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9
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]10<h1>TableGen Fundamentals</h1>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]11
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]12<div class="doc_text">
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]13<ul>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]14 <li><a href="#introduction">Introduction</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]15 <ol>
16 <li><a href="#concepts">Basic concepts</a></li>
17 <li><a href="#example">An example record</a></li>
18 <li><a href="#running">Running TableGen</a></li>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]19 </ol></li>
20 <li><a href="#syntax">TableGen syntax</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]21 <ol>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]22 <li><a href="#primitives">TableGen primitives</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]23 <ol>
24 <li><a href="#comments">TableGen comments</a></li>
25 <li><a href="#types">The TableGen type system</a></li>
26 <li><a href="#values">TableGen values and expressions</a></li>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]27 </ol></li>
28 <li><a href="#classesdefs">Classes and definitions</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]29 <ol>
30 <li><a href="#valuedef">Value definitions</a></li>
31 <li><a href="#recordlet">'let' expressions</a></li>
32 <li><a href="#templateargs">Class template arguments</a></li>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]33 <li><a href="#multiclass">Multiclass definitions and instances</a></li>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]34 </ol></li>
35 <li><a href="#filescope">File scope entities</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]36 <ol>
37 <li><a href="#include">File inclusion</a></li>
38 <li><a href="#globallet">'let' expressions</a></li>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]39 </ol></li>
40 </ol></li>
41 <li><a href="#backends">TableGen backends</a>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]42 <ol>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]43 <li><a href="#">todo</a></li>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]44 </ol></li>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]45</ul>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]46</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]47
Chris Lattner020e1fc2004-05-23 21:07:27 +0000[diff] [blame]48<div class="doc_author">
49 <p>Written by <a href="mailto:sabre@nondot.org">Chris Lattner</a></p>
50</div>
51
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]52<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]53<h2><a name="introduction">Introduction</a></h2>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]54<!-- *********************************************************************** -->
55
56<div class="doc_text">
57
58<p>TableGen's purpose is to help a human develop and maintain records of
59domain-specific information. Because there may be a large number of these
60records, it is specifically designed to allow writing flexible descriptions and
61for common features of these records to be factored out. This reduces the
62amount of duplication in the description, reduces the chance of error, and
63makes it easier to structure domain specific information.</p>
64
65<p>The core part of TableGen <a href="#syntax">parses a file</a>, instantiates
66the declarations, and hands the result off to a domain-specific "<a
67href="#backends">TableGen backend</a>" for processing. The current major user
Chris Lattner7f500132004-07-26 21:16:55 +0000[diff] [blame]68of TableGen is the <a href="CodeGenerator.html">LLVM code generator</a>.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]69
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]70<p>Note that if you work on TableGen much, and use emacs or vim, that you can
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]71find an emacs "TableGen mode" and a vim language file in the
72<tt>llvm/utils/emacs</tt> and <tt>llvm/utils/vim</tt> directories of your LLVM
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]73distribution, respectively.</p>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]74
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]75</div>
76
77<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]78<h3><a name="concepts">Basic concepts</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]79
80<div class="doc_text">
81
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]82<p>TableGen files consist of two key parts: 'classes' and 'definitions', both
83of which are considered 'records'.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]84
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]85<p><b>TableGen records</b> have a unique name, a list of values, and a list of
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]86superclasses. The list of values is the main data that TableGen builds for each
87record; it is this that holds the domain specific information for the
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]88application. The interpretation of this data is left to a specific <a
89href="#backends">TableGen backend</a>, but the structure and format rules are
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]90taken care of and are fixed by TableGen.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]91
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]92<p><b>TableGen definitions</b> are the concrete form of 'records'. These
93generally do not have any undefined values, and are marked with the
94'<tt>def</tt>' keyword.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]95
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]96<p><b>TableGen classes</b> are abstract records that are used to build and
97describe other records. These 'classes' allow the end-user to build
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]98abstractions for either the domain they are targeting (such as "Register",
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]99"RegisterClass", and "Instruction" in the LLVM code generator) or for the
100implementor to help factor out common properties of records (such as "FPInst",
101which is used to represent floating point instructions in the X86 backend).
102TableGen keeps track of all of the classes that are used to build up a
103definition, so the backend can find all definitions of a particular class, such
104as "Instruction".</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]105
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]106<p><b>TableGen multiclasses</b> are groups of abstract records that are
David Greene753ed8f2009-04-22 16:42:54 +0000[diff] [blame]107instantiated all at once. Each instantiation can result in multiple
108TableGen definitions. If a multiclass inherits from another multiclass,
109the definitions in the sub-multiclass become part of the current
110multiclass, as if they were declared in the current multiclass.</p>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]111
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]112</div>
113
114<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]115<h3><a name="example">An example record</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]116
117<div class="doc_text">
118
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]119<p>With no other arguments, TableGen parses the specified file and prints out
120all of the classes, then all of the definitions. This is a good way to see what
121the various definitions expand to fully. Running this on the <tt>X86.td</tt>
122file prints this (at the time of this writing):</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]123
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]124<div class="doc_code">
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]125<pre>
126...
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]127<b>def</b> ADD32rr { <i>// Instruction X86Inst I</i>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]128 <b>string</b> Namespace = "X86";
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]129 <b>dag</b> OutOperandList = (outs GR32:$dst);
130 <b>dag</b> InOperandList = (ins GR32:$src1, GR32:$src2);
131 <b>string</b> AsmString = "add{l}\t{$src2, $dst|$dst, $src2}";
132 <b>list</b>&lt;dag&gt; Pattern = [(set GR32:$dst, (add GR32:$src1, GR32:$src2))];
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]133 <b>list</b>&lt;Register&gt; Uses = [];
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]134 <b>list</b>&lt;Register&gt; Defs = [EFLAGS];
135 <b>list</b>&lt;Predicate&gt; Predicates = [];
136 <b>int</b> CodeSize = 3;
137 <b>int</b> AddedComplexity = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]138 <b>bit</b> isReturn = 0;
139 <b>bit</b> isBranch = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]140 <b>bit</b> isIndirectBranch = 0;
141 <b>bit</b> isBarrier = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]142 <b>bit</b> isCall = 0;
Dan Gohman69cc2cb2008-12-03 18:15:48 +0000[diff] [blame]143 <b>bit</b> canFoldAsLoad = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]144 <b>bit</b> mayLoad = 0;
145 <b>bit</b> mayStore = 0;
146 <b>bit</b> isImplicitDef = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]147 <b>bit</b> isConvertibleToThreeAddress = 1;
148 <b>bit</b> isCommutable = 1;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]149 <b>bit</b> isTerminator = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]150 <b>bit</b> isReMaterializable = 0;
151 <b>bit</b> isPredicable = 0;
152 <b>bit</b> hasDelaySlot = 0;
Dan Gohman453d64c2009-10-29 18:10:34 +0000[diff] [blame]153 <b>bit</b> usesCustomInserter = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]154 <b>bit</b> hasCtrlDep = 0;
155 <b>bit</b> isNotDuplicable = 0;
156 <b>bit</b> hasSideEffects = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]157 <b>bit</b> neverHasSideEffects = 0;
158 InstrItinClass Itinerary = NoItinerary;
159 <b>string</b> Constraints = "";
160 <b>string</b> DisableEncoding = "";
161 <b>bits</b>&lt;8&gt; Opcode = { 0, 0, 0, 0, 0, 0, 0, 1 };
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]162 Format Form = MRMDestReg;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]163 <b>bits</b>&lt;6&gt; FormBits = { 0, 0, 0, 0, 1, 1 };
164 ImmType ImmT = NoImm;
165 <b>bits</b>&lt;3&gt; ImmTypeBits = { 0, 0, 0 };
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]166 <b>bit</b> hasOpSizePrefix = 0;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]167 <b>bit</b> hasAdSizePrefix = 0;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]168 <b>bits</b>&lt;4&gt; Prefix = { 0, 0, 0, 0 };
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]169 <b>bit</b> hasREX_WPrefix = 0;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]170 FPFormat FPForm = ?;
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]171 <b>bits</b>&lt;3&gt; FPFormBits = { 0, 0, 0 };
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]172}
173...
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]174</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]175</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]176
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]177<p>This definition corresponds to a 32-bit register-register add instruction in
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]178the X86. The string after the '<tt>def</tt>' string indicates the name of the
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]179record&mdash;"<tt>ADD32rr</tt>" in this case&mdash;and the comment at the end of
180the line indicates the superclasses of the definition. The body of the record
181contains all of the data that TableGen assembled for the record, indicating that
182the instruction is part of the "X86" namespace, the pattern indicating how the
183the instruction should be emitted into the assembly file, that it is a
184two-address instruction, has a particular encoding, etc. The contents and
185semantics of the information in the record is specific to the needs of the X86
186backend, and is only shown as an example.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]187
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]188<p>As you can see, a lot of information is needed for every instruction
189supported by the code generator, and specifying it all manually would be
Dan Gohman5aa39192010-02-26 02:15:17 +0000[diff] [blame]190unmaintainable, prone to bugs, and tiring to do in the first place. Because we
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]191are using TableGen, all of the information was derived from the following
192definition:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]193
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]194<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]195<pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]196let Defs = [EFLAGS],
197 isCommutable = 1, <i>// X = ADD Y,Z --&gt; X = ADD Z,Y</i>
198 isConvertibleToThreeAddress = 1 <b>in</b> <i>// Can transform into LEA.</i>
199def ADD32rr : I&lt;0x01, MRMDestReg, (outs GR32:$dst),
200 (ins GR32:$src1, GR32:$src2),
201 "add{l}\t{$src2, $dst|$dst, $src2}",
202 [(set GR32:$dst, (add GR32:$src1, GR32:$src2))]&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]203</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]204</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]205
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]206<p>This definition makes use of the custom class <tt>I</tt> (extended from the
207custom class <tt>X86Inst</tt>), which is defined in the X86-specific TableGen
208file, to factor out the common features that instructions of its class share. A
209key feature of TableGen is that it allows the end-user to define the
210abstractions they prefer to use when describing their information.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]211
212</div>
213
214<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]215<h3><a name="running">Running TableGen</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]216
217<div class="doc_text">
218
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]219<p>TableGen runs just like any other LLVM tool. The first (optional) argument
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]220specifies the file to read. If a filename is not specified, <tt>tblgen</tt>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]221reads from standard input.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]222
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]223<p>To be useful, one of the <a href="#backends">TableGen backends</a> must be
224used. These backends are selectable on the command line (type '<tt>tblgen
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]225-help</tt>' for a list). For example, to get a list of all of the definitions
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]226that subclass a particular type (which can be useful for building up an enum
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]227list of these records), use the <tt>-print-enums</tt> option:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]228
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]229<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]230<pre>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]231$ tblgen X86.td -print-enums -class=Register
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]232AH, AL, AX, BH, BL, BP, BPL, BX, CH, CL, CX, DH, DI, DIL, DL, DX, EAX, EBP, EBX,
233ECX, EDI, EDX, EFLAGS, EIP, ESI, ESP, FP0, FP1, FP2, FP3, FP4, FP5, FP6, IP,
234MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7, R10, R10B, R10D, R10W, R11, R11B, R11D,
235R11W, R12, R12B, R12D, R12W, R13, R13B, R13D, R13W, R14, R14B, R14D, R14W, R15,
236R15B, R15D, R15W, R8, R8B, R8D, R8W, R9, R9B, R9D, R9W, RAX, RBP, RBX, RCX, RDI,
237RDX, RIP, RSI, RSP, SI, SIL, SP, SPL, ST0, ST1, ST2, ST3, ST4, ST5, ST6, ST7,
238XMM0, XMM1, XMM10, XMM11, XMM12, XMM13, XMM14, XMM15, XMM2, XMM3, XMM4, XMM5,
239XMM6, XMM7, XMM8, XMM9,
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]240
241$ tblgen X86.td -print-enums -class=Instruction
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]242ABS_F, ABS_Fp32, ABS_Fp64, ABS_Fp80, ADC32mi, ADC32mi8, ADC32mr, ADC32ri,
243ADC32ri8, ADC32rm, ADC32rr, ADC64mi32, ADC64mi8, ADC64mr, ADC64ri32, ADC64ri8,
244ADC64rm, ADC64rr, ADD16mi, ADD16mi8, ADD16mr, ADD16ri, ADD16ri8, ADD16rm,
245ADD16rr, ADD32mi, ADD32mi8, ADD32mr, ADD32ri, ADD32ri8, ADD32rm, ADD32rr,
246ADD64mi32, ADD64mi8, ADD64mr, ADD64ri32, ...
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]247</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]248</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]249
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]250<p>The default backend prints out all of the records, as described <a
251href="#example">above</a>.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]252
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]253<p>If you plan to use TableGen, you will most likely have to <a
254href="#backends">write a backend</a> that extracts the information specific to
255what you need and formats it in the appropriate way.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]256
257</div>
258
259
260<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]261<h2><a name="syntax">TableGen syntax</a></h2>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]262<!-- *********************************************************************** -->
263
264<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]265
266<p>TableGen doesn't care about the meaning of data (that is up to the backend to
267define), but it does care about syntax, and it enforces a simple type system.
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]268This section describes the syntax and the constructs allowed in a TableGen file.
269</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]270
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]271</div>
272
273<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]274<h3><a name="primitives">TableGen primitives</a></h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]275
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]276<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]277<h4><a name="comments">TableGen comments</a></h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]278
279<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]280
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]281<p>TableGen supports BCPL style "<tt>//</tt>" comments, which run to the end of
282the line, and it also supports <b>nestable</b> "<tt>/* */</tt>" comments.</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]283
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]284</div>
285
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]286<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]287<h4>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]288 <a name="types">The TableGen type system</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]289</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]290
291<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]292
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]293<p>TableGen files are strongly typed, in a simple (but complete) type-system.
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]294These types are used to perform automatic conversions, check for errors, and to
295help interface designers constrain the input that they allow. Every <a
296href="#valuedef">value definition</a> is required to have an associated type.
297</p>
298
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]299<p>TableGen supports a mixture of very low-level types (such as <tt>bit</tt>)
300and very high-level types (such as <tt>dag</tt>). This flexibility is what
301allows it to describe a wide range of information conveniently and compactly.
302The TableGen types are:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]303
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]304<dl>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]305<dt><tt><b>bit</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]306 <dd>A 'bit' is a boolean value that can hold either 0 or 1.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]307
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]308<dt><tt><b>int</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]309 <dd>The 'int' type represents a simple 32-bit integer value, such as 5.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]310
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]311<dt><tt><b>string</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]312 <dd>The 'string' type represents an ordered sequence of characters of
313 arbitrary length.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]314
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]315<dt><tt><b>bits</b>&lt;n&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]316 <dd>A 'bits' type is an arbitrary, but fixed, size integer that is broken up
317 into individual bits. This type is useful because it can handle some bits
318 being defined while others are undefined.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]319
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]320<dt><tt><b>list</b>&lt;ty&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]321 <dd>This type represents a list whose elements are some other type. The
322 contained type is arbitrary: it can even be another list type.</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]323
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]324<dt>Class type</dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]325 <dd>Specifying a class name in a type context means that the defined value
326 must be a subclass of the specified class. This is useful in conjunction with
327 the <b><tt>list</tt></b> type, for example, to constrain the elements of the
328 list to a common base class (e.g., a <tt><b>list</b>&lt;Register&gt;</tt> can
329 only contain definitions derived from the "<tt>Register</tt>" class).</dd>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]330
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]331<dt><tt><b>dag</b></tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]332 <dd>This type represents a nestable directed graph of elements.</dd>
333
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]334<dt><tt><b>code</b></tt></dt>
Chris Lattner28175bf2010-04-22 16:45:27 +0000[diff] [blame]335 <dd>This represents a big hunk of text. This is lexically distinct from
336 string values because it doesn't require escapeing double quotes and other
337 common characters that occur in code.</dd>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]338</dl>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]339
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]340<p>To date, these types have been sufficient for describing things that
341TableGen has been used for, but it is straight-forward to extend this list if
342needed.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]343
344</div>
345
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]346<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]347<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]348 <a name="values">TableGen values and expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]349</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]350
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]351<div class="doc_text">
352
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]353<p>TableGen allows for a pretty reasonable number of different expression forms
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]354when building up values. These forms allow the TableGen file to be written in a
355natural syntax and flavor for the application. The current expression forms
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]356supported include:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]357
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]358<dl>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]359<dt><tt>?</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]360 <dd>uninitialized field</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]361<dt><tt>0b1001011</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]362 <dd>binary integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]363<dt><tt>07654321</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]364 <dd>octal integer value (indicated by a leading 0)</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]365<dt><tt>7</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]366 <dd>decimal integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]367<dt><tt>0x7F</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]368 <dd>hexadecimal integer value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]369<dt><tt>"foo"</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]370 <dd>string value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]371<dt><tt>[{ ... }]</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]372 <dd>code fragment</dd>
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]373<dt><tt>[ X, Y, Z ]&lt;type&gt;</tt></dt>
374 <dd>list value. &lt;type&gt; is the type of the list
David Greene26433c22009-06-08 22:38:07 +0000[diff] [blame]375element and is usually optional. In rare cases,
376TableGen is unable to deduce the element type in
377which case the user must specify it explicitly.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]378<dt><tt>{ a, b, c }</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]379 <dd>initializer for a "bits&lt;3&gt;" value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]380<dt><tt>value</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]381 <dd>value reference</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]382<dt><tt>value{17}</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]383 <dd>access to one bit of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]384<dt><tt>value{15-17}</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]385 <dd>access to multiple bits of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]386<dt><tt>DEF</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]387 <dd>reference to a record definition</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]388<dt><tt>CLASS&lt;val list&gt;</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]389 <dd>reference to a new anonymous definition of CLASS with the specified
390 template arguments.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]391<dt><tt>X.Y</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]392 <dd>reference to the subfield of a value</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]393<dt><tt>list[4-7,17,2-3]</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]394 <dd>A slice of the 'list' list, including elements 4,5,6,7,17,2, and 3 from
395 it. Elements may be included multiple times.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]396<dt><tt>(DEF a, b)</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]397 <dd>a dag value. The first element is required to be a record definition, the
398 remaining elements in the list may be arbitrary other values, including nested
399 `<tt>dag</tt>' values.</dd>
Bill Wendling8402d022008-02-12 07:09:05 +0000[diff] [blame]400<dt><tt>!strconcat(a, b)</tt></dt>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]401 <dd>A string value that is the result of concatenating the 'a' and 'b'
402 strings.</dd>
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]403<dt><tt>!cast&lt;type&gt;(a)</tt></dt>
David Greenee8f3b272009-05-14 21:22:49 +0000[diff] [blame]404 <dd>A symbol of type <em>type</em> obtained by looking up the string 'a' in
405the symbol table. If the type of 'a' does not match <em>type</em>, TableGen
Benjamin Kramereaccdd32009-08-05 15:42:44 +0000[diff] [blame]406aborts with an error. !cast&lt;string&gt; is a special case in that the argument must
David Greeneefa19612009-06-29 20:05:29 +0000[diff] [blame]407be an object defined by a 'def' construct.</dd>
David Greene98ed3c72009-05-14 21:54:42 +0000[diff] [blame]408<dt><tt>!subst(a, b, c)</tt></dt>
409 <dd>If 'a' and 'b' are of string type or are symbol references, substitute
410'b' for 'a' in 'c.' This operation is analogous to $(subst) in GNU make.</dd>
David Greenee917fff2009-05-14 22:23:47 +0000[diff] [blame]411<dt><tt>!foreach(a, b, c)</tt></dt>
412 <dd>For each member 'b' of dag or list 'a' apply operator 'c.' 'b' is a
413dummy variable that should be declared as a member variable of an instantiated
414class. This operation is analogous to $(foreach) in GNU make.</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]415<dt><tt>!head(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]416 <dd>The first element of list 'a.'</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]417<dt><tt>!tail(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]418 <dd>The 2nd-N elements of list 'a.'</dd>
David Greene2f7cf7f2011-01-07 17:05:37 +0000[diff] [blame]419<dt><tt>!empty(a)</tt></dt>
David Greened571b3c2009-05-14 22:38:31 +0000[diff] [blame]420 <dd>An integer {0,1} indicating whether list 'a' is empty.</dd>
David Greene3587eed2009-05-14 23:26:46 +0000[diff] [blame]421<dt><tt>!if(a,b,c)</tt></dt>
Bruno Cardoso Lopes4d1d7982010-06-17 00:31:36 +0000[diff] [blame]422 <dd>'b' if the result of 'int' or 'bit' operator 'a' is nonzero,
423 'c' otherwise.</dd>
David Greene297bfe62010-01-05 19:11:42 +0000[diff] [blame]424<dt><tt>!eq(a,b)</tt></dt>
Chris Lattner7ff33462010-10-31 19:22:57 +0000[diff] [blame]425 <dd>'bit 1' if string a is equal to string b, 0 otherwise. This
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]426 only operates on string, int and bit objects. Use !cast&lt;string&gt; to
Bruno Cardoso Lopes77a4a562010-06-16 23:24:12 +0000[diff] [blame]427 compare other types of objects.</dd>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]428</dl>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]429
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]430<p>Note that all of the values have rules specifying how they convert to values
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]431for different types. These rules allow you to assign a value like "<tt>7</tt>"
432to a "<tt>bits&lt;4&gt;</tt>" value, for example.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]433
434</div>
435
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]436<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]437<h3>
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]438 <a name="classesdefs">Classes and definitions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]439</h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]440
Misha Brukman94192b62004-06-03 16:59:59 +0000[diff] [blame]441<div class="doc_text">
442
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]443<p>As mentioned in the <a href="#concepts">intro</a>, classes and definitions
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]444(collectively known as 'records') in TableGen are the main high-level unit of
445information that TableGen collects. Records are defined with a <tt>def</tt> or
446<tt>class</tt> keyword, the record name, and an optional list of "<a
Misha Brukman31551592004-06-03 23:42:24 +0000[diff] [blame]447href="#templateargs">template arguments</a>". If the record has superclasses,
Jeff Cohendd24d7c2005-10-24 16:54:55 +0000[diff] [blame]448they are specified as a comma separated list that starts with a colon character
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]449("<tt>:</tt>"). If <a href="#valuedef">value definitions</a> or <a
450href="#recordlet">let expressions</a> are needed for the class, they are
451enclosed in curly braces ("<tt>{}</tt>"); otherwise, the record ends with a
452semicolon.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]453
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]454<p>Here is a simple TableGen file:</p>
455
456<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]457<pre>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]458<b>class</b> C { <b>bit</b> V = 1; }
459<b>def</b> X : C;
460<b>def</b> Y : C {
461 <b>string</b> Greeting = "hello";
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]462}
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]463</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]464</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]465
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]466<p>This example defines two definitions, <tt>X</tt> and <tt>Y</tt>, both of
467which derive from the <tt>C</tt> class. Because of this, they both get the
468<tt>V</tt> bit value. The <tt>Y</tt> definition also gets the Greeting member
469as well.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]470
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]471<p>In general, classes are useful for collecting together the commonality
472between a group of records and isolating it in a single place. Also, classes
473permit the specification of default values for their subclasses, allowing the
474subclasses to override them as they wish.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]475
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]476</div>
477
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]478<!---------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]479<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]480 <a name="valuedef">Value definitions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]481</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]482
483<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]484
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]485<p>Value definitions define named entries in records. A value must be defined
John Criswell407f6d42004-02-12 18:11:53 +0000[diff] [blame]486before it can be referred to as the operand for another value definition or
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]487before the value is reset with a <a href="#recordlet">let expression</a>. A
488value is defined by specifying a <a href="#types">TableGen type</a> and a name.
489If an initial value is available, it may be specified after the type with an
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]490equal sign. Value definitions require terminating semicolons.</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]491
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]492</div>
493
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]494<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]495<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]496 <a name="recordlet">'let' expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]497</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]498
499<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]500
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]501<p>A record-level let expression is used to change the value of a value
502definition in a record. This is primarily useful when a superclass defines a
503value that a derived class or definition wants to override. Let expressions
504consist of the '<tt>let</tt>' keyword followed by a value name, an equal sign
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]505("<tt>=</tt>"), and a new value. For example, a new class could be added to the
506example above, redefining the <tt>V</tt> field for all of its subclasses:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]507
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]508<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]509<pre>
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]510<b>class</b> D : C { let V = 0; }
511<b>def</b> Z : D;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]512</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]513</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]514
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]515<p>In this case, the <tt>Z</tt> definition will have a zero value for its "V"
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]516value, despite the fact that it derives (indirectly) from the <tt>C</tt> class,
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]517because the <tt>D</tt> class overrode its value.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]518
519</div>
520
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]521<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]522<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]523 <a name="templateargs">Class template arguments</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]524</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]525
526<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]527
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]528<p>TableGen permits the definition of parameterized classes as well as normal
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]529concrete classes. Parameterized TableGen classes specify a list of variable
530bindings (which may optionally have defaults) that are bound when used. Here is
531a simple example:</p>
532
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]533<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]534<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]535<b>class</b> FPFormat&lt;<b>bits</b>&lt;3&gt; val&gt; {
536 <b>bits</b>&lt;3&gt; Value = val;
537}
538<b>def</b> NotFP : FPFormat&lt;0&gt;;
539<b>def</b> ZeroArgFP : FPFormat&lt;1&gt;;
540<b>def</b> OneArgFP : FPFormat&lt;2&gt;;
541<b>def</b> OneArgFPRW : FPFormat&lt;3&gt;;
542<b>def</b> TwoArgFP : FPFormat&lt;4&gt;;
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]543<b>def</b> CompareFP : FPFormat&lt;5&gt;;
544<b>def</b> CondMovFP : FPFormat&lt;6&gt;;
545<b>def</b> SpecialFP : FPFormat&lt;7&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]546</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]547</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]548
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]549<p>In this case, template arguments are used as a space efficient way to specify
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]550a list of "enumeration values", each with a "<tt>Value</tt>" field set to the
551specified integer.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]552
553<p>The more esoteric forms of <a href="#values">TableGen expressions</a> are
554useful in conjunction with template arguments. As an example:</p>
555
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]556<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]557<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]558<b>class</b> ModRefVal&lt;<b>bits</b>&lt;2&gt; val&gt; {
559 <b>bits</b>&lt;2&gt; Value = val;
560}
561
562<b>def</b> None : ModRefVal&lt;0&gt;;
563<b>def</b> Mod : ModRefVal&lt;1&gt;;
564<b>def</b> Ref : ModRefVal&lt;2&gt;;
565<b>def</b> ModRef : ModRefVal&lt;3&gt;;
566
567<b>class</b> Value&lt;ModRefVal MR&gt; {
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]568 <i>// Decode some information into a more convenient format, while providing
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]569 // a nice interface to the user of the "Value" class.</i>
570 <b>bit</b> isMod = MR.Value{0};
571 <b>bit</b> isRef = MR.Value{1};
572
573 <i>// other stuff...</i>
574}
575
576<i>// Example uses</i>
577<b>def</b> bork : Value&lt;Mod&gt;;
578<b>def</b> zork : Value&lt;Ref&gt;;
579<b>def</b> hork : Value&lt;ModRef&gt;;
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]580</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]581</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]582
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]583<p>This is obviously a contrived example, but it shows how template arguments
584can be used to decouple the interface provided to the user of the class from the
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]585actual internal data representation expected by the class. In this case,
586running <tt>tblgen</tt> on the example prints the following definitions:</p>
587
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]588<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]589<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]590<b>def</b> bork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]591 <b>bit</b> isMod = 1;
592 <b>bit</b> isRef = 0;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]593}
594<b>def</b> hork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]595 <b>bit</b> isMod = 1;
596 <b>bit</b> isRef = 1;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]597}
598<b>def</b> zork { <i>// Value</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]599 <b>bit</b> isMod = 0;
600 <b>bit</b> isRef = 1;
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]601}
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]602</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]603</div>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]604
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]605<p> This shows that TableGen was able to dig into the argument and extract a
606piece of information that was requested by the designer of the "Value" class.
607For more realistic examples, please see existing users of TableGen, such as the
608X86 backend.</p>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]609
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]610</div>
611
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]612<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]613<h4>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]614 <a name="multiclass">Multiclass definitions and instances</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]615</h4>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]616
617<div class="doc_text">
618
619<p>
620While classes with template arguments are a good way to factor commonality
621between two instances of a definition, multiclasses allow a convenient notation
622for defining multiple definitions at once (instances of implicitly constructed
623classes). For example, consider an 3-address instruction set whose instructions
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]624come in two forms: "<tt>reg = reg op reg</tt>" and "<tt>reg = reg op imm</tt>"
625(e.g. SPARC). In this case, you'd like to specify in one place that this
626commonality exists, then in a separate place indicate what all the ops are.
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]627</p>
628
629<p>
630Here is an example TableGen fragment that shows this idea:
631</p>
632
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]633<div class="doc_code">
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]634<pre>
635<b>def</b> ops;
636<b>def</b> GPR;
637<b>def</b> Imm;
638<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
639
640<b>multiclass</b> ri_inst&lt;<b>int</b> opc, <b>string</b> asmstr&gt; {
641 def _rr : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
642 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
643 def _ri : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
644 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
645}
646
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]647<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]648<b>defm</b> ADD : ri_inst&lt;0b111, "add"&gt;;
649<b>defm</b> SUB : ri_inst&lt;0b101, "sub"&gt;;
650<b>defm</b> MUL : ri_inst&lt;0b100, "mul"&gt;;
651...
652</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]653</div>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]654
Chris Lattner28368122006-09-01 22:01:36 +0000[diff] [blame]655<p>The name of the resultant definitions has the multidef fragment names
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]656 appended to them, so this defines <tt>ADD_rr</tt>, <tt>ADD_ri</tt>,
David Greenef00919a2009-04-22 22:17:51 +0000[diff] [blame]657 <tt>SUB_rr</tt>, etc. A defm may inherit from multiple multiclasses,
658 instantiating definitions from each multiclass. Using a multiclass
659 this way is exactly equivalent to instantiating the classes multiple
660 times yourself, e.g. by writing:</p>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]661
662<div class="doc_code">
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]663<pre>
664<b>def</b> ops;
665<b>def</b> GPR;
666<b>def</b> Imm;
667<b>class</b> inst&lt;<b>int</b> opc, <b>string</b> asmstr, <b>dag</b> operandlist&gt;;
668
669<b>class</b> rrinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
670 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
671 (ops GPR:$dst, GPR:$src1, GPR:$src2)&gt;;
672
673<b>class</b> riinst&lt;<b>int</b> opc, <b>string</b> asmstr&gt;
674 : inst&lt;opc, !strconcat(asmstr, " $dst, $src1, $src2"),
675 (ops GPR:$dst, GPR:$src1, Imm:$src2)&gt;;
676
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]677<i>// Instantiations of the ri_inst multiclass.</i>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]678<b>def</b> ADD_rr : rrinst&lt;0b111, "add"&gt;;
679<b>def</b> ADD_ri : riinst&lt;0b111, "add"&gt;;
680<b>def</b> SUB_rr : rrinst&lt;0b101, "sub"&gt;;
681<b>def</b> SUB_ri : riinst&lt;0b101, "sub"&gt;;
682<b>def</b> MUL_rr : rrinst&lt;0b100, "mul"&gt;;
683<b>def</b> MUL_ri : riinst&lt;0b100, "mul"&gt;;
684...
685</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]686</div>
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]687
Bruno Cardoso Lopesc4f61482010-06-05 02:11:52 +0000[diff] [blame]688<p>
689A defm can also be used inside a multiclass providing several levels of
690multiclass instanciations.
691</p>
692
693<div class="doc_code">
694<pre>
695<b>class</b> Instruction&lt;bits&lt;4&gt; opc, string Name&gt; {
696 bits&lt;4&gt; opcode = opc;
697 string name = Name;
698}
699
700<b>multiclass</b> basic_r&lt;bits&lt;4&gt; opc&gt; {
701 <b>def</b> rr : Instruction&lt;opc, "rr"&gt;;
702 <b>def</b> rm : Instruction&lt;opc, "rm"&gt;;
703}
704
705<b>multiclass</b> basic_s&lt;bits&lt;4&gt; opc&gt; {
706 <b>defm</b> SS : basic_r&lt;opc&gt;;
707 <b>defm</b> SD : basic_r&lt;opc&gt;;
708 <b>def</b> X : Instruction&lt;opc, "x"&gt;;
709}
710
711<b>multiclass</b> basic_p&lt;bits&lt;4&gt; opc&gt; {
712 <b>defm</b> PS : basic_r&lt;opc&gt;;
713 <b>defm</b> PD : basic_r&lt;opc&gt;;
714 <b>def</b> Y : Instruction&lt;opc, "y"&gt;;
715}
716
717<b>defm</b> ADD : basic_s&lt;0xf&gt;, basic_p&lt;0xf&gt;;
718...
719
720<i>// Results</i>
721<b>def</b> ADDPDrm { ...
722<b>def</b> ADDPDrr { ...
723<b>def</b> ADDPSrm { ...
724<b>def</b> ADDPSrr { ...
725<b>def</b> ADDSDrm { ...
726<b>def</b> ADDSDrr { ...
727<b>def</b> ADDY { ...
728<b>def</b> ADDX { ...
729</pre>
730</div>
731
Bruno Cardoso Lopes23f83212010-06-18 19:53:41 +0000[diff] [blame]732<p>
733defm declarations can inherit from classes too, the
734rule to follow is that the class list must start after the
735last multiclass, and there must be at least one multiclass
736before them.
737</p>
738
739<div class="doc_code">
740<pre>
741<b>class</b> XD { bits&lt;4&gt; Prefix = 11; }
742<b>class</b> XS { bits&lt;4&gt; Prefix = 12; }
743
744<b>class</b> I&lt;bits<4&gt; op> {
745 bits&lt;4&gt; opcode = op;
746}
747
748<b>multiclass</b> R {
749 <b>def</b> rr : I&lt;4&gt;;
750 <b>def</b> rm : I&lt;2&gt;;
751}
752
753<b>multiclass</b> Y {
754 <b>defm</b> SS : R, XD;
755 <b>defm</b> SD : R, XS;
756}
757
758<b>defm</b> Instr : Y;
759
760<i>// Results</i>
761<b>def</b> InstrSDrm {
762 bits&lt;4&gt; opcode = { 0, 0, 1, 0 };
763 bits&lt;4&gt; Prefix = { 1, 1, 0, 0 };
764}
765...
766<b>def</b> InstrSSrr {
767 bits&lt;4&gt; opcode = { 0, 1, 0, 0 };
768 bits&lt;4&gt; Prefix = { 1, 0, 1, 1 };
769}
770</pre>
771</div>
772
Chris Lattnerf01a85b2006-09-01 21:44:18 +0000[diff] [blame]773</div>
774
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]775<!-- ======================================================================= -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]776<h3>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]777 <a name="filescope">File scope entities</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]778</h3>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]779
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]780<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]781<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]782 <a name="include">File inclusion</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]783</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]784
785<div class="doc_text">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]786<p>TableGen supports the '<tt>include</tt>' token, which textually substitutes
787the specified file in place of the include directive. The filename should be
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]788specified as a double quoted string immediately after the '<tt>include</tt>'
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]789keyword. Example:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]790
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]791<div class="doc_code">
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]792<pre>
Chris Lattner55927232004-02-06 06:37:00 +0000[diff] [blame]793<b>include</b> "foo.td"
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]794</pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]795</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]796
797</div>
798
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]799<!-- -------------------------------------------------------------------------->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]800<h4>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]801 <a name="globallet">'let' expressions</a>
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]802</h4>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]803
804<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]805
806<p>"Let" expressions at file scope are similar to <a href="#recordlet">"let"
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]807expressions within a record</a>, except they can specify a value binding for
808multiple records at a time, and may be useful in certain other cases.
809File-scope let expressions are really just another way that TableGen allows the
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]810end-user to factor out commonality from the records.</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]811
Jeff Cohendd24d7c2005-10-24 16:54:55 +0000[diff] [blame]812<p>File-scope "let" expressions take a comma-separated list of bindings to
Matthijs Kooijman3abb3082008-10-20 08:45:34 +0000[diff] [blame]813apply, and one or more records to bind the values in. Here are some
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]814examples:</p>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]815
Bill Wendling7a05f002010-12-08 02:46:25 +0000[diff] [blame]816<div class="doc_code">
817<pre>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]818<b>let</b> isTerminator = 1, isReturn = 1, isBarrier = 1, hasCtrlDep = 1 <b>in</b>
819 <b>def</b> RET : I&lt;0xC3, RawFrm, (outs), (ins), "ret", [(X86retflag 0)]&gt;;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]820
Chris Lattner1215e322004-02-06 06:04:25 +0000[diff] [blame]821<b>let</b> isCall = 1 <b>in</b>
822 <i>// All calls clobber the non-callee saved registers...</i>
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]823 <b>let</b> Defs = [EAX, ECX, EDX, FP0, FP1, FP2, FP3, FP4, FP5, FP6, ST0,
824 MM0, MM1, MM2, MM3, MM4, MM5, MM6, MM7,
825 XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7, EFLAGS] <b>in</b> {
Dan Gohman2ed27532008-10-14 17:00:38 +0000[diff] [blame]826 <b>def</b> CALLpcrel32 : Ii32&lt;0xE8, RawFrm, (outs), (ins i32imm:$dst,variable_ops),
827 "call\t${dst:call}", []&gt;;
828 <b>def</b> CALL32r : I&lt;0xFF, MRM2r, (outs), (ins GR32:$dst, variable_ops),
829 "call\t{*}$dst", [(X86call GR32:$dst)]&gt;;
830 <b>def</b> CALL32m : I&lt;0xFF, MRM2m, (outs), (ins i32mem:$dst, variable_ops),
831 "call\t{*}$dst", []&gt;;
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]832 }
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]833</pre>
Bill Wendling7a05f002010-12-08 02:46:25 +0000[diff] [blame]834</div>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]835
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]836<p>File-scope "let" expressions are often useful when a couple of definitions
837need to be added to several records, and the records do not otherwise need to be
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]838opened, as in the case with the <tt>CALL*</tt> instructions above.</p>
839
Bruno Cardoso Lopes5f2adcc2010-06-10 02:42:59 +0000[diff] [blame]840<p>It's also possible to use "let" expressions inside multiclasses, providing
841more ways to factor out commonality from the records, specially if using
842several levels of multiclass instanciations. This also avoids the need of using
843"let" expressions within subsequent records inside a multiclass.</p>
844
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]845<pre class="doc_code">
Bruno Cardoso Lopes5f2adcc2010-06-10 02:42:59 +0000[diff] [blame]846<b>multiclass </b>basic_r&lt;bits&lt;4&gt; opc&gt; {
847 <b>let </b>Predicates = [HasSSE2] in {
848 <b>def </b>rr : Instruction&lt;opc, "rr"&gt;;
849 <b>def </b>rm : Instruction&lt;opc, "rm"&gt;;
850 }
851 <b>let </b>Predicates = [HasSSE3] in
852 <b>def </b>rx : Instruction&lt;opc, "rx"&gt;;
853}
854
855<b>multiclass </b>basic_ss&lt;bits&lt;4&gt; opc&gt; {
856 <b>let </b>IsDouble = 0 in
857 <b>defm </b>SS : basic_r&lt;opc&gt;;
858
859 <b>let </b>IsDouble = 1 in
860 <b>defm </b>SD : basic_r&lt;opc&gt;;
861}
862
863<b>defm </b>ADD : basic_ss&lt;0xf&gt;;
864</pre>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]865</div>
866
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]867<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]868<h2><a name="codegen">Code Generator backend info</a></h2>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]869<!-- *********************************************************************** -->
870
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]871<div class="doc_text">
872
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]873<p>Expressions used by code generator to describe instructions and isel
874patterns:</p>
875
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]876<dl>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]877<dt><tt>(implicit a)</tt></dt>
878 <dd>an implicitly defined physical register. This tells the dag instruction
879 selection emitter the input pattern's extra definitions matches implicit
880 physical register definitions.</dd>
Benjamin Kramerc940bcf2010-10-30 21:07:28 +0000[diff] [blame]881</dl>
Evan Chengef716b02009-10-05 02:51:06 +0000[diff] [blame]882</div>
883
884<!-- *********************************************************************** -->
NAKAMURA Takumifc8d9302011-04-18 23:59:50 +0000[diff] [blame]885<h2><a name="backends">TableGen backends</a></h2>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]886<!-- *********************************************************************** -->
887
888<div class="doc_text">
Bill Wendling1a19af92008-02-12 07:06:19 +0000[diff] [blame]889
890<p>TODO: How they work, how to write one. This section should not contain
891details about any particular backend, except maybe -print-enums as an example.
892This should highlight the APIs in <tt>TableGen/Record.h</tt>.</p>
893
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]894</div>
895
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]896<!-- *********************************************************************** -->
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]897
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]898<hr>
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]899<address>
900 <a href="http://jigsaw.w3.org/css-validator/check/referer"><img
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Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]904
905 <a href="mailto:sabre@nondot.org">Chris Lattner</a><br>
NAKAMURA Takumica46f5a2011-04-09 02:13:37 +0000[diff] [blame]906 <a href="http://llvm.org/">LLVM Compiler Infrastructure</a><br>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]907 Last modified: $Date$
Misha Brukman692cec02004-05-12 18:31:21 +0000[diff] [blame]908</address>
Chris Lattner149a2492004-02-06 05:42:53 +0000[diff] [blame]909
910</body>
911</html>