bytes, 8 bytes and more, respectively).
Nate Begeman	7e36c47	2006-01-13 23:26:38 +0000	[diff] [blame]	5842	</p>
				5843
				5844	</div>
				5845
				5846	<!-- _______________________________________________________________________ -->
				5847	<div class="doc_subsubsection">
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5848	<a name="int_ctpop">'<tt>llvm.ctpop.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5849	</div>
				5850
				5851	<div class="doc_text">
				5852
				5853	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5854	<p>This is an overloaded intrinsic. You can use llvm.ctpop on any integer bit
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5855	width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5856	<pre>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5857	declare i8 @llvm.ctpop.i8(i8 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5858	declare i16 @llvm.ctpop.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5859	declare i32 @llvm.ctpop.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5860	declare i64 @llvm.ctpop.i64(i64 <src>)
				5861	declare i256 @llvm.ctpop.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5862	</pre>
				5863
				5864	<h5>Overview:</h5>
				5865
				5866	<p>
Chris Lattner	ec6cb61	2006-01-16 22:38:59 +0000	[diff] [blame]	5867	The '<tt>llvm.ctpop</tt>' family of intrinsics counts the number of bits set in a
				5868	value.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5869	</p>
				5870
				5871	<h5>Arguments:</h5>
				5872
				5873	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5874	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5875	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5876	</p>
				5877
				5878	<h5>Semantics:</h5>
				5879
				5880	<p>
				5881	The '<tt>llvm.ctpop</tt>' intrinsic counts the 1's in a variable.
				5882	</p>
				5883	</div>
				5884
				5885	<!-- _______________________________________________________________________ -->
				5886	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5887	<a name="int_ctlz">'<tt>llvm.ctlz.*</tt>' Intrinsic</a>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5888	</div>
				5889
				5890	<div class="doc_text">
				5891
				5892	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5893	<p>This is an overloaded intrinsic. You can use <tt>llvm.ctlz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5894	integer bit width. Not all targets support all bit widths however.</p>
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5895	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5896	declare i8 @llvm.ctlz.i8 (i8 <src>)
				5897	declare i16 @llvm.ctlz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5898	declare i32 @llvm.ctlz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5899	declare i64 @llvm.ctlz.i64(i64 <src>)
				5900	declare i256 @llvm.ctlz.i256(i256 <src>)
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5901	</pre>
				5902
				5903	<h5>Overview:</h5>
				5904
				5905	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5906	The '<tt>llvm.ctlz</tt>' family of intrinsic functions counts the number of
				5907	leading zeros in a variable.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5908	</p>
				5909
				5910	<h5>Arguments:</h5>
				5911
				5912	<p>
Chris Lattner	cfe6b37	2005-05-07 01:46:40 +0000	[diff] [blame]	5913	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5914	integer type. The return type must match the argument type.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5915	</p>
				5916
				5917	<h5>Semantics:</h5>
				5918
				5919	<p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5920	The '<tt>llvm.ctlz</tt>' intrinsic counts the leading (most significant) zeros
				5921	in a variable. If the src == 0 then the result is the size in bits of the type
Reid Spencer	ca86e16	2006-12-31 07:07:53 +0000	[diff] [blame]	5922	of src. For example, <tt>llvm.ctlz(i32 2) = 30</tt>.
Andrew Lenharth	ec370fd	2005-05-03 18:01:48 +0000	[diff] [blame]	5923	</p>
				5924	</div>
Chris Lattner	3200628	2004-06-11 02:28:03 +0000	[diff] [blame]	5925
				5926
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5927
				5928	<!-- _______________________________________________________________________ -->
				5929	<div class="doc_subsubsection">
Chris Lattner	8a886be	2006-01-16 22:34:14 +0000	[diff] [blame]	5930	<a name="int_cttz">'<tt>llvm.cttz.*</tt>' Intrinsic</a>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5931	</div>
				5932
				5933	<div class="doc_text">
				5934
				5935	<h5>Syntax:</h5>
Reid Spencer	409e28f	2007-04-01 08:04:23 +0000	[diff] [blame]	5936	<p>This is an overloaded intrinsic. You can use <tt>llvm.cttz</tt> on any
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	5937	integer bit width. Not all targets support all bit widths however.</p>
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5938	<pre>
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5939	declare i8 @llvm.cttz.i8 (i8 <src>)
				5940	declare i16 @llvm.cttz.i16(i16 <src>)
Anton Korobeynikov	ec43a06	2007-03-22 00:02:17 +0000	[diff] [blame]	5941	declare i32 @llvm.cttz.i32(i32 <src>)
Chandler Carruth	6994040	2007-08-04 01:51:18 +0000	[diff] [blame]	5942	declare i64 @llvm.cttz.i64(i64 <src>)
				5943	declare i256 @llvm.cttz.i256(i256 <src>)
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5944	</pre>
				5945
				5946	<h5>Overview:</h5>
				5947
				5948	<p>
Reid Spencer	0b11820	2006-01-16 21:12:35 +0000	[diff] [blame]	5949	The '<tt>llvm.cttz</tt>' family of intrinsic functions counts the number of
				5950	trailing zeros.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5951	</p>
				5952
				5953	<h5>Arguments:</h5>
				5954
				5955	<p>
				5956	The only argument is the value to be counted. The argument may be of any
Reid Spencer	a517338	2007-01-04 16:43:23 +0000	[diff] [blame]	5957	integer type. The return type must match the argument type.
Chris Lattner	eff29ab	2005-05-15 19:39:26 +0000	[diff] [blame]	5958	</p>
				5959
				5960	<h5>Semantics:</h5>
				5961
				5962	<p>
				5963	The '<tt>llvm.cttz</tt>' intrinsic counts the trailing (least significant) zeros
				5964	in a variable. If the src == 0 then the result is the size in bits of the type
				5965	of src. For example, <tt>llvm.cttz(2) = 1</tt>.
				5966	</p>
				5967	</div>
				5968
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5969
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5970	<!-- ======================================================================= -->
				5971	<div class="doc_subsection">
				5972	<a name="int_overflow">Arithmetic with Overflow Intrinsics</a>
				5973	</div>
				5974
				5975	<div class="doc_text">
				5976	<p>
				5977	LLVM provides intrinsics for some arithmetic with overflow operations.
				5978	</p>
				5979
				5980	</div>
				5981
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5982	<!-- _______________________________________________________________________ -->
				5983	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5984	<a name="int_sadd_overflow">'<tt>llvm.sadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5985	</div>
				5986
				5987	<div class="doc_text">
				5988
				5989	<h5>Syntax:</h5>
				5990
				5991	<p>This is an overloaded intrinsic. You can use <tt>llvm.sadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	5992	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	5993
				5994	<pre>
				5995	declare {i16, i1} @llvm.sadd.with.overflow.i16(i16 %a, i16 %b)
				5996	declare {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				5997	declare {i64, i1} @llvm.sadd.with.overflow.i64(i64 %a, i64 %b)
				5998	</pre>
				5999
				6000	<h5>Overview:</h5>
				6001
				6002	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6003	a signed addition of the two arguments, and indicate whether an overflow
				6004	occurred during the signed summation.</p>
				6005
				6006	<h5>Arguments:</h5>
				6007
				6008	<p>The arguments (%a and %b) and the first element of the result structure may
				6009	be of integer types of any bit width, but they must have the same bit width. The
				6010	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6011	and <tt>%b</tt> are the two values that will undergo signed addition.</p>
				6012
				6013	<h5>Semantics:</h5>
				6014
				6015	<p>The '<tt>llvm.sadd.with.overflow</tt>' family of intrinsic functions perform
				6016	a signed addition of the two variables. They return a structure — the
				6017	first element of which is the signed summation, and the second element of which
				6018	is a bit specifying if the signed summation resulted in an overflow.</p>
				6019
				6020	<h5>Examples:</h5>
				6021	<pre>
				6022	%res = call {i32, i1} @llvm.sadd.with.overflow.i32(i32 %a, i32 %b)
				6023	%sum = extractvalue {i32, i1} %res, 0
				6024	%obit = extractvalue {i32, i1} %res, 1
				6025	br i1 %obit, label %overflow, label %normal
				6026	</pre>
				6027
				6028	</div>
				6029
				6030	<!-- _______________________________________________________________________ -->
				6031	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6032	<a name="int_uadd_overflow">'<tt>llvm.uadd.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6033	</div>
				6034
				6035	<div class="doc_text">
				6036
				6037	<h5>Syntax:</h5>
				6038
				6039	<p>This is an overloaded intrinsic. You can use <tt>llvm.uadd.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6040	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6041
				6042	<pre>
				6043	declare {i16, i1} @llvm.uadd.with.overflow.i16(i16 %a, i16 %b)
				6044	declare {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6045	declare {i64, i1} @llvm.uadd.with.overflow.i64(i64 %a, i64 %b)
				6046	</pre>
				6047
				6048	<h5>Overview:</h5>
				6049
				6050	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6051	an unsigned addition of the two arguments, and indicate whether a carry occurred
				6052	during the unsigned summation.</p>
				6053
				6054	<h5>Arguments:</h5>
				6055
				6056	<p>The arguments (%a and %b) and the first element of the result structure may
				6057	be of integer types of any bit width, but they must have the same bit width. The
				6058	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6059	and <tt>%b</tt> are the two values that will undergo unsigned addition.</p>
				6060
				6061	<h5>Semantics:</h5>
				6062
				6063	<p>The '<tt>llvm.uadd.with.overflow</tt>' family of intrinsic functions perform
				6064	an unsigned addition of the two arguments. They return a structure — the
				6065	first element of which is the sum, and the second element of which is a bit
				6066	specifying if the unsigned summation resulted in a carry.</p>
				6067
				6068	<h5>Examples:</h5>
				6069	<pre>
				6070	%res = call {i32, i1} @llvm.uadd.with.overflow.i32(i32 %a, i32 %b)
				6071	%sum = extractvalue {i32, i1} %res, 0
				6072	%obit = extractvalue {i32, i1} %res, 1
				6073	br i1 %obit, label %carry, label %normal
				6074	</pre>
				6075
				6076	</div>
				6077
				6078	<!-- _______________________________________________________________________ -->
				6079	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6080	<a name="int_ssub_overflow">'<tt>llvm.ssub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6081	</div>
				6082
				6083	<div class="doc_text">
				6084
				6085	<h5>Syntax:</h5>
				6086
				6087	<p>This is an overloaded intrinsic. You can use <tt>llvm.ssub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6088	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6089
				6090	<pre>
				6091	declare {i16, i1} @llvm.ssub.with.overflow.i16(i16 %a, i16 %b)
				6092	declare {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6093	declare {i64, i1} @llvm.ssub.with.overflow.i64(i64 %a, i64 %b)
				6094	</pre>
				6095
				6096	<h5>Overview:</h5>
				6097
				6098	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6099	a signed subtraction of the two arguments, and indicate whether an overflow
				6100	occurred during the signed subtraction.</p>
				6101
				6102	<h5>Arguments:</h5>
				6103
				6104	<p>The arguments (%a and %b) and the first element of the result structure may
				6105	be of integer types of any bit width, but they must have the same bit width. The
				6106	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6107	and <tt>%b</tt> are the two values that will undergo signed subtraction.</p>
				6108
				6109	<h5>Semantics:</h5>
				6110
				6111	<p>The '<tt>llvm.ssub.with.overflow</tt>' family of intrinsic functions perform
				6112	a signed subtraction of the two arguments. They return a structure — the
				6113	first element of which is the subtraction, and the second element of which is a bit
				6114	specifying if the signed subtraction resulted in an overflow.</p>
				6115
				6116	<h5>Examples:</h5>
				6117	<pre>
				6118	%res = call {i32, i1} @llvm.ssub.with.overflow.i32(i32 %a, i32 %b)
				6119	%sum = extractvalue {i32, i1} %res, 0
				6120	%obit = extractvalue {i32, i1} %res, 1
				6121	br i1 %obit, label %overflow, label %normal
				6122	</pre>
				6123
				6124	</div>
				6125
				6126	<!-- _______________________________________________________________________ -->
				6127	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6128	<a name="int_usub_overflow">'<tt>llvm.usub.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6129	</div>
				6130
				6131	<div class="doc_text">
				6132
				6133	<h5>Syntax:</h5>
				6134
				6135	<p>This is an overloaded intrinsic. You can use <tt>llvm.usub.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6136	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6137
				6138	<pre>
				6139	declare {i16, i1} @llvm.usub.with.overflow.i16(i16 %a, i16 %b)
				6140	declare {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6141	declare {i64, i1} @llvm.usub.with.overflow.i64(i64 %a, i64 %b)
				6142	</pre>
				6143
				6144	<h5>Overview:</h5>
				6145
				6146	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6147	an unsigned subtraction of the two arguments, and indicate whether an overflow
				6148	occurred during the unsigned subtraction.</p>
				6149
				6150	<h5>Arguments:</h5>
				6151
				6152	<p>The arguments (%a and %b) and the first element of the result structure may
				6153	be of integer types of any bit width, but they must have the same bit width. The
				6154	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6155	and <tt>%b</tt> are the two values that will undergo unsigned subtraction.</p>
				6156
				6157	<h5>Semantics:</h5>
				6158
				6159	<p>The '<tt>llvm.usub.with.overflow</tt>' family of intrinsic functions perform
				6160	an unsigned subtraction of the two arguments. They return a structure — the
				6161	first element of which is the subtraction, and the second element of which is a bit
				6162	specifying if the unsigned subtraction resulted in an overflow.</p>
				6163
				6164	<h5>Examples:</h5>
				6165	<pre>
				6166	%res = call {i32, i1} @llvm.usub.with.overflow.i32(i32 %a, i32 %b)
				6167	%sum = extractvalue {i32, i1} %res, 0
				6168	%obit = extractvalue {i32, i1} %res, 1
				6169	br i1 %obit, label %overflow, label %normal
				6170	</pre>
				6171
				6172	</div>
				6173
				6174	<!-- _______________________________________________________________________ -->
				6175	<div class="doc_subsubsection">
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6176	<a name="int_smul_overflow">'<tt>llvm.smul.with.overflow.*</tt>' Intrinsics</a>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6177	</div>
				6178
				6179	<div class="doc_text">
				6180
				6181	<h5>Syntax:</h5>
				6182
				6183	<p>This is an overloaded intrinsic. You can use <tt>llvm.smul.with.overflow</tt>
Bill Wendling	da01af7	2009-02-08 04:04:40 +0000	[diff] [blame]	6184	on any integer bit width.</p>
Bill Wendling	ac1df8e	2009-02-08 01:40:31 +0000	[diff] [blame]	6185
				6186	<pre>
				6187	declare {i16, i1} @llvm.smul.with.overflow.i16(i16 %a, i16 %b)
				6188	declare {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6189	declare {i64, i1} @llvm.smul.with.overflow.i64(i64 %a, i64 %b)
				6190	</pre>
				6191
				6192	<h5>Overview:</h5>
				6193
				6194	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6195	a signed multiplication of the two arguments, and indicate whether an overflow
				6196	occurred during the signed multiplication.</p>
				6197
				6198	<h5>Arguments:</h5>
				6199
				6200	<p>The arguments (%a and %b) and the first element of the result structure may
				6201	be of integer types of any bit width, but they must have the same bit width. The
				6202	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6203	and <tt>%b</tt> are the two values that will undergo signed multiplication.</p>
				6204
				6205	<h5>Semantics:</h5>
				6206
				6207	<p>The '<tt>llvm.smul.with.overflow</tt>' family of intrinsic functions perform
				6208	a signed multiplication of the two arguments. They return a structure —
				6209	the first element of which is the multiplication, and the second element of
				6210	which is a bit specifying if the signed multiplication resulted in an
				6211	overflow.</p>
				6212
				6213	<h5>Examples:</h5>
				6214	<pre>
				6215	%res = call {i32, i1} @llvm.smul.with.overflow.i32(i32 %a, i32 %b)
				6216	%sum = extractvalue {i32, i1} %res, 0
				6217	%obit = extractvalue {i32, i1} %res, 1
				6218	br i1 %obit, label %overflow, label %normal
				6219	</pre>
				6220
Reid Spencer	f86037f	2007-04-11 23:23:49 +0000	[diff] [blame]	6221	</div>
				6222
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6223	<!-- _______________________________________________________________________ -->
				6224	<div class="doc_subsubsection">
				6225	<a name="int_umul_overflow">'<tt>llvm.umul.with.overflow.*</tt>' Intrinsics</a>
				6226	</div>
				6227
				6228	<div class="doc_text">
				6229
				6230	<h5>Syntax:</h5>
				6231
				6232	<p>This is an overloaded intrinsic. You can use <tt>llvm.umul.with.overflow</tt>
				6233	on any integer bit width.</p>
				6234
				6235	<pre>
				6236	declare {i16, i1} @llvm.umul.with.overflow.i16(i16 %a, i16 %b)
				6237	declare {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6238	declare {i64, i1} @llvm.umul.with.overflow.i64(i64 %a, i64 %b)
				6239	</pre>
				6240
				6241	<h5>Overview:</h5>
				6242
Bill Wendling	41b485c	2009-02-08 23:00:09 +0000	[diff] [blame]	6243	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6244	a unsigned multiplication of the two arguments, and indicate whether an overflow
				6245	occurred during the unsigned multiplication.</p>
				6246
				6247	<h5>Arguments:</h5>
				6248
				6249	<p>The arguments (%a and %b) and the first element of the result structure may
				6250	be of integer types of any bit width, but they must have the same bit width. The
				6251	second element of the result structure must be of type <tt>i1</tt>. <tt>%a</tt>
				6252	and <tt>%b</tt> are the two values that will undergo unsigned
				6253	multiplication.</p>
				6254
				6255	<h5>Semantics:</h5>
				6256
				6257	<p>The '<tt>llvm.umul.with.overflow</tt>' family of intrinsic functions perform
				6258	an unsigned multiplication of the two arguments. They return a structure —
				6259	the first element of which is the multiplication, and the second element of
				6260	which is a bit specifying if the unsigned multiplication resulted in an
				6261	overflow.</p>
				6262
				6263	<h5>Examples:</h5>
				6264	<pre>
				6265	%res = call {i32, i1} @llvm.umul.with.overflow.i32(i32 %a, i32 %b)
				6266	%sum = extractvalue {i32, i1} %res, 0
				6267	%obit = extractvalue {i32, i1} %res, 1
				6268	br i1 %obit, label %overflow, label %normal
				6269	</pre>
				6270
				6271	</div>
				6272
Chris Lattner	8ff7590	2004-01-06 05:31:32 +0000	[diff] [blame]	6273	<!-- ======================================================================= -->
				6274	<div class="doc_subsection">
				6275	<a name="int_debugger">Debugger Intrinsics</a>
				6276	</div>
				6277
				6278	<div class="doc_text">
				6279	<p>
				6280	The LLVM debugger intrinsics (which all start with <tt>llvm.dbg.</tt> prefix),
				6281	are described in the <a
				6282	href="SourceLevelDebugging.html#format_common_intrinsics">LLVM Source Level
				6283	Debugging</a> document.
				6284	</p>
				6285	</div>
				6286
				6287
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6288	<!-- ======================================================================= -->
				6289	<div class="doc_subsection">
				6290	<a name="int_eh">Exception Handling Intrinsics</a>
				6291	</div>
				6292
				6293	<div class="doc_text">
				6294	<p> The LLVM exception handling intrinsics (which all start with
				6295	<tt>llvm.eh.</tt> prefix), are described in the <a
				6296	href="ExceptionHandling.html#format_common_intrinsics">LLVM Exception
				6297	Handling</a> document. </p>
				6298	</div>
				6299
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6300	<!-- ======================================================================= -->
				6301	<div class="doc_subsection">
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6302	<a name="int_trampoline">Trampoline Intrinsic</a>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6303	</div>
				6304
				6305	<div class="doc_text">
				6306	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6307	This intrinsic makes it possible to excise one parameter, marked with
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6308	the <tt>nest</tt> attribute, from a function. The result is a callable
				6309	function pointer lacking the nest parameter - the caller does not need
				6310	to provide a value for it. Instead, the value to use is stored in
				6311	advance in a "trampoline", a block of memory usually allocated
				6312	on the stack, which also contains code to splice the nest value into the
				6313	argument list. This is used to implement the GCC nested function address
				6314	extension.
				6315	</p>
				6316	<p>
				6317	For example, if the function is
				6318	<tt>i32 f(i8* nest %c, i32 %x, i32 %y)</tt> then the resulting function
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6319	pointer has signature <tt>i32 (i32, i32)*</tt>. It can be created as follows:</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6320	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6321	%tramp = alloca [10 x i8], align 4 ; size and alignment only correct for X86
				6322	%tramp1 = getelementptr [10 x i8]* %tramp, i32 0, i32 0
				6323	%p = call i8* @llvm.init.trampoline( i8* %tramp1, i8* bitcast (i32 (i8* nest , i32, i32)* @f to i8), i8 %nval )
				6324	%fp = bitcast i8* %p to i32 (i32, i32)*
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6325	</pre>
Bill Wendling	03295ca	2007-09-22 09:23:55 +0000	[diff] [blame]	6326	<p>The call <tt>%val = call i32 %fp( i32 %x, i32 %y )</tt> is then equivalent
				6327	to <tt>%val = call i32 %f( i8* %nval, i32 %x, i32 %y )</tt>.</p>
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6328	</div>
				6329
				6330	<!-- _______________________________________________________________________ -->
				6331	<div class="doc_subsubsection">
				6332	<a name="int_it">'<tt>llvm.init.trampoline</tt>' Intrinsic</a>
				6333	</div>
				6334	<div class="doc_text">
				6335	<h5>Syntax:</h5>
				6336	<pre>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6337	declare i8* @llvm.init.trampoline(i8* <tramp>, i8* <func>, i8* <nval>)
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6338	</pre>
				6339	<h5>Overview:</h5>
				6340	<p>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6341	This fills the memory pointed to by <tt>tramp</tt> with code
				6342	and returns a function pointer suitable for executing it.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6343	</p>
				6344	<h5>Arguments:</h5>
				6345	<p>
				6346	The <tt>llvm.init.trampoline</tt> intrinsic takes three arguments, all
				6347	pointers. The <tt>tramp</tt> argument must point to a sufficiently large
				6348	and sufficiently aligned block of memory; this memory is written to by the
Duncan Sands	c00c2ba	2007-08-22 23:39:54 +0000	[diff] [blame]	6349	intrinsic. Note that the size and the alignment are target-specific - LLVM
				6350	currently provides no portable way of determining them, so a front-end that
				6351	generates this intrinsic needs to have some target-specific knowledge.
				6352	The <tt>func</tt> argument must hold a function bitcast to an <tt>i8*</tt>.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6353	</p>
				6354	<h5>Semantics:</h5>
				6355	<p>
				6356	The block of memory pointed to by <tt>tramp</tt> is filled with target
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6357	dependent code, turning it into a function. A pointer to this function is
				6358	returned, but needs to be bitcast to an
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6359	<a href="#int_trampoline">appropriate function pointer type</a>
Duncan Sands	f7331b3	2007-09-11 14:10:23 +0000	[diff] [blame]	6360	before being called. The new function's signature is the same as that of
				6361	<tt>func</tt> with any arguments marked with the <tt>nest</tt> attribute
				6362	removed. At most one such <tt>nest</tt> argument is allowed, and it must be
				6363	of pointer type. Calling the new function is equivalent to calling
				6364	<tt>func</tt> with the same argument list, but with <tt>nval</tt> used for the
				6365	missing <tt>nest</tt> argument. If, after calling
				6366	<tt>llvm.init.trampoline</tt>, the memory pointed to by <tt>tramp</tt> is
				6367	modified, then the effect of any later call to the returned function pointer is
				6368	undefined.
Duncan Sands	36397f5	2007-07-27 12:58:54 +0000	[diff] [blame]	6369	</p>
				6370	</div>
				6371
				6372	<!-- ======================================================================= -->
				6373	<div class="doc_subsection">
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6374	<a name="int_atomics">Atomic Operations and Synchronization Intrinsics</a>
				6375	</div>
				6376
				6377	<div class="doc_text">
				6378	<p>
				6379	These intrinsic functions expand the "universal IR" of LLVM to represent
				6380	hardware constructs for atomic operations and memory synchronization. This
				6381	provides an interface to the hardware, not an interface to the programmer. It
Chris Lattner	d3eda89	2008-08-05 18:29:16 +0000	[diff] [blame]	6382	is aimed at a low enough level to allow any programming models or APIs
				6383	(Application Programming Interfaces) which
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6384	need atomic behaviors to map cleanly onto it. It is also modeled primarily on
				6385	hardware behavior. Just as hardware provides a "universal IR" for source
				6386	languages, it also provides a starting point for developing a "universal"
				6387	atomic operation and synchronization IR.
				6388	</p>
				6389	<p>
				6390	These do <em>not</em> form an API such as high-level threading libraries,
				6391	software transaction memory systems, atomic primitives, and intrinsic
				6392	functions as found in BSD, GNU libc, atomic_ops, APR, and other system and
				6393	application libraries. The hardware interface provided by LLVM should allow
				6394	a clean implementation of all of these APIs and parallel programming models.
				6395	No one model or paradigm should be selected above others unless the hardware
				6396	itself ubiquitously does so.
				6397
				6398	</p>
				6399	</div>
				6400
				6401	<!-- _______________________________________________________________________ -->
				6402	<div class="doc_subsubsection">
				6403	<a name="int_memory_barrier">'<tt>llvm.memory.barrier</tt>' Intrinsic</a>
				6404	</div>
				6405	<div class="doc_text">
				6406	<h5>Syntax:</h5>
				6407	<pre>
				6408	declare void @llvm.memory.barrier( i1 <ll>, i1 <ls>, i1 <sl>, i1 <ss>,
				6409	i1 <device> )
				6410
				6411	</pre>
				6412	<h5>Overview:</h5>
				6413	<p>
				6414	The <tt>llvm.memory.barrier</tt> intrinsic guarantees ordering between
				6415	specific pairs of memory access types.
				6416	</p>
				6417	<h5>Arguments:</h5>
				6418	<p>
				6419	The <tt>llvm.memory.barrier</tt> intrinsic requires five boolean arguments.
				6420	The first four arguments enables a specific barrier as listed below. The fith
				6421	argument specifies that the barrier applies to io or device or uncached memory.
				6422
				6423	</p>
				6424	<ul>
				6425	<li><tt>ll</tt>: load-load barrier</li>
				6426	<li><tt>ls</tt>: load-store barrier</li>
				6427	<li><tt>sl</tt>: store-load barrier</li>
				6428	<li><tt>ss</tt>: store-store barrier</li>
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6429	<li><tt>device</tt>: barrier applies to device and uncached memory also.</li>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6430	</ul>
				6431	<h5>Semantics:</h5>
				6432	<p>
				6433	This intrinsic causes the system to enforce some ordering constraints upon
				6434	the loads and stores of the program. This barrier does not indicate
				6435	<em>when</em> any events will occur, it only enforces an <em>order</em> in
				6436	which they occur. For any of the specified pairs of load and store operations
				6437	(f.ex. load-load, or store-load), all of the first operations preceding the
				6438	barrier will complete before any of the second operations succeeding the
				6439	barrier begin. Specifically the semantics for each pairing is as follows:
				6440	</p>
				6441	<ul>
				6442	<li><tt>ll</tt>: All loads before the barrier must complete before any load
				6443	after the barrier begins.</li>
				6444
				6445	<li><tt>ls</tt>: All loads before the barrier must complete before any
				6446	store after the barrier begins.</li>
				6447	<li><tt>ss</tt>: All stores before the barrier must complete before any
				6448	store after the barrier begins.</li>
				6449	<li><tt>sl</tt>: All stores before the barrier must complete before any
				6450	load after the barrier begins.</li>
				6451	</ul>
				6452	<p>
				6453	These semantics are applied with a logical "and" behavior when more than one
				6454	is enabled in a single memory barrier intrinsic.
				6455	</p>
				6456	<p>
				6457	Backends may implement stronger barriers than those requested when they do not
				6458	support as fine grained a barrier as requested. Some architectures do not
				6459	need all types of barriers and on such architectures, these become noops.
				6460	</p>
				6461	<h5>Example:</h5>
				6462	<pre>
				6463	%ptr = malloc i32
				6464	store i32 4, %ptr
				6465
				6466	%result1 = load i32* %ptr <i>; yields {i32}:result1 = 4</i>
				6467	call void @llvm.memory.barrier( i1 false, i1 true, i1 false, i1 false )
				6468	<i>; guarantee the above finishes</i>
				6469	store i32 8, %ptr <i>; before this begins</i>
				6470	</pre>
				6471	</div>
				6472
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6473	<!-- _______________________________________________________________________ -->
				6474	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6475	<a name="int_atomic_cmp_swap">'<tt>llvm.atomic.cmp.swap.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6476	</div>
				6477	<div class="doc_text">
				6478	<h5>Syntax:</h5>
				6479	<p>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6480	This is an overloaded intrinsic. You can use <tt>llvm.atomic.cmp.swap</tt> on
				6481	any integer bit width and for different address spaces. Not all targets
				6482	support all bit widths however.</p>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6483
				6484	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6485	declare i8 @llvm.atomic.cmp.swap.i8.p0i8( i8* <ptr>, i8 <cmp>, i8 <val> )
				6486	declare i16 @llvm.atomic.cmp.swap.i16.p0i16( i16* <ptr>, i16 <cmp>, i16 <val> )
				6487	declare i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* <ptr>, i32 <cmp>, i32 <val> )
				6488	declare i64 @llvm.atomic.cmp.swap.i64.p0i64( i64* <ptr>, i64 <cmp>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6489
				6490	</pre>
				6491	<h5>Overview:</h5>
				6492	<p>
				6493	This loads a value in memory and compares it to a given value. If they are
				6494	equal, it stores a new value into the memory.
				6495	</p>
				6496	<h5>Arguments:</h5>
				6497	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6498	The <tt>llvm.atomic.cmp.swap</tt> intrinsic takes three arguments. The result as
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6499	well as both <tt>cmp</tt> and <tt>val</tt> must be integer values with the
				6500	same bit width. The <tt>ptr</tt> argument must be a pointer to a value of
				6501	this integer type. While any bit width integer may be used, targets may only
				6502	lower representations they support in hardware.
				6503
				6504	</p>
				6505	<h5>Semantics:</h5>
				6506	<p>
				6507	This entire intrinsic must be executed atomically. It first loads the value
				6508	in memory pointed to by <tt>ptr</tt> and compares it with the value
				6509	<tt>cmp</tt>. If they are equal, <tt>val</tt> is stored into the memory. The
				6510	loaded value is yielded in all cases. This provides the equivalent of an
				6511	atomic compare-and-swap operation within the SSA framework.
				6512	</p>
				6513	<h5>Examples:</h5>
				6514
				6515	<pre>
				6516	%ptr = malloc i32
				6517	store i32 4, %ptr
				6518
				6519	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6520	%result1 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 4, %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6521	<i>; yields {i32}:result1 = 4</i>
				6522	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6523	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6524
				6525	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6526	%result2 = call i32 @llvm.atomic.cmp.swap.i32.p0i32( i32* %ptr, i32 5, %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6527	<i>; yields {i32}:result2 = 8</i>
				6528	%stored2 = icmp eq i32 %result2, 5 <i>; yields {i1}:stored2 = false</i>
				6529
				6530	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 8</i>
				6531	</pre>
				6532	</div>
				6533
				6534	<!-- _______________________________________________________________________ -->
				6535	<div class="doc_subsubsection">
				6536	<a name="int_atomic_swap">'<tt>llvm.atomic.swap.*</tt>' Intrinsic</a>
				6537	</div>
				6538	<div class="doc_text">
				6539	<h5>Syntax:</h5>
				6540
				6541	<p>
				6542	This is an overloaded intrinsic. You can use <tt>llvm.atomic.swap</tt> on any
				6543	integer bit width. Not all targets support all bit widths however.</p>
				6544	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6545	declare i8 @llvm.atomic.swap.i8.p0i8( i8* <ptr>, i8 <val> )
				6546	declare i16 @llvm.atomic.swap.i16.p0i16( i16* <ptr>, i16 <val> )
				6547	declare i32 @llvm.atomic.swap.i32.p0i32( i32* <ptr>, i32 <val> )
				6548	declare i64 @llvm.atomic.swap.i64.p0i64( i64* <ptr>, i64 <val> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6549
				6550	</pre>
				6551	<h5>Overview:</h5>
				6552	<p>
				6553	This intrinsic loads the value stored in memory at <tt>ptr</tt> and yields
				6554	the value from memory. It then stores the value in <tt>val</tt> in the memory
				6555	at <tt>ptr</tt>.
				6556	</p>
				6557	<h5>Arguments:</h5>
				6558
				6559	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6560	The <tt>llvm.atomic.swap</tt> intrinsic takes two arguments. Both the
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6561	<tt>val</tt> argument and the result must be integers of the same bit width.
				6562	The first argument, <tt>ptr</tt>, must be a pointer to a value of this
				6563	integer type. The targets may only lower integer representations they
				6564	support.
				6565	</p>
				6566	<h5>Semantics:</h5>
				6567	<p>
				6568	This intrinsic loads the value pointed to by <tt>ptr</tt>, yields it, and
				6569	stores <tt>val</tt> back into <tt>ptr</tt> atomically. This provides the
				6570	equivalent of an atomic swap operation within the SSA framework.
				6571
				6572	</p>
				6573	<h5>Examples:</h5>
				6574	<pre>
				6575	%ptr = malloc i32
				6576	store i32 4, %ptr
				6577
				6578	%val1 = add i32 4, 4
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6579	%result1 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val1 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6580	<i>; yields {i32}:result1 = 4</i>
				6581	%stored1 = icmp eq i32 %result1, 4 <i>; yields {i1}:stored1 = true</i>
				6582	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 8</i>
				6583
				6584	%val2 = add i32 1, 1
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6585	%result2 = call i32 @llvm.atomic.swap.i32.p0i32( i32* %ptr, i32 %val2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6586	<i>; yields {i32}:result2 = 8</i>
				6587
				6588	%stored2 = icmp eq i32 %result2, 8 <i>; yields {i1}:stored2 = true</i>
				6589	%memval2 = load i32* %ptr <i>; yields {i32}:memval2 = 2</i>
				6590	</pre>
				6591	</div>
				6592
				6593	<!-- _______________________________________________________________________ -->
				6594	<div class="doc_subsubsection">
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6595	<a name="int_atomic_load_add">'<tt>llvm.atomic.load.add.*</tt>' Intrinsic</a>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6596
				6597	</div>
				6598	<div class="doc_text">
				6599	<h5>Syntax:</h5>
				6600	<p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6601	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.add</tt> on any
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6602	integer bit width. Not all targets support all bit widths however.</p>
				6603	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6604	declare i8 @llvm.atomic.load.add.i8..p0i8( i8* <ptr>, i8 <delta> )
				6605	declare i16 @llvm.atomic.load.add.i16..p0i16( i16* <ptr>, i16 <delta> )
				6606	declare i32 @llvm.atomic.load.add.i32..p0i32( i32* <ptr>, i32 <delta> )
				6607	declare i64 @llvm.atomic.load.add.i64..p0i64( i64* <ptr>, i64 <delta> )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6608
				6609	</pre>
				6610	<h5>Overview:</h5>
				6611	<p>
				6612	This intrinsic adds <tt>delta</tt> to the value stored in memory at
				6613	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6614	</p>
				6615	<h5>Arguments:</h5>
				6616	<p>
				6617
				6618	The intrinsic takes two arguments, the first a pointer to an integer value
				6619	and the second an integer value. The result is also an integer value. These
				6620	integer types can have any bit width, but they must all have the same bit
				6621	width. The targets may only lower integer representations they support.
				6622	</p>
				6623	<h5>Semantics:</h5>
				6624	<p>
				6625	This intrinsic does a series of operations atomically. It first loads the
				6626	value stored at <tt>ptr</tt>. It then adds <tt>delta</tt>, stores the result
				6627	to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6628	</p>
				6629
				6630	<h5>Examples:</h5>
				6631	<pre>
				6632	%ptr = malloc i32
				6633	store i32 4, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6634	%result1 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 4 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6635	<i>; yields {i32}:result1 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6636	%result2 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 2 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6637	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6638	%result3 = call i32 @llvm.atomic.load.add.i32.p0i32( i32* %ptr, i32 5 )
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6639	<i>; yields {i32}:result3 = 10</i>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6640	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 15</i>
Andrew Lenharth	ab0b949	2008-02-21 06:45:13 +0000	[diff] [blame]	6641	</pre>
				6642	</div>
				6643
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6644	<!-- _______________________________________________________________________ -->
				6645	<div class="doc_subsubsection">
				6646	<a name="int_atomic_load_sub">'<tt>llvm.atomic.load.sub.*</tt>' Intrinsic</a>
				6647
				6648	</div>
				6649	<div class="doc_text">
				6650	<h5>Syntax:</h5>
				6651	<p>
				6652	This is an overloaded intrinsic. You can use <tt>llvm.atomic.load.sub</tt> on
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6653	any integer bit width and for different address spaces. Not all targets
				6654	support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6655	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6656	declare i8 @llvm.atomic.load.sub.i8.p0i32( i8* <ptr>, i8 <delta> )
				6657	declare i16 @llvm.atomic.load.sub.i16.p0i32( i16* <ptr>, i16 <delta> )
				6658	declare i32 @llvm.atomic.load.sub.i32.p0i32( i32* <ptr>, i32 <delta> )
				6659	declare i64 @llvm.atomic.load.sub.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6660
				6661	</pre>
				6662	<h5>Overview:</h5>
				6663	<p>
				6664	This intrinsic subtracts <tt>delta</tt> to the value stored in memory at
				6665	<tt>ptr</tt>. It yields the original value at <tt>ptr</tt>.
				6666	</p>
				6667	<h5>Arguments:</h5>
				6668	<p>
				6669
				6670	The intrinsic takes two arguments, the first a pointer to an integer value
				6671	and the second an integer value. The result is also an integer value. These
				6672	integer types can have any bit width, but they must all have the same bit
				6673	width. The targets may only lower integer representations they support.
				6674	</p>
				6675	<h5>Semantics:</h5>
				6676	<p>
				6677	This intrinsic does a series of operations atomically. It first loads the
				6678	value stored at <tt>ptr</tt>. It then subtracts <tt>delta</tt>, stores the
				6679	result to <tt>ptr</tt>. It yields the original value stored at <tt>ptr</tt>.
				6680	</p>
				6681
				6682	<h5>Examples:</h5>
				6683	<pre>
				6684	%ptr = malloc i32
				6685	store i32 8, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6686	%result1 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 4 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6687	<i>; yields {i32}:result1 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6688	%result2 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6689	<i>; yields {i32}:result2 = 4</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6690	%result3 = call i32 @llvm.atomic.load.sub.i32.p0i32( i32* %ptr, i32 5 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6691	<i>; yields {i32}:result3 = 2</i>
				6692	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = -3</i>
				6693	</pre>
				6694	</div>
				6695
				6696	<!-- _______________________________________________________________________ -->
				6697	<div class="doc_subsubsection">
				6698	<a name="int_atomic_load_and">'<tt>llvm.atomic.load.and.*</tt>' Intrinsic</a><br>
				6699	<a name="int_atomic_load_nand">'<tt>llvm.atomic.load.nand.*</tt>' Intrinsic</a><br>
				6700	<a name="int_atomic_load_or">'<tt>llvm.atomic.load.or.*</tt>' Intrinsic</a><br>
				6701	<a name="int_atomic_load_xor">'<tt>llvm.atomic.load.xor.*</tt>' Intrinsic</a><br>
				6702
				6703	</div>
				6704	<div class="doc_text">
				6705	<h5>Syntax:</h5>
				6706	<p>
				6707	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_and</tt>,
				6708	<tt>llvm.atomic.load_nand</tt>, <tt>llvm.atomic.load_or</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6709	<tt>llvm.atomic.load_xor</tt> on any integer bit width and for different
				6710	address spaces. Not all targets support all bit widths however.</p>
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6711	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6712	declare i8 @llvm.atomic.load.and.i8.p0i8( i8* <ptr>, i8 <delta> )
				6713	declare i16 @llvm.atomic.load.and.i16.p0i16( i16* <ptr>, i16 <delta> )
				6714	declare i32 @llvm.atomic.load.and.i32.p0i32( i32* <ptr>, i32 <delta> )
				6715	declare i64 @llvm.atomic.load.and.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6716
				6717	</pre>
				6718
				6719	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6720	declare i8 @llvm.atomic.load.or.i8.p0i8( i8* <ptr>, i8 <delta> )
				6721	declare i16 @llvm.atomic.load.or.i16.p0i16( i16* <ptr>, i16 <delta> )
				6722	declare i32 @llvm.atomic.load.or.i32.p0i32( i32* <ptr>, i32 <delta> )
				6723	declare i64 @llvm.atomic.load.or.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6724
				6725	</pre>
				6726
				6727	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6728	declare i8 @llvm.atomic.load.nand.i8.p0i32( i8* <ptr>, i8 <delta> )
				6729	declare i16 @llvm.atomic.load.nand.i16.p0i32( i16* <ptr>, i16 <delta> )
				6730	declare i32 @llvm.atomic.load.nand.i32.p0i32( i32* <ptr>, i32 <delta> )
				6731	declare i64 @llvm.atomic.load.nand.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6732
				6733	</pre>
				6734
				6735	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6736	declare i8 @llvm.atomic.load.xor.i8.p0i32( i8* <ptr>, i8 <delta> )
				6737	declare i16 @llvm.atomic.load.xor.i16.p0i32( i16* <ptr>, i16 <delta> )
				6738	declare i32 @llvm.atomic.load.xor.i32.p0i32( i32* <ptr>, i32 <delta> )
				6739	declare i64 @llvm.atomic.load.xor.i64.p0i32( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6740
				6741	</pre>
				6742	<h5>Overview:</h5>
				6743	<p>
				6744	These intrinsics bitwise the operation (and, nand, or, xor) <tt>delta</tt> to
				6745	the value stored in memory at <tt>ptr</tt>. It yields the original value
				6746	at <tt>ptr</tt>.
				6747	</p>
				6748	<h5>Arguments:</h5>
				6749	<p>
				6750
				6751	These intrinsics take two arguments, the first a pointer to an integer value
				6752	and the second an integer value. The result is also an integer value. These
				6753	integer types can have any bit width, but they must all have the same bit
				6754	width. The targets may only lower integer representations they support.
				6755	</p>
				6756	<h5>Semantics:</h5>
				6757	<p>
				6758	These intrinsics does a series of operations atomically. They first load the
				6759	value stored at <tt>ptr</tt>. They then do the bitwise operation
				6760	<tt>delta</tt>, store the result to <tt>ptr</tt>. They yield the original
				6761	value stored at <tt>ptr</tt>.
				6762	</p>
				6763
				6764	<h5>Examples:</h5>
				6765	<pre>
				6766	%ptr = malloc i32
				6767	store i32 0x0F0F, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6768	%result0 = call i32 @llvm.atomic.load.nand.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6769	<i>; yields {i32}:result0 = 0x0F0F</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6770	%result1 = call i32 @llvm.atomic.load.and.i32.p0i32( i32* %ptr, i32 0xFF )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6771	<i>; yields {i32}:result1 = 0xFFFFFFF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6772	%result2 = call i32 @llvm.atomic.load.or.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6773	<i>; yields {i32}:result2 = 0xF0</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6774	%result3 = call i32 @llvm.atomic.load.xor.i32.p0i32( i32* %ptr, i32 0F )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6775	<i>; yields {i32}:result3 = FF</i>
				6776	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = F0</i>
				6777	</pre>
				6778	</div>
				6779
				6780
				6781	<!-- _______________________________________________________________________ -->
				6782	<div class="doc_subsubsection">
				6783	<a name="int_atomic_load_max">'<tt>llvm.atomic.load.max.*</tt>' Intrinsic</a><br>
				6784	<a name="int_atomic_load_min">'<tt>llvm.atomic.load.min.*</tt>' Intrinsic</a><br>
				6785	<a name="int_atomic_load_umax">'<tt>llvm.atomic.load.umax.*</tt>' Intrinsic</a><br>
				6786	<a name="int_atomic_load_umin">'<tt>llvm.atomic.load.umin.*</tt>' Intrinsic</a><br>
				6787
				6788	</div>
				6789	<div class="doc_text">
				6790	<h5>Syntax:</h5>
				6791	<p>
				6792	These are overloaded intrinsics. You can use <tt>llvm.atomic.load_max</tt>,
				6793	<tt>llvm.atomic.load_min</tt>, <tt>llvm.atomic.load_umax</tt>, and
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6794	<tt>llvm.atomic.load_umin</tt> on any integer bit width and for different
				6795	address spaces. Not all targets
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6796	support all bit widths however.</p>
				6797	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6798	declare i8 @llvm.atomic.load.max.i8.p0i8( i8* <ptr>, i8 <delta> )
				6799	declare i16 @llvm.atomic.load.max.i16.p0i16( i16* <ptr>, i16 <delta> )
				6800	declare i32 @llvm.atomic.load.max.i32.p0i32( i32* <ptr>, i32 <delta> )
				6801	declare i64 @llvm.atomic.load.max.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6802
				6803	</pre>
				6804
				6805	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6806	declare i8 @llvm.atomic.load.min.i8.p0i8( i8* <ptr>, i8 <delta> )
				6807	declare i16 @llvm.atomic.load.min.i16.p0i16( i16* <ptr>, i16 <delta> )
				6808	declare i32 @llvm.atomic.load.min.i32..p0i32( i32* <ptr>, i32 <delta> )
				6809	declare i64 @llvm.atomic.load.min.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6810
				6811	</pre>
				6812
				6813	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6814	declare i8 @llvm.atomic.load.umax.i8.p0i8( i8* <ptr>, i8 <delta> )
				6815	declare i16 @llvm.atomic.load.umax.i16.p0i16( i16* <ptr>, i16 <delta> )
				6816	declare i32 @llvm.atomic.load.umax.i32.p0i32( i32* <ptr>, i32 <delta> )
				6817	declare i64 @llvm.atomic.load.umax.i64.p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6818
				6819	</pre>
				6820
				6821	<pre>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6822	declare i8 @llvm.atomic.load.umin.i8..p0i8( i8* <ptr>, i8 <delta> )
				6823	declare i16 @llvm.atomic.load.umin.i16.p0i16( i16* <ptr>, i16 <delta> )
				6824	declare i32 @llvm.atomic.load.umin.i32..p0i32( i32* <ptr>, i32 <delta> )
				6825	declare i64 @llvm.atomic.load.umin.i64..p0i64( i64* <ptr>, i64 <delta> )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6826
				6827	</pre>
				6828	<h5>Overview:</h5>
				6829	<p>
				6830	These intrinsics takes the signed or unsigned minimum or maximum of
				6831	<tt>delta</tt> and the value stored in memory at <tt>ptr</tt>. It yields the
				6832	original value at <tt>ptr</tt>.
				6833	</p>
				6834	<h5>Arguments:</h5>
				6835	<p>
				6836
				6837	These intrinsics take two arguments, the first a pointer to an integer value
				6838	and the second an integer value. The result is also an integer value. These
				6839	integer types can have any bit width, but they must all have the same bit
				6840	width. The targets may only lower integer representations they support.
				6841	</p>
				6842	<h5>Semantics:</h5>
				6843	<p>
				6844	These intrinsics does a series of operations atomically. They first load the
				6845	value stored at <tt>ptr</tt>. They then do the signed or unsigned min or max
				6846	<tt>delta</tt> and the value, store the result to <tt>ptr</tt>. They yield
				6847	the original value stored at <tt>ptr</tt>.
				6848	</p>
				6849
				6850	<h5>Examples:</h5>
				6851	<pre>
				6852	%ptr = malloc i32
				6853	store i32 7, %ptr
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6854	%result0 = call i32 @llvm.atomic.load.min.i32.p0i32( i32* %ptr, i32 -2 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6855	<i>; yields {i32}:result0 = 7</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6856	%result1 = call i32 @llvm.atomic.load.max.i32.p0i32( i32* %ptr, i32 8 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6857	<i>; yields {i32}:result1 = -2</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6858	%result2 = call i32 @llvm.atomic.load.umin.i32.p0i32( i32* %ptr, i32 10 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6859	<i>; yields {i32}:result2 = 8</i>
Mon P Wang	e3b3a72	2008-07-30 04:36:53 +0000	[diff] [blame]	6860	%result3 = call i32 @llvm.atomic.load.umax.i32.p0i32( i32* %ptr, i32 30 )
Mon P Wang	2887310	2008-06-25 08:15:39 +0000	[diff] [blame]	6861	<i>; yields {i32}:result3 = 8</i>
				6862	%memval1 = load i32* %ptr <i>; yields {i32}:memval1 = 30</i>
				6863	</pre>
				6864	</div>
Andrew Lenharth	22c5c1b	2008-02-16 01:24:58 +0000	[diff] [blame]	6865
				6866	<!-- ======================================================================= -->
				6867	<div class="doc_subsection">
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6868	<a name="int_general">General Intrinsics</a>
				6869	</div>
				6870
				6871	<div class="doc_text">
				6872	<p> This class of intrinsics is designed to be generic and has
				6873	no specific purpose. </p>
				6874	</div>
				6875
				6876	<!-- _______________________________________________________________________ -->
				6877	<div class="doc_subsubsection">
				6878	<a name="int_var_annotation">'<tt>llvm.var.annotation</tt>' Intrinsic</a>
				6879	</div>
				6880
				6881	<div class="doc_text">
				6882
				6883	<h5>Syntax:</h5>
				6884	<pre>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6885	declare void @llvm.var.annotation(i8* <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6886	</pre>
				6887
				6888	<h5>Overview:</h5>
				6889
				6890	<p>
				6891	The '<tt>llvm.var.annotation</tt>' intrinsic
				6892	</p>
				6893
				6894	<h5>Arguments:</h5>
				6895
				6896	<p>
Tanya Lattner	d2e8442	2007-06-18 23:42:37 +0000	[diff] [blame]	6897	The first argument is a pointer to a value, the second is a pointer to a
				6898	global string, the third is a pointer to a global string which is the source
				6899	file name, and the last argument is the line number.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6900	</p>
				6901
				6902	<h5>Semantics:</h5>
				6903
				6904	<p>
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6905	This intrinsic allows annotation of local variables with arbitrary strings.
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6906	This can be useful for special purpose optimizations that want to look for these
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6907	annotations. These have no other defined use, they are ignored by code
				6908	generation and optimization.
				6909	</p>
Tanya Lattner	6d806e9	2007-06-15 20:50:54 +0000	[diff] [blame]	6910	</div>
				6911
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6912	<!-- _______________________________________________________________________ -->
				6913	<div class="doc_subsubsection">
Tanya Lattner	e1a8da0	2007-09-21 23:57:59 +0000	[diff] [blame]	6914	<a name="int_annotation">'<tt>llvm.annotation.*</tt>' Intrinsic</a>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6915	</div>
				6916
				6917	<div class="doc_text">
				6918
				6919	<h5>Syntax:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6920	<p>This is an overloaded intrinsic. You can use '<tt>llvm.annotation</tt>' on
				6921	any integer bit width.
				6922	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6923	<pre>
Tanya Lattner	d3989a8	2007-09-22 00:03:01 +0000	[diff] [blame]	6924	declare i8 @llvm.annotation.i8(i8 <val>, i8* <str>, i8* <str>, i32 <int> )
				6925	declare i16 @llvm.annotation.i16(i16 <val>, i8* <str>, i8* <str>, i32 <int> )
				6926	declare i32 @llvm.annotation.i32(i32 <val>, i8* <str>, i8* <str>, i32 <int> )
				6927	declare i64 @llvm.annotation.i64(i64 <val>, i8* <str>, i8* <str>, i32 <int> )
				6928	declare i256 @llvm.annotation.i256(i256 <val>, i8* <str>, i8* <str>, i32 <int> )
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6929	</pre>
				6930
				6931	<h5>Overview:</h5>
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6932
				6933	<p>
				6934	The '<tt>llvm.annotation</tt>' intrinsic.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6935	</p>
				6936
				6937	<h5>Arguments:</h5>
				6938
				6939	<p>
				6940	The first argument is an integer value (result of some expression),
				6941	the second is a pointer to a global string, the third is a pointer to a global
				6942	string which is the source file name, and the last argument is the line number.
Tanya Lattner	39cfba6	2007-09-21 23:56:27 +0000	[diff] [blame]	6943	It returns the value of the first argument.
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6944	</p>
				6945
				6946	<h5>Semantics:</h5>
				6947
				6948	<p>
				6949	This intrinsic allows annotations to be put on arbitrary expressions
				6950	with arbitrary strings. This can be useful for special purpose optimizations
				6951	that want to look for these annotations. These have no other defined use, they
				6952	are ignored by code generation and optimization.
Dan Gohman	0e451ce	2008-10-14 16:51:45 +0000	[diff] [blame]	6953	</p>
Tanya Lattner	b636788	2007-09-21 22:59:12 +0000	[diff] [blame]	6954	</div>
Jim Laskey	dd4ef1b	2007-03-14 19:31:19 +0000	[diff] [blame]	6955
Anton Korobeynikov	4cb8618	2008-01-15 22:31:34 +0000	[diff] [blame]	6956	<!-- _______________________________________________________________________ -->
				6957	<div class="doc_subsubsection">
				6958	<a name="int_trap">'<tt>llvm.trap</tt>' Intrinsic</a>
				6959	</div>
				6960
				6961	<div class="doc_text">
				6962
				6963	<h5>Syntax:</h5>
				6964	<pre>
				6965	declare void @llvm.trap()
				6966	</pre>
				6967
				6968	<h5>Overview:</h5>
				6969
				6970	<p>
				6971	The '<tt>llvm.trap</tt>' intrinsic
				6972	</p>
				6973
				6974	<h5>Arguments:</h5>
				6975
				6976	<p>
				6977	None
				6978	</p>
				6979
				6980	<h5>Semantics:</h5>
				6981
				6982	<p>
				6983	This intrinsics is lowered to the target dependent trap instruction. If the
				6984	target does not have a trap instruction, this intrinsic will be lowered to the
				6985	call of the abort() function.
				6986	</p>
				6987	</div>
				6988
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6989	<!-- _______________________________________________________________________ -->
				6990	<div class="doc_subsubsection">
Misha Brukman	dccb025	2008-11-22 23:55:29 +0000	[diff] [blame]	6991	<a name="int_stackprotector">'<tt>llvm.stackprotector</tt>' Intrinsic</a>
Bill Wendling	69e4adb	2008-11-19 05:56:17 +0000	[diff] [blame]	6992	</div>
				6993	<div class="doc_text">
				6994	<h5>Syntax:</h5>
				6995	<pre>
				6996	declare void @llvm.stackprotector( i8* <guard>, i8** <slot> )
				6997
				6998	</pre>
				6999	<h5>Overview:</h5>
				7000	<p>
				7001	The <tt>llvm.stackprotector</tt> intrinsic takes the <tt>guard</tt> and stores
				7002	it onto the stack at <tt>slot</tt>. The stack slot is adjusted to ensure that
				7003	it is placed on the stack before local variables.
				7004	</p>
				7005	<h5>Arguments:</h5>
				7006	<p>
				7007	The <tt>llvm.stackprotector</tt> intrinsic requires two pointer arguments. The
				7008	first argument is the value loaded from the stack guard
				7009	<tt>@__stack_chk_guard</tt>. The second variable is an <tt>alloca</tt> that
				7010	has enough space to hold the value of the guard.
				7011	</p>
				7012	<h5>Semantics:</h5>
				7013	<p>
				7014	This intrinsic causes the prologue/epilogue inserter to force the position of
				7015	the <tt>AllocaInst</tt> stack slot to be before local variables on the
				7016	stack. This is to ensure that if a local variable on the stack is overwritten,
				7017	it will destroy the value of the guard. When the function exits, the guard on
				7018	the stack is checked against the original guard. If they're different, then
				7019	the program aborts by calling the <tt>__stack_chk_fail()</tt> function.
				7020	</p>
				7021	</div>
				7022
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7023	<!-- *********************************************************************** -->
Chris Lattner	0095054	2001-06-06 20:29:01 +0000	[diff] [blame]	7024	<hr>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7025	<address>
				7026	<a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7027	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7028	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	7029	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7030
				7031	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
Reid Spencer	05fe4b0	2006-03-14 05:39:39 +0000	[diff] [blame]	7032	<a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br>
Misha Brukman	daa4cb0	2004-03-01 17:47:27 +0000	[diff] [blame]	7033	Last modified: $Date$
				7034	</address>
Chris Lattner	c7d3ab3	2008-01-04 04:33:49 +0000	[diff] [blame]	7035
Misha Brukman	9d0919f	2003-11-08 01:05:38 +0000	[diff] [blame]	7036	</body>
				7037	</html>