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Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	1	<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"
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Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	3	<html>
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				5	<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
				6	<title>LLVM Bitcode File Format</title>
				7	<link rel="stylesheet" href="llvm.css" type="text/css">
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	8	</head>
				9	<body>
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	10	<h1> LLVM Bitcode File Format</h1>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	11	<ol>
				12	<li><a href="#abstract">Abstract</a></li>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	13	<li><a href="#overview">Overview</a></li>
				14	<li><a href="#bitstream">Bitstream Format</a>
				15	<ol>
				16	<li><a href="#magic">Magic Numbers</a></li>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	17	<li><a href="#primitives">Primitives</a></li>
				18	<li><a href="#abbrevid">Abbreviation IDs</a></li>
				19	<li><a href="#blocks">Blocks</a></li>
				20	<li><a href="#datarecord">Data Records</a></li>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	21	<li><a href="#abbreviations">Abbreviations</a></li>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	22	<li><a href="#stdblocks">Standard Blocks</a></li>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	23	</ol>
				24	</li>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	25	<li><a href="#wrapper">Bitcode Wrapper Format</a>
				26	</li>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	27	<li><a href="#llvmir">LLVM IR Encoding</a>
				28	<ol>
				29	<li><a href="#basics">Basics</a></li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	30	<li><a href="#MODULE_BLOCK">MODULE_BLOCK Contents</a></li>
				31	<li><a href="#PARAMATTR_BLOCK">PARAMATTR_BLOCK Contents</a></li>
				32	<li><a href="#TYPE_BLOCK">TYPE_BLOCK Contents</a></li>
				33	<li><a href="#CONSTANTS_BLOCK">CONSTANTS_BLOCK Contents</a></li>
				34	<li><a href="#FUNCTION_BLOCK">FUNCTION_BLOCK Contents</a></li>
				35	<li><a href="#TYPE_SYMTAB_BLOCK">TYPE_SYMTAB_BLOCK Contents</a></li>
				36	<li><a href="#VALUE_SYMTAB_BLOCK">VALUE_SYMTAB_BLOCK Contents</a></li>
				37	<li><a href="#METADATA_BLOCK">METADATA_BLOCK Contents</a></li>
				38	<li><a href="#METADATA_ATTACHMENT">METADATA_ATTACHMENT Contents</a></li>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	39	</ol>
				40	</li>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	41	</ol>
				42	<div class="doc_author">
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	43	<p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a>,
				44	<a href="http://www.reverberate.org">Joshua Haberman</a>,
				45	and <a href="mailto:housel@acm.org">Peter S. Housel</a>.
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	46	</p>
				47	</div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	48
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	49	<!-- *********************************************************************** -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	50	<h2><a name="abstract">Abstract</a></h2>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	51	<!-- *********************************************************************** -->
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	52
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	53	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	54
				55	<p>This document describes the LLVM bitstream file format and the encoding of
				56	the LLVM IR into it.</p>
				57
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	58	</div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	59
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	60	<!-- *********************************************************************** -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	61	<h2><a name="overview">Overview</a></h2>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	62	<!-- *********************************************************************** -->
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	63
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	64	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	65
				66	<p>
				67	What is commonly known as the LLVM bitcode file format (also, sometimes
				68	anachronistically known as bytecode) is actually two things: a <a
				69	href="#bitstream">bitstream container format</a>
				70	and an <a href="#llvmir">encoding of LLVM IR</a> into the container format.</p>
				71
				72	<p>
Reid Spencer	58d0547	2007-05-12 08:01:52 +0000	[diff] [blame]	73	The bitstream format is an abstract encoding of structured data, very
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	74	similar to XML in some ways. Like XML, bitstream files contain tags, and nested
				75	structures, and you can parse the file without having to understand the tags.
				76	Unlike XML, the bitstream format is a binary encoding, and unlike XML it
				77	provides a mechanism for the file to self-describe "abbreviations", which are
				78	effectively size optimizations for the content.</p>
				79
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	80	<p>LLVM IR files may be optionally embedded into a <a
				81	href="#wrapper">wrapper</a> structure that makes it easy to embed extra data
				82	along with LLVM IR files.</p>
				83
				84	<p>This document first describes the LLVM bitstream format, describes the
				85	wrapper format, then describes the record structure used by LLVM IR files.
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	86	</p>
				87
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	88	</div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	89
				90	<!-- *********************************************************************** -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	91	<h2><a name="bitstream">Bitstream Format</a></h2>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	92	<!-- *********************************************************************** -->
				93
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	94	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	95
				96	<p>
				97	The bitstream format is literally a stream of bits, with a very simple
				98	structure. This structure consists of the following concepts:
				99	</p>
				100
				101	<ul>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	102	<li>A "<a href="#magic">magic number</a>" that identifies the contents of
				103	the stream.</li>
				104	<li>Encoding <a href="#primitives">primitives</a> like variable bit-rate
				105	integers.</li>
				106	<li><a href="#blocks">Blocks</a>, which define nested content.</li>
				107	<li><a href="#datarecord">Data Records</a>, which describe entities within the
				108	file.</li>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	109	<li>Abbreviations, which specify compression optimizations for the file.</li>
				110	</ul>
				111
				112	<p>Note that the <a
				113	href="CommandGuide/html/llvm-bcanalyzer.html">llvm-bcanalyzer</a> tool can be
				114	used to dump and inspect arbitrary bitstreams, which is very useful for
				115	understanding the encoding.</p>
				116
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	117	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	118	<h3>
				119	<a name="magic">Magic Numbers</a>
				120	</h3>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	121
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	122	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	123
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	124	<p>The first two bytes of a bitcode file are 'BC' (0x42, 0x43).
				125	The second two bytes are an application-specific magic number. Generic
				126	bitcode tools can look at only the first two bytes to verify the file is
				127	bitcode, while application-specific programs will want to look at all four.</p>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	128
				129	</div>
				130
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	131	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	132	<h3>
				133	<a name="primitives">Primitives</a>
				134	</h3>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	135
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	136	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	137
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	138	<p>
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	139	A bitstream literally consists of a stream of bits, which are read in order
				140	starting with the least significant bit of each byte. The stream is made up of a
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	141	number of primitive values that encode a stream of unsigned integer values.
Chris Lattner	f958dd2	2010-01-20 17:53:51 +0000	[diff] [blame]	142	These integers are encoded in two ways: either as <a href="#fixedwidth">Fixed
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	143	Width Integers</a> or as <a href="#variablewidth">Variable Width
				144	Integers</a>.
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	145	</p>
				146
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	147	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	148	<h4>
				149	<a name="fixedwidth">Fixed Width Integers</a>
				150	</h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	151
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	152	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	153
				154	<p>Fixed-width integer values have their low bits emitted directly to the file.
				155	For example, a 3-bit integer value encodes 1 as 001. Fixed width integers
				156	are used when there are a well-known number of options for a field. For
				157	example, boolean values are usually encoded with a 1-bit wide integer.
				158	</p>
				159
				160	</div>
				161
				162	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	163	<h4>
				164	<a name="variablewidth">Variable Width Integers</a>
				165	</h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	166
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	167	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	168
				169	<p>Variable-width integer (VBR) values encode values of arbitrary size,
				170	optimizing for the case where the values are small. Given a 4-bit VBR field,
				171	any 3-bit value (0 through 7) is encoded directly, with the high bit set to
				172	zero. Values larger than N-1 bits emit their bits in a series of N-1 bit
				173	chunks, where all but the last set the high bit.</p>
				174
				175	<p>For example, the value 27 (0x1B) is encoded as 1011 0011 when emitted as a
				176	vbr4 value. The first set of four bits indicates the value 3 (011) with a
				177	continuation piece (indicated by a high bit of 1). The next word indicates a
				178	value of 24 (011 << 3) with no continuation. The sum (3+24) yields the value
				179	27.
				180	</p>
				181
				182	</div>
				183
				184	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	185	<h4><a name="char6">6-bit characters</a></h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	186
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	187	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	188
				189	<p>6-bit characters encode common characters into a fixed 6-bit field. They
Chris Lattner	f1d64e9	2007-05-12 07:50:14 +0000	[diff] [blame]	190	represent the following characters with the following 6-bit values:</p>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	191
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	192	<div class="doc_code">
				193	<pre>
				194	'a' .. 'z' — 0 .. 25
				195	'A' .. 'Z' — 26 .. 51
				196	'0' .. '9' — 52 .. 61
				197	'.' — 62
				198	'_' — 63
				199	</pre>
				200	</div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	201
				202	<p>This encoding is only suitable for encoding characters and strings that
				203	consist only of the above characters. It is completely incapable of encoding
				204	characters not in the set.</p>
				205
				206	</div>
				207
				208	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	209	<h4><a name="wordalign">Word Alignment</a></h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	210
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	211	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	212
				213	<p>Occasionally, it is useful to emit zero bits until the bitstream is a
				214	multiple of 32 bits. This ensures that the bit position in the stream can be
				215	represented as a multiple of 32-bit words.</p>
				216
				217	</div>
				218
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	219	</div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	220
				221	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	222	<h3>
				223	<a name="abbrevid">Abbreviation IDs</a>
				224	</h3>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	225
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	226	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	227
				228	<p>
				229	A bitstream is a sequential series of <a href="#blocks">Blocks</a> and
				230	<a href="#datarecord">Data Records</a>. Both of these start with an
				231	abbreviation ID encoded as a fixed-bitwidth field. The width is specified by
				232	the current block, as described below. The value of the abbreviation ID
				233	specifies either a builtin ID (which have special meanings, defined below) or
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	234	one of the abbreviation IDs defined for the current block by the stream itself.
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	235	</p>
				236
				237	<p>
				238	The set of builtin abbrev IDs is:
				239	</p>
				240
				241	<ul>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	242	<li><tt>0 - <a href="#END_BLOCK">END_BLOCK</a></tt> — This abbrev ID marks
				243	the end of the current block.</li>
				244	<li><tt>1 - <a href="#ENTER_SUBBLOCK">ENTER_SUBBLOCK</a></tt> — This
				245	abbrev ID marks the beginning of a new block.</li>
				246	<li><tt>2 - <a href="#DEFINE_ABBREV">DEFINE_ABBREV</a></tt> — This defines
				247	a new abbreviation.</li>
				248	<li><tt>3 - <a href="#UNABBREV_RECORD">UNABBREV_RECORD</a></tt> — This ID
				249	specifies the definition of an unabbreviated record.</li>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	250	</ul>
				251
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	252	<p>Abbreviation IDs 4 and above are defined by the stream itself, and specify
				253	an <a href="#abbrev_records">abbreviated record encoding</a>.</p>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	254
				255	</div>
				256
				257	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	258	<h3>
				259	<a name="blocks">Blocks</a>
				260	</h3>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	261
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	262	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	263
				264	<p>
				265	Blocks in a bitstream denote nested regions of the stream, and are identified by
				266	a content-specific id number (for example, LLVM IR uses an ID of 12 to represent
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	267	function bodies). Block IDs 0-7 are reserved for <a href="#stdblocks">standard blocks</a>
				268	whose meaning is defined by Bitcode; block IDs 8 and greater are
Benjamin Kramer	8040cd3	2009-10-12 14:46:08 +0000	[diff] [blame]	269	application specific. Nested blocks capture the hierarchical structure of the data
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	270	encoded in it, and various properties are associated with blocks as the file is
				271	parsed. Block definitions allow the reader to efficiently skip blocks
				272	in constant time if the reader wants a summary of blocks, or if it wants to
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	273	efficiently skip data it does not understand. The LLVM IR reader uses this
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	274	mechanism to skip function bodies, lazily reading them on demand.
				275	</p>
				276
				277	<p>
				278	When reading and encoding the stream, several properties are maintained for the
				279	block. In particular, each block maintains:
				280	</p>
				281
				282	<ol>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	283	<li>A current abbrev id width. This value starts at 2 at the beginning of
				284	the stream, and is set every time a
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	285	block record is entered. The block entry specifies the abbrev id width for
				286	the body of the block.</li>
				287
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	288	<li>A set of abbreviations. Abbreviations may be defined within a block, in
				289	which case they are only defined in that block (neither subblocks nor
				290	enclosing blocks see the abbreviation). Abbreviations can also be defined
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	291	inside a <tt><a href="#BLOCKINFO">BLOCKINFO</a></tt> block, in which case
				292	they are defined in all blocks that match the ID that the BLOCKINFO block is
				293	describing.
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	294	</li>
				295	</ol>
				296
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	297	<p>
				298	As sub blocks are entered, these properties are saved and the new sub-block has
				299	its own set of abbreviations, and its own abbrev id width. When a sub-block is
				300	popped, the saved values are restored.
				301	</p>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	302
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	303	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	304	<h4><a name="ENTER_SUBBLOCK">ENTER_SUBBLOCK Encoding</a></h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	305
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	306	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	307
				308	<p><tt>[ENTER_SUBBLOCK, blockid<sub>vbr8</sub>, newabbrevlen<sub>vbr4</sub>,
				309	<align32bits>, blocklen<sub>32</sub>]</tt></p>
				310
				311	<p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	312	The <tt>ENTER_SUBBLOCK</tt> abbreviation ID specifies the start of a new block
				313	record. The <tt>blockid</tt> value is encoded as an 8-bit VBR identifier, and
				314	indicates the type of block being entered, which can be
				315	a <a href="#stdblocks">standard block</a> or an application-specific block.
				316	The <tt>newabbrevlen</tt> value is a 4-bit VBR, which specifies the abbrev id
				317	width for the sub-block. The <tt>blocklen</tt> value is a 32-bit aligned value
				318	that specifies the size of the subblock in 32-bit words. This value allows the
				319	reader to skip over the entire block in one jump.
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	320	</p>
				321
				322	</div>
				323
				324	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	325	<h4><a name="END_BLOCK">END_BLOCK Encoding</a></h4>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	326
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	327	<div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	328
				329	<p><tt>[END_BLOCK, <align32bits>]</tt></p>
				330
				331	<p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	332	The <tt>END_BLOCK</tt> abbreviation ID specifies the end of the current block
				333	record. Its end is aligned to 32-bits to ensure that the size of the block is
				334	an even multiple of 32-bits.
				335	</p>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	336
				337	</div>
				338
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	339	</div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	340
				341	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	342	<h3>
				343	<a name="datarecord">Data Records</a>
				344	</h3>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	345
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	346	<div>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	347	<p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	348	Data records consist of a record code and a number of (up to) 64-bit
				349	integer values. The interpretation of the code and values is
				350	application specific and may vary between different block types.
				351	Records can be encoded either using an unabbrev record, or with an
				352	abbreviation. In the LLVM IR format, for example, there is a record
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	353	which encodes the target triple of a module. The code is
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	354	<tt>MODULE_CODE_TRIPLE</tt>, and the values of the record are the
				355	ASCII codes for the characters in the string.
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	356	</p>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	357
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	358	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	359	<h4><a name="UNABBREV_RECORD">UNABBREV_RECORD Encoding</a></h4>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	360
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	361	<div>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	362
				363	<p><tt>[UNABBREV_RECORD, code<sub>vbr6</sub>, numops<sub>vbr6</sub>,
				364	op0<sub>vbr6</sub>, op1<sub>vbr6</sub>, ...]</tt></p>
				365
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	366	<p>
				367	An <tt>UNABBREV_RECORD</tt> provides a default fallback encoding, which is both
				368	completely general and extremely inefficient. It can describe an arbitrary
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	369	record by emitting the code and operands as VBRs.
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	370	</p>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	371
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	372	<p>
				373	For example, emitting an LLVM IR target triple as an unabbreviated record
				374	requires emitting the <tt>UNABBREV_RECORD</tt> abbrevid, a vbr6 for the
				375	<tt>MODULE_CODE_TRIPLE</tt> code, a vbr6 for the length of the string, which is
				376	equal to the number of operands, and a vbr6 for each character. Because there
				377	are no letters with values less than 32, each letter would need to be emitted as
				378	at least a two-part VBR, which means that each letter would require at least 12
				379	bits. This is not an efficient encoding, but it is fully general.
				380	</p>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	381
				382	</div>
				383
				384	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	385	<h4><a name="abbrev_records">Abbreviated Record Encoding</a></h4>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	386
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	387	<div>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	388
				389	<p><tt>[<abbrevid>, fields...]</tt></p>
				390
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	391	<p>
				392	An abbreviated record is a abbreviation id followed by a set of fields that are
				393	encoded according to the <a href="#abbreviations">abbreviation definition</a>.
				394	This allows records to be encoded significantly more densely than records
				395	encoded with the <tt><a href="#UNABBREV_RECORD">UNABBREV_RECORD</a></tt> type,
				396	and allows the abbreviation types to be specified in the stream itself, which
				397	allows the files to be completely self describing. The actual encoding of
				398	abbreviations is defined below.
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	399	</p>
				400
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	401	<p>The record code, which is the first field of an abbreviated record,
				402	may be encoded in the abbreviation definition (as a literal
				403	operand) or supplied in the abbreviated record (as a Fixed or VBR
				404	operand value).</p>
				405
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	406	</div>
				407
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	408	</div>
				409
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	410	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	411	<h3>
				412	<a name="abbreviations">Abbreviations</a>
				413	</h3>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	414
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	415	<div>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	416	<p>
				417	Abbreviations are an important form of compression for bitstreams. The idea is
				418	to specify a dense encoding for a class of records once, then use that encoding
				419	to emit many records. It takes space to emit the encoding into the file, but
				420	the space is recouped (hopefully plus some) when the records that use it are
				421	emitted.
				422	</p>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	423
				424	<p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	425	Abbreviations can be determined dynamically per client, per file. Because the
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	426	abbreviations are stored in the bitstream itself, different streams of the same
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	427	format can contain different sets of abbreviations according to the needs
				428	of the specific stream.
				429	As a concrete example, LLVM IR files usually emit an abbreviation
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	430	for binary operators. If a specific LLVM module contained no or few binary
				431	operators, the abbreviation does not need to be emitted.
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	432	</p>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	433
				434	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	435	<h4><a name="DEFINE_ABBREV">DEFINE_ABBREV Encoding</a></h4>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	436
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	437	<div>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	438
				439	<p><tt>[DEFINE_ABBREV, numabbrevops<sub>vbr5</sub>, abbrevop0, abbrevop1,
				440	...]</tt></p>
				441
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	442	<p>
				443	A <tt>DEFINE_ABBREV</tt> record adds an abbreviation to the list of currently
				444	defined abbreviations in the scope of this block. This definition only exists
				445	inside this immediate block — it is not visible in subblocks or enclosing
				446	blocks. Abbreviations are implicitly assigned IDs sequentially starting from 4
				447	(the first application-defined abbreviation ID). Any abbreviations defined in a
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	448	<tt>BLOCKINFO</tt> record for the particular block type
				449	receive IDs first, in order, followed by any
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	450	abbreviations defined within the block itself. Abbreviated data records
				451	reference this ID to indicate what abbreviation they are invoking.
				452	</p>
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	453
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	454	<p>
				455	An abbreviation definition consists of the <tt>DEFINE_ABBREV</tt> abbrevid
				456	followed by a VBR that specifies the number of abbrev operands, then the abbrev
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	457	operands themselves. Abbreviation operands come in three forms. They all start
				458	with a single bit that indicates whether the abbrev operand is a literal operand
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	459	(when the bit is 1) or an encoding operand (when the bit is 0).
				460	</p>
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	461
				462	<ol>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	463	<li>Literal operands — <tt>[1<sub>1</sub>, litvalue<sub>vbr8</sub>]</tt>
				464	— Literal operands specify that the value in the result is always a single
				465	specific value. This specific value is emitted as a vbr8 after the bit
				466	indicating that it is a literal operand.</li>
				467	<li>Encoding info without data — <tt>[0<sub>1</sub>,
				468	encoding<sub>3</sub>]</tt> — Operand encodings that do not have extra
				469	data are just emitted as their code.
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	470	</li>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	471	<li>Encoding info with data — <tt>[0<sub>1</sub>, encoding<sub>3</sub>,
				472	value<sub>vbr5</sub>]</tt> — Operand encodings that do have extra data are
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	473	emitted as their code, followed by the extra data.
Chris Lattner	daeb63c	2007-05-12 07:49:15 +0000	[diff] [blame]	474	</li>
				475	</ol>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	476
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	477	<p>The possible operand encodings are:</p>
				478
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	479	<ul>
				480	<li>Fixed (code 1): The field should be emitted as
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	481	a <a href="#fixedwidth">fixed-width value</a>, whose width is specified by
				482	the operand's extra data.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	483	<li>VBR (code 2): The field should be emitted as
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	484	a <a href="#variablewidth">variable-width value</a>, whose width is
				485	specified by the operand's extra data.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	486	<li>Array (code 3): This field is an array of values. The array operand
				487	has no extra data, but expects another operand to follow it, indicating
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	488	the element type of the array. When reading an array in an abbreviated
				489	record, the first integer is a vbr6 that indicates the array length,
				490	followed by the encoded elements of the array. An array may only occur as
				491	the last operand of an abbreviation (except for the one final operand that
				492	gives the array's type).</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	493	<li>Char6 (code 4): This field should be emitted as
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	494	a <a href="#char6">char6-encoded value</a>. This operand type takes no
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	495	extra data. Char6 encoding is normally used as an array element type.
				496	</li>
				497	<li>Blob (code 5): This field is emitted as a vbr6, followed by padding to a
Chris Lattner	dcd006b	2009-04-06 21:50:39 +0000	[diff] [blame]	498	32-bit boundary (for alignment) and an array of 8-bit objects. The array of
				499	bytes is further followed by tail padding to ensure that its total length is
				500	a multiple of 4 bytes. This makes it very efficient for the reader to
				501	decode the data without having to make a copy of it: it can use a pointer to
				502	the data in the mapped in file and poke directly at it. A blob may only
				503	occur as the last operand of an abbreviation.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	504	</ul>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	505
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	506	<p>
				507	For example, target triples in LLVM modules are encoded as a record of the
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	508	form <tt>[TRIPLE, 'a', 'b', 'c', 'd']</tt>. Consider if the bitstream emitted
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	509	the following abbrev entry:
				510	</p>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	511
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	512	<div class="doc_code">
				513	<pre>
				514	[0, Fixed, 4]
				515	[0, Array]
				516	[0, Char6]
				517	</pre>
				518	</div>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	519
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	520	<p>
				521	When emitting a record with this abbreviation, the above entry would be emitted
				522	as:
				523	</p>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	524
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	525	<div class="doc_code">
Bill Wendling	903bcc4	2009-04-04 22:36:02 +0000	[diff] [blame]	526	<p>
				527	<tt>[4<sub>abbrevwidth</sub>, 2<sub>4</sub>, 4<sub>vbr6</sub>, 0<sub>6</sub>,
				528	1<sub>6</sub>, 2<sub>6</sub>, 3<sub>6</sub>]</tt>
				529	</p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	530	</div>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	531
				532	<p>These values are:</p>
				533
				534	<ol>
				535	<li>The first value, 4, is the abbreviation ID for this abbreviation.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	536	<li>The second value, 2, is the record code for <tt>TRIPLE</tt> records within LLVM IR file <tt>MODULE_BLOCK</tt> blocks.</li>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	537	<li>The third value, 4, is the length of the array.</li>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	538	<li>The rest of the values are the char6 encoded values
				539	for <tt>"abcd"</tt>.</li>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	540	</ol>
				541
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	542	<p>
				543	With this abbreviation, the triple is emitted with only 37 bits (assuming a
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	544	abbrev id width of 3). Without the abbreviation, significantly more space would
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	545	be required to emit the target triple. Also, because the <tt>TRIPLE</tt> value
				546	is not emitted as a literal in the abbreviation, the abbreviation can also be
				547	used for any other string value.
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	548	</p>
				549
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	550	</div>
				551
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	552	</div>
				553
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	554	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	555	<h3>
				556	<a name="stdblocks">Standard Blocks</a>
				557	</h3>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	558
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	559	<div>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	560
				561	<p>
				562	In addition to the basic block structure and record encodings, the bitstream
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	563	also defines specific built-in block types. These block types specify how the
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	564	stream is to be decoded or other metadata. In the future, new standard blocks
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	565	may be added. Block IDs 0-7 are reserved for standard blocks.
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	566	</p>
				567
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	568	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	569	<h4><a name="BLOCKINFO">#0 - BLOCKINFO Block</a></h4>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	570
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	571	<div>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	572
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	573	<p>
				574	The <tt>BLOCKINFO</tt> block allows the description of metadata for other
				575	blocks. The currently specified records are:
				576	</p>
				577
				578	<div class="doc_code">
				579	<pre>
				580	[SETBID (#1), blockid]
				581	[DEFINE_ABBREV, ...]
Chris Lattner	f9a3ec8	2009-04-26 22:21:57 +0000	[diff] [blame]	582	[BLOCKNAME, ...name...]
				583	[SETRECORDNAME, RecordID, ...name...]
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	584	</pre>
				585	</div>
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	586
				587	<p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	588	The <tt>SETBID</tt> record (code 1) indicates which block ID is being
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	589	described. <tt>SETBID</tt> records can occur multiple times throughout the
				590	block to change which block ID is being described. There must be
				591	a <tt>SETBID</tt> record prior to any other records.
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	592	</p>
				593
				594	<p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	595	Standard <tt>DEFINE_ABBREV</tt> records can occur inside <tt>BLOCKINFO</tt>
				596	blocks, but unlike their occurrence in normal blocks, the abbreviation is
				597	defined for blocks matching the block ID we are describing, <i>not</i> the
				598	<tt>BLOCKINFO</tt> block itself. The abbreviations defined
				599	in <tt>BLOCKINFO</tt> blocks receive abbreviation IDs as described
				600	in <tt><a href="#DEFINE_ABBREV">DEFINE_ABBREV</a></tt>.
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	601	</p>
				602
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	603	<p>The <tt>BLOCKNAME</tt> record (code 2) can optionally occur in this block. The elements of
				604	the record are the bytes of the string name of the block. llvm-bcanalyzer can use
Chris Lattner	f9a3ec8	2009-04-26 22:21:57 +0000	[diff] [blame]	605	this to dump out bitcode files symbolically.</p>
				606
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	607	<p>The <tt>SETRECORDNAME</tt> record (code 3) can also optionally occur in this block. The
				608	first operand value is a record ID number, and the rest of the elements of the record are
				609	the bytes for the string name of the record. llvm-bcanalyzer can use
Chris Lattner	f9a3ec8	2009-04-26 22:21:57 +0000	[diff] [blame]	610	this to dump out bitcode files symbolically.</p>
				611
Chris Lattner	f19b8e4	2007-10-08 18:42:45 +0000	[diff] [blame]	612	<p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	613	Note that although the data in <tt>BLOCKINFO</tt> blocks is described as
				614	"metadata," the abbreviations they contain are essential for parsing records
				615	from the corresponding blocks. It is not safe to skip them.
Chris Lattner	7300af5	2007-05-13 00:59:52 +0000	[diff] [blame]	616	</p>
				617
				618	</div>
Chris Lattner	3a1716d	2007-05-12 05:37:42 +0000	[diff] [blame]	619
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	620	</div>
				621
				622	</div>
				623
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	624	<!-- *********************************************************************** -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	625	<h2><a name="wrapper">Bitcode Wrapper Format</a></h2>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	626	<!-- *********************************************************************** -->
				627
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	628	<div>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	629
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	630	<p>
				631	Bitcode files for LLVM IR may optionally be wrapped in a simple wrapper
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	632	structure. This structure contains a simple header that indicates the offset
				633	and size of the embedded BC file. This allows additional information to be
				634	stored alongside the BC file. The structure of this file header is:
				635	</p>
				636
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	637	<div class="doc_code">
Bill Wendling	903bcc4	2009-04-04 22:36:02 +0000	[diff] [blame]	638	<p>
				639	<tt>[Magic<sub>32</sub>, Version<sub>32</sub>, Offset<sub>32</sub>,
				640	Size<sub>32</sub>, CPUType<sub>32</sub>]</tt>
				641	</p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	642	</div>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	643
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	644	<p>
				645	Each of the fields are 32-bit fields stored in little endian form (as with
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	646	the rest of the bitcode file fields). The Magic number is always
				647	<tt>0x0B17C0DE</tt> and the version is currently always <tt>0</tt>. The Offset
				648	field is the offset in bytes to the start of the bitcode stream in the file, and
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	649	the Size field is the size in bytes of the stream. CPUType is a target-specific
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	650	value that can be used to encode the CPU of the target.
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	651	</p>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	652
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	653	</div>
Chris Lattner	6fa6a32	2008-07-09 05:14:23 +0000	[diff] [blame]	654
				655	<!-- *********************************************************************** -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	656	<h2><a name="llvmir">LLVM IR Encoding</a></h2>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	657	<!-- *********************************************************************** -->
				658
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	659	<div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	660
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	661	<p>
				662	LLVM IR is encoded into a bitstream by defining blocks and records. It uses
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	663	blocks for things like constant pools, functions, symbol tables, etc. It uses
				664	records for things like instructions, global variable descriptors, type
				665	descriptions, etc. This document does not describe the set of abbreviations
				666	that the writer uses, as these are fully self-described in the file, and the
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	667	reader is not allowed to build in any knowledge of this.
				668	</p>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	669
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	670	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	671	<h3>
				672	<a name="basics">Basics</a>
				673	</h3>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	674
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	675	<div>
				676
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	677	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	678	<h4><a name="ir_magic">LLVM IR Magic Number</a></h4>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	679
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	680	<div>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	681
				682	<p>
				683	The magic number for LLVM IR files is:
				684	</p>
				685
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	686	<div class="doc_code">
Bill Wendling	903bcc4	2009-04-04 22:36:02 +0000	[diff] [blame]	687	<p>
				688	<tt>[0x0<sub>4</sub>, 0xC<sub>4</sub>, 0xE<sub>4</sub>, 0xD<sub>4</sub>]</tt>
				689	</p>
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	690	</div>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	691
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	692	<p>
				693	When combined with the bitcode magic number and viewed as bytes, this is
				694	<tt>"BC 0xC0DE"</tt>.
				695	</p>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	696
				697	</div>
				698
				699	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	700	<h4><a name="ir_signed_vbr">Signed VBRs</a></h4>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	701
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	702	<div>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	703
				704	<p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	705	<a href="#variablewidth">Variable Width Integer</a> encoding is an efficient way to
				706	encode arbitrary sized unsigned values, but is an extremely inefficient for
				707	encoding signed values, as signed values are otherwise treated as maximally large
				708	unsigned values.
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	709	</p>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	710
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	711	<p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	712	As such, signed VBR values of a specific width are emitted as follows:
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	713	</p>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	714
				715	<ul>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	716	<li>Positive values are emitted as VBRs of the specified width, but with their
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	717	value shifted left by one.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	718	<li>Negative values are emitted as VBRs of the specified width, but the negated
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	719	value is shifted left by one, and the low bit is set.</li>
				720	</ul>
				721
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	722	<p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	723	With this encoding, small positive and small negative values can both
				724	be emitted efficiently. Signed VBR encoding is used in
				725	<tt>CST_CODE_INTEGER</tt> and <tt>CST_CODE_WIDE_INTEGER</tt> records
				726	within <tt>CONSTANTS_BLOCK</tt> blocks.
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	727	</p>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	728
				729	</div>
				730
				731
				732	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	733	<h4><a name="ir_blocks">LLVM IR Blocks</a></h4>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	734
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	735	<div>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	736
				737	<p>
				738	LLVM IR is defined with the following blocks:
				739	</p>
				740
				741	<ul>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	742	<li>8 — <a href="#MODULE_BLOCK"><tt>MODULE_BLOCK</tt></a> — This is the top-level block that
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	743	contains the entire module, and describes a variety of per-module
				744	information.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	745	<li>9 — <a href="#PARAMATTR_BLOCK"><tt>PARAMATTR_BLOCK</tt></a> — This enumerates the parameter
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	746	attributes.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	747	<li>10 — <a href="#TYPE_BLOCK"><tt>TYPE_BLOCK</tt></a> — This describes all of the types in
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	748	the module.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	749	<li>11 — <a href="#CONSTANTS_BLOCK"><tt>CONSTANTS_BLOCK</tt></a> — This describes constants for a
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	750	module or function.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	751	<li>12 — <a href="#FUNCTION_BLOCK"><tt>FUNCTION_BLOCK</tt></a> — This describes a function
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	752	body.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	753	<li>13 — <a href="#TYPE_SYMTAB_BLOCK"><tt>TYPE_SYMTAB_BLOCK</tt></a> — This describes the type symbol
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	754	table.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	755	<li>14 — <a href="#VALUE_SYMTAB_BLOCK"><tt>VALUE_SYMTAB_BLOCK</tt></a> — This describes a value symbol
Bill Wendling	bb7425f	2009-04-04 22:27:03 +0000	[diff] [blame]	756	table.</li>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	757	<li>15 — <a href="#METADATA_BLOCK"><tt>METADATA_BLOCK</tt></a> — This describes metadata items.</li>
				758	<li>16 — <a href="#METADATA_ATTACHMENT"><tt>METADATA_ATTACHMENT</tt></a> — This contains records associating metadata with function instruction values.</li>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	759	</ul>
				760
				761	</div>
				762
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	763	</div>
				764
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	765	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	766	<h3>
				767	<a name="MODULE_BLOCK">MODULE_BLOCK Contents</a>
				768	</h3>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	769
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	770	<div>
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	771
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	772	<p>The <tt>MODULE_BLOCK</tt> block (id 8) is the top-level block for LLVM
				773	bitcode files, and each bitcode file must contain exactly one. In
				774	addition to records (described below) containing information
				775	about the module, a <tt>MODULE_BLOCK</tt> block may contain the
				776	following sub-blocks:
				777	</p>
				778
				779	<ul>
				780	<li><a href="#BLOCKINFO"><tt>BLOCKINFO</tt></a></li>
				781	<li><a href="#PARAMATTR_BLOCK"><tt>PARAMATTR_BLOCK</tt></a></li>
				782	<li><a href="#TYPE_BLOCK"><tt>TYPE_BLOCK</tt></a></li>
				783	<li><a href="#TYPE_SYMTAB_BLOCK"><tt>TYPE_SYMTAB_BLOCK</tt></a></li>
				784	<li><a href="#VALUE_SYMTAB_BLOCK"><tt>VALUE_SYMTAB_BLOCK</tt></a></li>
				785	<li><a href="#CONSTANTS_BLOCK"><tt>CONSTANTS_BLOCK</tt></a></li>
				786	<li><a href="#FUNCTION_BLOCK"><tt>FUNCTION_BLOCK</tt></a></li>
				787	<li><a href="#METADATA_BLOCK"><tt>METADATA_BLOCK</tt></a></li>
				788	</ul>
				789
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	790	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	791	<h4><a name="MODULE_CODE_VERSION">MODULE_CODE_VERSION Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	792
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	793	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	794
				795	<p><tt>[VERSION, version#]</tt></p>
				796
				797	<p>The <tt>VERSION</tt> record (code 1) contains a single value
				798	indicating the format version. Only version 0 is supported at this
				799	time.</p>
				800	</div>
				801
				802	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	803	<h4><a name="MODULE_CODE_TRIPLE">MODULE_CODE_TRIPLE Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	804
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	805	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	806	<p><tt>[TRIPLE, ...string...]</tt></p>
				807
				808	<p>The <tt>TRIPLE</tt> record (code 2) contains a variable number of
				809	values representing the bytes of the <tt>target triple</tt>
				810	specification string.</p>
				811	</div>
				812
				813	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	814	<h4><a name="MODULE_CODE_DATALAYOUT">MODULE_CODE_DATALAYOUT Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	815
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	816	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	817	<p><tt>[DATALAYOUT, ...string...]</tt></p>
				818
				819	<p>The <tt>DATALAYOUT</tt> record (code 3) contains a variable number of
				820	values representing the bytes of the <tt>target datalayout</tt>
				821	specification string.</p>
				822	</div>
				823
				824	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	825	<h4><a name="MODULE_CODE_ASM">MODULE_CODE_ASM Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	826
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	827	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	828	<p><tt>[ASM, ...string...]</tt></p>
				829
				830	<p>The <tt>ASM</tt> record (code 4) contains a variable number of
				831	values representing the bytes of <tt>module asm</tt> strings, with
				832	individual assembly blocks separated by newline (ASCII 10) characters.</p>
				833	</div>
				834
				835	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	836	<h4><a name="MODULE_CODE_SECTIONNAME">MODULE_CODE_SECTIONNAME Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	837
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	838	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	839	<p><tt>[SECTIONNAME, ...string...]</tt></p>
				840
				841	<p>The <tt>SECTIONNAME</tt> record (code 5) contains a variable number
				842	of values representing the bytes of a single section name
				843	string. There should be one <tt>SECTIONNAME</tt> record for each
				844	section name referenced (e.g., in global variable or function
				845	<tt>section</tt> attributes) within the module. These records can be
				846	referenced by the 1-based index in the <i>section</i> fields of
				847	<tt>GLOBALVAR</tt> or <tt>FUNCTION</tt> records.</p>
				848	</div>
				849
				850	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	851	<h4><a name="MODULE_CODE_DEPLIB">MODULE_CODE_DEPLIB Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	852
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	853	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	854	<p><tt>[DEPLIB, ...string...]</tt></p>
				855
				856	<p>The <tt>DEPLIB</tt> record (code 6) contains a variable number of
				857	values representing the bytes of a single dependent library name
				858	string, one of the libraries mentioned in a <tt>deplibs</tt>
				859	declaration. There should be one <tt>DEPLIB</tt> record for each
				860	library name referenced.</p>
				861	</div>
				862
				863	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	864	<h4><a name="MODULE_CODE_GLOBALVAR">MODULE_CODE_GLOBALVAR Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	865
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	866	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	867	<p><tt>[GLOBALVAR, pointer type, isconst, initid, linkage, alignment, section, visibility, threadlocal]</tt></p>
				868
				869	<p>The <tt>GLOBALVAR</tt> record (code 7) marks the declaration or
				870	definition of a global variable. The operand fields are:</p>
				871
				872	<ul>
				873	<li><i>pointer type</i>: The type index of the pointer type used to point to
				874	this global variable</li>
				875
				876	<li><i>isconst</i>: Non-zero if the variable is treated as constant within
				877	the module, or zero if it is not</li>
				878
				879	<li><i>initid</i>: If non-zero, the value index of the initializer for this
				880	variable, plus 1.</li>
				881
				882	<li><a name="linkage"><i>linkage</i></a>: An encoding of the linkage
				883	type for this variable:
				884	<ul>
				885	<li><tt>external</tt>: code 0</li>
				886	<li><tt>weak</tt>: code 1</li>
				887	<li><tt>appending</tt>: code 2</li>
				888	<li><tt>internal</tt>: code 3</li>
				889	<li><tt>linkonce</tt>: code 4</li>
				890	<li><tt>dllimport</tt>: code 5</li>
				891	<li><tt>dllexport</tt>: code 6</li>
				892	<li><tt>extern_weak</tt>: code 7</li>
				893	<li><tt>common</tt>: code 8</li>
				894	<li><tt>private</tt>: code 9</li>
				895	<li><tt>weak_odr</tt>: code 10</li>
				896	<li><tt>linkonce_odr</tt>: code 11</li>
				897	<li><tt>available_externally</tt>: code 12</li>
				898	<li><tt>linker_private</tt>: code 13</li>
				899	</ul>
				900	</li>
				901
				902	<li><i>alignment</i>: The logarithm base 2 of the variable's requested
				903	alignment, plus 1</li>
				904
				905	<li><i>section</i>: If non-zero, the 1-based section index in the
				906	table of <a href="#MODULE_CODE_SECTIONNAME">MODULE_CODE_SECTIONNAME</a>
				907	entries.</li>
				908
				909	<li><a name="visibility"><i>visibility</i></a>: If present, an
				910	encoding of the visibility of this variable:
				911	<ul>
				912	<li><tt>default</tt>: code 0</li>
				913	<li><tt>hidden</tt>: code 1</li>
				914	<li><tt>protected</tt>: code 2</li>
				915	</ul>
				916	</li>
				917
				918	<li><i>threadlocal</i>: If present and non-zero, indicates that the variable
				919	is <tt>thread_local</tt></li>
				920
Rafael Espindola	bea4626	2011-01-08 16:42:36 +0000	[diff] [blame]	921	<li><i>unnamed_addr</i>: If present and non-zero, indicates that the variable
Bill Wendling	9046413	2011-04-08 21:43:08 +0000	[diff] [blame]	922	has <tt>unnamed_addr</tt></li>
Rafael Espindola	bea4626	2011-01-08 16:42:36 +0000	[diff] [blame]	923
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	924	</ul>
				925	</div>
				926
				927	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	928	<h4><a name="MODULE_CODE_FUNCTION">MODULE_CODE_FUNCTION Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	929
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	930	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	931
				932	<p><tt>[FUNCTION, type, callingconv, isproto, linkage, paramattr, alignment, section, visibility, gc]</tt></p>
				933
				934	<p>The <tt>FUNCTION</tt> record (code 8) marks the declaration or
				935	definition of a function. The operand fields are:</p>
				936
				937	<ul>
				938	<li><i>type</i>: The type index of the function type describing this function</li>
				939
				940	<li><i>callingconv</i>: The calling convention number:
				941	<ul>
				942	<li><tt>ccc</tt>: code 0</li>
				943	<li><tt>fastcc</tt>: code 8</li>
				944	<li><tt>coldcc</tt>: code 9</li>
				945	<li><tt>x86_stdcallcc</tt>: code 64</li>
				946	<li><tt>x86_fastcallcc</tt>: code 65</li>
				947	<li><tt>arm_apcscc</tt>: code 66</li>
				948	<li><tt>arm_aapcscc</tt>: code 67</li>
				949	<li><tt>arm_aapcs_vfpcc</tt>: code 68</li>
				950	</ul>
				951	</li>
				952
				953	<li><i>isproto</i>: Non-zero if this entry represents a declaration
				954	rather than a definition</li>
				955
				956	<li><i>linkage</i>: An encoding of the <a href="#linkage">linkage type</a>
				957	for this function</li>
				958
				959	<li><i>paramattr</i>: If nonzero, the 1-based parameter attribute index
				960	into the table of <a href="#PARAMATTR_CODE_ENTRY">PARAMATTR_CODE_ENTRY</a>
				961	entries.</li>
				962
				963	<li><i>alignment</i>: The logarithm base 2 of the function's requested
				964	alignment, plus 1</li>
				965
				966	<li><i>section</i>: If non-zero, the 1-based section index in the
				967	table of <a href="#MODULE_CODE_SECTIONNAME">MODULE_CODE_SECTIONNAME</a>
				968	entries.</li>
				969
				970	<li><i>visibility</i>: An encoding of the <a href="#visibility">visibility</a>
				971	of this function</li>
				972
				973	<li><i>gc</i>: If present and nonzero, the 1-based garbage collector
				974	index in the table of
				975	<a href="#MODULE_CODE_GCNAME">MODULE_CODE_GCNAME</a> entries.</li>
Rafael Espindola	bea4626	2011-01-08 16:42:36 +0000	[diff] [blame]	976
				977	<li><i>unnamed_addr</i>: If present and non-zero, indicates that the function
NAKAMURA Takumi	4d6deb0	2011-04-09 09:51:57 +0000	[diff] [blame]	978	has <tt>unnamed_addr</tt></li>
Rafael Espindola	bea4626	2011-01-08 16:42:36 +0000	[diff] [blame]	979
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	980	</ul>
				981	</div>
				982
				983	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	984	<h4><a name="MODULE_CODE_ALIAS">MODULE_CODE_ALIAS Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	985
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	986	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	987
				988	<p><tt>[ALIAS, alias type, aliasee val#, linkage, visibility]</tt></p>
				989
				990	<p>The <tt>ALIAS</tt> record (code 9) marks the definition of an
				991	alias. The operand fields are</p>
				992
				993	<ul>
				994	<li><i>alias type</i>: The type index of the alias</li>
				995
				996	<li><i>aliasee val#</i>: The value index of the aliased value</li>
				997
				998	<li><i>linkage</i>: An encoding of the <a href="#linkage">linkage type</a>
				999	for this alias</li>
				1000
				1001	<li><i>visibility</i>: If present, an encoding of the
				1002	<a href="#visibility">visibility</a> of the alias</li>
				1003
				1004	</ul>
				1005	</div>
				1006
				1007	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1008	<h4><a name="MODULE_CODE_PURGEVALS">MODULE_CODE_PURGEVALS Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1009
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1010	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1011	<p><tt>[PURGEVALS, numvals]</tt></p>
				1012
				1013	<p>The <tt>PURGEVALS</tt> record (code 10) resets the module-level
				1014	value list to the size given by the single operand value. Module-level
				1015	value list items are added by <tt>GLOBALVAR</tt>, <tt>FUNCTION</tt>,
				1016	and <tt>ALIAS</tt> records. After a <tt>PURGEVALS</tt> record is seen,
				1017	new value indices will start from the given <i>numvals</i> value.</p>
				1018	</div>
				1019
				1020	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1021	<h4><a name="MODULE_CODE_GCNAME">MODULE_CODE_GCNAME Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1022
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1023	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1024	<p><tt>[GCNAME, ...string...]</tt></p>
				1025
				1026	<p>The <tt>GCNAME</tt> record (code 11) contains a variable number of
				1027	values representing the bytes of a single garbage collector name
				1028	string. There should be one <tt>GCNAME</tt> record for each garbage
				1029	collector name referenced in function <tt>gc</tt> attributes within
				1030	the module. These records can be referenced by 1-based index in the <i>gc</i>
				1031	fields of <tt>FUNCTION</tt> records.</p>
				1032	</div>
				1033
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1034	</div>
				1035
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1036	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1037	<h3>
				1038	<a name="PARAMATTR_BLOCK">PARAMATTR_BLOCK Contents</a>
				1039	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1040
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1041	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1042
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1043	<p>The <tt>PARAMATTR_BLOCK</tt> block (id 9) contains a table of
				1044	entries describing the attributes of function parameters. These
				1045	entries are referenced by 1-based index in the <i>paramattr</i> field
				1046	of module block <a name="MODULE_CODE_FUNCTION"><tt>FUNCTION</tt></a>
				1047	records, or within the <i>attr</i> field of function block <a
				1048	href="#FUNC_CODE_INST_INVOKE"><tt>INST_INVOKE</tt></a> and <a
				1049	href="#FUNC_CODE_INST_CALL"><tt>INST_CALL</tt></a> records.</p>
				1050
				1051	<p>Entries within <tt>PARAMATTR_BLOCK</tt> are constructed to ensure
				1052	that each is unique (i.e., no two indicies represent equivalent
				1053	attribute lists). </p>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1054
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1055	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1056	<h4><a name="PARAMATTR_CODE_ENTRY">PARAMATTR_CODE_ENTRY Record</a></h4>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1057
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1058	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1059
				1060	<p><tt>[ENTRY, paramidx0, attr0, paramidx1, attr1...]</tt></p>
				1061
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1062	<p>The <tt>ENTRY</tt> record (code 1) contains an even number of
				1063	values describing a unique set of function parameter attributes. Each
				1064	<i>paramidx</i> value indicates which set of attributes is
				1065	represented, with 0 representing the return value attributes,
				1066	0xFFFFFFFF representing function attributes, and other values
				1067	representing 1-based function parameters. Each <i>attr</i> value is a
				1068	bitmap with the following interpretation:
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1069	</p>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1070
				1071	<ul>
				1072	<li>bit 0: <tt>zeroext</tt></li>
				1073	<li>bit 1: <tt>signext</tt></li>
				1074	<li>bit 2: <tt>noreturn</tt></li>
				1075	<li>bit 3: <tt>inreg</tt></li>
				1076	<li>bit 4: <tt>sret</tt></li>
				1077	<li>bit 5: <tt>nounwind</tt></li>
				1078	<li>bit 6: <tt>noalias</tt></li>
				1079	<li>bit 7: <tt>byval</tt></li>
				1080	<li>bit 8: <tt>nest</tt></li>
				1081	<li>bit 9: <tt>readnone</tt></li>
				1082	<li>bit 10: <tt>readonly</tt></li>
				1083	<li>bit 11: <tt>noinline</tt></li>
				1084	<li>bit 12: <tt>alwaysinline</tt></li>
				1085	<li>bit 13: <tt>optsize</tt></li>
				1086	<li>bit 14: <tt>ssp</tt></li>
				1087	<li>bit 15: <tt>sspreq</tt></li>
				1088	<li>bits 16–31: <tt>align <var>n</var></tt></li>
				1089	<li>bit 32: <tt>nocapture</tt></li>
				1090	<li>bit 33: <tt>noredzone</tt></li>
				1091	<li>bit 34: <tt>noimplicitfloat</tt></li>
				1092	<li>bit 35: <tt>naked</tt></li>
				1093	<li>bit 36: <tt>inlinehint</tt></li>
				1094	<li>bits 37–39: <tt>alignstack <var>n</var></tt>, represented as
				1095	the logarithm base 2 of the requested alignment, plus 1</li>
				1096	</ul>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1097	</div>
				1098
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1099	</div>
				1100
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1101	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1102	<h3>
				1103	<a name="TYPE_BLOCK">TYPE_BLOCK Contents</a>
				1104	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1105
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1106	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1107
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1108	<p>The <tt>TYPE_BLOCK</tt> block (id 10) contains records which
				1109	constitute a table of type operator entries used to represent types
				1110	referenced within an LLVM module. Each record (with the exception of
				1111	<a href="#TYPE_CODE_NUMENTRY"><tt>NUMENTRY</tt></a>) generates a
				1112	single type table entry, which may be referenced by 0-based index from
				1113	instructions, constants, metadata, type symbol table entries, or other
				1114	type operator records.
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1115	</p>
				1116
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1117	<p>Entries within <tt>TYPE_BLOCK</tt> are constructed to ensure that
				1118	each entry is unique (i.e., no two indicies represent structurally
				1119	equivalent types). </p>
				1120
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1121	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1122	<h4><a name="TYPE_CODE_NUMENTRY">TYPE_CODE_NUMENTRY Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1123
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1124	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1125
				1126	<p><tt>[NUMENTRY, numentries]</tt></p>
				1127
				1128	<p>The <tt>NUMENTRY</tt> record (code 1) contains a single value which
				1129	indicates the total number of type code entries in the type table of
				1130	the module. If present, <tt>NUMENTRY</tt> should be the first record
				1131	in the block.
				1132	</p>
				1133	</div>
				1134
				1135	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1136	<h4><a name="TYPE_CODE_VOID">TYPE_CODE_VOID Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1137
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1138	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1139
				1140	<p><tt>[VOID]</tt></p>
				1141
				1142	<p>The <tt>VOID</tt> record (code 2) adds a <tt>void</tt> type to the
				1143	type table.
				1144	</p>
				1145	</div>
				1146
				1147	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1148	<h4><a name="TYPE_CODE_FLOAT">TYPE_CODE_FLOAT Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1149
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1150	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1151
				1152	<p><tt>[FLOAT]</tt></p>
				1153
				1154	<p>The <tt>FLOAT</tt> record (code 3) adds a <tt>float</tt> (32-bit
				1155	floating point) type to the type table.
				1156	</p>
				1157	</div>
				1158
				1159	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1160	<h4><a name="TYPE_CODE_DOUBLE">TYPE_CODE_DOUBLE Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1161
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1162	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1163
				1164	<p><tt>[DOUBLE]</tt></p>
				1165
				1166	<p>The <tt>DOUBLE</tt> record (code 4) adds a <tt>double</tt> (64-bit
				1167	floating point) type to the type table.
				1168	</p>
				1169	</div>
				1170
				1171	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1172	<h4><a name="TYPE_CODE_LABEL">TYPE_CODE_LABEL Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1173
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1174	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1175
				1176	<p><tt>[LABEL]</tt></p>
				1177
				1178	<p>The <tt>LABEL</tt> record (code 5) adds a <tt>label</tt> type to
				1179	the type table.
				1180	</p>
				1181	</div>
				1182
				1183	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1184	<h4><a name="TYPE_CODE_OPAQUE">TYPE_CODE_OPAQUE Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1185
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1186	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1187
				1188	<p><tt>[OPAQUE]</tt></p>
				1189
				1190	<p>The <tt>OPAQUE</tt> record (code 6) adds an <tt>opaque</tt> type to
				1191	the type table. Note that distinct <tt>opaque</tt> types are not
				1192	unified.
				1193	</p>
				1194	</div>
				1195
				1196	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1197	<h4><a name="TYPE_CODE_INTEGER">TYPE_CODE_INTEGER Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1198
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1199	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1200
				1201	<p><tt>[INTEGER, width]</tt></p>
				1202
				1203	<p>The <tt>INTEGER</tt> record (code 7) adds an integer type to the
				1204	type table. The single <i>width</i> field indicates the width of the
				1205	integer type.
				1206	</p>
				1207	</div>
				1208
				1209	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1210	<h4><a name="TYPE_CODE_POINTER">TYPE_CODE_POINTER Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1211
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1212	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1213
				1214	<p><tt>[POINTER, pointee type, address space]</tt></p>
				1215
				1216	<p>The <tt>POINTER</tt> record (code 8) adds a pointer type to the
				1217	type table. The operand fields are</p>
				1218
				1219	<ul>
				1220	<li><i>pointee type</i>: The type index of the pointed-to type</li>
				1221
				1222	<li><i>address space</i>: If supplied, the target-specific numbered
				1223	address space where the pointed-to object resides. Otherwise, the
				1224	default address space is zero.
				1225	</li>
				1226	</ul>
				1227	</div>
				1228
				1229	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1230	<h4><a name="TYPE_CODE_FUNCTION">TYPE_CODE_FUNCTION Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1231
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1232	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1233
				1234	<p><tt>[FUNCTION, vararg, ignored, retty, ...paramty... ]</tt></p>
				1235
				1236	<p>The <tt>FUNCTION</tt> record (code 9) adds a function type to the
				1237	type table. The operand fields are</p>
				1238
				1239	<ul>
				1240	<li><i>vararg</i>: Non-zero if the type represents a varargs function</li>
				1241
				1242	<li><i>ignored</i>: This value field is present for backward
				1243	compatibility only, and is ignored</li>
				1244
				1245	<li><i>retty</i>: The type index of the function's return type</li>
				1246
				1247	<li><i>paramty</i>: Zero or more type indices representing the
				1248	parameter types of the function</li>
				1249	</ul>
				1250
				1251	</div>
				1252
				1253	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1254	<h4><a name="TYPE_CODE_STRUCT">TYPE_CODE_STRUCT Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1255
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1256	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1257
				1258	<p><tt>[STRUCT, ispacked, ...eltty...]</tt></p>
				1259
				1260	<p>The <tt>STRUCT </tt> record (code 10) adds a struct type to the
				1261	type table. The operand fields are</p>
				1262
				1263	<ul>
				1264	<li><i>ispacked</i>: Non-zero if the type represents a packed structure</li>
				1265
				1266	<li><i>eltty</i>: Zero or more type indices representing the element
				1267	types of the structure</li>
				1268	</ul>
				1269	</div>
				1270
				1271	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1272	<h4><a name="TYPE_CODE_ARRAY">TYPE_CODE_ARRAY Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1273
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1274	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1275
				1276	<p><tt>[ARRAY, numelts, eltty]</tt></p>
				1277
				1278	<p>The <tt>ARRAY</tt> record (code 11) adds an array type to the type
				1279	table. The operand fields are</p>
				1280
				1281	<ul>
				1282	<li><i>numelts</i>: The number of elements in arrays of this type</li>
				1283
				1284	<li><i>eltty</i>: The type index of the array element type</li>
				1285	</ul>
				1286	</div>
				1287
				1288	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1289	<h4><a name="TYPE_CODE_VECTOR">TYPE_CODE_VECTOR Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1290
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1291	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1292
				1293	<p><tt>[VECTOR, numelts, eltty]</tt></p>
				1294
				1295	<p>The <tt>VECTOR</tt> record (code 12) adds a vector type to the type
				1296	table. The operand fields are</p>
				1297
				1298	<ul>
				1299	<li><i>numelts</i>: The number of elements in vectors of this type</li>
				1300
				1301	<li><i>eltty</i>: The type index of the vector element type</li>
				1302	</ul>
				1303	</div>
				1304
				1305	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1306	<h4><a name="TYPE_CODE_X86_FP80">TYPE_CODE_X86_FP80 Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1307
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1308	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1309
				1310	<p><tt>[X86_FP80]</tt></p>
				1311
				1312	<p>The <tt>X86_FP80</tt> record (code 13) adds an <tt>x86_fp80</tt> (80-bit
				1313	floating point) type to the type table.
				1314	</p>
				1315	</div>
				1316
				1317	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1318	<h4><a name="TYPE_CODE_FP128">TYPE_CODE_FP128 Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1319
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1320	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1321
				1322	<p><tt>[FP128]</tt></p>
				1323
				1324	<p>The <tt>FP128</tt> record (code 14) adds an <tt>fp128</tt> (128-bit
				1325	floating point) type to the type table.
				1326	</p>
				1327	</div>
				1328
				1329	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1330	<h4><a name="TYPE_CODE_PPC_FP128">TYPE_CODE_PPC_FP128 Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1331
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1332	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1333
				1334	<p><tt>[PPC_FP128]</tt></p>
				1335
				1336	<p>The <tt>PPC_FP128</tt> record (code 15) adds a <tt>ppc_fp128</tt>
				1337	(128-bit floating point) type to the type table.
				1338	</p>
				1339	</div>
				1340
				1341	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1342	<h4><a name="TYPE_CODE_METADATA">TYPE_CODE_METADATA Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1343
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1344	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1345
				1346	<p><tt>[METADATA]</tt></p>
				1347
				1348	<p>The <tt>METADATA</tt> record (code 16) adds a <tt>metadata</tt>
				1349	type to the type table.
				1350	</p>
				1351	</div>
				1352
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1353	</div>
				1354
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1355	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1356	<h3>
				1357	<a name="CONSTANTS_BLOCK">CONSTANTS_BLOCK Contents</a>
				1358	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1359
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1360	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1361
				1362	<p>The <tt>CONSTANTS_BLOCK</tt> block (id 11) ...
				1363	</p>
				1364
				1365	</div>
				1366
				1367
				1368	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1369	<h3>
				1370	<a name="FUNCTION_BLOCK">FUNCTION_BLOCK Contents</a>
				1371	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1372
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1373	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1374
				1375	<p>The <tt>FUNCTION_BLOCK</tt> block (id 12) ...
				1376	</p>
				1377
				1378	<p>In addition to the record types described below, a
				1379	<tt>FUNCTION_BLOCK</tt> block may contain the following sub-blocks:
				1380	</p>
				1381
				1382	<ul>
				1383	<li><a href="#CONSTANTS_BLOCK"><tt>CONSTANTS_BLOCK</tt></a></li>
				1384	<li><a href="#VALUE_SYMTAB_BLOCK"><tt>VALUE_SYMTAB_BLOCK</tt></a></li>
				1385	<li><a href="#METADATA_ATTACHMENT"><tt>METADATA_ATTACHMENT</tt></a></li>
				1386	</ul>
				1387
				1388	</div>
				1389
				1390
				1391	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1392	<h3>
				1393	<a name="TYPE_SYMTAB_BLOCK">TYPE_SYMTAB_BLOCK Contents</a>
				1394	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1395
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1396	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1397
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1398	<p>The <tt>TYPE_SYMTAB_BLOCK</tt> block (id 13) contains entries which
				1399	map between module-level named types and their corresponding type
				1400	indices.
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1401	</p>
				1402
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1403	<!-- _______________________________________________________________________ -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1404	<h4><a name="TST_CODE_ENTRY">TST_CODE_ENTRY Record</a></h4>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1405
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1406	<div>
Chris Lattner	299f424	2010-05-21 22:20:54 +0000	[diff] [blame]	1407
				1408	<p><tt>[ENTRY, typeid, ...string...]</tt></p>
				1409
				1410	<p>The <tt>ENTRY</tt> record (code 1) contains a variable number of
				1411	values, with the first giving the type index of the designated type,
				1412	and the remaining values giving the character codes of the type
				1413	name. Each entry corresponds to a single named type.
				1414	</p>
				1415	</div>
				1416
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1417	</div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1418
				1419	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1420	<h3>
				1421	<a name="VALUE_SYMTAB_BLOCK">VALUE_SYMTAB_BLOCK Contents</a>
				1422	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1423
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1424	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1425
				1426	<p>The <tt>VALUE_SYMTAB_BLOCK</tt> block (id 14) ...
				1427	</p>
				1428
				1429	</div>
				1430
				1431
				1432	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1433	<h3>
				1434	<a name="METADATA_BLOCK">METADATA_BLOCK Contents</a>
				1435	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1436
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1437	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1438
				1439	<p>The <tt>METADATA_BLOCK</tt> block (id 15) ...
				1440	</p>
				1441
				1442	</div>
				1443
				1444
				1445	<!-- ======================================================================= -->
NAKAMURA Takumi	05d0265	2011-04-18 23:59:50 +0000	[diff] [blame]	1446	<h3>
				1447	<a name="METADATA_ATTACHMENT">METADATA_ATTACHMENT Contents</a>
				1448	</h3>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1449
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1450	<div>
Chris Lattner	5c303e8	2009-10-29 04:25:46 +0000	[diff] [blame]	1451
				1452	<p>The <tt>METADATA_ATTACHMENT</tt> block (id 16) ...
Chris Lattner	69b3e40	2007-05-13 01:39:44 +0000	[diff] [blame]	1453	</p>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	1454
				1455	</div>
				1456
NAKAMURA Takumi	f5af6ad	2011-04-23 00:30:22 +0000	[diff] [blame]	1457	</div>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	1458
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	1459	<!-- *********************************************************************** -->
				1460	<hr>
				1461	<address> <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1462	src="http://jigsaw.w3.org/css-validator/images/vcss-blue" alt="Valid CSS"></a>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	1463	<a href="http://validator.w3.org/check/referer"><img
Misha Brukman	4440870	2008-12-11 17:34:48 +0000	[diff] [blame]	1464	src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a>
Chris Lattner	e9ef457	2007-05-12 03:23:40 +0000	[diff] [blame]	1465	<a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumi	b9a3363	2011-04-09 02:13:37 +0000	[diff] [blame]	1466	<a href="http://llvm.org/">The LLVM Compiler Infrastructure</a><br>
Reid Spencer	2c1ce4f	2007-01-20 23:21:08 +0000	[diff] [blame]	1467	Last modified: $Date$
				1468	</address>
				1469	</body>
				1470	</html>